Environment Agency. River Tees Salmon Action Plan Review. February 2009 APEM REF: EA

Transcription

1 Environment Agency River Tees Salmon Action Plan Review February 2009 APEM REF: EA

2 CLIENTS: Environment Agency ADDRESS: Tyneside House Skinnerburn Road Newcastle Business Park Newcastle Upon Tyne PROJECT No: EA DATE OF ISSUE: February 2009 PROJECT MANAGERS: Dr Adrian Williams SENIOR SCIENTISTS: Dr Nigel Milner Nicola O Keeffe, M.Sc. Dr Annemarie Clarke Heather Webb, M.Sc. Final Report EA ii

3 EXECUTIVE SUMMARY This document presents a Salmon Action Plan (SAP) for the River Tees and forms part of the Environment Agency s (EA s) strategy for the management of salmon fisheries in England and Wales. These plans will be updated at regular intervals and progressively integrated into the 6-yearly Water Framework Directive Planning Cycle. This report refers to the stock assessment and management actions as set out in the original Tees SAP (1999), modified by any new circumstances, information or actions arising since then. It seeks to ensure that actions which are taken to control exploitation and address any limiting factors on the performance of the stock and fisheries are appropriate, proportionate and effective. The Tees catchment covers an area of approximately 1,930 km 2 and flows from its source at Tees Head in Cumbria entering the North Sea 160 km downstream near Middlesbrough. Major tributaries of the Tees include the Rivers Lune, Balder, Greta, Skerne and Leven. A tidal barrage was constructed across the Tees at Stockton in 1995 and there are numerous reservoirs throughout the catchment. The River Tees has been subject historically to serious pollution and is currently a recovering river supporting a small but increasing salmon and sea-trout in-river rod fishery. Since 1982 salmon rod catches have increased and in 2008 the Tees was ranked 25 th amongst English and Welsh salmon rivers. The performance of salmon stocks for rivers in England and Wales is assessed using a compliance scheme based upon conservation limits (CL). The CL for the River Tees has been identified as 14.9 million eggs. The Tees is not achieving its current conservation limit which is to be expected for a river in a recovery phase. Based on its current recovery the river is expected to achieve its management target between 2023 and A number of limiting factors on Tees salmon have been identified and discussed. Namely exploitation by various net and rod fisheries (North East Coast net fishery, West Greenland, Ireland etc), water quality and quantity, obstructions to migration, loss of spawning and rearing habitat due to the construction of reservoirs, predation, the Tees Barrage and climate change. Whilst significant improvements have been seen in water quality in the estuary this is likely to continue to be a limiting factor on the Tees for a number of years. As water quality improves other issues need to be addressed including passage of fish past the barrage, under utilisation of the catchment for salmon spawning, and exploitation. This report discusses each of the issues in turn and details what actions have been carried out to date. Actions which were identified in the original SAP (1999) which have not yet been completed are still appropriate to the next round of SAP development and further actions are outlined. Final Report EA iii

4 CONTENTS 1 INTRODUCTION THE ROLE OF SALMON ACTION PLANS (SAPS) DESCRIPTION OF THE TEES CATCHMENT CURRENT AND PREDICTED STOCK PERFORMANCE DESCRIPTION OF THE FISHERIES (RODS AND NETS) MIGRATORY FISHERIES MONITORING HATCHERY STOCKING IN-RIVER FISHERIES MONITORING DISTRIBUTION OF SPAWNING AND UTILISATION OF THE CATCHMENT CONSERVATION LIMIT COMPLIANCE ASSESSMENT Egg deposition compliance Freshwater production SUMMARY LIMITING FACTORS EXPLOITATION North East coast net fishery River Tees rods Distant water interceptory fisheries Unreported and illegal catches HABITAT Water quality Water quantity Channel structure and siltation Habitat improvements Obstructions Other catchment specific factors CLIMATE CHANGE PROPOSED ACTIONS INTRODUCTION ACTIONS REVIEW (ACTIONS NUMBERED AS IN TABLE 4.1) RATIONALE FOR FUTURE SAP ACTIONS PRIORITISING ACTIONS CONSULTATION MONITORING THE PLAN REFERENCES...71 TEES SAP REVIEW APPENDICES...75 APPENDIX I. CURRENT AND PREDICTED STOCK PERFORMANCE...76 DESCRIPTION OF THE FISHERIES (RODS AND NETS)...76 APPENDIX II...97 INTERIM MANAGEMENT TARGETS...97 APPENDIX III ESTIMATING THE EFFECT OF THE NECSF BUYOUT ON TEES ROD CATCHES Final Report EA iv

5 1 INTRODUCTION 1.1 The Role of Salmon Action Plans (SAPs) The Environment Agency s strategy for the management of salmon fisheries in England and Wales (NRA, 1996) requires the production of an individual Salmon Action Plan (SAP) for each principal salmon river. As well as updating these plans at regular intervals, they will be progressively integrated into the 6-yearly Water Framework Directive Planning Cycle. The EA s national strategy is currently undergoing review and consultation, with the aim of a revised approach to be implemented by This present report refers to the stock assessment and management actions as set out in the original Tees SAP, modified by any new circumstances, information or actions arising since then. Whilst the strategy recognises the need to maintain a national overview of salmon conservation, the key component requires individual stocks to be managed effectively. Government has instructed the Agency to set Conservation Limits (CLs) as Biological Reference Points (BRPs) for individual rivers and to refine them and their use to take account of improvements in methodologies and new data. CLs are minimum threshold points below which stocks should not fall. However salmon abundance always varies naturally. Therefore the management aim is to keep stocks at higher levels such that a compliant stock is above the CL for at least 80% of the time (4 years out of 5, on average). This approach is endorsed by the North Atlantic Salmon Conservation Organisation (NASCO), the inter-governmental body concerned with salmon conservation in the North Atlantic. The UK is linked to its recommendations and advice via the European Union. SAPs form part of the NASCO Implementation Plan for England and Wales and set out the river specific actions to manage and conserve salmon stocks in the coming 5 years, with particular reference to some of the key NASCO agreements. This review of the River Tees Salmon Action Plan seeks to ensure that actions which are taken to control exploitation and address any limiting factors on the performance of the stock and fisheries are appropriate, proportionate and effective. This Salmon Action Plan review document should be read alongside the original SAP Consultation and Final Action Plan documents published in 1999 together with the following plans: River basin planning: summary of significant water management issues Northumbria River Basin District, CAMS, flood risk management plans, the AMP 4 programme and NLOs, local byelaws and supporting materials. SAP Reviews and Strategic Environmental Assessment (SEA) Salmon Action Plans and their Reviews fall under Directive 2001/42/EC (the SEA Directive). This requires responsible authorities (public bodies) to undertake a Strategic Environmental Assessment (SEA) of the effects the plans have on the environment. SEA is an important tool to ensure that a broad range of relevant environmental effects, which could potentially result from the implementation of the plan, are taken into account in the decision making process. EA

6 The SEA Directive has been implemented in England by the Environmental Assessment of Plans and Programmes Regulations (SI 2004, No 1633), for plans that relate to England or are cross-border with any other part of the UK. In Wales, the Environmental Assessment of Plans and Programmes Regulations (Wales) (SI 2004, No 1656) apply. Salmon Action Plans (SAPs) fall under the requirements of the SEA Directive for two key reasons: There is a statutory requirement to produce them (Art. 2 (a) of the Directive), as a result of the 1998 Ministerial Direction. They have the potential to "set the framework for future development consents" (Art. 3(2) (a) and (4) of the Directive). SAP Reviews fall under the category of 'Minor Modifications' (Art. 3 (3) of the Directive), and therefore only require SEA if there are likely to be significant environmental effects. A screening consultation (Article 3 (6) of the Directive) was undertaken in 2005 / 06 with the consultation bodies (English Nature, The Countryside Agency, English Heritage, Countryside Council for Wales and CADW). We agreed that such significant environmental effects were only likely for SAPs that fall within or affect Natura 2000 sites (sites designated as Special Areas of Conservation), and / or are riverine SACs where (any) fish species are a feature of interest. In such situations, the SAP Review would need to be subject to statutory SEA. The SAP Review for the River Tees has been determined not to require SEA. However, some aspects of the SEA Process have been incorporated into the SAP Review as good practice. 1.2 Description of the Tees catchment The Tees catchment covers an area of approximately 1,930 km 2 (Figure 1.1). The source of the River Tees is at Tees Head in Cumbria. Rising high in the North Pennine hills (893 m Above Ordnance Datum), within 10 km of the sources of the South Tyne and the Wear, the river flows in a south easterly direction and over High Force waterfall near Middleton in Teesdale. Continuing eastward the river travels past Barnard Castle, then on to the more populated lowland areas of Darlington, Yarm, Stockton, Billingham and finally Middlesbrough before it enters the North Sea, 160 km from its source. Major tributaries of the River Tees are the Rivers Lune, Balder, Greta, Skerne and Leven. The length of river in the catchment is ca. 393 km. The upland part of the catchment, dominated by peaty soils, is characterised by steep slopes resulting in a flashy regime that rapidly responds to rainfall events. However, the numerous reservoirs located in this region accommodate these flows so reducing the influence of flood flows. The lower Tees and its estuary are highly urbanised and industrialised. Industrial activities are dominated by chemical and steel making, both of which produce comparatively large quantities of industrial waste. A tidal barrage, including a fish pass, was constructed across the Tees at Stockton-on-Tees in The geology of the upper Tees catchment is principally underlain by Carboniferous limestones with some sandstones and shales present. The Whin Sill (quartz dolerite) intrudes through these strata. The lower catchment is mostly composed of Permian marl EA

7 and limestone, with some Triassic and Jurassic sandstones and mudstones (Hudson- Edwards et al., 1997). In many places the river and its tributaries are flowing over bedrock and natural waterfalls are common around the catchment. The two major waterfalls on the main river are High Force and Cauldron Snout, both formed from the Great Whin Sill outcrop. There are numerous statutory designations within the Tees catchment. The North Pennine Moors is a Special Protection Area (SPA), and part of Upper Teesdale is also a designated National Nature Reserve. The upper Tees catchment also lies within the North Pennine Moors Area of Outstanding Natural Beauty (AONB). Thrislington Plantation in the River Skerne catchment is designated a Special Area of Conservation (SAC) and a National Nature Reserve. The Teesmouth and Cleveland Coast is PA and RAMSAR designated. There is also a Teesmouth National Nature Reserve. There are over 59 SSSI s within the catchment, and it also supports UK Biodiversity Action plan species including the native white-clawed crayfish, otters and water voles. The Skerne catchment, and much of the catchment to the east of Barnard Castle has been designated a Nitrate Vulnerable Zone under the EC Nitrates Directive. With regard to the Freshwater Fisheries Directive (FFD), 355 km of the River Tees are designated stretches. The majority of these are salmonid designations (279 km) with the remaining 76 km being cyprinid. There are also 19 stillwaters (530 ha) that are protected, 5 salmonid designations totalling 44 ha, and 14 cyprinid designations totalling 486 ha. The native white-clawed crayfish (Austropotamobius pallipes) can be found in many locations throughout County Durham and the Tees Valley. The invasive non-native signal crayfish (Pacifastacus leniusculus) however appears to have established itself on the River Tees and is out-competing the native species for the same habitat and threatening native populations with the crayfish plague. This infection is widespread but non lethal amongst signal crayfish, but results in mass mortalities in native crayfish. It is caused by a fungal pathogen Aphanomyces astaci. EA

8 Figure 1.1 The River Tees Catchment EA APEM Scientific Report EA

9 Catchment details Table 1.1 Summary of River Tees catchment details Surface Area 1,930 km 2 Length of river km River (source to sea) 160 km Topography Max level 893 km Above Ordnance Datum Geology Mainly Millstone Grit and Carboniferous Limestone, with 85% superficial deposits of peat and boulder clay. Widely overlain by recent glacial deposits. Estimated Catchment Population 800,000 (based on 2001 census data) Water Resources Annual Average Rainfall River Flow (at Broken Scar) Mean Daily Flow Dry Weather Flow (Q95)* Minimum Daily Flow Maximum Daily Flow * Q95 = Flow exceeded 95% of the time mm in the headwaters dropping to 600 mm near the estuary m 3 s m 3 s m 3 s m 3 s -1 Water Quality (GQA 1996) Class Length, km A B C 63.5 D 61.6 E 30.9 F 1 EA

10 2 CURRENT AND PREDICTED STOCK PERFORMANCE 2.1 Description of the fisheries (rods and nets) Overview The River Tees was an important salmon river in the 19 th century with around 10,000 fish being netted from the river in 1867 (Netboy, 1968). A combination of industrial pollution and barriers destroyed runs. These problems were partly resolved by the end of the 19th century to enable net catches of 5,000 to 9,000 between 1905 and 1916; but expanding industrial pollution developed again, eliminating the migratory fisheries between the 1930s and 1980s. The Tees now supports small but increasing salmon and sea trout in-river rod fisheries. In addition to angling, salmon returning to the Tees are exploited by the North East Salmon Fishery (NECSF) along the Yorkshire and Northumbrian coasts. Annual stock assessment reported to ICES and collated by the North Atlantic Salmon Working Group has documented a continuing theme of declining 1SW and MSW salmon in the Southern European Commission area of NASCO since the 1970s. While rates of decline were less during the current SAP period (1999-present) nevertheless at a national scale stocks are below the spawning escapement reserves and declines have been worse for MSW compared with 1SW salmon (e.g. Cefas/EA, 2008). Within this overall pattern individual rivers have performed differently according to local circumstances. The Tees is one of a group of rivers that have increased against the national trend, because they are recovering from very low points as environmental conditions, principally estuarine water quality, have improved. This has been reflected in the long term increasing catches in the Tees rod fishery, which have also been influenced by regulatory changes. This section outlines the key points of a review of stock and fishery performance, mainly during the life time of the 1999 SAP, and more details are given in Appendix I. Sea trout fisheries are also described because they will be included in future SAPs. North East Coast Salmon Fishery The NECSF, which is controlled by the Environment Agency (EA), comprises drift nets operating out to 6 miles and shore based T and J nets. It is significant as the single biggest net fishery in England and Wales and also because the fishery (the offshore drift nets in particular) exploits salmon and sea trout entering all NE rivers and fish destined for the Tweed (mainly) and other east coast Scottish rivers. It is thus a highly mixed stock fishery. The locations of the major sectors of the NECSF are shown in Figure 2.1. The biggest of these lies in the North Northumbria area and the District 2, southern, fishery immediately adjacent to the Tees is small, there being no drift nets and only 1 T net (2 in 2007). The main event in the net fisheries during the lifetime of the current Tees SAP was the partial buyout of drift nets in All the NECSF fisheries intercept salmon and sea trout generally migrating in a northerly direction (Potter, 1985). Thus, the net fisheries of most relevance to the Tees are likely to be the South Northumbrian drift and coastal T nets and the Yorkshire drift and coastal T and J nets. Of these the most significant are the Yorkshire T and J nets, licences for which increased from 11 and 17 before the buyout to 27 and 31 respectively since 2004 (Appendix Table AI.1). EA

11 Figure 2.1 Location of the North east Coast salmon Fishery principal sectors NECSF salmon catches have always been dominated by the drift net component (e.g. 91% in the period ). Total salmon catch increased rapidly in the 1960s through the introduction of monofilament drift nets and increased effort, with declared catches of over 60,000 fish being reported in the 1970s and 1980s (Figure 2.2). EA

12 Northumbria Yorkshire Declared salmon cath Figure 2.2 North East Coast Salmon Fishery annual salmon net catch 1952 to Sea trout catches have followed a broadly similar pattern to salmon, but fewer fish are caught overall (Figure 2.3), and because of their presumed more coastal migrations sea trout are more vulnerable to the T&J net fisheries. Northumbria Yorkshire Declared sea trout catch Figure 2.3 North East Coast Salmon Fishery annual sea trout net catch 1952 to EA

13 In order to reduce the mixed stock problem and thereby secure better salmon fishery management, Net Limitation Orders (NLO) were introduced in 1992 and 2002 and a permanent buyout of most drift net licences was achieved in 2003, which reduced drift net fishing effort from 142 licences in 1992 to 16 (Figure 2.4). Figure 2.4 Number of drift and T and J licences issued annually in the Northumbria and Yorkshire net fisheries, 1996 to Following the drift net buyout there was some redistribution of effort (Figure 2.4) and catch (Figure 2.5a) to the shore-based T&J nets; but the overall effect has been a decrease in total NECSF salmon catch since 2003 (Figure 2.2) and a reduction in the proportion of catch taken in the mixed stock drift net fishery to 57% ( ). The net fisheries more adjacent to the Tees (south Northumbrian and the Yorkshire fisheries) have always taken a small proportion of the NECSF salmon catch and this has reduced even further since the buyout (Figure 2.5a). A reallocation of effort towards the T&J nets following the buyout would be expected to result in their recording relatively greater catches of sea trout. This happened and the biggest catch increase was in the Yorkshire T&J nets (Figure 2.5b), which also had more licences issued since 2004 (Appendix Table AI.1). However, in spite of the increased effort in the north Northumbrian T net fishery (71% increase in days fished) the sea trout catch actually slightly decreased (Figure 2.5b) compared with a 50% increase in salmon catch. This and the reduced catch per licence in all the fisheries (see Appendix I) suggested that a reduction in sea trout abundance occurred over that period. EA

14 Annual salmon catch a) SALMON NH(N) drift nets NH(N) T nets NH(S) drift nets NH(S) T nets YKS drift nets YKS T&J nets b) SEA TROUT Annual sea trout catch NH(N) drift nets NH(N) T nets NH(S) drift nets NH(S) T nets YKS drift nets YKS T&J nets Figure 2.5 5yr mean a) salmon and b) sea trout catch in NECSF sectors before ( ) and after ( ) the drift net buyout. NH=Northumbria, (N) = North, (S) = South, YKS = Yorkshire. Tees rod fishery Following a long period of no rod fishery due to severe pollution problems salmon rod catches have increased on the Tees since 1982 (Figure 2.6). In 2007 the 5 year ( ) average catch was 139, and the Tees ranked 25 th amongst English and Welsh salmon rivers (EA, 2008a). EA

15 Annual declared salmon rod catch Figure 2.6 River Tees declared salmon rod catch between 1900 and Declared sea trout rod catch has followed a pattern similar to salmon, although catches were reported intermittently since the mid 1960s when no salmon were declared caught. Catch has decreased since a peak in 2004 (Figure 2.7). Annual declared sea trout rod catch Figure 2.7 River Tees declared sea trout rod catch between 1952 and Rod catches of both species vary seasonally (Figure 2.8). Currently ( mean) for salmon, 3%, 24%, 73% are taken in Pre-June, June to August and September to October respectively. Sea trout are marginally more dispersed across the season with 3%, 47% and EA

16 48% being caught in the same periods. In both species the majority of the total annual increase has been due to an increase in the September-October components. However, for sea trout declines have occurred across all monthly catches since they peaked in 2004 (see Appendix I for detail). % of annual catch Tees SAL Tees Sea trout Feb Mar Apr May Jun Jul Aug Sep Oct Figure 2.8 Average monthly salmon and sea trout rod catches on Tees during the period 1996 to Catch and release (C&R) has been practiced on the Tees for many years, becoming compulsory on angled salmon caught pre-june 16 th after the Spring Salmon Byelaws were introduced in Currently the 5 year mean ( ) release rate is 66% for salmon and 61% for sea trout. C&R varies seasonally being, for salmon, 100% pre-june then 62, 36, 52, 60 and 71% in the months June to October respectively. Fishing effort for salmon and sea trout (days fished recorded on combined salmon/sea trout licence returns) has remained stable at around 2,000 angler days per year since 1994 on the Tees, which has the lowest fishing effort in comparison with other NE rivers (Figure 2.9). Common features were the drop in 1999, probably a consequence of the introduction of the spring salmon measures and in 2001, probably due to access restrictions during the foot and mouth outbreak. EA

17 Coquet Tyne Wear Tees Days fished per year Figure 2.9 Changes in rod fishing effort (days fished per years) on the Tees and other North east rivers. Catch per effort (as catch per license day, CPLD) in the rod fisheries shows contrasting trends in the two species (Figure 2.10). For salmon, trends were positive with some flattening off in recent years on the Tyne and Coquet. Sea trout CPLD has decreased on the Tyne and Coquet since around 2001, but appeared to be more stable on the Tees and Wear. This may be indicative of sea trout stock decline and reflects a broadly similar pattern shown by the net fishery catch per effort. EA

18 Sea trout catch per licence day) Salmon catch per licence day a) Salmon Coquet Tyne Wear Tees b) Sea trout Coquet Tyne Wear Tees Figure 2.10 Recent trends (1994 to 2007) in a) salmon and b) sea trout catch per rod licence on the Tees and other NE rivers. Recovery and catch expectation There are evident recent similarities between fishery performance on the Tees and other NE rivers (Figure 2.10) and these can be compared over a longer period to show the long term recovery patterns (Figure 2.11). EA

19 Coquet Tyne Wear Tees Esk Salmon rod catch (N+1) Figure 2.11 Comparison of annual salmon rod catches (N) in the Coquet, Tyne, Wear, Tees and Esk. Catches shown as N+1, with N adjusted for reporting rate. The Tees, Wear and Tyne have been subject historically to serious pollution, but the Coquet and Esk, are comparatively pristine rivers, with catches likely to be affected mainly by external factors such as changes in fishing effort or marine mortality (including NECSF fishing mortality). Since 1990 the rate of change has been similar in all rivers and the time from start to achieving 80% of maximum likely catch is similar in all three rivers at years (see Appendix III). The Tees recovery began later than in the Wear and Tyne, and has been substantial since 1982, but with considerable fluctuations until the late 1990s. Such fluctuations appear to be common in the early years of salmon stock recovery in polluted rivers and probably reflect the initially inconsistent year to year water quality improvements coupled with greater random variation when stocks of salmon are still low. Differences in catch pattern changes amongst these adjacent recovering rivers can be attributed mainly to varying rates of environmental improvement (mainly water quality). However, behind the river-specific patterns can be seen some common features which are probably due to factors such as systematic influence on fishing effort and catches (river flows, foot and mouth restrictions, recording method etc) or to external factors such as marine mortality and return rates from sea. Thus the dip in catches between the mid 1980s and early 1990s was common to all rivers, as was the small peak in A key SAP management objective for the river lies in maximising natural salmon production, so it is important to know what the limits on this might be and when they have been reached in order to compare current performance with predicted expectations. The limits on production, and hence catch, are likely to be linked to the availability and quality of spawning and rearing area in the Tees. Detailed data on this are lacking, although preliminary estimates were used in the derivation of the Conservation Limit. An impression can however be obtained by comparing Tees salmon catches with those of other rivers in England, Wales and Scotland plotted against river area (Figure 2.12). Rivers differ in their hydrological and geomorphological features, which in turn govern drainage patterns, channel structure, spawning and rearing area availability and biological productivity. EA

20 E&W Scotland Tees Mean rod catch Catchment Area, km 2 Figure 2.12 The relationship between rod catch (N) and river catchment size (A) for English, Welsh and Scottish salmon rivers combined (excluding the Tees, shown as ). Ln(N)=1.205 ln(a) , R 2 = 60.9%, n= 111, F 1,109 = 170. The data used in the regression in Figure 2.12 are means of annual catches for 1994 to The highest 5yr mean declared catch so far seen in the current recovery phase of the Tees ( ) is 139. The predicted mean rod catch for the average river of the size of the Tees (1,270 km 2 ) is 674 (95% confidence limits, 441-1,031). The differences between rivers of the same size are fixed mainly by their physical and productivity features; so for each there is only so much room for variation and rivers may be naturally high or low for their size. On the Tees for example its comparatively high proportion of channel bedrock would suggest a lower salmon production than in a river with more gravel-cobble substrates. Even with these caveats, a reasonable upper rod catch limit (5yr mean) for the Tees in pristine condition, given its history, current catchment accessibility and at current rates of exploitation and marine survival might lie between 400 and 1,000 salmon. Any further refinement would require a detailed assessment of the physical habitat and other features determining the river s productivity. Effects of catch and release on catch data Catch and release has increased on the Tees to over 60% and this will have had an increasing error effect on reported catches due to second and possibly third recaptures of released fish. At a release rate of 50% the apparent catch is 5.5% greater than true catch (Appendix I) and the effect would also increase the estimated escapement based on rod catch by a similar (but slightly smaller) error. To put some perspective on this, if the release rates were 20% and 100% then, based on this approximate calculation, the errors would have been 2% and 11% EA

21 respectively. The error increases with exploitation rate. In practice, the error would be lower than shown above because the exploitation rates applying to released fish would be somewhat less than the value applied to first time captures. No allowance has been made for the catch and release effect in this report, to retain consistency with past practice, but it would be advisable to consider it in future assessments. 2.2 Migratory fisheries monitoring Overview Historically, Tees migratory salmon and sea trout stocks and fisheries have been monitored mainly by catch returns (see above), a trap at the Tees Barrage and through juvenile electric fishing surveys carried out by the EA. Fish trap and counter The trap on the fish pass at the Tees Barrage has been in continuous operation since May 1995 and catches a proportion of salmon and sea trout entering the River Tees. The trap has resulted in the physical capture of all upstream migrants using the pass. Catches in the trap vary according to the attraction of the various routes over the barrage as well as depending on the amount of water flowing downstream and fish behaviour. It can be seen from the fish trap data that the run of both salmon and sea trout into the river appears to have increased since 1995, although less so for sea trout (Figure 2.13). Salmon numbers peaked in 2004 at 571 fish, with a smaller peak in the numbers of sea trout entering the river also observed (439 fish). Between 2000 and 2002 sea trout numbers increased considerably peaking in 2001 at over 1,000 fish before falling to levels previously observed. A low flow year in 2003 likely contributed to the decline in fish numbers observed with a 53% and 43% fall in the number of salmon and sea trout respectively. Decreases in the number of salmon observed in 2005 and 2006 were also seen at the Tyne fish counter. In 2008 the monthly upstream counts of salmon were generally greater than those observed previously, especially for September and October when 174 and 153 salmon were recorded respectively (Figure 2.14). The numbers of sea trout throughout 2008 in comparison were slightly lower than those previously recorded (Figure 2.15). The data since 1995 show that the main peak of entry into the river is in September and October for both salmon and sea trout. Observations by Tees Barrage staff also suggest an increasing number of fish migrating upstream through the canoe slalom, since the removal of the one way valves, and fish are seen regularly swimming over the barrage gates at high tides. EA

22 Tees Barrage Fish Trap Number Of Fish Salmon Sea Trout Linear (Sea Trout) Linear (Salmon) Figure 2.13 Tees Barrage fish trap annual upstream counts of migratory adult salmonids (salmon plus sea trout) Tees Barrage Fish Trap Salmon Number Of Fish Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2008 Mean of Figure 2.14 Tees Barrage fish trap monthly upstream counts of migratory salmon so far in 2008 EA

23 Tees Barrage Fish Trap Sea Trout Number Of Fish Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2008 Mean of Figure 2.15 Tees Barrage fish trap monthly upstream counts of migratory sea trout so far in 2008 A number of studies have been carried out to attempt to ascertain the efficiency and selectivity of the fish pass however, to date no decision has been made from the results of these. In 1996 Durham University carried out a one year study looking at the number of microtagged fish caught in the fish trap and observations of fish swimming over the barrage gates. The results of this study were rejected by MAFF who highlighted the need for a tagging and tracking study. Following this, in 2002 Cefas undertook a year long tracking and tagging study using 103 salmon and 53 sea trout which had been caught from the lock, trap and in seine nets, tagged and then moved back downstream. A significant loss of fish and tags occurred and only 3 salmon and 2 sea trout were successfully tracked ascending the barrage, 1 by the canoe slalom and 4 by the gates. A preliminary investigation in 2005, again carried out by Cefas, looked at identifying and testing suitable downstream netting locations and new temperature tags. The use of temperature tags enabled the determination of predation events primarily through changes in temperature records. Changes in temperature records above the ambient water temperature and up to the maximum for the tag are considered to indicate a predation event. Subsequent cooling of the sensor indicates either the ingestion of another meal in the event of temporary cooling or the excretion of the tag with prolonged cooling. This study was not however designed to monitor the barrage performance. Nineteen fish in total were tagged, 6 salmon and 13 sea trout. Of these 9 were lost to seals, 7 approached the barrage and 1 went over. Significant oil pollution was present in the river at this time and the canoe slalom was closed. Trap catches also fell and the results were therefore deemed inconclusive. A further study has since been commissioned, beginning in 2008, to provide further information on the efficacy of the fish pass at the Tees Barrage. This study is being carried out by Cefas and will continue for three years. The route and success of passage will be determined through the tagging and tracking of adult salmonids. EA

24 2.3 Hatchery stocking The Tees was stocked with salmon from Kielder hatchery between 1985 and A total of 1.29 million fish were stocked at annual rates of up to 108,000 and at ages 0+ (72%) and 1+ (22%). Of the 1+ fish, 48% were micro-tagged as part of a MAFF study on exploitation in interceptory seas salmon fisheries (Jowitt and Russell, 1994). The benefits of the full programme have not been assessed, but a provisional review was carried out by Shelley (1994). Shelley reported that of 102,794 micro-tagged salmon stocked in the Tees up to 1994 a total of 6 were reported from the Tees rod fishery by 1995 of 411 total recaptures, the remainder being taken in other rod and net fisheries. These values (adjusted by raising factors) represented overall tagged fish contribution to the Tees rod catch of 6% up to No more that 2 tagged fish were reported in any one year, but because not all fish were tagged, some other hatchery contribution would have been expected. However, the absence of any returns in several years suggests that returns of untagged fish would also have been low. While some benefit from the stocking would be expected, it is thought unlikely to have been large, but given the scarcity of data the contribution to the Tees recovery cannot be reliably quantified Annual stocking Figure 2.16 Annual variation in salmon stocking in the River Tees, In-river fisheries monitoring An annual programme of juvenile surveys has operated since 1991 across the Tees catchment, with the exception of 1998, when surveys were cancelled due to high river flows. These surveys provide information on the temporal and spatial distribution and abundance of the juvenile salmon and sea trout stocks. The density both at individual sites and across the catchment can also be described through the National Fisheries Classification Scheme (NFCS), which assigns grades to sites based on abundance expressed as fish numbers per 100m 2 (Table 2.1). EA

25 Table 2.1 Densities of 0+ and >1+ salmon (per 100m 2 ) assigned to each NFCS grade A B C D E F 0+ > None recorded >1+ > None recorded Semi-quantitative surveys, by which estimates of minimum population abundance are obtained, have been undertaken at several sites on the main river and tributaries since 1991 with the number of sites ranging from 0 to 8 on the main river and 1 to 12 on the tributaries (Table 2.2). Some of the survey sites were closely related to stocking sites and this may have influenced the densities recorded. Table 2.3 shows the percentage of sites achieving each NFCS Grade in the last survey, carried out in 2007, some years after stocking had ceased. No sites achieved an NFCS grade above D for 0+ salmon, whilst for >1+ fish, sites on the main river achieved grades of between B and E and tributary sites recorded all grades except C. Table 2.2 Number of juvenile salmonid survey sites carried out across the Tees catchment between 1991 and 2007 Main river Tributaries Table 2.3 The number of sites achieving each NFCS juvenile salmon grade in the 2007 surveys of the Tees catchment 0+ >1+ Main river Tributaries Main river Tributaries A B C D E F EA

26 Figure 2.17 and Figure 2.18 compare NFCS grades for 0+ fish between 1991 and 2007 and Figure 2.19 and Figure 2.20 >1+ fish over the same period. Historically the majority of sites surveyed within the Tees catchment have achieved an NFCS grade of E for salmon (0+ and >1+). On the main river in 1991 and 1992 NFCS grades of F (no salmon) were recorded at all sites for both age classes of fish. Since then >1+ salmon have been found at all sites on the main river (Figure 2.19) however NFCS grades of F were still recorded for 0+ salmon at a number of sites between 1993 and 1997 and in 2001, 2006 and 2007 (Figure 2.17). Since the beginning of this century improvements in the number of 0+ salmon recorded on the main river have been seen with 25% or more of sites achieving grade D or above (Figure 2.17). A similar pattern has been observed on the tributaries with over 10% of sites consistently achieving grade D for 0+ salmon since 2003 (Figure 2.18). Densities of >1+ salmon have shown a greater improvement than 0+ fish with at least 25% of sites achieving NFCS grades of B or C for >1+ salmon from 2002 onwards (Figure 2.18 and Figure 2.19). 0% A B C D E F 10% 20% % of sites achieving NFCS grade 30% 40% 50% 60% 70% 80% 90% 100% 1991 (1) 1992 (4) 1993 (2) 1994 (7) 1995 (7) 1996 (7) 1997 (7) 1998 (0) 1999 (8) 2000 (4) 2001 (4) 2002 (4) 2003 (4) 2004 (3) 2005 (4) 2006 (4) 2007 (4) Survey Year (no. of sites in brackets) Figure 2.17 Percentage of sites on the main River Tees achieving each NFCS grade for 0+ salmon during surveys carried out as part of the RJSMP since 1991 EA

27 A B C D E F 0% 10% 20% % of sites achieving NFCS grade 30% 40% 50% 60% 70% 80% 90% 100% 1991 (1) 1992 (5) 1993 (5) 1994 (2) 1995 (5) 1996 (3) 1997 (3) 1998 (2) 1999 (2) 2000 (12) 2001 (8) 2002 (7) 2003 (9) 2004 (9) 2005 (7) 2006 (7) 2007 (9) Survey Year (no. of sites in brackets) Figure 2.18 Percentage of sites on tributaries of the River Tees achieving each NFCS grade for 0+ salmon during surveys carried out as part of the RJSMP since % A B C D E F 10% 20% % of sites achieving NFCS grade 30% 40% 50% 60% 70% 80% 90% 100% 1991 (1) 1992 (4) 1993 (2) 1994 (7) 1995 (7) 1996 (7) 1997 (7) 1998 (0) 1999 (8) 2000 (4) 2001 (4) 2002 (4) 2003 (4) 2004 (3) 2005 (4) 2006 (4) 2007 (4) Survey Year (no. of sites in brackets) Figure 2.19 Percentage of sites on the main River Tees achieving each NFCS grade for >1+ salmon during surveys carried out as part of the RJSMP since 1991 EA

28 A B C D E F 0% 10% 20% % of sites achiving NFCS grade 30% 40% 50% 60% 70% 80% 90% 100% 1991 (1) 1992 (5) 1993 (5) 1994 (2) 1995 (5) 1996 (3) 1997 (3) 1998 (2) 1999 (2) 2000 (12) 2001 (8) 2002 (7) 2003 (9) 2004 (9) 2005 (7) 2006 (7) 2007 (9) Survey Year (no. of sites in brackets) Figure 2.20 Percentage of sites on tributaries of the River Tees achieving each NFCS grade for >1+ salmon during surveys carried out as part of the RJSMP since 1991 Some sites on the main river and tributaries have been sampled on a number of occasions throughout the 1990s and 2000s, enabling comparison of fish densities at these sites over time. On the main River Tees the site at High Coniscliffe has been surveyed annually between 1994 and 1997, 2001 and 2003 and between 2005 and 2007 (Figure 2.21). Densities of 0+ fish at High Coniscliffe were seen to improve slightly in the early part of this century. No fish have however been recorded here since Densities of >1+ fish at this site have fluctuated over the survey period increasing to a maximum density of 2 fish/100m 2 in Egglestone Abbey has been surveyed annually over the period 1991 to 1997 and 1999 to 2007 (Figure 2.22). Fish densities at this site, in comparison to High Coniscliffe, have generally been much greater and have shown a steady improvement over the sampling period reaching a maximum so far of sixteen 0+ fish per 100m 2 in 2007 and twelve >1+ fish per 100m 2 in EA

29 5 0+ >1+ 4 Density 100m Figure 2.21 Fish densities at High Coniscliffe on the River Tees between 1994 and > Density 100m Figure 2.22 Fish densities at Egglestone Abbey on the River Tees between 1991 and 2007 EA

30 On the tributaries of the River Tees the greatest number of annual surveys over the period 1991 to 2007 have been undertaken on Egglestone Burn and on the River Balder. Densities of both 0+ and >1+ fish on Egglestone Burn have seen an improvement over the 16 year period with densities of 0+ fish generally above 4 and >1+ fish generally above 8 since 2002 (Figure 2.23). On the River Balder there have been a number of years when no 0+ fish were caught (Figure 2.24). Older >1+ fish have however been recorded on most occasions with a maximum density so far recorded in 1993 at 17 fish/100m 2. Since then densities of >1+ fish have remained at or below 5 fish/100m > Density 100m Figure 2.23 Fish densities on Egglestone Burn between 1991 and 2007 EA

31 Density 100m > Figure 2.24 Fish densities on the River Balder between 1992 and Distribution of spawning and utilisation of the catchment Redd locations Redds have been recorded at numerous locations on the River Tees between the confluence with the River Skerne near Darlington and Low Force (Figure 2.25). The greatest number of redds have been recorded upstream of Eggleston and there is a relatively high density between Stapleton and Whorlton. Redds have also been recorded on a number of the tributaries of the Tees including Clow Beck, Summerhouse Beck, Bowless Beck, Deepdale Beck and Baydale Beck. EA

32 Figure 2.25 Redd location throughout the Tees catchment. EA APEM Scientific Report EA

33 Wetted area During the last SAP for the River Tees data from a geographical information system (GIS) was used to calculate total wetted area of the river system. Modifications were made to these data to eliminate areas inaccessible due to manmade and natural obstructions and average width discrepancies. The total useable area was calculated as 5,295,662 m 2. This area included all accessible areas including the impounded reach above the barrage. During the current SAP review the wetted area figure has again been recalculated to evaluate the loss of potential spawning habitat throughout the catchment as a result of the various obstructions. For the purposes of this assessment all streams of Strahler 1 were omitted from calculations as it was not considered that these areas would be accessible to salmon. The total wetted area of the Tees catchment was calculated at 18,663,578 m 2. Of this 5,823,077 m 2 (31%) is impassable due to man-made or natural obstructions to migration, including the reservoirs. The reaches upstream of Rutherford Bridge, which are only passable to migratory salmon under certain conditions equates to 1,383,638 m 2 (7%). The total wetted area of reaches passable to migratory salmon was calculated as 11,456,803 m 2 (62%) including reaches below the barrage and between the barrage and Low Worsal. Of this 7,755,540 m 2 is between Low Worsal and High Force (the upstream migratory barrier), Grassholme and Hury Reservoirs. Table 2.4 gives a summary of the wetted areas for different areas throughout the catchment. Further field measurements are however required to make a more accurate assessment of wetted area in the Tees in terms of using these figures for calculation of the Conservation Limit. Area Table 2.4 Wetted areas of the Tees catchment Accessibility Total wetted area (m 2 ) Upstream of Cow Green Impassable 467,354 Upstream of High Force Impassable 1,396,070 Upstream Grassholme and Selset Upstream Hury, Blackton, Balderhead Upstream Rutherford Bridge Impassable 823,561 Impassable 378,770 Passable under certain conditions 1,383,638 Upstream Alwent Hall Impassable 506,957 Upstream Old Leven Woods Low Worsal to High Force Downstream of Low Worsal Impassable 2,250,366 Passable 7,755,540 Passable 3,701,262 % of total catchment area EA

34 Figure 2.26 Accessibility of areas of river in the Tees catchment due to natural and manmade obstructions EA

35 2.6 Conservation limit compliance assessment Egg deposition compliance The performance of salmon stocks for rivers in England and Wales is assessed using a compliance scheme based upon conservation limits (CL). The CL is the level of stock that maximise the surplus yield and is just one of many Biological Reference Points that could be used (Potter et al., 2003), but is an approach agreed with Defra, in line with NASCO guidelines and is the policy set out in the National Salmon Strategy (NRA, 1996). The detail of CL derivation is given in EA Guidelines (EA, 2003). To complete the annual compliance testing, three sets of calculations are required: 1) to set the CL, 2) to estimate current egg deposition and 3) to derive a statistical assessment of prevailing egg deposition and trends against the CL. The detail of these procedures is given in EA Guidelines (EA, 2003) and in intermittent enhancements to the methods outlined in the annual ICES salmon stock assessment reports (e.g. Cefas/EA, 2007). All of the calculations require assumptions to be made that introduce uncertainty into the assessments and which display various degrees of reliability and robustness. The CL is set from the overall relationship between spawning stock (or egg equivalents) and adults (or egg equivalents) returning as their progeny. This requires two expressions to be derived, 1) between eggs and smolts and 2) between smolts and returning adults. Because very few rivers have the former it is derived, according to EA SAP protocols, by adjusting the relationship for the River Bush in Northern Ireland (for which data exist) by the habitat features of each river, the Tees in this case. The second relationship, between smolts and adults (eggs), is derived using various assumptions on marine survival rate, sex ratios, 1/MSW ratios and fecundity (eggs per female). At the time of the original SAP this marine survival, based upon monitored rivers in the UK during the 1960s and 1970s was determined to be 25% for 1SW salmon and 15% for MSW fish (EA, 1998). In the face of observed reductions in marine survival these figures were revised by the EA and incorporated into the conservation limit process in April The revised figures assumed a lower survival rate of 11% for 1SW salmon and 5% for MSW fish. The CL can be expressed as a total egg deposition, or as a density, (eggs/100m 2 ) of wetted rearing area, which allows relative comparison between rivers. By definition a (just) compliant stock is one in which the egg deposition (or spawning escapement) is at or above the CL level for 80% of the time on average, i.e. 4 years out of five. Thus the CL is the 20%ile of the escapement distribution (with Standard Distribution, SD) during a particular test period (10years). Correspondingly, the average stock level in that period is the 50%ile and this level is termed the Management Target (MT) The two values are related by the formula; MT = CL * SD (the constant of being derived from probability tables for the standard normal distribution). Changes to the marine survival assumptions in 2002 reduced the Tees CL from 20.5 million eggs to the current level of 14.9 million eggs equivalent to an egg deposition of 240 per 100m 2. Other assumptions used in the CL and compliance are summarised in Table 2.5. EA

36 Table 2.5 Spawning targets for the River Tees catchment as determined within the original SAP document detailing assumptions made during calculation process. TARGET VALUE Maximum gain (MG) egg target 330 eggs m 2 or 20.5 million eggs pre eggs m 2 or 14.9 million eggs post 2002 Spawners equivalent to MG egg target 5,401 Total rod catch (adjusted) equivalent to MG 533 target Total declared rod catch equivalent to MG 485 target Parameters used to calculate the above: Actual wetted area = m 3 Marine survival (to high sea fisheries) = 16.8% Fecundity = 6940 Females = 62.2% Post rod fishery mortality = 9% Rod exploitation = 9.6% Rod catch declaration = Pre % & 93 76% and 2004 onwards 91% The River Tees egg deposition has increased marginally during the SAP period however it has never been compliant and has consistently failed to meet its target by over 50% (Figure 2.27). 25 no. of eggs (millions) Estimated egg depostion Conservation limit Management target Figure 2.27 Egg deposition compliance assessment between 1994 and Note change in Conservation Limit in Note that the term compliance shown in Figure 2.28 is not statistical compliance, it is merely the position of the annual egg deposition relative to the CL; if it is above the CL then it is in that sense compliant. True statistical compliance, taking into account the recent variation in abundance, has been based on statistical methods that were changed in 2004 to introduce an element accounting for the time trend (Cefas/EA, 2005) and this is the method used at the moment. EA

37 The new technique summarises the performance of the salmon stock using Bayesian regression analyses of the egg deposition estimates over the last 10 years. The analysis fits a 20 th percentile regression line (of egg deposition against time) and a 90% probability interval to the data. The method calculates the probability of this 20 percentile regression line being above the conservation limit and therefore whether the management target of exceeding the limit 4 years out of 5 is likely to be met. If this probability is low (less than 5%) then the river fails to comply and if it high (more than 95%) the river complies with the conservation limit. The extrapolation of this 20 percentile regression line also gives an indication of the future performance of the salmon stock and whether management interventions are required. Figure 2.28 details the log egg deposition over time for the River Tees up to and including 2007 and gives an indication of the prediction of stock performance into the future. The River Tees is currently failing its conservation limit with annual egg deposition estimates well below the <5% conservation limit pass value. Although a slight upward trend is predicted in the future this is still below the CL. On the basis of the current recovery rate the Tees is expected to achieve its management target of million eggs between 2023 and % probability interval lower 90%CI 20th percentile River Tees Annual egg deposition estimates Conservation Limit (Pr(pass) < 5%) 1.2 Log egg deposition Year Interim targets Figure 2.28 River Tees statistical compliance with salmon conservation limit. The Tees is not achieving its current conservation limit and over the last 5 years (2003 to 2007) has achieved average compliance of 29% (range 17 to 37%) (Cefas/EA, 2008). This is normal for a river in a recovery phase and in due course, providing that limiting factors are controlled, the river s natural productivity would be reached. It is therefore useful to have some estimate of the trajectory of recovery in order to set interim targets against which to monitor and assess progress. EA

38 Predicting recovery requires an estimate of the maximum productivity (here indexed by rod catch) and some model of the rate of recovery: both are problematic. The rate of recovery of salmon populations is a complex topic, not previously studied, and influenced by factors such as rate of intrinsic population increase, the ability of salmon to reach and colonise subcatchments, and the effects of environmental quality acting on survival at sea and in freshwater. k=400 k=700 k=1,000 CL catch equivalent Tees rod catch (declared) Figure 2.29 Predicted Tees rod catch, based on logistic fit constrained by maximum values (k) of 400, 700, and 1,000. The Management Target, equivalent to the current Tees CL, is shown by the horizontal line at 513. Maximum productivity values were taken from Figure 2.12, to be 400, 700 and 1,000 (see above text) and a simple logistic model was fitted to catch data to estimate the time course of recovery under each of these three scenarios (Figure 2.29) (see Appendix II for detail, rationale and assumptions). Table 2.6 Interim targets as salmon rod catch for the River Tees under three different maximum declared annual catch (k) scenarios of 400, 700 and 1,000. year catch estimates k=400 k=700 k=1, Using ten year intervals the projected mean catches for the year 2020 for example, ranged between 327 and 483 (Table 2.6), offering a means to set interim targets, which can if required be translated into egg depositions. EA

39 The projections also give an indication of when the Tees Conservation Limit (CL) might be met. A just compliant salmon stock on the Tees would have a median declared catch of 513 (or 564, adjusted for reporting rate). This is equivalent to the management target for the river (larger than the CL) and, under the maximum catch scenarios of 700 and 1,000, this would be reached in years 2029 and 2023 respectively (Figure 2.30). TYNE WEAR TEES Mean annual rod catch Figure 2.30 Comparison of predicted recoveries of Tyne, Wear and Tees assuming simple logistic curve fits to catch data. Other rivers are further into their recovery phases. Comparing the Tees with the Tyne and Wear (Figure 2.30), shows that the patterns and rates of recovery were broadly similar, although starting from different times (details are in Appendix II). Similar curve fitting procedures were applied to these rivers, assuming k values of 4,600 and 1,000 for the Tyne and Wear respectively (see Appendix II for determination of these values) and if a maximum catch of 700 is used for the Tees the times to recover to 80% of the maxima are 46, 48 and 58 years for the Tees, Wear and Tyne respectively. These projections come with high uncertainty and should be viewed with caution. Such models are gross simplifications of complex systems responding to constantly changing productivity as the range of factors affecting salmon and their fisheries and environment take their various effects over time. Nevertheless, in the short term (10 20 years) the values in Table 2.6 give options for interim targets for the Tees, and the choice depends upon which k values are considered to be most appropriate for the Tees and its management policy Freshwater production EA

40 Egg deposition derived from smolt production In addition to the assessment of fry and parr freshwater production, it is possible to assess the salmon productivity through the estimation of smolt output and thus give another comparison with the CL compliance. Using smolt estimates the eggs required to produce those smolts can be estimated using standard salmon survival figures of 50% parr to smolt survival, 33% fry to parr and 10% egg to fry and assuming an average smolt age of 2 years. Comparison of these smolt-based egg deposition estimates with those determined by the rod-based assessment can show big differences. It was not possible to carry out this alternative calculation of egg deposition for the Tees however, as sufficient smolt data were not available. 2.7 Summary The River Tees has been subject historically to serious pollution and is currently a recovering river supporting a small but increasing salmon and sea-trout in-river rod fishery. Since 1982, following a long period of no rod fishery, salmon rod catches have increased and in 2008 the Tees was ranked 25 th amongst English and Welsh salmon rivers. The Tees is however not achieving its current conservation limit which is to be expected for a river in a recovery phase. Based on its current recovery the river is expected to achieve its management target between 2023 and EA

41 3 LIMITING FACTORS 3.1 Exploitation Exploitation occurs through legal licensed rod and net fishing, variously in the river, coastal waters and distant waters, and illegal fishing throughout. Since the 1999 Tees SAP measures have been put in place to reduce the levels of exploitation across England and Wales, including the Tees. The key regulatory actions have been: Net Limitation orders, 1992 and 2002 National Spring Salmon Byelaws, 1999 Drift net fishery buyout, North East coast net fishery The NECSF is a limiting factor for the Tees because it harvests salmon and sea trout entering all NE rivers and thus is a factor constraining runs, rod catches and the escapement of salmon and sea trout into the river. Any form of exploitation, nets or rods, affects stock and fishery performance later in the salmon life cycle. This section examines the effect on Tees salmon stocks of changes in the regulation and operation of the NECSF. The history of its regulations and the fishery performance is described in Section 2.1 and the detail of the calculations summarised here are in Appendix II. The size of the potential effect depends upon the numbers of salmon caught by the NECSF and the exploitation rate on Tees origin fish and the fishery had a small influence on the Tees compared with more northerly rivers. As always with such data, there are caveats with respect to the accuracy of the declared catches, the level of illegal fishing and the effect of other factors that may operate, such as trends in marine survival. The buyout led to a catch reduction of 22,090 salmon in the five year averages before and after the buyout. This reduction of 71% was accompanied by proportional redistribution of catch amongst the offshore drift nets and shore-based T&J nets. Thus the drift and T&J net catches were 91% and 9% before the buyout and 58 and 42% afterwards. This latter change marked a reduction in the mixed stock nature of the fishery and therefore achievement of better salmon fishery management, which was its main aim. However, because of the different vulnerabilities to the fisheries, the effect was reversed for sea trout, for which the drift and T&J net catches were 59% and 51% before the buyout and 13% and 87% afterwards. The overall NECSF catch reduction left more fish available to enter rivers in the North East England and the adjacent Scottish rivers. Precise or accurate estimation of the numbers of fish spared is not possible with the available assessment data, particularly on the Tees in which rod catches are still small. However approximate allocations of the spared fish to NE rivers and to the Scottish rivers are summarised in Table 3.1 and details are given in Appendix III. EA

42 Table 3.1 Allocation of spared buyout catch (see Appendix Table AIII.1) to NE rivers based on proportional mean catch Mean rod catches Allocation Allocated Rod catch estimate RIVER Diff % change % Run U=10% U=20 % Coquet Tyne Wear Tees Esk Others Total NE Scotland SUM = For the Tees a rod exploitation rate of about 10% is assumed indicating a catch increase of 24 fish. Because other simultaneous factors would have acted on the run and rod catch, as a conservative assumption it may be proposed that only half of this increase, perhaps fish, may have been a direct consequence of reduced exploitation in the NECSF. This represents between a quarter and a half of the catch increase (40 fish) over that time and 7-14% of the mean annual rod catch. The spawning escapement would have increased also, by between 100 and 200 salmon. Note that this is an upper estimate because the bulk of the NECSF effect (as catch reduction) lies in the north Northumbrian fishery which for geographical reasons may have a lower effect on salmon returning to the Tees than say on Tyne salmon. No estimate was feasible for sea trout given the even greater uncertainties involved River Tees rods The rod fishery, although still small, is a limiting factor on the Tees salmon spawning stock through its 10% exploitation on salmon (EA, 1999). During the SAP lifetime the 5yr mean rod catch has increased from 84 in 1999 to 153 in The Spring Salmon Byelaws introduced nationally in 1999 imposed compulsory catch and release before June 16 th. They were based on concerns over early running, spring (pre-june) MSW salmon, following NASCO guidance and the annual ICES assessments of the Southern European stock complex (ICES 2006). Voluntary catch and release has continued throughout the year. Tees spring salmon catch is very small, 1.4% (2 fish) in 2007 and 3.0% over and is apparently stable at its low level. The 1999 Byelaws have saved 48 fish (53 adjusted for reporting rate) and has removed that limiting factor. The remaining (June to October) rod fishery is not considered a material limiting factor requiring further controls, given the continuing catch and release levels and the evidence of increasing runs, in spite of the fishery. Assuming a post release survival rate of 85% (EA RFERAC chairs paper July 2007), C&R has resulted in a total benefit to the Tees spawning escapement between 1999 and 2007 of 580 salmon, with a range of 44 to 98 fish per year. EA

43 3.1.3 Distant water interceptory fisheries In addition to exploitation in homewater net and rod fisheries, Tees adult salmon stock are also exposed to distant water commercial fisheries outside of the jurisdiction of the EA including those in West Greenland, Faroes and Ireland, during their marine migration. West Greenland During the late 1980s and 1990s the West Greenland fishery exploited up to 20% of the MSW salmon destined to return to European and North American rivers. Following quota reductions, a series of buy-outs and the setup of a management programme between the late 1980s and 2002, catches of between 300 and 900 t have been reduced to a subsistence fishery of approximately 10 t or less. As a result of these initiatives exploitation from this distant water fishery is now estimated to represent less than 1% of English and Welsh salmon stocks. Faroes Both grilse and MSW salmon of northern European origin have historically been exploited within the Faroes fishery. Despite peaks in annual catches of up to 1,027 t in the 1980s it has been estimated that the fishery exploited less than 1% of English and Welsh salmon stocks. Funds supported by NASF secured the buy-out of the fishery quota between 1991 and 1998, leaving a 23 t research fishery only. Although no buy-out has been made during the following years, no fishing took place in 1999 and just one boat reporting a catch of 8 t fished in The fishery has continued to not operate from 2001 to date. It has been estimated that the cessation of this fishery has resulted in approximately 1,200 returning adult salmon to the English and Welsh stocks. Ireland The Ireland fishery exploits salmon from rivers throughout England and Wales to varying degrees, with the Welsh rivers losing the greatest proportion of stock. Management measures were implemented on the fishery in 1997 restricting the allowable catches. Tagging studies have enabled the assessment of the extent of exploitation on a number of English and Welsh rivers salmon stocks. It was determined that prior to the 1997 management measures that the fishery exploited approximately 1.3% (± 0.4) of the Tees salmon stocks which reduced to 0.5% (± 0.7) from 1997 onwards. The Irish Government closed the fishery in Although this fishery cessation is predicted to result in the return of approximately 5,000 more salmon to the England and Wales stock the benefit is expected to be felt predominantly within the south and west of England and Wales Unreported and illegal catches Historically it has been considered that under-reporting of catches in the North East coastal net fishery represent approximately 7%. In the lead up to the buy-out however, in response to rumours that compensation would be in relation to declared catches, it is believed that some licensees may have over-reported their catches in an attempt to secure a larger pay out. During this three year period an under-reporting raising factor was therefore excluded and the reported catch was taken to represent the total. Since the partial buy out of the net fishery, the under-reporting factor used has returned to 7%. EA

44 As with the net fishery, the declared rod catch is considered to be an under-estimate of the total annual catch due to under-reporting. Under the SAP guidelines the under-reporting factor is considered to be the same for all salmon rivers across the UK. The figure used was determined by the EA through a national investigation of the number of returns declared following reminders. For rod catch returns made after 1994 the raising factor used is 10%. Although this value is currently used nationwide it is considered likely that it is unsatisfactory for some rivers and may result in both under and over estimates, it is not clear as to whether either of these are the case for the Tees. Illegal catches and as a result losses to the salmon stock are difficult to quantify for individual rivers beyond that of known cases through enforcement operations. Consultation with regional staff during 1998 and again in 2003 suggested that illegal catches represented between 5 and 18% and 5 and 24% of the total catch for the two years respectively. It is considered that the majority of this will be represented by by-catch from licensed commercial fisheries legitimately targeting marine and estuarine species although some will also be taking places within rivers by rods. As such, those rivers with licensed commercial activities are likely to experience a higher illegal exploitation rate than those with rods alone. In light of the difficulties in setting individual river raising factors to account for this illegal loss, a national value of 12% is currently applied to all rivers in the UK. Again this is likely to result in both under and over estimates for some UK rivers. The individual situation for the Tees is currently largely unknown. In addition to under-reporting and illegal catches, further losses to the stock not currently accounted for may include other non-catch fishing mortality. These will predominantly be from direct and indirect fishing impacts such as fish dying and falling from fishing gear or being taken out by predators, fish being released or escaping but subsequently dying, lost or foul-hooked fish and exhaustion or damage. In the case of the Tees, predation losses from seals in the estuary may be significant due to influences of the barrage and delays of fish movements, but this has not been quantified. Losses may also be experienced by those individuals released through the catch and release byelaw enforcement although a study undertaken in 2003 on the River Eden suggested that upwards of 85% of individuals caught and released survived to spawning. There are however, further possible indirect impacts due to this stress which may influence the success or productivity of the spawning event. The North East/Yorkshire area remains the only in the country with a specific EA Fisheries Enforcement Team and has 13 fully warranted staff members. Enforcement activity is split into two levels, High Impact Fisheries Enforcement (HIFE) and low level enforcement. HIFE concentrates upon anti-poaching, illegal fish movements and high level rod and line enforcement. The team operates under an Intelligence Driven Patrol system (IDP) collating and disseminating intelligence which is then used to direct patrols and operations in an effective and efficient manner through a priority grading system. The system is based on a traffic light system where red is of high priority, amber medium and green low. A summary of patrols for the period 2005 to 2007 are detailed within Table 3.2. Table 3.2 Patrol figures for the period 2005 to 2007 on the River Tees Year Red patrols Amber patrols EA

45 Gathering of intelligence and identification of suspects by way of directed surveillance was subject to new legislation in 2001 and specific operations now require formal authorisation at a managerial level within the EA under the Regulation of Investigatory Powers Act Such authorisations provide a measure of enforcement activity in each area. Table 3.3 details the surveillance operations authorised on the River Tees catchment and estuary between 2001 and Table 3.3 Numbers of surveillance authorisations on the River Tees catchment and estuary between 2001 and Year Surveillance authorisations Since 2000 there have been 81 documented intelligence reports of the use of illegal methods to take or attempt to take salmon from the Tees catchment and the adjacent coastal area. These methods include unlicensed/illegal netting and unlicensed and illegal methods using rod and line. There has been an increase in the number of offences since 2000 with a total of 18 having been recorded over the seven year period totalling resulting in fines totalling 2,250 and costs of 1,725 (Table 3.4). In addition to illegal catch patrols enforcement officers also undertake regular rod licence evasion checks. Table 3.4 Numbers of incident on the Tees with fines and costs imposed. Year Offences Offenders Fines ( ) Costs ( ) 2000# # , * ,250 1,725 # formal caution * plus a 12 month conditional discharge and 12 month ban on holding a fishing licence. With an improvement in the Tees salmon stocks illegal activity could show an upward trend. The fisheries enforcement team have the resources to meet this challenge and will continue with its intelligence led policing to protect and enhance the Tees salmon stocks. EA

46 3.2 Habitat Water quality The headwaters of the Tees and the middle reaches have generally good water quality although the influence of the River Skerne is sufficient to cause a class down grade in the main river for about 6 km. In terms of water quality the Tees is recognised as a river on the mend and all major dischargers have plans in place to reduce pollution loads in the Tees estuary. Consents and authorisations to discharge are being reviewed and tightened in order to reflect requirements for effluent improvements. Rehabilitation of the estuary has been planned in parallel with the Tees Barrage, which has led to a significant improvement in upstream water quality. The freshwater river is now protected from the polluting influence of the tidal waters, allowing efforts to be focused on cleaning up and reducing discharges to the estuary. The recently produced Tees Estuary Present & Future report documents the present state of the Tees Estuary and raises issues that will need consideration if further improvements are to be made. River water quality in the Tees catchment is primarily of good quality as indicated by the General Quality Assessment (GQA) scheme. Data for the period were provided by the EA. These data show that 71% of the monitored watercourses in the catchment achieved A or B water quality status. Waters of C and D status were less prevalent at 23%. The poorer water quality categories accounted for less than 6% of the watercourses monitored, and these occurred in the River Skerne and its tributaries: Demons Beck, Woodham Burn and Carrs, as well as in Cowbridge Beck (category E) while the lowest quality water (category F) accounted for 1 km of water in Cowbridge Beck. Pollution and discharges Mining Tributaries (including Harwood Beck and the River Lune) in the upper Tees catchment drain part of the Northern Pennine Pb-Zn-fluorite-baryte orefield. Historically mining was important, with lead (Pb) mining peaking between 1815 and 1880 and zinc (Zn) mining peaking between 1880 and 1920 (Hudson-Edwards et al., 1997 and references therein). The last mine in the area closed in The methods used for ore extraction and on-site processing produced significant quantities of contaminated waste water and fine particles which were subsequently discharged to running water for removal. Metals released to the catchment included lead (pb), zinc (Zn), cadmium (Cd), Copper (Cu), iron (Fe) and manganese (Mn). It has been estimated that contamination by the sediment-borne load extended for ca. 70 km downriver (Hudson-Edwards et al., 1997 and references therein), so passing below High Force and reaching the stretch of river accessible to salmon stocks. The bulk sediment mineralogy of the Tees overbank river sediments by Hudson-Edwards et al., (1997) indicated that the Northern Pennine ore deposits typically accounted for between 5 and 15% of the sediments. While sediments in the mining areas had concentrations of heavy metals more than 10 times the estimated pre-mining values, a decrease was observed downstream. Sulphides and carbonate forms of metals were only abundant within 5 km of the mining areas, while iron oxyhydroxides were the dominant form of metal pollution in the downstream reaches. Such a distribution is likely a combination of chemical weathering of mine-waste tips or alluvium and gravimetric sorting during sediment transport. The prevalence of the metal-bearing iron oxyhydroxides in the downstream reaches has important EA

47 implications. Some are soluble under either acid or reducing conditions, when the metals they contain may become remobilised to the sediment or water column. The authors also report on data from the British Geological Survey s Geochemical Baseline Survey of the Environment (G-BASE) which indicated that apart from the upland mining areas high concentrations of heavy metals were present in the River Skerne, around the major urban areas of Darlington and Middlesborough, and near the A1(M) motorway. Hudson-Edwards et al., (1997) report that determining the amount of remobilised, contaminated alluvium is difficult. Mapping of floodplain sequences at Barnard Castle and Hurworth-on-Tees indicated little or no lateral channel movement over the past 120 years, suggesting any contaminated sediment will have accumulated in-channel or over-bank. There is limited sediment storage between Barnard Castle and Winston, but after Winston the floodplain widens allowing greater sediment distribution. Although marked channel incision in this locality (20 m) indicates only restricted re-working of any metal-contaminated sediments. Accordingly, should river dynamics change a large store of contaminants is potentially present for remobilisation to the aquatic environment. Water Regulation There are a number of impoundments along the River Tees. The Cow Green dam was completed in 1970, and is the most studied impoundment. Regulation of the Tees from this reservoir has led to physical and chemical effects on water quality in the River Tees. Annual water temperature fluctuations are decreased by 1-2 C, and diel fluctuations in water temperature are also reduced (Crisp, 1977). The increase in spring water temperature is delayed by up to 50 days, while the decrease in autumn is also delayed by up to 20 days. Impoundment also has consequences to the ionic composition of water, with variation decreasing and becoming more seasonal rather than related to water flow characteristics (Crisp, 1977). The reservoir also acts as a sediment trap (Crisp (1977) suggested that inputs to the reservoir would be on the order of kg year -1 ) modifying the quantity and quality of the downstream suspended solids load. There is evidence that the regulated flow has also had an impact on the composition of the macroinvertebrate community (Armitage, 2006), possibly due to the imposition of a narrower range of environmental conditions and increased flow stability. The lack of perturbation for a prolonged period of time has resulted in a fragile community composition, exceptionally susceptible to perturbation. Water Colour Water colour is another issue facing the upper catchment. Much of the upper Tees catchment is an area of blanket bog, with heather and grass moorland. Values of up to 120 hazen have been recorded at the Broken Scar WwTW. Land management practices that lead to the exposure and drying out of peat contribute to this. The high humic content of the water could lead to an increased chemical oxygen demand (COD) in affected waters, with this demand transported downstream to areas habitable by salmon. Northumbrian Water (NWL) currently run the Tees Water Colour Project, in partnership with Durham University, North Pennines AONB Partnership Peatscapes Project, EA, Natural England, DEFRA and the RSPB. This project aims to develop, demonstrate and promote a more holistic approach, linking upland catchment management with water treatment, to try and address deteriorating water quality at the source, in the upstream catchment. The project began in 2005 and is set to continue until To date the project has gone a long way to achieving its goals. A number of key achievements have been: EA

48 Establishing and maintaining working partnerships with local landowner and partner organisations. Investigation into the relationships between water colour and water treatment via modelling. Grip blocking works over an area of approximately 100 ha of moorland during January Feb 2008.A total of 5,583 peat dams were installed and 264 grips blocked, with additional grip re-profiling along several larger eroded grips. Hydrological monitoring of this grip blocking is being undertaken by Durham University. Saline stratification (Upper Estuary) In the 1999 River Tees SAP Consultation document water quality in the estuary was highlighted as being one of the key factors likely to limit the recovery of the salmon stocks in the Tees. The lower Tees estuary was considered virtually dead in the 1970s, with the complete absence of oxygen in the surface waters during the summer months along much of the estuary (Burt and Rees, 2001). Significant progress has been made in its recovery. In the late 1990s dissolved oxygen was present throughout the estuary over the course of a full year for the first time in 50 years. Despite this, recent data indicates that low DO concentrations can still occur, sufficiently frequently as to potentially limit migration, or lead to the exposure of fish to a high stress environment (P. Frear, pers. comm.). Data on DO from the data loggers situated at Portrack (grid ref.: NZ ) from April through June 2008 are shown in Figure 3.1. The upper panel (A) illustrates the results from a fixed data sondes mounted on a wall, while the lower panel (B) illustrates the readings from the floating recorder located further out into the estuary channel. Two areas of concern seem apparent: that occasional periods of very low oxygen concentration occur, and the decreasing trend in maximum oxygen concentrations with time. Comparison of the fixed and floating records indicates that low DO concentrations are more prevalent towards the centre of the channel, and that occasions when low DO could potentially block migration (by reaching across the channel width) are less frequent. When compared with the salinity data from the probes it is clear that the periods of low DO coincide with high tide indicating the influence of saline stratification on the oxygen regime. The temporal trend in decreasing maximum DO concentrations from April through May is likely due to a combination of factors. A longer time-series would be required for analysis, unfortunately this will not be possible as due to vandalism the units have had to be removed from the river. The data do make it clear however, that low DO concentrations still occur in the Tees estuary, probably as a result of saline stratification, and that they may well have a detrimental impact on use of the estuary by salmon and other fish. Data from 2007 (not shown) show a similar pattern of periods of low DO coinciding with high tides. Prolonged drought periods may also cause problems with low dissolved oxygen concentrations in the future. Figure 3.2 and 3.3 show dissolved oxygen levels recorded throughout 1995 and 2003, both of which were drought years. These data show numerous periods of very low oxygen concentrations in the estuary. An improvement can be seen between 1995 and 2003 which is believed to be due to the improvements brought about during the AMP3 environment programme which ran from 2000 to EA

49 Adequate concentrations of dissolved oxygen in water are critical for the survival of salmonids. Reduced levels of dissolved oxygen can impact growth and development of different life stages of fish, including eggs, alevins, and fry, as well as the swimming, feeding and reproductive ability of juveniles and adults. Under extreme low dissolved oxygen conditions, generally agreed as <3 mg/l, this can be lethal. EA

50 EA A :32:00 11:00:00 09:32:00 10:00:00 Dissolved oxygen (mg/l) April May B :32:00 10:00:00 10:32:00 11:00:00 09:32:00 10:00:00 10:02:00 10:30:00 22/05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ /05/ 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(A fixed data sonde, B floating recorder).

51 /01/ /01/ /01/ /02/ /02/ /03/ /03/ /04/ /04/ /05/ /05/ /06/ /06/ /07/ /07/ /07/ /08/ /08/ /09/ /09/1995 Dissolved Oxygen (mg/l) Figure 3.2 Dissolved oxygen records from the Portrack data loggers, situated in the tidal Tees Estuary throughout Dissolved O xygen (mg/l) /01/ /02/ /03/ /04/ /05/ /06/ /07/ /08/ /09/ /10/ /11/ /12/2003 Figure 3.3 Dissolved oxygen records from the Portrack data loggers, situated in the tidal Tees Estuary throughout 2003 Freshwater Fisheries Directive compliance The most recently available Pollution Reduction Programme (PRP) as required by Article 5 of Directive 78/659/EEC (Freshwater Fish Directive: FFD) for the River Tees was updated in July 2006 with data from Of the 393 km length of the River Tees, 355 km are designated stretches under the FFD. The majority of these are salmonid designations (279 km) with the remaining 76 km being cyprinid. EA

52 In 2005 only six stretches were reported as failing the imperative standards of the FFD. All the stretches were located in Billingham Beck, a key tributary joining the estuarine River Tees approximately 2 km downstream of the barrage. The total length of non-compliance was 25.4 km, which equates to 7.15 % of river length. Amongst these six stretches there are only two determinands that are failed: total ammonium and zinc. Details of the non-compliant stretches are shown in Table 3.5 Table 3.5 Details of FFD non-compliant stretches in the River Tees. Data from River Stretch Length (km) Class Sample Point Failing determinand Billingham Beck Bishopton Beck to Carlton Beck 4.6 C total ammonium Billingham Beck Brierley Beck to tidal limit 7.1 C total ammonium Billingham Beck Carlton beck to Brierley Beck 4.0 C total ammonium Billingham Beck Elstob Beck to Bishopton Beck 1.0 C zinc Billingham Beck Source to Trib NZ C zinc Billingham Beck Trib NZ to Elstob Beck 5.3 C zinc For the failure to meet total ammonium standards in the Bishopton Beck to Carlton Beck stretch, the Agency states that there is no known cause. No problems with the consented sewage and trade discharges were reported, and concentrations of ammonia in effluents were within the consented levels. In March 2005 the EA suggested diffuse pollution and wet weather run-off on the basis of high levels of suspended solids at the sampling point, and the next sampling site upstream. Conversely, a summer failing may have been related to insufficient dilution of diffuse pollution due to low flows. Similarly, no known cause could be found for the other two failures in the Carlton Beck to Brierley Beck, Brierley Beck to tidal limit stretch. No problems with the sewage treatment works (STW) were reported on the corresponding dates. While diffuse pollution was the most likely contributory factor, it was noted that Bishopton STW discharged ammonia at higher concentrations than normal on 27 th January and 28 th February. While this STW is considerably further upstream, it could also have contributed to the failures. With regard to the zinc failings, the EA reported that the affected stretches had all been placed into the most stringent zinc band by default in the compliance assessment due to the lack of hardness data. Available results, combined with the fact that the immediate downstream stretches are in the least stringent zinc band, suggest that on collection of hardness data the currently failing stretches will also be moved to the least stringent band and will therefore not fail the Imperative guidelines. Actions to address these failures include the close monitoring of future results and consented discharges to observe any trends for the stretches failing the total ammonium standard. A review of the sampling points will ensure suitable data is available. For the stretches where the zinc standard is being failed the collection of hardness data will be used to correctly place the stretch in the appropriate Band. This action is likely to confirm that the stretch does not fail the zinc standard for the FFD. EA

53 In 2004 the situation was considerably different, with many more stretches failing to meet the FFD standards. The 2006 PRP gives full details of the failing stretches, while the pertinent details are summarised here. Stretches failing the more stringent Guidelines values accounted for km of designated river length (the equivalent of 88.4 %) with failings recorded on Aldbrough Beck, River Balder, Clow Beck, Eggleston Burn, River Greta, Harwood Beck, Langley Beck, River Leven, River Lune/Long Grain Beck, River Skerne, and the River Tees. Failing determinands were: nitrite, total ammonium, BOD5 and non-ionised ammonia. This was the equivalent of 88.4 % of the designated river length. In 2004, Billingham Beck (24.5 km equivalent to 7.15 % of designated river length) failed both the Imperative and Guideline standards of the FFD. Determinands failing Guideline standards were dissolved oxygen, non-ionised ammonia, total ammonium, BOD5, nitrite, suspended solids. Determinands failing the Imperative standards were, as in 2005, total ammonium and zinc. Eleven schemes from the AMP3 programmes were implemented on the River Tees during the latter part of 2004 and during These had been targeted at discharges within the designated FFD stretches, with the aim of meeting the requirements of the Urban Wastewater Treatment Directive (UWWTD), the FFD and River Quality Objectives (RQO). The schemes implemented during AMP3 will also act to reduce organic pollution to the watercourses in the catchment. This will likely increase dissolved oxygen concentrations, with following benefits to fish populations. During the AMP4 programme ( ) one further discharge (from Aycliffe STW to Demons Beck) is designated for improvement. Further investigations within AMP4 may also indirectly benefit fisheries within the Tees catchment. These are investigation into the potential benefit to the estuary from nutrient removal at Bran Sands STW and an investigation into the impact of land management in the upper Tees catchment on water colour Water quantity The Tees is an important water supply river. The upper reaches are used extensively for public water supply and for industry around Darlington and Teesside. In addition to its geology, climate and landuse, the character of the River Tees is influenced by major reservoir construction. There are reservoirs at Cow Green on the Tees (125 ha), Selset and Grassholme on the River Lune and Blackton, Hury and Balderhead on the River Balder. Compensation releases are made from these reservoirs in order to maintain flow in the Tees and provide water to the industrial Teeside during dry weather. Flows can also be maintained by releases from Kielder Reservoir on the Tyne via abstraction through the Tyne-Tees Tunnel at Riding Mill (EA, 2004ab). Annual rainfall in the catchment varies from 2,000 mm over the Pennines to approximately 600 mm over Middlesborough (EA, 2004b and 2008). Annual potential evaporation is around 300 mm in the headwaters and 500 mm in the lowlands (EA, 2004a). An area of approximately 637 square kilometres has not been assessed through CAMS. This area includes the River Tees, which covers the majority of the catchment. There are a total of 18 licensed abstractions within the assessed part of the Tees which authorise a total EA

54 abstraction volume of 2,158,297 cubic metres per year. A further 108 abstractions are reported for the Tees in the Catchment Fluvial Geomorphological Audit (EA, 2004a). The main purpose of this abstraction is for industry although abstraction for domestic, agriculture and private water is undertaken. There are 80 consented discharges in the assessed Tees CAMS area, 1/3 of which are from sewage treatment works. The remainder are mainly from industrial and business sites. Wet peat soils and steep valley sides in addition to moorland gripping in the headwaters promote rapid runoff although the increased flows are moderated to some extent by the numerous reservoirs in the upper catchment. Hydrological analyses were conducted on the data available for the Tees catchment in the Catchment Fluvial Geomorphological Audit (EA, 2004a). Since 1957 there has been a slight increase in monthly mean discharge at Broken Scar gauging station, but this is not reported as significant. The Q10 (the threshold at which 10% of the flows during that year exceed that discharge) has remained at around 40 m 3 s -1 over the past 5 decades but with particularly high Q10 flows recorded in 1998, 2000 and Data from six gauging stations on the Tees indicate years which experienced exceptionally high flow between 1957 and 1993 include 1966 (August), 1968 (September), 1982 (January), 1986 (August) and 1991 (February). Low flow years appear to be 1959, 1964, 1971, 1973, 1975, 1976, 1989 and The most significant change in flows over the period is that of the Q95 with average flows increasing 323% between 1957 and 1961 and 1998 to 2002 from 1.02 and 4.32 m 3 s -1 respectively, suggesting that the volume of water being discharged under low flow conditions has increased. This is likely attributable to catchment changes (more extensive urbanisation promoting surface runoff), flow regulation and maintaining a minimum flow or an increase in precipitation, or a combination of these factors Channel structure and siltation Habitat is crucial for healthy salmon stocks and they require a variety of habitat types at different life stages (Crisp 1996, Hendry et al. 2003), all of which need to be available in appropriate proportions and locations for the life cycle to be completed. Consequently, any impact on river habitat in the Tees has the potential to reduce salmon production. Natural modification of river habitat can occur over time due to environmental changes and variations in river flow. However, anthropogenic impacts have the greatest impact on channel structure and habitat modification (Hendry et al. 2003). Principal causes of habitat deterioration include agricultural practices, land drainage, water supply, hydropower, flood control and weir construction (Hendry and Cragg-Hine, 1997). Siltation of spawning habitat is an impact of prime concern. The presence of fine sediment on gravels reduces permeation of oxygen into interstitial spaces and inhibits removal of metabolic waste (Armstrong et al. 2003). In addition, organic matter within the sediment depletes dissolved oxygen levels which lead to fatalities of embryos or salmon fry (Theurer et al. 1998). Rivers in the Tees catchment are affected by siltation and habitat degradation due to land use changes and the intensification of agriculture, as are many rivers throughout England and Wales (EA, 2008b). The reservoirs on the Tees and its upland tributaries have a strong influence on sediment, in particular the Rivers Lune and Balder store a large and permanent volume of coarse sediment in the channel as a result of reservoir construction upstream limiting flow (EA, 2004b). Deepdale Beck also contains a significant amount of EA

55 fines which are sourced from upstream (EA, 2004b). Siltation also affects water quality in the River Leven, although agri-environment schemes are in place to address this impact on the river (EA, 2008b). Bankside erosion and associated scour predominantly caused by agricultural practices and poor management of land use, for example, overgrazing of livestock and cattle poaching can elevate fine sediment levels and increase deposition rates (Armstrong et al. 2003). Part of the 1993 reform of common agricultural policy involved a move to area based subsidies as opposed to headage based, this has reduced the problem of overgrazing nationally. In the Lower Tees localised bank erosion is evident where poaching is prevalent and bank material is incohesive. In the upper catchment erosion is also widespread on Bowlees and Egglestone Becks and the River Greta where the riparian zone is fragmented and where there is a high level of poaching (EA, 2004b). In the Upper Tees there are vegetated in-channel deposits which effectively narrow the course of the river in several locations and create a 2-stage channel (EA, 2004b). The Lower Tees is a relatively inactive system modified through resectioning with channel narrowing evident through marginal, medial and point bar deposition and vegetation. The EA operate a routine maintenance programme on the Tees which includes aquatic weed control, grass cutting and vermin control (on flood banks) and maintenance of the in channel structures (EA, 2004a). A rolling programme of works is also undertaken, although predominantly on the tributaries of the Tees, not the main river itself, including channel clearance, de-silting and the removal of large obstructions to river flow (EA, 2004a) Habitat improvements There is currently a surplus of suitable spawning sites on the main river and many of the upper tributaries. As the salmon run recovers surveys will need to be undertaken to establish which areas are being under utilised by salmon within the currently accessible areas in order to target areas for improvement. Fish passes are now in place on the River Skerne and Clow Beck but there are still a number of tributaries that may be suitable for salmon spawning if obstructions were passed. The most significant of these is the River Leven with 4 weirs that if passed would open up a large section of potentially suitable habitat. As part of weir refurbishment a fish pass at Leven Bridge was commissioned in July It has been identified that physical habitat conditions are possible limiting salmon spawning in the Tees catchment and several habitat improvement schemes which may benefit spawning, nursery and resting areas for fish species have been proposed under the Salmon Rivers Project (EA, 2004ab). This project was commissioned by the EA in August 2003 and aims to provide a catchment-scale approach towards the management of physical habitat conditions for salmon fisheries. Key issues identified in the Catchment Fluvial Geomorphological Audit of the Tees Catchment (EA, 2004a) are: Reservoir construction (in the 1800s and Cow Green in 1970) and flow regulation has a significant impact on the flow regime and sediment supply and transport. Many cobbles and gravel deposited as side, point and medial bars are colonised with vegetation. There are active cobble/gravel bars, but relatively few in number EA

56 compared to pre-dam construction. Coarse sediment availability from the upper reaches and tributaries is also reduced. Localised bank erosion is exacerbated by lack of riparian zone and cattle poaching. In some locations, bank protection measures are failing and in some cases increasing the rate of erosion and bank retreat Obstructions There are a total of 35 obstructions to fish passage throughout the Tees catchment of various types, both natural and manmade (Figure 3.4). These are 4 natural waterfalls, 1 dam, 27 weirs (including flat V weirs and crump weirs), 2 bridge footings and the Tees Barrage. The barrage is the first barrier to the upstream migration of salmon in the Tees and in order to facilitate the passage of migratory fish past this a dedicated Denil type fish pass was included in the construction. The barrage is discussed in more detail in Section 2.2 and below. High Force and Cauldron Snout are the two major waterfalls on the main river and are impassable to migratory fish. There are also plans to extend the canoe slalom as part of the 2012 Olympics and this may have implications for fish passage, although there is currently a proposal for two new fish passes within the canoe course (P. Frear pers. comm.). Poor estuarine water quality may also act as a barrier to the migration of salmon. EA

57 Figure 3.4 Obstructions to migration in the Tees catchment EA APEM Scientific Report EA

58 Loss of spawning and rearing area The various artificial barriers on the Tees catchment will have reduced the overall juvenile salmon production capacity of the catchment. Those reservoirs that block access to otherwise accessible areas (e.g. not including the Cow Green reservoir, it being upstream of High Force) did not have mitigation agreements at the time of their construction with the exception of Hury Reservoir where a fish pass is present although currently unusable. There may be opportunities for negotiating such agreements in the face of the now increased capacity for salmon stock redevelopment resulting from improved estuarine conditions. This would require estimates of the production capacity of the lost areas and evaluated mitigation proposals that might include stocking (cf Kielder on the Tyne) or other options such as seminatural spawning channels, habitat expansion or improvement Other catchment specific factors Predation Throughout their various life stages Atlantic salmon are preyed upon by a number of piscivorous species. Numerous studies have been carried out to gather data on predator abundance, diet and energy requirements in order to model their potential impact upon the populations of their prey. Predation on the salmon populations of the River Tees catchment will include piscivorous birds and fish during the juvenile life stages and in addition to these predatory species, mammals during the migratory smolt and adult life stages. The migratory nature of salmon put them at particular risk to predation due to the congregation of often large numbers of individuals moving and being focused within areas of the catchment during both the seaward smolt migration and spawning migration period of adults. The Tees Barrage in particular will have a direct impact on migratory salmonid predation as large numbers of adults congregate below the barrage during the summer months. Seals have lived within the estuary of the River Tees for centuries and Seal Sands SSSI situated at the mouth of the estuary supports large numbers of common (harbour) and grey seals. Two hundred years ago harbour seal numbers in the estuary were estimated at around 1000 individuals however numbers then rapidly declined and by the mid 1800 s only animals remained and breeding had ceased (INCA, 2006). By 1862 only three harbour seals remained and by the 1930s no seals were present at all (INCA, 2006). A number of factors were likely responsible for this demise including the increase in the amount of shipping through the estuary, creating disturbance and leading to loss of haul-out and pupping sites as a result of an increased need for dredging (INCA, 2006). Intensive industrialisation along the banks of the river may also have created disturbance and greatly polluted the estuary. Following the clean up of the River Tees in the mid 20 th Century harbour seals began to reappear and by the mid 1980s a resident population of 17 seals was recorded (INCA, 2006). The Tees Seals Research Programme, coordinated by INCA monitored the Tees seals colony each year between 1989 and 2006 (INCA, 2006). Results of the 2006 survey report a maximum number of harbour seals observed in one day of 69 and 26 grey seals, illustrating a steady increase since monitoring began. Harbour seals have also reportedly been seen hauling out in Billingham Beck since EA

59 The harbour seals breed at Seal Sands between mid/late June to early July whilst the grey seals found here probably originate from the Farne Islands or the Humber (INCA, 2006). The Farne islands situated off the Northumbria Coast support one of the most important colonies of Atlantic grey seals in Europe. Most of the grey seals leave the River Tees during the winter to breed, however, a few non-breeding individuals, particular juveniles, will remain at Seal Sands (INCA, 2006). As such, both salmon smolts and adults of Tees origin may be intercepted and preyed upon by seals along the Northumbria coast during their migratory movements. There is also reported to be a continual presence of several seals below the barrage. Seals are generalist predators which feed on the most abundant prey available (Butler et al., 2006) although some suggestions have been made that harbour seals become specialist predators of adult salmon when feeding in rivers (Butler et al., 2006). Aggregative responses of seals to the estuarine and freshwater areas that salmon smolts and adults pass through on their migration route have also been frequently recorded (Carter et al., 2006 and Middlemas et al., 2005). Although the impact is not currently well understood the perceived contribution of seals to salmon population declines has led to calls from fisheries stakeholders for seal predation to be controlled (Middlemas et al., 2005 and Butler et al., 2006).A three year tagging study (Cefas) is currently underway which is hoped will provide both information on fish passage across the barrage as well as an indication of seal predation. Tags from, and remains of, salmon have been found in the stomachs and faeces of many piscivorous birds with species including the gannet (Morus bassanus L.), cormorant (Phalacrocorax carbo sinensis L.), gulls (Larus sp.), goosander (Mergus merganser merganser) and the red-breasted merganser (Mergus serrator serrator L.) found to prey on salmon parr and salmon smolts (Shearer et al.,1987; Feltham and MacLean, 1996; Koed et al., 2006). The foraging activities of goosanders in relation to the seaward migration of smolts has been studied by numerous authors (e.g. Kalas et al. 1993; Feltham and MacLean 1996 and Svenning et al., 2005) and, like seals, they have been found to aggregate in estuarine areas during smolt migration. In the River Bush in Ireland it was estimated that between 51% and 66% of wild salmon smolt were predated by cormorants on a 40 km stretch of river (Koed et al., 2006). Analysis of stomach contents of goosanders by Kalas et al., (1993) revealed about 25% of prey items were salmon and that overall, for 1989, an estimated 2% of the smolts passing the estuary during seaward migration were predated by goosanders. Greenstreet et al., (1993) reported that predation on smolts can be as high as 50 to 70% with predators congregating at river mouths at the time of the smolt run. As a result, a nocturnal smolt migration pattern is common, acting as an anti-predator strategy (Greenstreet et al., 1993 and Kalas et al., 1993). Any barriers or partial barriers to migration, such as the Tees Barrage, will further increase susceptibility to predation as they will cause fish to aggregate in one area. Tees Barrage Situated approximately 16 km from the sea at Stockton, the Tees Barrage, which became operational in 1994, was designed to protect the River Tees from pollution discharged to the estuary. In order to facilitate the passage of migratory fish past the barrage, a dedicated Denil type fish pass was included in the construction however the efficacy of this is yet to be determined. Observations at the barrage have indicated that migratory fish use the fish pass, EA

60 the navigation lock, the canoe slalom and the barrage gates. It has not however been possible to determine the extent to which each route is used or whether the majority of fish are able to pass the barrage without undue delay. The three year tagging study currently under way (Cefas) should help to determine this. A new canoe slalom course, incorporating a new fish pass, may also offer additional migration routes. 3.3 Climate change The Central England Temperature index indicates an increase in air temperature over the last century of 0.86 C. The most noticeable rise is from the 1990s onwards, and over the past decade most years have had a mean annual temperature above the 1907 to 2007 trend line (Solomon and Lightfoot, 2007). Various emission scenarios result in temperature increase predictions between C by The extent of warming will be greater in the south and east than in the north and west (UKCIP, 2002). Air and river temperature are closely linked and recent measurements also indicate increased river water temperatures but to a lesser extent (Davidson et al., 2006). Sea temperatures are also thought to have risen and are predicted to continue to rise. For example in the River Wye annual mean river temperatures appear to have increased by C over the last 20 years with similar trends observed in sea surface temperatures at nearby sites (Davidson and Hazelwood, 2005). Changes in marine and freshwater temperatures and associated climatic variation could affect the life history and survival of migratory fish by acting on their physiology, phenology and biological systems. Such changes would directly influence population and community structure as a result of their associated affects on performance, resource use, thermal habitat availability and survival. Estimated marine survival of salmon smolts has decreased over the last 25 years, and smolt returns for a number of chalk stream stocks in the British Isles between 1989 and 2007 are considerably lower than during the preceding years (Solomon and Lightfoot, 2007). Although exact mechanisms remain unclear this is likely to be due, at least in part, to increases in sea temperature. Before returning to freshwater to spawn, salmon spend 1 to 4 winters at sea. Those remaining at sea for longer (multi-sea winter salmon, MSW) attain larger body sizes and have greater fecundity than those spending a single winter at sea (grilse). In the UK there has been a significant increase in the proportion of grilse in the salmon run as opposed to MSW salmon which has repercussions for the fecundity of the returning population. In addition, the winter North Atlantic Oscillation Index (wnaoi) can act as a proxy for climate change (Boylan and Adams, 2006). The wnaoi is a phenomenon associated with winter fluctuations in temperatures, rainfall and storminess over much of Europe and it has been indicated that with an increase in wnaoi there is a decrease in the time Atlantic salmon spend at sea (Jonsson and Jonsson, 2004). Reasons for this remain to be clarified, however, temperature is expected to play a key role as salmon require a suitable thermal habitat with ocean temperatures of 6-8ºc when at sea, and changes in sea temperature over recent decades may have reduced the availability of this habitat (Reddin and Friedland, 1996). Although evidence for decreases in marine survival is increasing (Friedland, 1998). Once salmon return to freshwater to spawn they may be impacted by further aspects of climate change including increased river water temperatures, greater risk of summer low flows, heavier winter precipitation and changes in sea level (UKCIP, 2002). In freshwater habitats increasing water temperatures during egg incubation may result in the early emergence of migratory fish fry, it may also depress oxygen concentrations within redds, EA

61 leading to an increased risk of mortality. Increased water temperature may have direct mortality effects and behavioural changes as well as decreasing the age of smoltification in salmon with Davidson and Hazelwood (2005) reporting a significant reduction in mean smolt age in salmon stocks in the River Wye in relation to rising temperatures. Predictions for salmon in the River Wye are that, under the low emissions scenario for 'greenhouse gases', growth rates in older smolts will improve progressively through the 2020s and 2050s but decline or level out in the 2080s (Davidson and Hazelwood, 2005). Similar growth patterns up to the 2050s are predicted under the high emissions scenario, however after this rates will decline to well below the average (Davidson and Hazelwood, 2005). This decline is of concern as it could lead to reduced survival through increased predation due to predominance of smaller individuals. Greater risk of summer low flows would decrease the percentage of time for which minimum physical habitat requirements for migratory species are met (Walsh and Kilsby, 2007), and the flow required to initiate migration could be achieved less frequently. High flows are predicted to increase by up to 1.5% which may lead to the wash out of eggs and displacement of newly emerged fish as well as increasing the potential for increased sediment loads causing siltation of redds. Wetter springs may also induce earlier migrations which may subsequently reduce marine survival (Davidson and Hazelwood, 2005). In addition, increased flow power can augment the rates of erosion of river banks leading to channel widening and siltation. Elevated levels of silt within the water column can be particularly detrimental for salmon due to deposition over spawning gravels which can prevent the hatching of eggs and cause mortality of newly hatched alevins and fry (see Section 3.2.3: Channel Structure and Siltation). Such predicted changes in water temperature are exacerbated by other sources of environmental change which have more localised impacts. For example, thermal effluent inputs into freshwater systems are likely to increase and can have direct impacts on salmon growth and survival within specific areas of a river catchment. Overall, further research into the potential impacts of climate change on salmon is required and management actions are likely to be necessary to reduce the continuing elevation of water temperatures in freshwater systems. EA

62 4 PROPOSED ACTIONS 4.1 Introduction. The River Tees has consistently failed to meet its conservation limit and on the basis of the current recovery rate it is not expected to achieve its management target until between 2023 and The actions set out within the original SAP will have undoubtedly assisted in this trend, for example the continuing improvement of water quality in the lower river and estuary, along with others not recommended in the original SAP but which have arisen within its lifetime (e.g. the NECSF buy-out, national Spring Salmon Byelaws, Salmon Stock Conservation Review and NASCO guidance). The following section details the progress of actions recommended within the original SAP which have been undertaken by the EA area staff, national teams and collaboration with stakeholders and other partnerships. The EU Water Framework Directive came into being during the SAP lifetime and this will have potentially profound effects on the way that environmental management will be designed and delivered through River Basin Management Plans. In principle, the emphasis it places on outcomes expressed in measures of ecological health should be an important driver for changes bringing benefits to salmon and sea trout. 4.2 Actions Review (actions numbered as in Table 4.1) 1. Improvement of water quality in the lower river and estuary 1.1 Continue to negotiate discharge improvements. Prosecute offenders. Continued improvements to estuarine water quality through discharge consents process and close liaison with industry. The Tees is now recognised as a river on the mend with all major discharges now having plans in place to reduce pollution loads into the estuary. Consents and authorisations to discharge are being reviewed and tightened. The Tees Barrage has led to significant improvements in upstream water quality with the freshwater river now protected from the polluted tidal waters. GQA grades have improved and river water quality in the catchment is primarily of good quality with 71% of the monitored watercourses achieving GQA grade A or B. 2. Reservoir release policy 2.1 Assess applicability of Kielder releases study currently underway in Tyne catchment. This study was completed in 1997 and concluded that whilst in theory Kielder releases were capable of ameliorating DO conditions in the Tyne estuary, they were impractical because of the volume required to release continuously and the resulting problems for winter refill and environmental impacts higher up the river. A similar release programme is not therefore considered applicable in the Tees catchment to improve DO conditions in the estuary. 3. Free passage past the Tees Barrage 3.1 Undertake acoustic tracking of fish past barrage. Two studies have been carried out to date to ascertain the efficiency and selectivity of the fish pass however neither EA

63 has been adequate enough to provide the information necessary to determine this. Agreement on Tees Barrage monitoring programme, using fish tracking to assess the numbers of salmon and sea trout passing the barrage and their behaviour in the vicinity of the structure. A new enhanced tracking study, by Cefas, is being funded by Barrage owners and began in March 2008, to continue for 3 years This study will also assess the impact of seal predation. There is also a proposal for two new fish passes within the canoe course at the barrage. 4. Improve evaluation of compliance against spawning target through better assessment of egg deposition and run size estimation 4.1 Operate effective fish counter. An effective fish counter located at the barrage would provide useful data to determine run size 4.2 Continue to gain information from the log book scheme. Anglers log book scheme scrapped due to insufficient interest from anglers. Renew angling interest through scheme promotion. EA Conservation Limits in all rivers were revised in 2002 to take into account changes in marine survival. Procedures for egg deposition estimates have been improved by new models to estimate rod exploitation rate. 5. Low potential for juvenile salmon production in certain reaches 5.1 Identify extent to which bankside and instream habitat has been degraded by land use. Geomorphology project completed. Key areas to be identified and projects developed. 5.2 Maintain liaison with developers to ensure impacts of new developments are minimised. A further 2,000 tonnes of gravel have been introduced to the River Balder to mitigate for the loss of spawning gravels due to reservoirs. 1 km (double bank) of riparian fencing funded for Langley Beck to improve spawning substrate through reduced silt input and livestock poaching. Fish pass installed at Leven Bridge on the River Leven in 2006/2007 as part of weir refurbishment works. Pass was commissioned in July Spring salmon spawning and nursery areas have not been identified for protection 6.1 Feasibility study being conducted on River Eden in NW. Key spawning areas identified. Geomorphology project by Babtie Brown and Root for the Tees catchment was completed in 2004, key areas to be identified and projects developed. 7. Enforcement operations to reduce illegal exploitation 7.1 Utilise best practice and new technology where appropriate. Education scheme via local media with local angling clubs to promote catch and release resulted in a 73% EA

64 return rate in Ongoing enforcement activities/implementation of 1992 NLO/byelaw enforcement. 8. Promote new regional byelaws relating to fishing near obstructions 8.1 Promote changes. Ongoing byelaw enforcement. 9. Control rod and net exploitation 9.1 Reduce exploitation on spring run. Implement National Spring Salmon Byelaws, Measures were introduced in 1999 and 48 spring salmon were saved between 1999 and 2007 by the compulsory catch and release. 9.2 Continue implementation of 1992 NLOs. The 2002 NLO continued the same provisions as the 1992 NLO for a further ten years. A mid-term review of the 2002 NLO is currently (Jan 2008) in hand by NE Region. 9.3 Promote voluntary catch and release by anglers. Continues at a high level (72% in 2007) 9.4 Support, promote and facilitate net Buyout (2003). This was achieved and the benefits are assessed in this review. 9.5 Review national Byelaws and their effectiveness. 4.3 Rationale for Future SAP Actions The Environment Agency s corporate strategy for 2006 to 2011 is called Creating a better place and summarises the organisations vision for the environment into the future. Its aim of a better place for people and wildlife, for present and for future generations is hoped to be achieved through nine environmental goals: What the EA wants: A better quality of life for people An enhanced environment for wildlife. Requires the need to protect and improve the environment by providing: Cleaner air for everyone Improved and protected inland and coastal waters Restored, protected land with healthy soils. Need to make some major changes and help everybody achieve: A greener business world Wiser sustainable use of natural resources Need to manage two very real risks by: EA

65 Limiting and adapting to climate change Reducing flood risk. A number of these goals will assist in the protection and enhancement of salmon stocks throughout the UK and are fundamental in the development of actions for future SAP s. There is acknowledgement within the strategy however, which has been further emphasised by DEFRA resource cuts that the EA can not do it all themselves. There is therefore a strong need for effective partnerships, persuading others to act and work with the EA. This will undoubtedly be an important aspect within the River Tees SAP in light of its current failure to meet its conservation limit. A further change will be the incorporation of SAP activities into integrated River Basin Management Plans as part of the delivery of the Water Framework Directive. While a future SAP will continue to show the salmon fishery related aims and activities, it is anticipated that sea trout requirements will also be explicitly addressed in future plans. This is a natural development, considering the common fisheries management and legislation governing these species and their overlapping ecology and environmental requirements. Continuing and future SAP actions are likely to fall into two broad categories: 1. Active tasks that will either restore or increase the natural capacity of the river to produce salmon and increase the number of adults available to use it. 2. Maintenance and protection tasks to retain the current good status, such as environmental and stock protection and developing community involvement in fisheries through fishery development, promotion of participation, public awareness and collaborative programmes. 4.4 Prioritising Actions Those actions in Table 4.1 that are not yet completed are all still appropriate to the next round of SAP development. These include aspects associated with the improvement of water quality, under utilisation and low potential for juvenile salmon production in certain areas of the catchment, identification of key spawning and nursery areas and improvements to the evaluation of egg deposition compliance. In addition to the continuing important operational tasks such as enforcement, environmental protection and regulation some items require emphasis because of the risk they pose or the opportunity they present for fishery improvement. New topics are outlined in Table 4.2. These enhance actions in Table 4.1. Key to a number of these actions is increased inter-organisational cooperation and collaboration (e.g. with British Waterways and NWL) EA

66 Table 4.1 Summary of key options identified in the 1999 SAP (those in italics came about subsequently), showing priority, status and likely position in future SAP Issue Limiting Factors Options Priority Future SAP 1. Improvement of water quality in the lower river and estuary Historic practices and licences. Rate of scheme completion. 1.1 Continue to negotiate discharge improvements. Prosecute offenders. H CONTINUE 2. Reservoir release policy 3. Free passage past the Tees Barrage Lack of information on ecological effects of reservoir releases. Obstruction caused by barrage 2.1 Assess applicability of Kielder releases study currently carried out on the Tyne catchment. L COMPLETE 3.1 Undertake acoustic tracking of fish past barrage. H CONTINUE 4. Improve evaluation of compliance against spawning target through better assessment of egg deposition and run size estimation. 5. Low potential for juvenile salmon production in certain reaches Inaccurate estimate of rod exploitation. Populations constrained by physical habitat 4.1 Operate effective fish counter. 4.2 Promote log book scheme to renew angler interest 5.1 Identify extent to which bankside and instream habitat has been degraded by land use. 5.2 Maintain liaison with developers to ensure impacts of new developments are minimised H H M H CONTINUE CONTINUE CONTINUE CONTINUE 6. Spring salmon spawning and nursery areas have not been identified for protection. Distribution of spring salmon spawning and nursery areas unknown 6.1 Feasibility study being conducted on River Eden in NW. Key spawning areas identified. Geomorphology project for the Tees has been completed, key areas to be identified and projects developed. L CONTINUE 7. Enforcement Resources. 7.1 Utilise best practice and new technology where M CONTINUE EA

67 Issue Limiting Factors Options Priority Future SAP operations to reduce illegal exploitation. 8. Promote new regional byelaws relating to fishing near obstructions 9. Control rod and net exploitation appropriate. Increased exploitation 8.1 Promote changes H CONTINUE Ensure exploitation does not limit stock recovery. 9.1 Reduce exploitation on spring run. Implement National Spring Salmon Byelaws, Continue implementation of 1992 NLOs. 9.3 Promote voluntary catch and release by anglers. 9.4 Support, promote and facilitate net Buyout (2003) 9.5 Review national Byelaws and their effectiveness. H CONTINUE EA

68 Table 4.2 Suggested additional actions for future SAP and incorporation into River Basin Management Plans Issue Limiting Factors Options Priority Future SAP 1. Reduced salmon and sea trout smolt production from inaccessible areas 2. Degraded habitat for spawning and juvenile rearing Reservoir construction Land use Reduced production of salmon smolts 1.1 Evaluate extent of lost area, mitigation options and benefits. 1.2 Explore opportunities for negotiated agreement to deliver such mitigation by appropriate means. 2.1 Actions from the 2004 Tees Geomorphology Action Plan. 2.2 Develop habitat inventory, identify limiting factors (involvement of Tees Rivers Trust). H H H H 2.3 Review the benefits (through surveys of spawning and production) from the gravel works on the Balder and habitat works on Langley beck. 2.4 Once assessed requirement for habitat management. Improvement in land management. 2.5 Investigate opportunities for reservoir mitigation i.e. creation of spawning habitat, gravel replenishment, compensation flow management. Liaison with NWL. M H M 3. Protect and enhance environmental quality and ecosystem health Reduced potential rate of recovery of salmonid stocks 3.1 Implementation of the Water Framework Directive as part of the NE River Basin Management planning H 4. Improved fish passage Increased adult mortality through predation, disease and illegal fishing. 4.1 Revision of the Tees Barrage operating agreement to take into account new fish pass arrangements within the canoe slalom and act on the results of the Cefas tracking study. Adapt H EA

69 Issue Limiting Factors Options Priority Future SAP flow regimes to improve fish passage at all states of tide. 4.2 Examine and implement options for improved fish passage at the Tees barrage through flow management measures. H 4.3 Evaluate all obstructions to fish passage on the River Tees and produce a prioritised programme of work to improve passability. M 5. Improve migratory fish monitoring Current stock levels only partially understood. 5.1 Evaluate potential sites for full river fish counters and under water sonar to estimate returning stock size. Identify bottlenecks to migration (smolts and adults). H 5.2 Investigate the location of spring salmon spawning areas M 5.2 Implement and promote anglers log book scheme, incorporating the format adopted for the Tyne. Include reward schemes and special events. M 5.3 Review historical juvenile survey data to better describe riverine production and bottlenecks and to refine CL M 6.1 Predation Seal predation on salmon. 6.1 Examine methods of managing sea predation and implement seal scaring measures. H EA

70 5 CONSULTATION To ensure that the views of interested parties could be considered and incorporated where appropriate into the SAP review process for the River Tees, two forms of consultation have been undertaken. The first centres around the production and hosting of a web based questionnaire and the second a workshop. Web-based questionnaire The web-based questionnaire was hosted for a period of approximately three and a half months on the North-East regions fisheries pages of the Environment Agency s website. The questionnaire encompassed the main issues that have arisen in previous SAP discussion on the Tees summarised into a total of 23 issues. Participants were asked to indicate those issues they considered of greatest importance through a scoring process. To ensure some discrimination and prioritisation of the relative importance of the different issues, limits were set for the number of scores that could be assigned throughout the table. These limits were set as follows; a maximum of 7 rank 1 scores, 13 rank 2 scores, 18 rank 3 scores and 20 rank 4 scores, the number of rank 5 scores was unlimited. The opportunity was also given for participants to elaborate on any of the issues they felt were particularly important or any that were missing through the use of a comments box. The issues included within the questionnaire were as follows: o In-stream habitat quality e.g. cover, substrate o Spawning habitat availability o Bankside habitat e.g. trees, flood banks o Physical obstructions e.g. dams, weirs, culverts o Siltation o Estuarine water quality o Diffuse pollution e.g. pesticides, minewaters o Food supply e.g. fly life decline o Flow regimes e.g. low/high flows, timing o Over fishing o Illegal fishing o Reliability of rod catch data, e.g. under reporting o Mine discharges o Sewage discharges o Agriculture o Hydro power development o Reservoir releases o Land drainage e.g. upland, urban o Flood defence o Abstraction o Forestry o Climate change o Predation e.g. seals and/or birds EA

71 EA APEM Scientific Report EA

72 A total of 67 responses were received for the River Tees questionnaire up to the 31 st October The Tees Barrage appears to consistently be seen as the most important issue with predation and physical obstructions ranking as the most important issues. Physical obstructions were ranked as score 1 by 85% of participants and predation by 79%. Issues ranked as the least important include hydropower, mine discharges and climate change. Figure 5.1 details the results of the questionnaire and highlight the relative rankling of each of these issue by participants. Workshop A workshop was held on the 12 th November 2008 to discuss the River Tees SAP review consultation document. Workshop attendance invitations were sent to interested parties along with a draft copy of the report. Attendees of the workshop included members of various local angling groups: Darlington Anglers, Stockton Angling Ltd, Pike Anglers Club of Great Britain, Thornaby AA, Hutton Rudby Fly-Fishing Club and Darlington Brown Trout Club. Representatives from the Salmon and Trout Association, Tees Rivers Trust, Northumbrian Water, British Waterways, Farming and Wildlife Advisory Group and Get Hooked on Fishing were also present. A number of local residents also attended. A brief introduction to the consultation document was given including the results of the web-based questionnaire. A number of break-out discussion sessions were then held to discuss in more detail the main issues within the catchment and possible future actions to improve salmon stocks. Issues discussed included: Spawning habitats the need to identify and maintain habitats, Enforcement more visibility is required, Water quality what are the impacts on smolt mortality? Improvements to land management and bank side habitats, Industry collaboration, Inter-organisational collaboration with British Waterways, Water companies, EA etc, Impacts of climate change, Barrage and predation, Suggested recommended actions arsing from these discussion have been included within the proposed actions for future SAP s for the River Tees (Section 4). EA

73 River Tees SAP Questionnaire Responses 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% In-stream habitat quality Spawning habitat availability Bankside habitat Physical obstructions Siltation Estuarine water quality Diffuse pollution Food supply Flow regimes Over fishing Illegal fishing Reliability of rod catch data Mine discharges Sewage discharges Agriculture Hydro power development Reservoir releases Land drainage Flood defence Abstraction Forestry Climate change Predation Percentage of Responses Limiting Factor Rank 1: Most Important Rank 2 Rank 3 Rank 4 Rank 5: Least Important Figure 5.1 Results from the web based questionnaire regarding issues limiting the salmon stocks of the Tees catchment EA

74 6 MONITORING THE PLAN Progress of the plan will be monitored by the Agency via liaison with the Regional Fisheries Advisory Committee, Fish Fora and when required via local improvement associations. Key Performance Indicators will be used to measure the progress made. A national report will be produced by April of the following year and will go to the Fisheries, Ecology and Recreation Advisory Committee of the Agency. This report will include details of compliance against the spawning targets set for each year. Salmon stock performance will be reported to ICES in April each year and an assessment made of the need for any further exploitation controls to be put in place. Plans will be monitored in relation to the WFD planning process and to comply with the Strategic Environmental Assessment Directive, the efficacy of the actions should be monitored where the appropriate data are already being collected by the Agency to define a baseline environmental context. EA

75 7 REFERENCES Armitage, P.D. (2006) Long-term faunal changes in a regulated and unregulated stream Cow Green thirty years on. River Research and Applications, 22 (9): Armstrong, J.D., Kemp, P.S., Kennedy, G.J.A., Ladle, M., and Milner, N.J. (2003) Habitat requirements of Atlantic salmon and brown trout in rivers and streams. Fisheries Research, 62: Butler, J.R.A., Middlemas, S.J., Graham, I.M., Thompson, P.M. and Armstrong, J.D. (2006) Modelling the impacts of removing sea predation from Atlantic salmon, Salmo salar, rivers in Scotland: a tool for targeting conflict resolution. Fisheries Management and Ecology, 13: Boylan, P. and Adams, C.E. (2006) The influence of broad scale climatic phenomena on long term trends in Atlantic salmon population size: an example from the River Foyle, Ireland. Journal of Fish Biology, 68: Burt, N. and Rees, A. (Eds) (2001) Guidelines for the assessment and planning of Estuarine Barrages. Thomas Telford Ltd. pp 536. Carter, T.J., Pierce, G.J., Hislop, J.R.G., Houseman, J.A., and Boyle, P.R. (2001) Predation by seals on salmonids in two Scottish estuaries. Fisheries Management and Ecology, 8: Cefas/Environment Agency (2005) Salmon stocks and fisheries in England and Wales, Cefas, London, 79pp. Cefas/Environment Agency (2006) Salmon stocks and fisheries in England and Wales, Cefas, London, 36pp. Cefas/Environment Agency (2007) Salmon stocks and fisheries in England and Wales, Cefas, London, 97pp. Cefas/Environment Agency (2008) Annual Assessment of salmon stocks and fisheries in England and Wales 2007: preliminary assessment prepared for ICES, April Environment Agency, Cefas, Lowestoft. 107pp. Crisp, D.T. (1977) Some physical and chemical effects of the Cow green (Upper Teesdale) impoundment. Freshwater Biology, 7: Crisp, D.T. (1996) Environmental requirements of common riverine European salmonid fish species in fresh water with particular reference to physical and chemical aspects. Hydrobiologia, 323: Davidson, I.C., Hazelwood, M.S. and Cove, R.J. (2006) Predicted Growth of Juvenile Trout and Salmon in Four Rivers in England and Wales Based on Past and Possible Future Temperature Regimes Linked to Climate Change. Sea Trout Biology, Conservation and Management, EA

76 Environment Agency (1999) River Tees Salmon Action Plan Consultation Report. Environment Agency, Newcastle, 33pp. Environment Agency (2003) Salmon Action Plan Guidelines. Version 2. Environment Agency, Bristol. Environment Agency. (2004a). Catchment Fluvial Geomorphological Audit of the Tees Catchment. Detailed Geomorphological Survey (Report B). June Environment Agency. (2004b). Catchment Geomorphological Action Plan: The River Tees Catchment. June Environment Agency. (2008). The Tees Catchment Abstraction Management Strategy. Environment Agency, Bristol. Environment Agency. (2008) Fisheries Statistics 2007, Salmon and Freshwater fisheries statistics for England and Wales, 2007, EA Bristol. Feltham, M.J. and MacLean, J.C. (1996) Carlin tag recoveries as an indicator of predation on salmon smolts by goosanders and red-breasted mergansers. Journal of Fihs Biology, 48(2): Friedland, K.D. (1998) Ocean climate influences on critical Atlantic salmon (Salmo salar) life history events. Canadian Journal of Fisheries and Aquatic Sciences, 55: Greenstreat, S.P.R., Morgan, R.I.G., Barnett, S., and Redhead, P. (1993) Variation in the Number of Shags Phalacrocorax aristotelis and Common Seals Phoca vitulina near the Mouth of an Atlantic Salmon Salmo salar River at the Time of the Smolt Run. The Journal of Animal Ecology, 62(3): Hendry, K., Cragg-Hine, D., O Grady, M., Sambrook, H. and Stephen, A. (2003) Management of habitat for rehabilitation and enhancement of salmonids stocks. Fisheries Research, 62: Hendry., K. and Cragg-Hine, D. (1997) Restoration of riverine salmon habitats. Fisheries Technical Manual 4, Environment Agency, Bristol, UK. Hudson-Edwards, K., Macklin, M. and Taylor, M. (1997) Historic metal mining inputs to Tees river sediment. The Science of the Total Environment, 194/195: ICES (2006) Report of the ICES Advisory Committee on Fishery Management, North Atlantic Salmon Stocks, to the North Atlantic Salmon Conservation Organisation, Industry Nature Conservation Association, INCA (2006) Tees Seals Research Programme. Monitoring Report No.18 ( ) Jowitt, A. and Russell, I. C. (1994) Analysis of North East Salmonid Microtagging Data. Confidential Report to the Environment Agency. EA

77 Kalas, J.A., Heggberget, T.G., Bjørn, P.A. and Reitan, O. (1993) Feeding behaviour and diet of goosanders (Mergus merganser) in relation to salmonid seaward migration. Aquatic Living Resources, 6: Koed, A., Baktoft, H. and Bak, B.D. (2006) Causes of mortality of Atlantic salmon (Salmo salar) and brown trout (Salmon trutta) smolts in a restored river and its estuary. River Research and Applications, 22: Krebs, C.J. (1978) Ecology: the experimental analysis of distribution and abundance. Harper and Row, London. 678pp. MAFF, SOAEFD, EA (1996) Report of the technical Working Group on the English North-east Coast Salmon Fishery, MAFF Nobel House De 17 th, 1996, 27pp. Mawle, G.W and Milner, N.J. (2003) The recovery of salmon rivers in England and Wales. Proceedings of Atlantic Salmon Symposium, Edinburgh, July Blackwell Science, Oxford, Middlemas, S.J., Barton, T.R., Armstrong, J.D. and Thompson, P.M. (2005) Functional and aggregative responses of harbour seals to changes in salmonid abundance. Proceedings of the Royal Society of Biological Sciences, 273: Milner, N.J. Russell, I.C., Aprahamian, M., Inverarity, R., Shelley, J., and Rippon, P. (2004) The role of stocking in recovery of the River Tyne salmon fisheries. Fisheries Technical Report No. 2004/1, Environment Agency, July 2004, 68pp. National Rivers Authority, NRA (1996) National Salmon Strategy. NRA, Bristol. Netboy, A. (1968) The Atlantic salmon a vanishing species? Faber and Faber, London. 457pp. Potter, E.C.E. (1985) Salmonid migrations off the North East coast of England. Proc. 16 th Annual Study Course of the institute of Fisheries Management, University of York, September 1985 pp Potter, E.C.E. and Swain, A. (1982) Effects of the English north-east coast salmon fisheries on Scottish salmon catches. MAFF Directorate of Fisheries Research. Fisheries Research Technical Report No. 67. Potter, E.C.E., MacLean, J.C., Wyatt, R.J. and Campbell, R.N.B. (2003) Managing the exploitation of migratory salmonids. Fisheries Research, 62: Reddin, D. and Friedland, K. (1996) Decline in Scottish spring salmon and thermal habitat in the Northwest Atlantic: How are they related? In: D. Mills (ed.) Enhancement of Spring Salmon. Moulin, Pitlochry, Perthshire, Scotland, UK: The Atlantic Salmon Trust, pp Shelley, J. (1994) A review of microtagging and stocking of hatchery salmon in the North East Region National River Authority Internal Report. NRA Newcastle upon Tyne. EA

78 Solomon, D. and Lightfoot, G. (2007) Climate change and chalkstream salmon. Environment Agency Scientific Report v.1.5. Svenning, A., Fagermo, S.E., Barrett, R.T., Borgstrom, R., Vader, W., Pedersen, T. and Sandring, S. (2005). Goosander predation and its potential impacts on Atlantic salmon smolts in the River Tana estuary, northern Norway. Journal of Fish Biology, 66(4): Theurer, F.D., Harrod, T.R. and Theurer, M. (1998) Sedimentation and salmonids in Engalnd and Wales. Report P2-103, Environment Agency, Bristol (1998) 70pp. UK Climate Impacts Programme, UKCIP (2002) Climate change scenarios in the UK: The UKCIP02 Briefing Report, April Walsh, C.L. and Kilsby, C.G. (2007) Implications of climate change on flow regime affecting Atlantic salmon. Hydrol. Earth Syst, Sci, 11 (3): EA

79 TEES SAP REVIEW APPENDICES This appendix contains the more detailed assessments and descriptions supporting the main Tees SAP review report text. EA

80 APPENDIX I. CURRENT AND PREDICTED STOCK PERFORMANCE Description of the fisheries (rods and nets) The River Tees was an important salmon river in the 19 th century with around 10,000 fish being netted from the river in 1867 (Netboy, 1968). A combination of industrial pollution and barriers destroyed runs. These were partly resolved by the end of the 19th century to enable net catches of 5,000 to 9,000 between 1905 to 1916; but expanding industrial pollution developed again, eliminating the migratory fisheries between the 1930s and 1980s. The Tees now supports small recovering (Mawle and Milner, 2003) salmon and sea trout fisheries. In addition to angling, salmon returning to the Tees are exploited by the North East Salmon Fishery (NECSF) along the Yorkshire and Northumbrian coasts. In this section the recent status and historical patterns in net and rod fisheries are described to show changes relevant to the current and future Tees SAP. Net fisheries The net fisheries are split into 7 Districts, 1 and 2 in Northumbria and 3 to 7 in Yorkshire. For most reporting purposes the fisheries are identified as North (District 1) and South (District 2) Northumbria and Yorkshire (Districts 3-7). District 2 covers the coast adjacent to the Tees (Figure AI.1). ` Figure AI.1 Location of North East Coast Salmon Fishery areas. Northumbria Districts 1 and 2 match = Northumbria North and South respectively. NB not to scale, for definitive boundaries see 2008 EA NLO review. EA

81 The NECSF comprises drift nets operating out to 6 miles and shore-based T & J nets. It is the single biggest net fishery in England and Wales. The drift nets in particular exploit salmon and sea trout entering all NE rivers (including the Tees), as well as fish destined for the Tweed and other Scottish East coast rivers. In provisional investigations (MAFF/SOAFD/ EA), % of Scottish fish have been estimated to be destined for the Tweed, 32% for the Tay, 18% to the Esk-Bernie and 2% each to the Dee and Forth. It is thus a highly mixed stock fishery which is regarded as inefficient form of management. In recognition of this, a ministerial review in October 1991 considered it desirable to phase out the drift net fishery to aid and improver the management of east coast stocks,...but gradually so as not to cause unnecessary hardship. The phase out of drift nets in the NECSF began in 1993 with the implementation of the 1992 NLO and by 2002 the licences issued annually had reduced from 142 in 1992 to 69. A buyout of most of the remaining drift net licences further reduced licences to 16 from 2003 onwards, but left the T and J nets licences unaffected. Consequently, there was some shift in potential fishing effort from the offshore drift net to the inshore T and J nets in the NECSF fishery as a whole (Figure AI.2). Figure AI.2 Change in net licences issued in the NECSF, 1996 to present, showing the impact of the net buy out in NH = Northumbria, YKS = Yorkshire. The biggest of the fisheries lies in the North Northumbria area (Table AI.1) and the District 2, southern, fishery immediately adjacent to the Tees is very small there being no drift nets and only 1 T net (2 in 2007) in the southern area, the section closest to the Tees estuary. All the NECSF fisheries intercept salmon and sea trout generally migrating in a northerly direction (Potter, 1985). Thus, on balance, the big drift net fisheries in north Northumbria may have less influence on runs entering the Tees than on more northerly rivers. The net fisheries of most relevance to the Tees are likely to be the South Northumbrian drift and coastal T nets and the Yorkshire drift and coastal T&J nets. Of these the most significant are likely to be the Yorkshire T&J nets, licences for which increased from 11 to 17 before the buyout to 27 to 31 since 2004 (Table AI.1). EA

82 Table AI.1 Annual licences issued in NECSF, Region Location Type Northumbria North drift nets T Nets South drift nets T Nets Yorkshire Coastal drift nets Tor J nets SUM DRIFT SUM T&J SUM All nets Net fishery catch data are limited as indices of local stock performance because of the NECSF s mixed stock nature, changes in methods (monofilament nets in the 1960s caused an increase in catch efficiency) and continuing reduction in effort through regulatory changes. Figure AI.3 North East Coast Salmon Fishery declared salmon net catch 1952 to 2007, showing Northumberland and Yorkshire catches. Nevertheless the long term salmon catch history of the whole NECSF (Figure AI.3) shows its importance and the predominance of the Northumbrian component (on average 92% of catch since 1994) which involves catches from south of the River Tees to the Scottish Border. In the 1980s annual salmon catches of 60,000 to 80,000 were recorded, but there has been a reduction since then, partly due to changing fishing regulations and partly to declining marine return rates (e.g. Cefas/EA, 2006). Immediately prior to the net buyout the 5yr mean salmon catch was 31,109 and afterwards ( ) it was 9,019. EA

83 Figure AI.4 North East Coast declared sea trout net catch 1952 to 2007, showing Northumberland and Yorkshire catches. The sea trout catch taken by the net fishery is also important, being numerically greater than the salmon catch (58% of the total combined species catch since 1994). Immediately prior to the net buyout the 5yr mean ( ) declared sea trout catch was 32,097 and afterwards ( ) it was 20,069. EA