EUROPEAN SEA BASS - HOOK AND LINE CAUGHT Dicentrarchus labra Sometimes known as: Bass, capemouth, common bass, European bass, king of the mullets, sea bass, sea dace, sea perch, white mullet, white salmon SUMMARY European Sea Bass are found throughout the Mediterranean and Black Seas and along the Atlantic coast of Europe. They reach sexual maturity between 4 to 8 years of age, and may live for 30 years. Although the abundance of European Sea Bass is not known throughout its entire range, populations around the United Kingdom are sustainably fished. European Sea Bass are caught by a variety of gears including hook and line. Hook and line fisheries typically cause little, if any, damage to the sea floor, and result in low levels of bycatch. Criterion Points Final Score Color Life History 1.50 2.40-4.00 Abundance 2.25 1.60-2.39 Habitat Quality and Fishing Gear Impacts 3.25 0.00-1.59 Management 1.25 Bycatch 3.00 Final Score 2.25 Color
LIFE HISTORY Core Points (only one selection allowed) If a value for intrinsic rate of increase ( r ) is known, assign the score below based on this value. If no r-value is available, assign the score below for the correct age at 50% maturity for females if specified, or for the correct value of growth rate ('k'). If no estimates of r, age at 50% maturity, or k are available, assign the score below based on maximum age. 1.00 Intrinsic rate of increase <0.05; OR age at 50% maturity >10 years; OR growth rate <0.15; OR maximum age >30 years. 2.00 Intrinsic rate of increase = 0.05-0.15; OR age at 50% maturity = 5-10 years; OR a growth rate = 0.16 0.30; OR maximum age = 11-30 years. There is little published information about the life history of European Sea Bass. They reach sexual maturity between 4 to 8 years of age, at lengths of 31-35 cm for males and 40-45 cm for females (DARDNI 2010). The maximum life span of European Sea Bass is 30 years (MI 2009). Although some information is lacking, like growth rates, the available details about life history warrant a core point of 2. 3.00 Intrinsic rate of increase >0.16; OR age at 50% maturity = 1-5 years; OR growth rate >0.30; OR maximum age <11 years. Points of Adjustment (multiple selections allowed) -0.25 Species has special behaviors that make it especially vulnerable to fishing pressure (e.g., spawning aggregations; site fidelity; segregation by sex; migratory bottlenecks; unusual attraction to gear; etc.). -0.25 Species has a strategy for sexual development that makes it especially vulnerable to fishing pressure (e.g., age at 50% maturity >20 years; sequential hermaphrodites; extremely low fecundity). -0.25 Species has a small or restricted range (e.g., endemism; numerous evolutionarily significant units; restricted to one coastline; e.g., American lobster; striped bass; endemic reef fishes). European Sea Bass are found throughout the Mediterranean and Black Seas and along the Atlantic coast of Europe including the Bay of Biscay, English Channel, and the Irish and North Sea (Kottelat and Freyhof 2007; Seafish 2009) and off the coast of northern Africa. Tagging studies indicate the Irish population of European Sea Bass does not mix with the English and French populations (Pawson et al. 2007 a). We consider this a small range.
-0.25 Species exhibits high natural population variability driven by broad-scale environmental change (e.g. El Nino; decadal oscillations). There is some indication that warm water adapted fish species like European Sea Bass, will replace cold water adapted species like cod as ocean water temperatures rise (Heip et al. 2009; Defra 2011). For example, European Sea Bass have extended their range north through the North Sea and to southern Norway in response to warming ocean temperatures (Seafish 2009). In the Severn Estuary and inner Bristol Channel, changes in abundance of European Sea Bass between years also appear to be related to differences in water temperature between years (Claridge and Potter 1983). In addition, the reproductive success of European Sea Bass around England and Wales is climate driven and controlled by large-scale environmental variation (ICES 2004), with warmer water temperatures since the late 1980 s having aided the growth and recruitment of European Sea Bass (ICES 2004). Because large-scale environmental variation can influence their growth and distribution patterns, points are subtracted. +0.25 Species does not have special behaviors that increase ease or population consequences of capture OR has special behaviors that make it less vulnerable to fishing pressure (e.g., species is widely dispersed during spawning). +0.25 Species has a strategy for sexual development that makes it especially resilient to fishing pressure (e.g., age at 50% maturity <1 year; extremely high fecundity). European Sea Bass can produce many eggs (estimates not available) up to four times in one reproductive season (Asturiano et al. 2000). However, they reach sexual maturity at a medium age (4-8 years) and therefore we consider European Sea Bass to have medium levels of fecundity and points were not added. Spawning occurs in mid-water areas and therefore most spawning areas are not known (MI 2009). Two spawning areas are the Celtic Sea and Cromwell coast, where spawning occurs from February to May (MI 2009). +0.25 Species is distributed over a very wide range (e.g., throughout an entire hemisphere or ocean basin; e.g., swordfish; tuna; Patagonian toothfish). +0.25 Species does not exhibit high natural population variability driven by broad-scale environmental change (e.g., El Nino; decadal oscillations). 1.50 Points for Life History
ABUNDANCE Core Points (only one selection allowed) Compared to natural or un-fished level, the species population is: 1.00 Low: Abundance or biomass is <75% of BMSY or similar proxy (e.g., spawning potential ratio). 2.00 Medium: Abundance or biomass is 75-125% of BMSY or similar proxy; OR population is approaching or recovering from an overfished condition; OR adequate information on abundance or biomass is not available. An assessment by the International Council for Exploration of the Sea (ICES) in 2004, concluded that European Sea Bass populations in the North Sea, English Channel and off the west coast of England and Wales were being sustainably fished (ICES 2004). A separate analysis showed that because the fisheries target older fish, the fishery has continued to develop sustainably (Pawson et al. 2007b). No assessment of European Sea Bass has been completed in Northern Irish waters and fishing has been prohibited in southern Ireland since the 1990 s, so the abundance of European Sea Bass in Irish waters is not known (DARDNI 2010). However, heavy fishing in the 1980 s combined with no management measures is thought to have caused a decrease in fish numbers (DARDNI 2010). The abundance of European Sea Bass in the Bay of Biscay, Mediterranean and Black Seas is also unknown (ICES 2004; Seafish 2009). We have assigned a middle score because the abundance of European Sea Bass appears healthy in its northern range, and unknown throughout the rest of its range. 3.00 High: Abundance or biomass is >125% of BMSY or similar proxy. Points of Adjustment (multiple selections allowed) -0.25 The population is declining over a generational time scale (as indicated by biomass estimates or standardized CPUE). -0.25 Age, size or sex distribution is skewed relative to the natural condition (e.g., truncated size/age structure or anomalous sex distribution). European Sea Bass have a maximum life span of 30 years (MI 2009) and can grow to 1 m in length (IGFA 2001). However, there is no information indicating whether age or size patterns have changed over time, so no points are subtracted.
-0.25 Species is listed as "overfished" OR species is listed as "depleted", "endangered", or "threatened" by recognized national or international bodies. -0.25 Current levels of abundance are likely to jeopardize the availability of food for other species or cause substantial change in the structure of the associated food web. +0.25 The population is increasing over a generational time scale (as indicated by biomass estimates or standardized CPUE). The biomass of European Sea Bass around England and Wales doubled from 1985 to 2004 (ICES 2004). However, there is little information from other areas where European Sea Bass are found, so no points are added. +0.25 Age, size or sex distribution is functionally normal. +0.25 Species is close to virgin biomass. +0.25 Current levels of abundance provide adequate food for other predators or are not known to affect the structure of the associated food web. European Sea Bass feed on shrimp, mollusks and fish, with the latter being the main prey item for adult fish (Kottelat and Freyhof 2007). It is likely that current levels of abundance do not negatively impact the structure of the associated food web (Seafish 2009), so points are added. 2.25 Points for Abundance HABITAT QUALITY AND FISHING GEAR IMPACTS Core Points (only one selection allowed) Select the option that most accurately describes the effect of the fishing method upon the habitat that it affects 1.00 The fishing method causes great damage to physical and biogenic habitats (e.g., cyanide; blasting; bottom trawling; dredging). 2.00 The fishing method does moderate damage to physical and biogenic habitats (e.g., bottom gillnets; traps and pots; bottom longlines).
3.00 The fishing method does little damage to physical or biogenic habitats (e.g., hand picking; hand raking; hook and line; pelagic long lines; mid-water trawl or gillnet; purse seines). In Europe, France catches the most European Sea Bass, followed by the United Kingdom, Portugal, Spain, the Netherlands and Denmark (Drouot et al. 2009). The European Sea Bass fishery is the fourth most important in France. European Sea Bass are targeted by a number of fisheries including gillnets and pair trawls as well as by a small artisanal hook and line fishery in the UK, the focus of this report (BRC 2004). Of the 2,498 vessels identified as targeting and or landing European Sea Bass during 2004, in the North Sea, English Channel and Atlantic, 73 were hook and line vessels (Drouot et al. 2009). Most fisheries operate in inshore waters, estuaries, around wrecks, rock outcrops, reefs and on offshore banks (Seafish 2009). Hook and line fisheries generally do little if any damage to the seafloor. Points of Adjustment (multiple selections allowed) -0.25 Habitat for this species is so compromised from non-fishery impacts that the ability of the habitat to support this species is substantially reduced (e.g., dams; pollution; coastal development). -0.25 Critical habitat areas (e.g., spawning areas) for this species are not protected by management using time/area closures, marine reserves, etc. Critical habitat areas are not protected. -0.25 No efforts are being made to minimize damage from existing gear types OR new or modified gear is increasing habitat damage (e.g., fitting trawls with roller rigs or rockhopping gear; more robust gear for deep-sea fisheries). -0.25 If gear impacts are substantial, resilience of affected habitats is very slow (e.g., deep water corals; rocky bottoms). +0.25 Habitat for this species remains robust and viable and is capable of supporting this species. European Sea Bass are a euryhaline species of fish (Saillanta et al. 2002), meaning that they can live in waters that differ greatly in salinity. Adult European Sea Bass inhabit well-defined feeding areas that commonly occur in inshore waters prior to migrating south and west to spawning locations (Pawson et al. 2007a). Their distribution changes seasonally due to migrations between these two areas (Quayle and Righton 2007). In the North Sea and English Channel, European Sea Bass can make very quick long distance migrations of up to 400 km (Defra 2011). In the Severn Estuary and inner Bristol Channel of the UK, European Sea Bass move into the estuary in late August/September, with peak abundance being reached between September and November (Claridge and
Potter 1983). The Bass then move seaward in the later autumn/winter as water temperatures in the estuary begin to decline (Claridge and Potter 1983). Juveniles are commonly found in estuaries and lagoons with lower salinity compared to the open ocean and it is during this early stage that the sex of the fish is determined (Saillanta et al. 2002). Small juvenile fish are found in estuaries and shallow bays after the month of June (Reynolds et al. 2003) where they remain for 4 to 5 years, leaving once they reach about 36 cm in size (Pawson et al. 2007a). After leaving the inshore waters, these larger fish move out around the coast (Pickett et al. 2004). There is no indication that this habitat cannot sustain the population of European Sea Bass so we have awarded points. +0.25 Critical habitat areas (e.g., spawning areas) for this species are protected by management using time/area closures, marine reserves, etc. +0.25 Gear innovations are being implemented over a majority of the fishing area to minimize damage from gear types OR no innovations necessary because gear effects are minimal. Gear innovations are not needed because the effects of the hook and line fishery are minimal (Morgan and Chuenpagdee 2003). +0.25 If gear impacts are substantial, resilience of affected habitats is fast (e.g., mud or sandy bottoms) OR gear effects are minimal. 3.25 Points for Habitat Quality and Fishing Gear Impacts
MANAGEMENT Core Points (only one selection allowed) Select the option that most accurately describes the current management of the fisheries of this species. 1.00 Regulations are ineffective (e.g., illegal fishing or overfishing is occurring) OR the fishery is unregulated (i.e., no control rules are in effect). 2.00 Management measures are in place over a major portion over the species' range but implementation has not met conservation goals OR management measures are in place but have not been in place long enough to determine if they are likely to achieve conservation and sustainability goals. Management measures for the European Sea Bass fishery vary between countries. Despite being an important commercial species in the United Kingdom and Irish waters, they are not managed through the Common Fisheries Policy and are no longer assessed by the International Council for the Exploration of the Seas (ICES) (DARDNI 2010). In addition, there are no quotas or other direct controls on catch or effort (Seafish 2009) but minimum size limits, seasonal nursery area closures and restrictions on gill nets were introduced by England and Wales in 1990 (DARDNI 2010). The Republic of Ireland introduced a prohibition on the commercial sale of European Sea Bass, a bag limit, and closed season management measures during the same time period (DARDNI 2010). Northern Ireland management measures include a minimum size limit and net restrictions (DARDNI 2010). Commercial fishing for European Sea Bass has been prohibited in southern Ireland since the 1990 s (DARDNI 2010). In European Union waters, there is also a minimum size limit and a restriction on gillnet mesh size (Seafish 2009). These management measures have protected juveniles and increased the age at first capture to 5 or 6 years of age (Seafish 2009). France limits landings of European Sea Bass by trawlers in the English Channel from January to April (Seafish 2009). Scotland has no management measures in place for European Sea Bass but the UK has adopted weekly limits for the French pair trawl fishery (ICES 2004). In Northern Ireland, a proposal to protect and conserve European Sea Bass in inshore waters was presented in 2010 (DARDNI 2010). This proposal included the following management measures: a bag limit, prohibition on sale, size limit, gear restrictions (only rod and line allowed), and prohibition of the retention of European Sea Bass on any vessel from the United Kingdom fishing in the Northern Ireland zone (DARDNI 2010). 3.00 Substantial management measures are in place over a large portion of the species range and have demonstrated success in achieving conservation and sustainability goals.
Points of Adjustment (multiple selections allowed) -0.25 There is inadequate scientific monitoring of stock status, catch or fishing effort. Management measures, such as a minimum size limit, in England appear to have been effective and have provided both biological and economic benefits (Pawson et al. 2005). However, these measures appear to only protect European Sea Bass in UK inshore waters (Pawson et al. 2007b). Commercial catch and landings data from Northern Ireland is incomplete and inshore vessels are not required to submit data on the same level required from large commercial vessels (DARDNI 2010). It is also suspected that there are a large amount of unreported catches of European Sea Bass (Ulrich 2000). -0.25 Management does not explicitly address fishery effects on habitat, food webs, and ecosystems. Management does not explicitly address fishery effects on habitat, food webs or ecosystems. -0.25 This species is overfished and no recovery plan or an ineffective recovery plan is in place. -0.25 Management has failed to reduce excess capacity in this fishery or implements subsidies that result in excess capacity in this fishery. Managers have not reduced excess capacity in the European Sea Bass fishery (Drouot et al. 2009). In 2004, it was estimated that 2,498 vessels landed or targeted European Sea Bass in the North Sea, English Channel and Atlantic (Drouot et al. 2009). +0.25 There is adequate scientific monitoring, analysis and interpretation of stock status, catch and fishing effort. +0.25 Management explicitly and effectively addresses fishery effects on habitat, food webs, and ecosystems. +0.25 This species is overfished and there is a recovery plan (including benchmarks, timetables and methods to evaluate success) in place that is showing signs of success OR recovery plan is not needed. +0.25 Management has taken action to control excess capacity or reduce subsidies that result in excess capacity OR no measures are necessary because fishery is not overcapitalized. 1.25 Points for Management
BYCATCH Core Points (only one selection allowed) Select the option that most accurately describes the current level of bycatch and the consequences that result from fishing this species. The term, "bycatch" used in this document excludes incidental catch of a species for which an adequate management framework exists. The terms, "endangered, threatened, or protected," used in this document refer to species status that is determined by national legislation such as the U.S. Endangered Species Act, the U.S. Marine Mammal Protection Act (or another nation's equivalent), the IUCN Red List, or a credible scientific body such as the American Fisheries Society. 1.00 Bycatch in this fishery is high (>100% of targeted landings), OR regularly includes a "threatened, endangered or protected species." 2.00 Bycatch in this fishery is moderate (10-99% of targeted landings) AND does not regularly include "threatened, endangered or protected species" OR level of bycatch is unknown. 3.00 Bycatch in this fishery is low (<10% of targeted landings) and does not regularly include "threatened, endangered or protected species." Bycatch has historically been an issue in the European Sea Bass trawl and gillnet fisheries but not in the hook and line fishery (Seafish 2009). Although specific information on bycatch from the European Sea Bass hook and line fishery is not available, hook and line fisheries typically have a low level of bycatch (Morgan and Chuenpagdee 2003). Points of Adjustment (multiple selections allowed) -0.25 Bycatch in this fishery is a contributing factor to the decline of "threatened, endangered, or protected species" and no effective measures are being taken to reduce it. -0.25 Bycatch of targeted or non-targeted species (e.g., undersize individuals) in this fishery is high and no measures are being taken to reduce it. -0.25 Bycatch of this species (e.g., undersize individuals) in other fisheries is high OR bycatch of this species in other fisheries inhibits its recovery, and no measures are being taken to reduce it. European Sea Bass are caught as bycatch in pelagic purse seine fisheries in the Bay of Biscay from September until March (Seafish 2009). It is unknown if levels are high, so no points are subtracted.
-0.25 The continued removal of the bycatch species contributes to its decline. +0.25 Measures taken over a major portion of the species range have been shown to reduce bycatch of "threatened, endangered, or protected species" or bycatch rates are no longer deemed to affect the abundance of the "protected" bycatch species OR no measures needed because fishery is highly selective (e.g., harpoon; spear). +0.25 There is bycatch of targeted (e.g., undersize individuals) or non-targeted species in this fishery and measures (e.g., gear modifications) have been implemented that have been shown to reduce bycatch over a large portion of the species range OR no measures are needed because fishery is highly selective (e.g., harpoon; spear). +0.25 Bycatch of this species in other fisheries is low OR bycatch of this species in other fisheries inhibits its recovery, but effective measures are being taken to reduce it over a large portion of the range. +0.25 The continued removal of the bycatch species in the targeted fishery has had or will likely have little or no impact on populations of the bycatch species OR there are no significant bycatch concerns because the fishery is highly selective (e.g., harpoon; spear). 3.00 Points for Bycatch REFERENCES Asturiano, J.F., Sorbera, L.A., Ramos, J., Kime, D.E.., Carillo, m. and Zanuy, S. 2000. Hormonal regulation of the European sea bass (Dicentrarchus labrax, L.) reproductive cycle: an individualized female approach. Journal of Fish Biology 56:1155-1172. B.A.S.S. Restoration Committee (BRC). 2004. A review of the recreational and economic status of bass (Dicentrarchus labrax) in England and Wales and proposals for revised management of the UK bass fishery. Report for submission to Defra, the UK Government and the Devolved administrations. 65 p. Claridge, P.N. and Potter, I.C. 1983. Movements, abundance, age composition, and growth of bass, Dicentrarchus labrax, in the Severn Estuary and inner Bristol Channel. Journal of the Marine Biological Association of the United Kingdom 63:871-879. Department for Environment Food and Rural Affairs (Defra). 2011. Marine Science Yearbook 2009/2011. Department for Environment Food and Rural Affairs, London, UK. 56 p.
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Reynolds, W.J., Lancaster, J.E. and Pawson, M.G. 2003. Patterns of spawning and recruitment of sea bass to Bristol Channel nurseries in relation to the 1996 Sea Empress oil spill. Journal of Marine Biological Association 83: 1163-1170. Saillanta, E., Fostierc, A., Haffrayd, P., Menua, B. and Chataina, B. 2002. Saline preference for the European sea bass, Dicentrarchus labrax, larvae and juveniles: effect of salinity on early development and sex determination. Journal of Experimental Marine Biology and Ecology 287:103-117. Seafish. 2009. Responsible sourcing guide: sea bass. Seafish Version 2, June 2009. 6 p. Quale, V.A. and Righton, D. 2007. Preliminary observations of the behavior of sea bass (Dicentrarchus labrax) during migration. Center for Environment, Fisheries & Aquaculture Science, Lowestoft. 1 p. Ulrich, C. 2000. Modélisation multi-flottilles et multi-métiers des pécheries artisanales de la Manche. Evaluation plurispécifique des stocks, etude des interactions techniques et intégration dans la modelisation bioéconomique. Thése de doctorate de l ENSAR. 350 p. Walmsley, S. and Pawson, M. 2007. Length distribution of bass discards in the UK trawl fishery. Center for Environment, Fisheries & Aquaculture Science, Lowestoft. 18 p.