The 2004 Licence Area 1 (Lady Franklin Basin)

Transcription

1 The 2004 Licence Area 1 (Lady Franklin Basin) A summary of the environment and a preliminary assessment of environmental impacts from exploration and development of hydrocarbon resources Note prepared for the Bureau of Minerals and Petroleum, Government of Greenland 24 March 2004 National Environmental Research Institute, NERI Department of Arctic Environment Frederiksborgvej 399 P.O. Box 358 DK-4000 Roskilde Denmark

2 Contents The 2004 Licence Area 1 (Lady Franklin Basin) 1 Contents 2 1. Introduction 3 2. Summary 3 3. The physical environment 7 4. Ecological conditions and fishery 7 5. Expected exploration activities which can impact the environment Environmental impacts of seismic operations Environmental impacts of exploration drilling Environmental impacts of oil spills Regulation, monitoring and minimising the possible environmental consequences Exploitation Activities in winter General and specific information needs Relevant material 28 2

3 1. Introduction During the licence round 2004, four new areas will be opened for oil exploration. The westernmost of these covers a part of the Lady Franklin Basin, and is called Licence Area 1. It is situated west of the previous licence area Fylla, where the Statoil-group operated Licence Area 1 covers c. 10,500 km 2 (Figure 1). This note provides a summary of the environment in and near Licence Area 1, and it briefly describes the possible environmental effects from development of hydrocarbon resources including seismic surveys, exploration drilling and exploitation activities. However, focus will be on the exploration phase. Exploration activities are expected to take place in summer and autumn, when weather and ice conditions are most favourable for the activities. In case of a major find, development and exploitation activities are expected to take place throughout the year. Therefore possible effects of oil spills in the winter are briefly mentioned in this note. However, vital environmental information is still missing from this period of the year. This note includes proposals for further background studies for obtaining data to environmental impact assessments of the expected hydrocarbon activities in Licence Area 1 during an entire life cycle; that is seismic surveys, hydrocarbon exploration and exploitation, transport and decommissioning. 2. Summary Licence Area 1 is generally not well known from a biological point of view. But it is probably less biologically rich than the more coastal license areas. It is situated west of the important shrimp fishing grounds, and only fisheries for Greenland halibut takes place within the area. Hooded seals have a very important and localised whelping area, which dependant on the ice condition, may be situated within the license area. It is assumed that large concentration of little auks (dovekies) occur along the drift ice edge during their migration autumn and spring, and perhaps also in winter. 3

4 Figure 1. Geographic and hydrographic features of the Lady Franklin area (framed with red) and surrounding waters. 4

5 However, spilled oil from Licence Area 1 may drift and affect much larger areas, including the coast, where important (also in an international context) concentrations of seabirds and marine mammals occur. This area which potentially may be affected by an oil spill, is hereafter termed the region. The most serious environmental risk in Licence Area 1 will be an uncontrolled blowout of oil, which may lead to a large oil spill with long lasting effects. However, it is unlikely that the commercially utilised stocks of shrimp and Greenland halibut will be significantly affected by an oil spill from Licence Area 1. But fishery in oil-affected areas has to be suspended for a period. A large oil spill in Licence Area 1 may cause serious environmental impacts, particularly if the spill drifts to the coast. The most vulnerable biological resources in the region include: Seabird concentrations; in summer especially at breeding colonies and moulting areas and in winter at important feeding areas, Fish that spawn and forage in the tidal zone (capelin, lumpsucker and Arctic char), Fauna in shallow coastal waters. Licence Area 1 is outside the deep sea shrimp fishing grounds. An oil spill may also impact the very important whelping concentrations of hooded seals occurring on the drift ice within and near the southern part of the license area. Noise from seismic surveys and drillings may temporarily impact marine mammals and fish. Finally specific information needs related to regulation and impact assessment of hydrocarbon activities are described. These are in brief: Distribution and abundance of offshore birds in the region (62-69 N) outside the summer period; information, which could be achieved by a joint effort between the different license areas and public authorities. Baseline studies of sediment and benthic fauna including measurements of PAH (Polycyclic Aromatic Hydrocarbon) concentrations. These have to be carried out before intensive drilling programs are initiated. 5

6 Table 1. Important fish and exploited invertebrate species occurring in the region (62 o -69 o N). Species Main habitat Spawning area Spawning period Exploitation Blue mussel subtidal, rocky coast subtidal, rocky coast local Scallop Deep sea shrimp Snow crab Atlantic cod (offshore stock) inshore and on the banks with high current velocity, m depth mainly offshore, m depth inshore and on the banks with high current velocity, m depth larvae released at relatively shallow depth ( m) coastal and fjords, m depth banks south of 64 o N (formerly) western slope of banks, pelagic eggs and larvae in upper water column Greenland cod inshore/fjords inshore/fjords, demersal eggs, pelagic larvae March-May April-May March-April, February-March commercial and local very important commercial commercial Formerly important, now almost disappeared offshore, commercial and local commercial and local Arctic cod pelagic mainly N of 68 o N unknown - Sand eel on the banks at depths between 10 and 80 m on the banks, demersal eggs, larvae in the water column June-July to 66 o N, later further north important prey item Wolffish inshore and offshore hard bottom, one area known outside Maniitsoq, demersal eggs peaks in September commercial and local Atlantic salmon offshore and coastal freshwater in fresh water local Arctic char coastal, fjords freshwater in fresh water commercial and local Capelin coastal beach, demersal eggs April-June commercial and local, important prey item Atlantic halibut Greenland halibut Redfish offshore and inshore, deep water, offshore and inshore, deep water, offshore and in fjords, m depth maybe western slope of banks south of 66 o N, pelagic eggs and larvae, deep water offshore south of 66 o N, deep water, pelagic eggs and larvae main spawning southwest of Iceland, larvae drifts to West Greenland banks spring and local winter important commercial and local - commercial and local Lumpsucker pelagic coastal, demersal eggs May-June commercial and local 6

7 3. The physical environment Currents Licence Area 1 is situated in the central part of Davis Strait km from the coast and adjoining the border to Canada along the western edge (Figure 1). Water depths range from 700 m in the northern part to more than 2000 m in the southern. The West Greenland Current flows towards north east of the license area. This current carries water both from the cold East Greenland Polar Current and from the warm Irminger Current (a branch of the Gulf Stream). The mixture of these waters is relatively warn and keeps the coastal waters between 62 N and 66 N navigable throughout the year, although drift ice (the West Ice ) often occurs during winter. The main currents in Licence Area 1 are usually directed towards west and northwest and are eddies from the coastal current. These merge with the south going Labrador Current along the Canadian coast. 4. Ecological conditions and fishery Offshore Licence Area 1 is situated far from the coast of Greenland, and the general knowledge of the biology within the area is limited compared to more coast-near areas. The primary production in the waters of Licence Area 1 is probably much lesser than on the very rich fishing banks east of the area. There may, however, be a high spring production along the edge of the drift ice (the West Ice). Basic information on the most important species of fish, shrimp and molluscs occurring in the region is given in Table 1. During the 1970ies and 1980ies, dramatic changes was observed in the offshore fish assemblage. The most dramatic change was the collapse of the Atlantic cod stock. Presently there is important fisheries for deep sea shrimp and Greenland halibut in the offshore waters of the region (Figures 2 and 3). Within Licence Area 1 only fishery for Greenland Halibut takes place. Deep sea shrimp live on the sea floor in waters 100 to 600 deep. Shrimp larvae are pelagic, living in the water column. They are passively transported northwards across the fishing banks with the current. Licence Area 1 is outside the deep sea shrimp fishing grounds. 7

8 Figure 2. Distribution of the West Greenland fishery for deep sea shrimp. Based on catches in (Data provided by Greenland Institute of Natural Resources). 8

9 Figure 3. Distribution of offshore fishing grounds for Greenland halibut (indicated with blue fill). Based on catch sites reported in 1998 and (Data provided by Greenland Institute of Natural Resources). 9

10 Coastal zone The coastal zone of the region is dominated by bedrock shorelines with numerous skerries and extensive archipelagos. Small pocket beeches of sand and gravel are found here and there in bays in sheltered areas. Extensive sandy beaches are only found in the Marraq/Sermilik area south of Nuuk and near Frederikshåb Isblink glacier. In the latter area also barrier islands and coastal lagoons are present. The tidal amplitude is 3-4 m in the region and a rich subtidal flora and fauna occur on the bedrock shorelines and in the sediments. Lumpsucker and capelin are coastal spawners. Lumpsuckers stay outside the spawning season in deep offshore waters, while capelin stay in the fjords during most of the year. Arctic char is a third coastal fish. It feeds in near shore waters throughout the summer and spends the winter in rivers and lakes. All these fish species are utilised by the local people. Arctic char and capelin mainly on subsistence basis, while the lumpsucker fishery is commercial. Seabirds Seabirds are numerous both offshore and in the coastal zone of the region. The species show a wide range of ecological specialisation: Guillemots and murres dive deep to feed on fish both inshore and far from the coasts, and they spend long time swimming on the sea surface. Cormorants swim on the surface and dive for fish exclusively in the coastal zone. They spend less time on the surface than the guillemots and ducks because they prefer to rest on land. Kittiwakes and Arctic terns are specialised surface feeders, which dive from the air through the surface. Eider ducks swim on the surface and dive to the bottom to feed on molluscs and crustaceans. The seabirds occurring in the region are summarised in Table 2. Fourteen species of colonial seabirds breed in the region (Figure 4). Significant are thick-billed murres, razorbills, Atlantic puffins, kittiwakes, great cormorants. Other species breed dispersed along the coast such as skuas and whitetailed eagle. In late summer, post-breeders of several duck species gather in the coastal zone for moulting and foraging. One of the most important species moulting in the region is the Harlequin duck, which arrive from breeding grounds in both Greenland and Canada. 10

11 Figur 4. Distribution and size of seabird breeding colonies on the West Greenland coast. Colonies with less than 500 individuals omitted. 11

12 Figure 5. Distribution and densities of thick-billed murres along sailing routes in October. Based on data from 1998 and No data from white areas. 12

13 Table 2. Seabirds offshore and in the coastal zone of in the region (62 o N-69 o N). Species Occurrence Distribution Fulmar b/s/w year-round c & o Great shearwater s July-October o Cormorant b/s/w year-round c, mainly northern part in summer Eider b/s/m/w year-round c King eider (m, few) w August-September October-May c c & banks in w Long-tailed duck b/m/w year-round c & banks in w? Red-breasted merganser b/m/w year-round c Harlequin duck m w August-September September-April c (rocky shores) c (rocky shores) Ivory gull w December-May drift ice edge Kittiwake b/s/(w) year-round, few in c & o foraging winter Glaucous gull b/s/w year-round c & o Iceland gull b/s/w year-round c & o Great black-backed gull b/s/w year-round c & o Arctic tern b May - September c Thick-billed murre b/s/w year-round c & o Atlantic guillemot b/w year-round c & o Razorbill b/w year-round c & o Puffin b/w year-round c & o Black guillemot b/w summer winter c c & o Little auk (b) w May - August September - May c & o o White-tailed eagle b/w year-round c Occurrence categories: b: breeding. s: summering,. m: moulting, w: wintering. Categories of distribution: c: coastal, o: offshore. The coastal waters of the region are an extremely important winter habitat for seabirds. Large numbers of different auk species arrive to winter there in both inshore and offshore waters (Figure 5). The shallow parts of the banks, which can be partly covered by ice during winter, are important winter habitats for king eiders, and along ice free coasts numerous common eiders occur. Generally, the waters of the region are most important to seabirds in winter, when high numbers of auks and ducks occur, both offshore and in the coastal zone. Many of these wintering seabirds have their breeding grounds outside Greenland, mainly in Canada and Svalbard, making the West Greenland waters of high international conservation concern. 13

14 However, the knowledge on winter abundance and distribution of seabirds in the offshore parts of these waters is very limited. Table 3. Overview of marine mammals occurring in Licence Area 1 and in the region (62 o -69 o N). Stock size or occurrence some hundreds Protection/ exploitation Species Period Main habitat Licence Area 1 importance Bowhead March-May Pack ice/ice SA whale edge Minke whale April- Coastal November waters Protected (1930) NEI Hunting regulated Sei whale July-October? NEI rare Protected (1993) Humpback June- Edge of NEI some Protected whale November banks thousands (1986) Fin whale June-October Edge of NEI <2 000 Hunting banks regulated Blue whale July-October Edge of NEI very few Protected banks (1966) White whale November- Banks in NEI 8000 Hunting May northern part regulated Narwhal November- Deep water NEI 3000 Hunting May in northern regulated part Harbour April- Whole area NEI common Hunting porpoise November unregulated Bottlenose (June- Deep water NEI few Hunting whale August) unregulated Pilot whale June-October? NEI occasionally Hunting unregulated Killer whale June-August Whole area NEI rare Hunting unregulated Sperm whale May- Deep water NEI few Protected November (1985) Harp seal June-October Whole area NEI 2-3 mills. Hunting unregulated Hooded seal March- Whole area EI Hunting October unregulated Bearded seal Winter Mainly banks NEI here and Hunting in northern there unregulated part Stock status Vulnerable Unknown Vulnerable Vulnerable Vulnerable Endangered Vulnerable Vulnerable Unknown Unknown Unknown Unknown Unknown Not threatened Not threatened Not threatened Ringed seal Whole year Whole area NEI common Hunting unregulated Not threatened Harbour seal Whole year Coastal waters Not occurring very rare Hunting regulated Vulnerable/ threatened Polar bear Spring Ice edge NEI few Hunting regulated Not threatened Abbreviations used: SA: Area visited in early spring. NEI: Not ecological important, i.e. few animals present during summer. EI: Ecological important for a significant number of animals during summer. PA: Possible impact in coastal areas from an oil spill in Licence Area 1. 14

15 Within Licence Area 1 seabirds occur generally in relatively low concentration in the ice fee periods. No winter concentrations are known. However, we assume that large concentrations of little auks (dovekies) may occur along the edge of the drift ice during the migration periods spring and autumn, and possible also in winter. The rare ivory gull may also occur at the ice edge in significant concentrations. Marine mammals Many species of marine mammals (Table 3), occur in the region. Most of these are found in coastal waters and near the banks, while only few may occur in numbers within Licence Area 1. The most important marine mammals occurring there is the hooded seal. Hooded seals gather in large concentrations in a whelping area in March and April. The positions and extension of this whelping area is highly dynamic and dependent on the distribution and movements of the drift ice (Figure 6). Associated to the whelping hooded seals are polar bears. 5. Expected exploration activities which can impact the environment The exploration activities in Licence Area 1 include seismic operations and drillings, both of which may have environmental effects during normal operations. Furthermore, there is a risk of oil spills from accidental and uncontrolled blowouts during exploration drillings. Seismic operations Exploration drilling Risk of oil spill Marine seismic surveys are usually carried out by a ship towing a long cable with hydrophones and a powerful sound source. Pressure waves from the sound source may cause disturbance to fish and marine mammals. The sound source normally used is an array of air- or water guns that generates a powerful pulse in 10-second intervals. As sound absorption generally is much lower in water than in air, sound pulses can travel much longer distances in water than in air. Regional seismic surveys are characterised by widely spaced (many kilometres) survey lines, while the more localised surveys (2D and 3D seismics) usually covers small areas with densely spaced lines. Discharges from exploration drilling include cuttings, drilling fluids and production water. Furthermore, noise from the drilling rig may affect marine mammals. There is also a risk of accidental oil spills from blowout incidents. The probability of a large oil spill during exploration drilling is very small, but the risk is present. 15

16 Figure 6. Whelping area for hooded seal indicated with green. The specific whelping patches recorded in the years , 1984 and 1997 have been recorded within the shown area. Occurence: Whelping mainly in March an pups present in the ice until late April. Whelping takes places on the drifting ice, and the position and size of the whelping area is highly dynamic and dependent on the movements of the ice. 16

17 Oil spill drift Fate of spilled oil Model calculations for a major blowout offshore West Greenland indicated that even with good oil spill response capabilities, only % of the spill could be recovered near the drilling site (S.L. Ross 1992). This low recovery rate is primarily caused by harsh weather conditions, low visibility and short day length during the autumn; all factors which reduce the efficiency of containment booms and recovery gear and activities. The fate of oil released in the sea depends mainly on weather conditions and on the oil type. Light oil evaporates and disperses into the water column and is therefore often disappeared from the sea surface within 24 hours (in average weather conditions). Therefore light oil spilled from Licence Area 1 probably will not reach the shore. A heavy oil will have a life expectancy of days on the surface under average weather conditions, and therefore has the potential to reach the coast and spread over large areas. However, the longer time the oil stays on the surface the more will it weather, and gradually become less harmful to the environment. The drift on the sea surface depends on winds and currents. Oil from the Licence Area 1 will most likely drift to the north or west due to the general direction of the current. Model simulations has predicted that a large spill from a drill site a few nautical miles east of the northern part of Licence Area 1 may reach the coast somewhere between Paamiut (62ºN) and Attu (68º N). 6. Environmental impacts of seismic operations Fish Adult fish will generally avoid seismic pressure waves, seek towards the bottom, and will not be harmed. Young cod and redfish, as small as mm long, are also able to swim away from the mortal zone near the airguns (few meters). It has been estimated that fish will react to an operating seismic array at distances of more than 30 km, and that intense avoidance behaviour can be expected within 1-5 km. Several Norwegian studies measured declines in fish density more than 10 km from sites of intensive seismic activity (2D and 3D). Negative effects on fish stocks may therefore occur if adult fish are scared away from localised spawning ground during spawning season. Outside spawning grounds, fish stocks are probably not harmed by 17

18 the disturbance, but fisheries could be temporarily affected. This may apply to the fisheries of Greenland halibut, which takes place in the middle part of the licence area. Sand eel is the only fish, which spawn in the summer period (when seismic surveys are expected to take place). They occur however, not within Licence Area 1. Marine mammals Humpback whales The most probable impact to marine mammals by seismic activity is connected to the animal s communication and orientation. Marine mammals communicate through sound waves under water. Marine mammals also use the general sound patterns in the sea, and additionally, toothed whales utilise high frequency sonar for orientation and foraging. Seals display considerable tolerance to underwater noise. Whales also show some tolerance, but can react to noise from ships at considerable distances, especially in pack ice and in shallow water and if they perceive ships as a threat (due to hunt). Studies of whale reactions to ships have given much deviating results. Bowhead whales swimming quickly away from a seismic ship 24 km away, and minke whales accepting operating seismic arrays in distances down to 100 m, are examples of extremes in behaviour. Changes in behaviour such as reduced communication and altered dive patterns are other examples of observed reactions. Therefore, whales may be affected by an activity, even if they do not leave an area or change behaviour. On the other hand, a reaction is not necessarily a sign of negative effects. Experiences on whale reaction to underwater noise from seismic operations are ambiguous and the reactions of the whales cannot yet be predicted with certainty. Reaction distance seems to depend on species, activity disturbed and potential alternate migration paths and foraging areas. For example, a study in Australia showed that migrating humpback whales avoided seismic sound sources at distances of 4-8 km, but occasionally they came closer. In the Beaufort Sea autumn migrating bowhead whales avoid areas where the noise from exploratory drilling and seismic surveys execs db. The distances over which the Bowhead migratory pathways are altered are not yet known, but seems to be in the range km. The deflexions have forced hunters to travel further off shore to hunt Bowhead whales. 18

19 Satellite tracking recently showed that humpback whales from Toqqusaq Bank (south of the license area) utilised a large area, and therefore presumably are able to move to alternative foraging areas if they are disturbed. Whale concentrations usually occur closer to the coast at the fishing banks than Licence Area 1. Therefore, we expect a low whale density in the licence area during the summer period. 7. Environmental impacts of exploration drilling The possible environmental effects of exploration drillings are caused by discharges from the drilling, underwater noise from the drilling and the risk of oil spill from blowouts. Baseline studies of benthic fauna Underwater noise The environmental effect from discharges of cuttings, drilling fluids and production water during exploration drilling can be kept to a minimum by the use of modern technology. Baseline studies of benthic fauna and sediments including fish and shrimps should be conducted before an intensive drilling program and an exploitation phase. Among other things, baseline studies determine a local background level of hydrocarbons, especially PAH s (Polycyclic Aromatic Hydrocarbons). In this context it shall be noted that elevated oil concentrations may occur, due to natural oil seeps in the area. Exploration drilling may produce considerable underwater noise. The noise can reach levels equivalent to ice breakers in ice covered waters and exceed background noise as far away as 50 km. The primary source of noise is the rig propellers used for dynamic positioning. The drilling itself contributes also to the noise. Noise from drilling and propellers is continuos, contrary to seismic noise which are millisecond sound pulses at short intervals. The continuos noise may mask the communication of nearby whales. As with seismic operations, it is not known exactly how and at which distance the whales are impacted. Marine mammals are often observed within a few kilometres of drilling sites without visible signs of disturbance. But escape behaviour has also been observed on whales several kilometres away from the rig. The migration routes of the bowhead whales north of Alaska have been displaced from the coast by offshore drilling (see above). 19

20 However, no important concentrations of marine mammals are expected to occur within the licence area during summer when exploration drillings takes place. During drilling, a fisheries exclusion zone will be established around the drill site. This may occur in an area where fishery for Greenland halibut takes place. 8. Environmental impacts of oil spills A major oil spill from exploration drilling in Licence Area 1 may cause serious environmental consequences, especially if the spill reaches the coast. The most vulnerable (to oil spills) biological resources in the region (62º-69ºN) are seabirds, fish spawning and foraging in near shore waters and fauna in shallow coastal areas. Oil is toxic to nearly all organisms; however, the toxic effect depends on the composition and concentration of the oil and the sensitivity of the species affected. The concentration of oil in the water column during an offshore surface spill declines quickly with depth. Therefore it is mainly organisms living at or near the surface that will become exposed to high oil concentrations, as long as the oil is floating. Oil spills on the sea surface are generally considered as the most harmful, but the experience from oil, which sinks or is released from the seabed (subsurface blowout) is very limited. A subsurface blowout in deep water may never reach the surface, because the oil will be dispersed in the water column. However, high subsurface concentrations may occur for prolonged periods if mixing is restricted for example by spring layers. Plankton Fish Plankton organisms are typically distributed over large areas both horizontally and vertically. Therefore only small parts of the populations will become exposed to toxic oil concentrations even during large spills, why effects on populations most likely will be small and temporary. In open sea, an oil slick will usually not cause oil concentrations in the water column that are lethal to adult fish, due to dispersion and dilution. Furthermore, fish such as cod and salmon can detect oil and will attempt to avoid it. Oil spills affecting spawning areas and areas with high larval concentrations, may on the other hand cause significant mortality among eggs and larvae, because these are immobile and much more sensitive to oil in the water. Moreover eggs and larvae for some species will be concentrated close to the sea surface, where concentrations 20

21 of oil are highest. It is, however, very complex how an increased mortality of eggs and larvae, due to oil, will affect recruitment of adult fish to the stock. Most fish species produce very high numbers of eggs, but as natural mortality is high only very few eggs develop into adult fish. Most model calculations and experience from previous oil spills indicate that an offshore oil spill may only have a limited effect on recruitment to fish stocks. However, new Norwegian simulations of a worst case scenario for a large oil spill in the Barents Sea, indicates that a fish population effect may last several years. If e.g. 20% of the cod recruitment is lost due to oil mortality of eggs and larvae it can affect population size for the next 4-8 years. The probability of such a worst case incidence is extremely small in the Barents Sea scenario, and the high impact is depending on the spill matching the localised cod spawning area with high concentrations of eggs and/or larvae near the surface. Such localised spawning areas with high concentrations of eggs or larvae near the surface is not known from West Greenland offshore areas. In coastal areas, where oil can be trapped in shallow bays and inlets, oil concentrations in the water column can build up to levels that are lethal to adult fish. If oil is trapped on a calm surface or in the sediment in shallow water, the effect can be long lasting and stocks of stationary fish, crustaceans and molluscs may be impacted. Lumpsucker, capelin and Arctic char Shrimp An oil spill from Licence Area 1, which reaches the coast have the potential to reduce stocks of lumpsucker and capelin, because these fish spawn here and subsequently the sensitive eggs and larvae may be exposed to oil. Arctic char may be forced to stay in oil contaminated shallow waters when they move towards their native river to spawn and winter. The important stocks of deep sea shrimp found outside Licence Area 1 will probably not be affected by oil spills. Adult shrimp live on the bottom in relatively deep waters ( m), where oil concentrations from a surface spill will be very low. The shrimp stocks (same species as in Greenland) in Prince Williams Sound in Alaska were not affected by the large oil spill in However, free swimming shrimp larvae may encounter higher oil concentrations, for example near the surface. If oil sinks to the bottom or if the blowout is subsurface, toxic concentration may build up near the bottom where adult shrimp occur. 21

22 Tainting Suspension of fisheries Seabirds Seabird concentrations Tainting by oil residues in fish meat is a serious problem related to oil spills. Fish exposed even to very low concentrations of oil in the water, in their food or in the sediment may be tainted leaving them useless for human consumption. This problem is most pronounced in shallow waters, where high oil concentrations can persist for longer periods. Flatfish and bottom living invertebrates are particularly exposed. Tainting has, however, not been recorded in flatfish after oil spills in deeper offshore waters, where degradation, dispersion and dilution reduce to oil concentrations to low levels. In case of oil spills, it will be necessary to suspend fishery in the affected areas. Mainly to avoid the risk of marketing fish that are contaminated or even just tainted by oil. This may be the case for the Greenland halibut fishery within Licence Area 1 and also for the shrimp fisheries along the banks further east. Large oil spills may cause heavy economic losses due to marketing problems, and strict regulation and control of the fisheries in contaminated areas is necessary to ensure the quality of the fish available on the market. In offshore areas suspension usually will last some weeks, and longer in coastal waters. Coastal fishery was banned for four months after the Braer incident (Shetland Islands in 1993) and for nine months after the Exxon Valdez incident (Alaska in 1989). However, some shellfish fishing grounds were closed for more than 18 months after the Braer incident. It is well documented that birds are extremely vulnerable to oil spills in the marine environment. Birds, which rest and dive from the sea surface, such as auks, seaducks, cormorants and divers (loons) are most exposed to floating oil. But all seabirds face the risk of getting into contact with spilled oil on the surface. The feather plumage causes this particular vulnerability. Oil soaks easily into the plumage and destroys its insulation and buoyancy properties. Therefore oiled seabirds readily die from hypothermia, starvation or drowning. Birds may also ingest oil by cleaning their plumage and by feeding on oil contaminated food. Oil irritates the digestive organs, damage the liver, kidney and salt gland function and cause anaemia. Oiled plumage is the main cause of seabird losses following an oil spill, but long term effects after intoxication also occur. Many seabirds aggregate in small and limited areas for certain periods of their life cycles. Small amounts of oil in such areas may cause very high mortality among the 22

23 present birds. High seabird concentrations are found for example at breeding colonies, in moulting areas and in important feeding areas. Bird colonies Moulting seabirds Many Greenland seabirds breed in dense colonies, where high bird concentrations occur on the water in the breeding period, which often are initiated many weeks before the egg laying in early summer. Some Greenland seabirds gather in moulting areas after the breeding season. Here they change their the plumage, and as the flight feathers are shed simultaneously, they loose flying ability from two to seven weeks until the fresh feathers are full grown. Auks and most seaducks spend this flightless period at sea, where they are safe from terrestrial predators. Most seaducks gather in flocks during the moulting period in undisturbed and high quality feeding areas. Oiled birds drifted ashore are often the focus of the media when oil spills occur. However, seen from a resource management and scientific point of view, the concern is whether the oil spill induced mortality also affects the seabird populations both short-term and long-term. Or, in other words, the relevant ecological question must be: how are seabird populations affected by the oil spill? To answer this question, extensive studies of the natural dynamics of the affected populations and the surrounding ecosystem are necessary. Seabird life strategy The most oil spill vulnerable seabird populations are those with low reproductive capacity and a corresponding high average lifespan (low population turnover). Such a life strategy is found among auks, fulmars and many seaducks. For example do thick-billed murres not breed before 4-5 years of age and they lay only a single egg a year. This very low annual reproductive output is counterbalanced by a very long life of years. Such seabird populations are therefore particularly vulnerable to additional adult mortality for example caused by an oil spill. If a breeding colony of murres, for example, is completely wiped out by an oil spill it must be re-colonised from neighbouring colonies. And this is dependent on distance, size and productivity of these. If neighbouring colonies are declining, for example due to hunting, there will nor or only few birds available for re-colonisation. 23

24 In conclusion, major oil spills have the potential to deplete bird populations and wipe out single seabird breeding colonies. However, it is unlikely that an oil spill could exterminate an entire seabird population unless the population is small and has a very restricted distribution. The recovery of a seabird population may, nevertheless, be hindered after an oil spill, if other factors, such as hunting or by-catch in fisheries, reduce the growth potential of the population. Marine mammals Marine mammals necessarily have to surface to breathe, and in case of oil spill, they evidently will be exposed to the oil. However in open waters they can avoid oiled areas. But if oil is spilled in pack ice, it will aggregate in the restricted open water cracks and leads, where marine mammals are forced to breathe. Marine mammals are generally less sensitive to oiling than many other organisms. But there is concern for the situation where whales and seals are forced to inhale air with high concentrations of evaporated hydrocarbons, which may occur over oil covered waters. It is not likely that even a large oil spill in Licence Area 1 will cause major effects on the populations of marine mammals occurring there during summer and autumn. However, the concentration of whelping hooded seals in early spring may be vulnerable; particularly the pups lying on the ice in their natal coat. The high seal concentrations occur in late March and early April. Moreover may oil drift northwards to Store Hellefiskebanke where concentrations of wintering marine mammals such as walruses and white whales occur in the drift ice. 9. Regulation, monitoring and minimising the possible environmental consequences Seismic activities Temporal and spatial restrictions of seismic activities are the main mitigative measures, which could be applied to minimise potential impacts on the environment. In Norway, specific seismic activities are assessed in order to mitigate effects on migrating and spawning herring, and in Alaska some important Bowhead whale areas are closed for seismic activities during certain periods. 24

25 Similar restrictions regarding seismic activities in Licence Area 1 seem not meaningful as whales relatively few and no vulnerable fish spawn there in the summer period when seismic surveys are expected to take place. In Greenland, like in the UK and elsewhere, soft start of the air-gun arrays is among the stipulation concerning seismic surveys to minimise the disturbance of marine mammals. Exploration drillings The most serious potential environmental impact from exploration drillings in Licence Area 1 is a major oil spill, especially if the spill drift to the coast. To minimise this risk, drillings should be planned carefully and with high levels of safety precautions to prevent oil spills. Moreover an effective oil spill response plan is essential. The environmental effects from discharge of drilling fluid can be minimised by carefully selecting relevant additives to be used. It is recommended only to accept discharge of water based drilling fluid. Environmental effect of underwater noise from drilling rigs on marine mammals can be minimised by the use of the least noisy equipment. 10. Exploitation Activities The activities during a development and exploitation phase include drilling of production wells; seismic surveys to locate these drill sites, construction of production facilities, production activities, loading and transport of oil and finally decommissioning of the facilities. Environmental impacts The environmental impacts of many of these activities are the same as for similar exploration activities (see above), with oil spills as the most serious threat to the environment. Particularly the loading and transport of produced oil increase the risk for oil spills. For environmental impacts of oil spills, see above. Transport of oil by tank-ships increases also the area, which may be affected by a spill. Dependant on the sailing routes for such tankers, a larger area than the region described above, will be within the zone potentially exposed to oil spills. Other impacts may come from the production activities, such as chronic oil pollution from discharge of production water and flaring of gas. 25

26 We have not assessed impacts from construction and decommissioning activities in this context. This depends on more specific plans or scenarios from the involved companies and authorities. 11. Activities in winter Development and exploitation of oil in Licence Area 1 will include activities in winter. The possible environmental consequences of an oil spill in winter will be more serious than in the summer, mainly because of the large numbers of different seabirds wintering in the region. Adding to this is the fact that oil may persist for longer time on the sea surface, due to low temperatures, it may be transported for long distance in the ice and it is very difficult to combat oil in ice and during the short daylight period. The current knowledge of bird and marine mammal distribution and abundance in winter is, however, inadequate for a proper assessment of oil spill impacts. It is known that very large numbers of seabirds are found in West Greenland ice free waters during winter, and that seabirds and marine mammals can be very concentrated in leads and crack in the drift ice and along ice edges where spilled oil will tend to concentrate. Within Licence Area 1, particularly the whelping hooded seal in late winter should be considered when planning winter activities. 12. General and specific information needs General information needs Biological degradation NERI has together with Geological Survey of Denmark and Greenland (GEUS) and Roskilde University Centre (RUC) prepared a report to the Danish Environmental Agency advisory Committee on the Arctic (Mosbech 2002), about the need for further information in connection to environmental effects of oil spills in Greenland. The report identified a number of subjects where there is a general need of information. Needs with relevance to offshore oil activities in western Greenland are listed below (not in priority order). The specific needs of information connected to the environmental impact assessment of activities in Licence Area 1 will also contribute to the general information needed. There is a lack of knowledge on the potential for biological degradation of oil in aquatic environments in Greenland. That includes how microbial populations are affected, 26

27 effects of glacial silt (fine grained mineral particles) in the water and how oil degradation can be promoted through addition of nitrogen fertiliser without negative impacts of the fertiliser. Effects on invertebrates Significant mortality among invertebrates can occur in relation to oil spills and opportunistic species will dominate the start phase of re-colonisation. There is a lack of general knowledge on the ecological structure and on possible ecological key species among benthic invertebrates. Benthic fauna is exposed to a massive impact from bottom trawling in many areas and knowledge on this important issue is vital in order to predict and assess effects of oil spill on the benthic fauna. Bioturbation Spawning areas for capelin and lumpsucker Birds: long term studies of key species There is a lack of knowledge on the importance of the role benthic invertebrates has in the mixing of sediment (bioturbation) in shallow areas of the arctic. The mixing of sediment is significant in the breakdown of oil and bioturbation can be affected if the composition of benthic species is altered after an oil spill. Capelin and lumpsucker spawning in the shorezone and in shallow water are particular susceptible to effects from an oil spill. Spawning and fishing areas has been mapped, based on local knowledge. It is suggested that this mapping of spawning areas be followed up by biological investigations. Populations of seabirds are especially exposed to impacts from marine oil spills, even if healthy populations possess some resilience against singular catastrophes. There is a need for further mapping of seabird hot spots and especially with focus on key species under pressure, small populations and threatened (declining) populations. It is also important to link winter concentrations with breeding areas. The risk of impacts from oil spills has to be viewed in the light of other human impacts for example effects from hunting. Some protection of important bird species in Greenland from long term effects of oil spills can be obtained beforehand by ensuring stable and healthy populations. This concerns primarily the following species: common eider, king eider, harlequin duck and thick-billed murre, and secondarily, Atlantic puffin, little auk, longtailed duck, red-breasted merganser and brent goose. 27

28 Monitoring seabird colonies Specific information needs There is also a need for monitoring the ecology of seabirds within the region, primarily at their breeding colonies (and of species like common eider, kittiwake and thick-billed murre). Because long term effects of oil spill include impacts on breeding performance of such seabirds, monitoring programmes should include reproductive parameters. Information needs in connection with environmental assessment and regulation of activities in Licence Area 1 are: 1. Distribution and abundance of offshore birds in the region (62-69 N) outside the summer period; information, which could be achieved by a joint effort between the different license areas and public authorities. 2. Baseline studies of sediment and benthic fauna, including concentrations of PAH (Polycyclic Aromatic Hydrocarbon), before start of intensive drilling programs. 13. Relevant material In relation to environmental assessments of the oil activities in the Fylla area (which is situated east of Licence Area 1), a series of comprehensive analyses and descriptions have been made: Mosbech, A., R. Dietz, D. Boertmann & P. Johansen Oil Exploration in the Fylla Area, An Initial Assessment of Potential Environmental Impacts. National Environmental Research Institute, Denmark. NERI Technical Report no pp. Mosbech, A., Boertmann. D., Nymand, J., Riget, F. & Acquarone M, The Marine Environment in Southwest Greenland. Biological resources, resource use and sensitivity to oil spill. National Environmental Research Institute, Denmark. NERI Technical Report pp. Boertmann, D., Mosbech, A., & Johansen, P A review of biological resources in West Greenland sensitive to oil spills during winter. National Environmental Research Institute, Denmark. NERI Technical report No pp. Dietz, R, Teilmann, J., Jørgensen, M-P. H. & Jensen, M.W Satellite tracking of Humpback whales in West Greenland. National Environmental Research Institute, Denmark. NERI Technical report No pp. 28

29 An environmental atlas of Western Greenland was prepared with indications of sensitivity towards oil spill: Mosbech, A., Anthonsen, K.L., Blyth, A., Boertmann, D., Buch, E., Cake, D., Grøndahl, L., Hansen, K.Q., Kapel, H., Nielsen, S., Nielsen, N., Platen, F. von, Potter, S. & Rasch, M Environmental Oil Spill Sensitivity Atlas for the West Greenland Coastal Zone. The Danish Energy Agency, Ministry of Environment and Energy. 281 pp. + appendix 153 pp. Available on CD-ROM, Print (limited distribution) and on the internet (http/:environmental-atlas.dmu). This atlas is presently under extension, and will when finished in spring 2004 cover the West Greenland coast from Cape Farewell at 60º N to southern Upernavik District at 72º N. Models of drift and fate of oil spills in western Greenland were carried out about 10 years ago (SL Ross and DHI): Ross, S.L. 1992: Evaluation of the behaviour and cleanup of offshore oil-well blowout spills in west Greenland. 87 pp. + app. S.L. Ross Ltd. 87 pp. + app. Christensen, F.T., Steensboe, J. S. and Mosbech, A. 1993: Oil spill simulations as a contingency planning tool offshore West Greenland: Proceedings of POAC 93, Vol. 2, pp Furthermore, a general evaluation of existing knowledge and information needs in connection with environmental impacts of oil spills in Greenland has been prepared: Mosbech, A. (ed.) Potential environmental impacts of oil spills in Greenland. An assessment of information status and research needs. National Environmental Research Institute. NERI Technical report No pp. 29