Aarhus University Seal / Aarhus Universitets segl

No. 22: The western Greenland Sea, a strategic environmental impact assessment of hydrocarbon activities

Please cite as: Boertmann, D. & Mosbech, A. (eds.) 2011. The western Greenland Sea, a strategic environmental impact assessment of hydrocarbon activities.  Aarhus University, DCE – Danish Centre for Environment and Energy, 268 pp. - Scientific Report from DCE – Danish Centre for Environment and Energy no. 22. http://www2.dmu.dk/Pub/SR22.pdf

Summary and conclusions

This document is a Strategic Environmental Impact Assessment (SEIA) of activities related to exploration, development and exploitation of hydrocarbons in the sea off Northeast Greenland between 68° and 81° N; the Greenland Sea assessment area (Figure 1).

A preliminary version of this document (Boertmann et al. 2009c) was issued in 2009. This is now updated with new information primarily derived from the background study program initiated by Bureau of Minerals and Petroleum. Despite the new information included, the knowledge on the biology is still much more limited than the two license areas in West Greenland – the Disko West and the Baffin Bay.

This SEIA was prepared by DCE - Danish Centre for Environment and Energy (formerly known as National Environmental Research Institute – NERI) and the Greenland Institute of Natural Resources.

The assessment area is shown in Figure 1, and it is the region which potentially could be impacted by oil exploration and exploitation activities within the licensing area. However, drift modelling indicates that an oil spill may drift beyond the borders of this area.

The expected activities in the ‘full life cycle’ of a petroleum field are briefly described. Exploration activities are likely to take place during summer and early autumn, because harsh weather and particularly sea ice hamper activities in winter and spring. However, if oil production is initiated activities will take place throughout the year.

The environment

The physical environment of the study area is briefly described with focus on oceanography and ice conditions. Sea ice and icebergs are present throughout the year, with the lowest concentrations in August and September. One of the most important physical features for the biological environment is the polynyas (ice-free or almost ice-free areas surrounded by sea ice). The most important polynyas are found at the entrance to Scoresby Sund, at Wollaston Forland (the Sirius Water Polynya) and at the northeast corner of Greenland (the Northeast Water Polynya), see Figure 5. These polynyas become free of ice very early in spring (April) and also have ice-free parts throughout the winter.

Accounts of some of the physical conditions in the assessment area have been issued by DMI in 2008 and 2011 (Hvidegaard et al. 2008, Pedersen et al. 2011).

The assessment area is situated within the Arctic region, with all the typical biological properties of this climatic region: low biodiversity, with some species very abundant and a relatively simple food web, having only a few steps from primary producers to top predators and with key species playing important roles in the ecology of the region (Figure 6).

In the marine environment the biologically most significant event is the spring bloom of planktonic algae, the primary producers in the food web (Figure 6). These are grazed upon by zooplankton, including the important copepods of the genus Calanus, which is one of the key species groups in the ecosystem. Copepods again form the most important prey for small fish, large crustaceans as well as some seabirds and marine mammals.

Benthos is the fauna living on and in the seabed. Benthic macrofauna species are an important component of coastal ecosystems. They consume a significant fraction of the available production and are in turn an important food source for fish, seabirds and mammals. Very little is known on the benthos communities in the assessment area.

In and on the underside of the sea ice a specialised community exists: the sympagic flora and fauna. Algae live in and on the ice and are grazed upon by crustaceans, which in turn sustain populations of polar cod and Arctic cod. Especially the multi-year ice has a very rich biological community.

Fish, seabirds, marine mammals and humans represent the higher trophic levels in the marine environment, where polar bear and man are the top predators.

The fish fauna is low in diversity, but some species are important: the polar cod is very numerous, both in the water column and associated with sea ice, and it constitutes a major food resource for seals, whales and seabirds. It is another key species. Other fish species in the assessment area include Greenland halibut and Arctic char, and capelin occurs in the southeastern offshore waters.

Seabirds are locally abundant with several species present in the study area in summer and spring. Many species breed in colonies mainly close to the polynyas, where dense aggregations of birds can be found as early as May. Other coastal aggregations of seabirds include moulting ducks in bays and fjords in the summer months. In spring and autumn millions of seabirds migrate through the offshore parts of the area on their passage between Svalbard and Russian breeding sites and Canadian wintering grounds.

The most important seabird species in the assessment area are common eider, thick-billed murre, little auk and ivory gull (Table 5). Almost all the seabirds leave the area for the winter to return in May and June. Thick-billed murre, common eider and black-legged kittiwake are all red-listed in Greenland due to declining populations, although mainly in West Greenland. Other red-listed bird species which occur in the marine part of the assessment area include Sabines gull, Arctic tern and light-bellied brent goose. Also ivory gull is red-listed (both nationally and internationally), mainly because of the expected reductions in its primary habitat, sea ice. The coasts of the Northeast Water are a stronghold for this species.

Furthermore, some species are designated as species of national responsibility (which means that the population in Greenland is so large that the local management of the species is vital to the entire population). The most important of these species is the little auk. Other national responsibility species occurring in the marine part of the assessment area are black guillemot and light-bellied brent goose.

Marine mammals are significant components of the ecosystem. Four species of seals as well as walrus, many species of whales and polar bear occur in the assessment area. The most important species that use the assessment area year round are narwhal, bowhead whale, walrus, bearded seal, ringed seal and polar bear (Table 6). They are often associated with ice edges, polynyas or shear zones, where open water is present. In addition, harp and hooded seals assemble in large numbers on the drift ice in March to whelp and later to moult. Several species of whales occur in the assessment area during summer. Of these, blue whales are probably the most important because of their conservation status.

Polar bear, walrus and bowhead whale are red-listed because their populations are small, declining or expected to decline because of climate change (polar bear). Blue whale is also red-listed, and the assessment area is probably a very important habitat for this species.

Human use of natural resources only occurs in the southern part of the assessment area. Subsistence hunting (marine mammals and seabirds) and fishing is carried out near the town of Ittoqqortoormiit/Scoresbysund and hunters from Tasiilaq occasional venture as far north as the southernmost part of the assessment area.

Commercial fishery is limited to Greenland halibut and this takes place in offshore areas in the southern part of the assessment area. The catches are small compared to other parts of Greenland.

Tourism is a growing industry in Greenland, and this is also the case in Ittoqqortoormiit/Scoresby­sund, where activities take place from early spring (April) and throughout the summer. There is a local operator and a few Icelandic operators also have activities in the Ittoqqortoormiit-area. Several cruise ships have visited the National Park and Ittoqqortoormiit annually in recent years.

Knowledge on background levels of contaminants such as hydrocarbons and heavy metals is important in assessing environmental impacts from petroleum activities. The available knowledge on background levels of hydrocarbons in the assessment area is limited, but the general picture is that levels are low.

Assessment

The assessments presented here are based on our present knowledge concerning the distribution of species and their tolerance and threshold levels toward human activities in relation to oil exploration. However, the Arctic is changing due to climate change, and this process moreover seems to accelerate, why conclusions and assessments may not apply to future conditions. Furthermore, the assessment area is remote and still poorly studied and an increase in knowledge also may contribute to future adjustments of assessments and conclusions.

Presently, we do not know much about the adaptation capacity of important species in the assessment area and how their sensitivity to human impacts might change under changing environmental conditions. Changes in habitat availability, e.g. due to reduced ice coverage, are to be expected, with consequences for the local fauna. This, as well as increased temperatures will affect the distribution patterns of relevant species, with consequences for the food web. Northward range expansion of fish targeted by commercial fisheries could for example result in increased fishing activities in the assessment area.

Normal operations – exploration

Exploration activities are temporary. They last for some years and will be spread throughout the license areas. They moreover take place during the ice free seasons – the summer and autumn. Seismic and site surveys have in recent years been conducted as late as November. Exploration drilling shall be terminated in the Baffin Bay area by September to provide an ice free window for relief drilling before sea ice arrives.

If no commercial discoveries are made, activities will terminate and all equipment be removed. If oil or gas is found, and appraisal shows it economically feasible to exploit, activities will proceed for many years.

The main environmental impacts of exploration activities are two-fold: They derive from noise generated either by seismic surveys or by the drilling platforms and they derive from the drilling process if cuttings and drilling mud are released to the sea.

The most noise sensitive organisms in the assessment area are the marine mammals, particularly the whales. They are sensitive to seismic surveys and may be displaced from extensive areas potentially including critical areas such as feeding grounds. As seismic surveys are temporary, the effects of a single survey are expected to be of short duration (e.g. weeks or a maximum of a few months). However, if several seismic surveys occur simultaneously, the disturbed area becomes much larger and cumulative effects will increase.

Drilling operations also have the potential to displace marine mammals. Migrating bowhead whales avoided an area of 10 km from drill ships in Alaska
(Richardson et al. 1990). Therefore and depending on the location in the assessment area, displacement of migrating and staging whales must be expected. The main species concerned are narwhal and bowhead whale during summer and autumn. Walrus and bearded seals may also be displaced from areas where drilling activity takes place.

Stronger (cumulative) impacts are expected if several drillings take place in adjacent areas or in the same area in consecutive years.

A derived effect of displacement of marine mammals may be reduced availability to hunters from Ittoqqortoormiit.

Noise from a single seismic survey has also the potential to scare adult fish away from fishing grounds, but this effect is temporary and normal conditions will re-establish after some days or weeks, mainly depending on fish species. As the commercial fishery is very limited within the assessment area, significant impacts are not expected.

Unless a zero-discharge policy is applied, drilling mud and cuttings will be released on the seabed, with local impacts on the benthos as a consequence. During exploration, when wells are few and dispersed, this impact can be minimal if proper mitigation is applied. This may include release of environmental safe and water based chemicals only (oil based drilling muds are not allowed in Greenland), such as defined by the OSPAR standards. But even non-toxic chemicals may impact benthic organisms. However, the knowledge on degradation and toxicity of even the environmentally safe chemicals under Arctic conditions is very limited, why use and discharge should be thoroughly evaluated and further testing of degradation and toxicity should be carried out.

Exploration drilling is an energy demanding process emitting large amounts of greenhouse gasses, why even a single drilling will increase the Greenland contribution significantly.

Finally there will be a risk for oil spills during exploration drilling, see below.

Environmental impacts from exploration activities are best mitigated by careful planning based on thorough environmental background studies, Best Environmental Practice (BEP) and Best Available Technique (BAT) as well as by application of the Precautionary Principle and international standards (IMO, OSPAR).

Normal operations – development and production

Development and production activities are difficult to evaluate when location and level of activity are unknown. Overall, impacts will depend on the number of activities, how far they are scattered in the areas in question, and also on their durability. In this context cumulative impacts will be important to consider.

The activities during development, production and transport are long-lasting, and there are several activities which have the potential to cause severe environmental impacts.

Emissions and discharges

The largest contribution to pollution from an oil field is expected to be the discharge of produced water (if not re-injected). This contains, besides oil residues, small amounts of substances which are acutely toxic or radioactive, contain heavy metals, have hormone-disruptive effects or a nutrient effect. Some of the substances may bio-accumulate. The knowledge on long-term effects of produced water in the marine environment is limited; there is, however, an increasing concern for this issue. In the Arctic for example, polar cod eggs and larvae aggregated under the ice, could be exposed to produced water, because this may accumulate in the same habitat. The most obvious way to mitigate effects of produced water is efficient cleaning before discharge or even better to re-inject it into the wells.

Discharge of ballast water is also of concern, because of risk of introducing non-native and invasive species. This is currently not a severe problem in the Arctic, but the risk will increase with climate change and the intensive tanker traffic related to a producing oil field. This problem may be reduced when the IMO-convention on ballast water is ratified.

Use of drilling mud and cuttings will continue as drillings will take place throughout most of the production time. Large amounts of the waste products will therefore have to be disposed of. If released to the seabed stronger impacts on fauna must be expected than during exploration because of the larger quantities released.

Development and production are energy-consuming activities which will contribute significantly to the Greenland emission of greenhouse gases. To illustrate this, a single large Norwegian production field emits more than twice the current total Greenland CO2 emission.

Noise

Drilling will continue throughout the development and production phase. Just as with exploration drilling there will be a risk of displacement of marine mammals from critical habitats. However, during operation the effects are permanent (or at least long term). Walrus and whales, particularly narwhal and bowhead whale are sensitive in this respect and may be permanently scared away from specific habitats. This could also impact hunters if quarry species are scared away from traditional hunting grounds.

Intensive helicopter flying also has the potential to displace seabirds and marine mammals from habitats (e.g. feeding grounds important for winter survival) as well as traditional hunting grounds, impacting on local people. Applying fixed flying lanes and altitudes will contribute to reduce impacts.

Placement of structures

Placement of offshore structures and infrastructure may locally impact seabed communities and there is a risk, in shallow areas, of spoiling important feeding grounds, particularly for walrus. If onshore structures are established there will be a risk of river obstruction impacting anadromous Arctic char and also of damage to unique coastal flora and fauna.

Finally, placement of structures and installations onshore will also have an aesthetic impact on the landscapes, an issue especially important to consider when evaluating impacts on tourism.

Commercial fishery will be affected by development and production if installations are placed in the fishing grounds. A safety zone (of typically 500 m) will be applied around the offshore facilities. Commercial fishery is currently limited and takes place only in the southern part of the assessment area, which right now is far outside the areas planned to be included in a licence round.

Illuminated structures and the flame from flaring may attract seabirds in the dark hours, and there will be a risk of mass mortality of especially eiders and perhaps little auks.

There is also a risk for impacting the tourism industry in the assessment area, as large and obvious industrial installations and activities will compromise the impression of unspoilt Arctic wilderness, which is the main asset to tourist operators.

Cumulative impacts

There will be a risk of cumulative impacts when several activities takes place either simultaneously or consecutive. For example, seismic surveys have a high potential for cumulative impacts. Cumulative impacts may also occur in combination with other human activities, such as hunting, taking place in the assessment area.

Mitigation

Careful planning of structure placement and transport corridors based on detailed background studies localizing sensitive ecosystem components, can reduce inevitable impacts, and strict Health, Safety and Environment (HSE) procedures, application of the Precautionary Principle in combination with Best Environmental Practice (BEP), Best Available Technique (BAT) and international standards (OSPAR) can contribute to reduce environmental impacts.

Accidents

The environmentally most severe accident from the activities described above is a large oil spill. Oil spills may occur either during drilling (blow-outs) or from accidents when storing or transporting oil. Large oil spills are relatively rare events today due to ever-improving technical solutions and HSE policies. However, the risk cannot be eliminated, and in a frontier area like the Greenland Sea with sea ice and icebergs, the probability of an accident will be elevated.

Oil spill trajectory modelling was carried out by DMI as a part of this SEIA. In most of the modelled oil spill drift scenarios oil did not reach the coasts, but stayed offshore. However, two of the 18 scenarios indicate that under certain conditions, oil may reach shores up to several hundred kilometres from the spill site.

Oil in ice

In general, oil spills occurring in the coastal zone are regarded as much more deleterious than oil spills in the open sea. This may, however, not apply in an area such as Greenland Sea, which is dominated by sea ice for the major part of the year. Ice will initially contain the oil between the floes and on the rough underside. However, as the ice moves around with currents such oil may be transported in an almost un-weathered state over long ranges, and may impact the environment, e.g. seabirds and marine mammals, far from the spill site when the ice melts. Oil may also be caught along ice edges, in polynyas and in the shear zone where sensitive “Valued Ecosystem Components” (VECs) aggregate, such as primary production, seabirds and marine mammals. Particular concern have been expressed about polar cod stocks, because this fish spawns in late winter, and the eggs accumulate just below the ice where spilled oil will also accumulate.

Furthermore, knowledge on the behaviour of spilled oil in ice environments is very limited and the technology for the clean-up of oil spills in ice-covered waters is inadequate and needs to be further developed (Brandvik et al. 2010).

Oil spills on the sea surface

The impact of a surface oil spill in the assessment area on primary production, plankton and fish/shrimp larvae in open waters will probably be low due to the large temporal and spatial variation of these events. There is, however, a risk of impacts (reduced production) on localised primary production areas. The same may be the case for localised concentrations of plankton and fish larvae if they occur in the uppermost part of the water column. However, on a wide scale only slight effects on these ecosystem components are expected. More vulnerable are seabird concentrations (see below).

Sub sea oil spills

The lessons learned form the Macondo-oilspill was that a subsea spill in very deep waters (1500 m) could give rise to huge subsea plumes of dispersed oil. This situation is less likely to occur in the licensing area, which is situated on the shelf with max. water depth of 530 m, although the same apparently also happened after the Ixtoc-spill in only 50 meters water depth.

Oil spills in the coastal zone

The coastal zone is especially sensitive to oil spills because of the high biodiversity. The sensitivity is also related to the fact that oil may be trapped in bays and fjords where high and toxic concentrations can build up in the water and even impact the seabed. Furthermore, local hunters use the coastal zone in the southern part of the assessment area.

Long-term impacts may occur in the coastal zone if oil is buried in sediments, among boulders, in mussel beds or is embedded in crevices in rocks. From such sites oil may seep and cause chronic pollution which may persist for decades. In Prince William Sound in Alaska such preserved oil has caused long-term effects on birds utilising the polluted coasts, and several populations have still not recovered.

Oil spill impacts on the seabed

Bottom-living organisms such as bivalves and crustaceans are vulnerable to oil spills; however, no effects are expected in the open water unless oil sinks to the seabed. In shallow waters (<?10-15 m), highly toxic concentrations of hydrocarbons can reach the seafloor with possible severe consequences for local benthos and thus also for species utilising the benthos – especially walrus, eider and king eider. But a subsea spill have the potential to impact the seabed communities in deeper waters too.

Oil spill impacts on fish

Impacts from a surface spill on adult fish stocks in the open sea are not expected. But if an oil spill occurs in ice-covered waters there is a risk to polar cod populations. This is an ecological key species and significant impacts on polar cod stocks may be transferred up in the food web (to other fish, seabirds and marine mammals).

A subsea spill may however, have the potential to impact demersal fish directly or through the food.

Oil spill impacts on seabirds

Bird populations particularly at risk of being impacted by an oil spill in the Greenland Sea area include the large breeding colonies of little auk and the two thick-billed murre colonies, all on the coasts of the Scoresby Sund Polynya. Furthermore, the large assemblages of pre-breeding eiders in the polynyas will be very exposed. Some red-listed seabird species (e.g. thick-billed murre, ivory gull) occur in the assessment area and the populations of these will be exposed to increased mortality in case of a large oil spill. The huge numbers of seabirds on migration through the assessment area in spring and autumn will also be at risk.

Oil spill impacts on marine mammals

Polar bears are especially vulnerable to oil spills because oiling of the fur may kill the bears. The other marine mammals are less sensitive to direct oiling, but for example, baleen whales may be vulnerable to oiling of their baleen. Bowhead whales, which occur in very low numbers (and are red-listed), belong to a stock which now is recovering from heavy exploitation. This recovery may be halted by even a slight increase in mortality. Walrus and bearded seal feeding on benthos may be exposed to oil through their food if oil sinks and accumulates on the seafloor.

Recent studies indicate that whales and seals are very sensitive to inhaling oil vapours, and particularly narwhals and bowhead whales could be vulnerable during an oil spill in winter when the availability of open waters is limited by the sea ice. Walruses and other seals living in the ice may also be vulnerable in this respect.

The seals whelping on the drift ice will be very sensitive to an oil spill in the area and many adults and pups may be fouled. Adult seals are rather robust to oiling, but pups are more likely to succumb. Walruses are also sensitive because the population is concentrated at relatively few sites, and oil on one individual may be transferred to many other due to the walruses behaviour of resting in close contact with each other.

Even though seals may tolerate some oil on their fur, such oiling may impact local hunters, as fouled skins are of no use and commercially worthless.

Oil spill impacts on fisheries

Oil spill effects on commercial fisheries are mainly linked to the closure of fishing grounds (Greenland halibut) for longer periods (weeks to months) due to the risks associated with marketing polluted or tainted fish. Effects on subsistence hunting and fishing will include closure of polluted coasts and probably also temporary changes in the distribution and habits of quarry species.

Oil spill impacts on tourism

The tourist industry in the assessment area is also expected to be negatively impacted by a large oil spill.

Long term impacts

Long term effect of residual oil caught in the beach sediments must be expected if oil hits the coasts. This was the case in the Prince Williams Sund, where oil from the Exxon Valdez spill in 1989 still is present in such habitats and still impacts the environment.

Areas sensitive to oil spills

In Figure 50 a number of areas especially sensitive to oils spills are shown. These are based on the available knowledge, and may be changed when new and improved information on seabirds, marine mammals and other sensitive components of the ecosystem have been provided.

Further studies

Compared to West Greenland the lack of information on the biological environment is much more pronounced for the assessment area covered by this SEIA. There is a general lack of knowledge on many of the ecological components, processes and interactions in time and space. To fill some of these information needs, BMP, GINR and DCE initiated and carried out a number of background studies in 2008, 2009 and 2010. The results from these studies have been incorporated in this revised and updated SEIA. See Section 11.1 for a review of the projects.

However there are still information needs, and further regional strategic studies as well as project specific studies have to be carried out in order to provide adequate data for future monitoring and the preparation of site-specific EIAs. A list of the most important studies identified so far is given in Section 11.2. Some of these research needs are generic to the Arctic and have also been identified by the Arctic Council Oil and Gas Assessment (Skjoldal et al. 2007). An international effort should address these needs.