Intertidal and subtidal zones
In case of an oil spill, the risk of the oil beaching is imminent. Hence the intertidal and subtidal zones are especially exposed to effects of oil spills and based on experience from e.g. the spill in Prince Williams Sound (Exxon Valdez) these habitats are also having the most long-lasting impacts. Thus to identify important or critical areas a robust baseline knowledge on tidal and subtidal community diversity and structure is essential.
Shorelines with a rich primary production are of high ecologically importance. The vegetation of the shoreline zones, the macro-algae, is benthic and perennial and hence provides a key baseline. The tidal and subtidal canopy of macro-algae is important for higher trophic levels of the food web by providing substrate for sessile animals, shelter from predation, protection against wave action, currents and desiccation or directly as a food source. Because of strong biological interactions in rocky intertidal and kelp forest communities, cascades of delayed, indirect impacts of oil spills (e.g. biogenic habitat loss and changes in prey-predator balances due to species specific mortality) may be much more severe than a direct impact of oil contamination.
Investigation of the marine benthic flora in the assessment area is scarce and has mainly been conducted as random floristic studies in late 1800 and early 1900. A few more recent and systematic studies of the macro-algal flora have been conducted at Mestersvig and in Young Sound. However, no studies on macroalgal communities have been performed on the Greenlandic east coast. It is thus proposed to study the algal communities at different latitudinal coastal sites to support identification of the most important and sensitive areas as well as shoreline clean-up strategies.
Benthic macro-fauna
The benthic macro-fauna is a key element in the functioning of the marine ecosystem. The macro-fauna process a major fraction of the organic material settling from the water column and thereby link primary production in the water column to higher trophic levels as the benthic organisms provide a vital food source for fish, birds and marine mammals. The benthic habitats and benthic communities of the assessment area have not presently been mapped and the biodiversity, community structure and the sensitivity to environmental stressors like offshore activities is not well known.
The environmental focus in the exploration phase is the impact of discharges during exploratory drilling and the potential impact of oil spills.
To minimize the impact of discharges during exploratory drilling the operating companies must undertake environmental baseline studies at their drilling sites. These studies include benthic sampling and under water video surveys. Based on these studies especially sensitive habitats like cold water corals and sponge gardens will be identified and discharges in these areas can be avoided. Furthermore the environmental baseline studies will also contribute to the general mapping of the benthic communities in the activity areas.
However, systematic sampling of benthic fauna at a regional scale is necessary for mapping community heterogeneity, which knowledge is essential to regulate and evaluate the scope of the drilling site environmental baseline studies, as well as optimizing sampling design if needed. Therefore a benthic sampling program in conjunction with studies of hydrography, water chemistry, pelagic biology, birds and mammals (Project 2.1) is proposed.
Benthic fauna identification support system
As part of the environmental baseline studies performed by the companies around the drilling locations, the benthic data collected to describe the benthic fauna communities in the areas are submitted to the database for biological data housed and maintained by DCE/GINR. However, the knowledge for identification of the benthic fauna connected to soft bottom, epi- and infauna in the assessment area, is sparse, difficult to access, and at the same time the investigations conducted so far indicate a high species diversity. These are factors contributing to complicate identification work and increase the need for quality assurance to avoid submission of erroneous identification. DCE thus recommends that the quality assurance on identification work is improved, by amending the DCE biological database to include search functions to:
· Check the identification correctness in a checklist based on earlier registrations of the species in the area.
· Verification of species identifications based on photo material of identified species collected in Greenland
These actions will assure that the continuously gathered data and knowledge will be available and provide as a tool and assistance for species identifications to the oil companies and their consultants. The possibility to have species identifications verified will strengthen the quality assurance of data submitted to the DCE/GINR biological database. Therefore a project delivering ID support and database development is proposed.