The Development and Current Status of Environmental Monitoring Programs in the North Sea

The North Sea is a small, intensely-utilized water mass surrounded by six highly-industrialized European nations. With a surface area of 575,300 km²it is smaller than Hudson Bay, yet it is the location for over 130 offshore oil and gas production facilities. With the development of these offshore oil and gas fields came their related onshore processing terminals. Some environmental monitoring at these terminals was envisaged as part of the EIA procedure adopted by the planning authorities. However, there was, until November 1984, no statutory requirement to conduct any environmental monitoring of offshore oil and gas installations. The UK Department of Energy, as part of the contractual obligations contained in the model clauses attached to exploration and production licences, can require an EIA to be carried out in an environmentally-sensitive area, e.g., Beatrice in the Moray Firth. Recent amendments to the UK legislation relating to offshore discharges of oily wastes from production and development wells will be discussed in relation to oil-based mud and production water. The current status of benthic monitoring programs in the North Sea is discussed in terms of both chemical and biological studies. Chemical monitoring has been used as an early warning system for the environmental effects of offshore oil and gas production. Methods for the detection of both organic and inorganic sedimentary contaminants are reviewed briefly. Benthic sampling techniques and data analysis are discussed and recent comparisons of chemical and biological data are presented. A recent survey in the Norwegian Sector showed a strong correlation between the numbers of benthic individuals and total sedimentary oil levels. Species abundance and diversity showed a negative correlation with total oil levels. Developments in environmental monitoring in the North Sea could see an emphasis being placed on determining the cumulative operational effects of oily discharges, especially of - - drill cuttings, and evaluating the long term recovery processes in sediments immediately surrounding sites of cuttings discharge. As the volumes of produced water discharged offshore continue to rise in the North Sea, the emphasis may shift to monitoring programs involving the water column directly, caged shellfish studies and the analysis of fish for tainting caused by discharged oil.