OSPAR COMMISSION FOR THE PROTECTION OF THE MARINE ENVIRONMENT OF THE NORTH-EAST ATLANTIC
QUALITY STATUS REPORT 2000: REGION II – GREATER NORTH SEA EXECUTIVE SUMMARY
This report is one of five regional quality status reports prepared by the OSPAR Commission as part of its commitment to produce the first quality status report of the North-east Atlantic by the year 2000. The report presents an assessment of marine environmental conditions and of its developments in that part of the maritime area of the OSPAR Convention which, for assessment purposes, is known as the Greater North Sea. The Greater North Sea is regarded as being bound by the coastlines of England, Scotland, Norway, Sweden, Denmark, Germany, the Netherlands, Belgium, and France, and by imaginary lines delimiting the western approaches to the Channel (5° W), the northern Atlantic between Scotland and Norway (62° N, 5° W), and the Baltic in the Danish Straits. This quality status report assesses information collected until 1999 and aims to describe the present status and temporal changes that have been observed in the Greater North Sea, building on the 1993 QSR. After the introductory chapter, the following topics are dealt with: geography, hydrography and climate (Chapter 2), human activities (Chapter 3), chemistry (Chapter 4) and biology (Chapter 5). Chapter 6 provides an overall assessment of the quality of the Greater North Sea.
The general improvements that have been made and the means provided for continuing improvement, through the implementation of OSPAR strategies and other programmes, are reassuring. Inputs of heavy metals, oil from refineries and cuttings, and phosphorus have significantly decreased. In addition, the dumping of sewage sludge ceased in 1998 and the number of chemicals used in mariculture have decreased. However, certain activities continue to give cause for concern because of their continued widespread impact or increasing trend, such as the impact of fisherie, inputs of nitrogen from agriculture, and inputs of oil and chemicals associated with increased quantities of produced water from offshore oil and gas. Concentrations of the antifouling agent tributyltin (TBT) still exceed safe levels in marina areas and biological effects remain a common phenomenon in the North Sea. An increasing number of synthetic compounds are being detected for which the ecological significance is not known. Though dredging impacts have diminished because of reduced contaminant loads, the quantities of dredged material are expected to increase in future, due to anticipated increases in the size of cargo vessels. Human impacts are greatest in the coastal zones. Many sensitive habitats with large ecological significance are disturbed or vanish due to a range of activities. It is foreseen that there may be significant impacts due to demographic developments and climate change. In conclusion, the intensive – sometimes conflicting – use of the North Sea causes a number of problems in relation to a healthy ecosystem and sustainable use. The ecosystems continue to suffer from a number of old problems, sometimes showing some signs of amelioration, but new problems have also arisen. The effects of hazardous substances, eutrophication, and the direct as well as indirect impacts of fisheries comprise the most important issues.
Main human pressures
To identify impacts of concern, human pressures on the North Sea environment have been ranked into four classes by using expert judgment, the results of which are shown in Chapter 6. The chapter focuses on the pressures of importance, supplying information on their impacts and the effectiveness of measures taken to reduce undesired impacts. Recommendations for future action are made for further consideration by the competent authorities. Although the impacts of the human pressures ranked in the lower priority classes are perceived to be less important, they may be of more serious concern in combination with other pressures. More information is provided in chapters 2 – 5. Owing to the very broad scope of its causes and effects, climate change has the potential for significant impacts on the North Sea. It may influence factors in the North-east Atlantic which control the climate of Western Europe. Human pressures on the North Sea were ranked in 4 priority classes.
- First priority class
The main impacts of fisheries result from the removal of target species, from seabed disturbance by towed demersal gear and from the discarding and mortality of non-target species. Many target fish stocks are outside Safe Biological Limits. These impacts are widespread and ecologically important and fully justify the further development and implementation of the ecosystem approach. Recommendations for consideration by the appropriate authorities are to continue efforts to reduce fleet capacity, the additional identification and use of closed areas which can protect juveniles and closed areas which are of conservation benefit through protecting benthos. The development of fishing gears which reduce or eliminate catches of non-target organisms and habitat disturbance is also encouraged.Trace organic contaminants
Trace organic contaminants occur throughout the Greater North Sea area. Some are persistent and recovery times for the environment can be very long. Some reductions in concentration have been observed, but an increasing number of synthetic compounds are detected, for which the ecological effects are largely unknown. Recommendations call for stronger efforts in the implementation of the OSPAR Strategy on Hazardous Substances, and the policies agreed within the frameworks of, for example, the North Sea Conferences, the European Union and the International Maritime Organization.Nutrients
The anthropogenic inputs of nutrients may cause eutrophication effects, for example increased phytoplankton blooms and oxygen depletion. Heaviest impacts are recognised in estuaries and fjords, the Wadden Sea, the German Bight, Kattegat and eastern Skagerrak. Since 1985, there has been a significant reduction in the total input of phosphorus and, although direct inputs of nutrients have reduced, there was no discernible reduction in the overall nitrogen inputs. The main recommendations are to pursue vigorously implementation of the OSPAR Strategy to Combat Eutrophication, and where applicable the EC urban wastewater treatment and nitrates directives, and to focus research efforts on links between nutrient enrichment and ecosystem responses.
Oil and PAHs
Reliable estimates on inputs of oil from rivers and land runoff are lacking. Significant reductions are noted for refineries and the offshore oil and gas industry, although for the latter, inputs from produced water have increased progressively in recent years. Polycyclic aromatic hydrocarbons (PAHs) are widespread in the North Sea, but inputs are unknown. Reductions of PAH inputs are expected by virtue of the reduction of inputs of oil. Recommendations include establishing better estimates of oil and PAH inputs from all land-based sources and of PAH concentrations and effects in the marine environment, fulfilling the objectives of the OSPAR Strategy for offshore oil and gas activities, and strengthening existing measures to ensure continuation of the present decline of illegal discharges of oil from ships.Heavy metals
Policy measures have been successful in reducing discharges and emissions of cadmium, mercury, lead and copper resulting in reductions of concentrations in sediments, water and biota. However, there is still evidence of local effects close to known sources. Further improvements will be achieved with the fulfilment of the OSPAR Strategy with regard to Hazardous substances.Other hazardous substances from sea-based sources (other than oil, PAHs and antifouling substances)
Inputs of hazardous substances occur from the offshore oil and gas industry particularly via produced water. Currently available information is too limited to make an assessment of their impacts. Inputs from shipping consist of elemental phosphorus (found on beaches), pesticides and lipophilic substances originating from the cleaning of tanks, burning fuel, discharges of wastes and loss of cargo. Recommendations call for more information on inputs, field concentrations, chemical fate and biological effects of the hazardous chemicals concerned. Effective implementation of the OSPAR Strategy for offshore oil and gas activities and various international agreements on shipping should be pursued, with co-operation on control, enforcement and sanctions further strengthened.Biological impacts
The introduction of non-indigenous species by shipping and mariculture as well as microbiological pollution from land may affect the health of organisms (including man) and the structure of ecosystems. It is recommended that the presence and further dispersal of non-indigenous species should be recorded, as well as the presence of algal toxins and pathogens, as required for the EU Shellfish Hygiene Directive.
Limitations in knowledge
Limited knowledge in the following subject areas was identified as particularly important:
- The possible impacts of climate change;
- Organic hazardous substances. There is a general lack of data in this area;
Chemicals from some sectors, for example the offshore industry, shipping and agriculture. Information on inputs, environmental concentrations and biological effects was not readily available;
Chronic and combined effects of hazardous substances on organisms, and effect concentrations and ecological impacts of substances affecting the hormone system;
Reliable quantitative information on sources and inputs of nutrients and the relationship with eutrophication, including the role of seasonal variations;
- Trend monitoring. At present, this is unsatisfactory in the OSPAR area;
Budgets and fluxes for substances, both within the North Sea area and between OSPAR regions. This could be addressed with better harmonised monitoring efforts;
- The lack of Background/Reference Concentrations and Ecotoxicological Assessment Criteria for several hazardous substances;
- Modelling of multi-species interactions in fisheries.
- The longer term impacts of fisheries, especially with regard to demersal gears and the seasonal and spatial variability in discards;
- Comparable data on economic aspects of the use of the North Sea;
- Assessment indicators regarding tourism;
Ecological Quality Objectives to contribute to the protection and conservation of the ecosystems and biological diversity of the maritime area.
The quality status report concludes with the following general recommendations:
* To ensure continued improvement of the quality of the North Sea, adequate resources should be made available to implement the OSPAR Strategies;
* Future assessments of the quality status of the North Sea could benefit from improved co-operation with other European and global fora;
* Steps should be taken to close the gaps in knowledge highlighted in this report, in particular regarding the occurrence and effects of hazardous substances in the marine environment;
* Further development of tools for the assessment of substances and effects of concern should be pursued, where possible integrating biological effects and chemical monitoring. More efficient data gathering is crucial, for example by one-off surveys by a lead laboratory;
* The impact of those human pressures thought likely to increase, or unlikely to diminish, should be reviewed in the short term and action taken accordingly;
* The implications for the North Sea environment of possible changes associated with global warming should be evaluated;
* The ecosystem approach needs further development and application to achieve effective protection and conservation of the ecosystems and biological diversity of the North Sea.