5. The North Sea

Release date	02/02/2006

5.1. Introduction

Belgium is a federal state divided in different regions. In matters of environmental protection, the federal government is competent for dealing with pollution at sea, marine nature conservation, fisheries, etc... Other aspects concerning the North Sea are dealt with through co-operation agreements, established between the Federal State and the Flemish Region. The responsibility for planning and implementing the national policy concerning the North Sea is thus shared by the federal and regional governments, and is co-ordinated by the 'Technical Commission for the North Sea', which also participates in the 'Federal Council for Sustainable Development'.

The competences and rights of the federal authorities are different according to the zone of the North Sea: territorial sea, continental shelf, exclusive economic zone (EEZ) or fishery zone. Belgium has not yet declared an EEZ, but intends to do so in the near future.

5.2. Status

5.2.1. Habitats

The natural coastal habitats occurring in Belgium consist of dunes, sandy beaches, and shallow subtidal sandbanks. Due to intense use, most of these habitats have reduced in quality and extent. The remaining areas are subject to several forms of disturbance. The subtidal area consists mainly of deposits of soft sediments. At some locations, small areas with habitats of intertidal mudflats, salt marches and estuaries can still be found. Artificial substrates along the coast include groynes, breakwaters, dikes and wrecks. These form a habitat for a community typical for rocky shores, with a high species diversity.

Especially the western area of the coast with very shallow subtidal sand and gravelbanks has an important ecological value. Because benthic species sometimes occur in great densities, they are very important in the food web. The dependence of the ecosystem on these few species makes it very vulnerable. The main threats for the ecological features of the marine habitats are fisheries, mineral extraction, dredging, pollution and recreation. Habitats of intertidal mudflats and sandflats have declined severely through harbour construction works and port development.

5.2.2. Species

As a consequence of overfishing in the North Sea a significant decrease in the population size of many fish species has been observed. This is particularly obvious for slowly reproducing species such as sharks, rays and skates, but also stocks of cod, herring, mackerel, plaice and sole have shown a serious decline. The decline of some fish stocks had its consequences for other species preying on them. The depletion of the herring stock for instance is probably one of the reasons for the severe decline in the population of the harbour porpoise, which has become rare in our waters. Other possible reasons are pollution and bycatch. Another cetacean that used to frequent our waters is the bottlenose dolphin, which is now an extremely rare visitor. The common seal had also virtually disappeared, but recently showed a slight recovery.

River construction works and pollution have caused the decline or complete disappearance of diadromic fish species (using either the sea for spawning and the fresh water environment for growing up, or vice versa). Species that became extinct in our waters are sturgeon, houting and salmon. Diadromic fish that declined, in some cases to an alarming level, are sea lamprey, lampern, eel, allis shad, twaite shad and smelt.

The probable reason for the complete disappearance of the dogwhelk, an animal of hard intertidal substrates, has been identified as TBT, used as an antifouling agent on ships' hulls. The use of TBT has now been regulated to a certain extent.

In winter internationally important numbers of birds, especially common scoter, occur at the western part of the coast. These ducks probably feed primarily on bivalve molluscs. Other birds wintering here, or at least using the area as a temporary resting place during migration, include velvet scoter, widgeon, eider duck, guillemot, razorbill, and divers. The Belgian coast is also an important wintering area for great crested grebes. From autumn till spring relatively large numbers of little gulls can be found while sandwich, little, and common terns are feeding around the port of Zeebrugge, which holds important breeding colonies of these birds. The whole year round other seabirds such as gulls, gannets and fulmars can be found at sea.

5.3. Activities and threats

5.3.1. Fisheries

The Belgian part of the North Sea is small compared to that of the other states surrounding it. The Belgian fishing fleet is the smallest of all North Sea states, with less than 1% of all catches. It is however an important economic activity for some local communities. The number of fishing vessels has shown a remarkable decrease (Fig. 5.1.), whereas the mean engine power increased from 97 kW per ship to 426 kW per ship.

The main fishing methods used off the Belgian coast are beam and otter trawling aimed at demersal fish and beam trawling for brown shrimp. To a much lesser extent bottom set gill nets are used, and only very occasionally fishermen use pelagic pair trawls. Total catches are around 30,000 tons (Fig. 5.1.). The most important fish species caught in Belgian waters are plaice, sole and cod. Valuable bycatches consist of whiting, turbot, brill, common dab, lemon sole and rays. Inshore, a relatively important directed fishery exists for brown shrimp.

Sports fishermen use rod and line, and very short bottom set gill nets, both predominantly in the vicinity of wrecks. Some recreational fishermen use bottom gill nets and fykes, set and emptied from the shore at low tide. Recreational shrimp fishery exists both from the shore and in using small boats. Catches of sports fishermen are insignificant compared to the catches of professional fishermen.

Fig. 5.1. Marine fisheries in Belgium: landings and fleet size from 1950 tot 1996 (Welvaert, 1997).

5.3.2. Sand and gravel extraction

Oil and gas exploration does not exist in Belgian waters. Besides fisheries, the only other natural resources exploited are minerals. Considerable amounts of sand and gravel are landed each year (Fig. 5.2.) and used for building and beach replenishment. Occasionally these minerals are used for port construction works.

Fig. 5.2. Marine mineral extraction in Belgium from 1979 to 1996 (MUMM).

5.3.3. Dredging

The Belgian coast is situated near the Channel, one of the worlds busiest shipping routes. Some ports, especially Zeebrugge and Antwerp are economically very important. In order to keep navigational channels and ports accessible for large ships, sustained dredging is required (Fig. 5.3.).

Dredging activities can have a direct and indirect impact on living organisms.

Physical impacts:

• Change in the sediment composition, not limited to the dredge site or dump site.
• Increase in turbidity of the water column.

Chemical impacts:

• Spreading of pollution, when present in the dredge spoil.
• Increase of pollutant content of the seawater through mobilisation of pollutants.

Biological impacts:

• Impact on the benthic community (especially sedentary) and spawning areas.
• Ecotoxicological impact on species.

Fig. 5.3. Amount of dredge spoil dumped at sea in Belgium from 1975 to 1996 (MUMM).

5.3.4. Pollution

Different human activities cause different kinds of pollution. In order to counteract pollution, different measures need to be taken according to each specific activity. The source of pollution can either be ship-based (litter, oil,...) or land-based (litter, harmful substances, nutrients, ...).

5.3.5. Recreation

In summer, the Belgian coast is flooded with hundreds of thousands of tourists, mainly attracted by the natural values of the area (dunes, sandy beaches, sea). This has a very significant economic consequence, which cannot be ignored in preparing the environmental policy.

The marina of Nieuwpoort is among the largest to be found in the North Sea area. Many thousands of yachts -mainly sailing ships- have their mooring here. Smaller marina's are situated at Oostende, Blankenberge and Zeebrugge.

5.4. Objectives

While conservation and restoration of ecological values are important issues, marine environmental management should also be aimed at a sustainable continuation of recreation, fisheries and other legitimate uses of the sea. Therefore a more holistic approach is needed. Administrations of the federal and regional authorities have thus started working together on an integrated management of the coastal zone. Because of the international character of the sea, objectives and management measures are usually set in an international framework (sometimes making it a very slow process). Measures agreed upon on an international level are to be taken up in national policy.

5.4.1. International treaties

The Belgian policy of sea management is based on the United Nations Convention on the Law of the Sea (UNCLOS; soon to be ratified by Belgium), the commitments of the International Conferences of the North Sea (NSC) and the regulations agreed on in the Oslo and Paris Conventions for the prevention of marine pollution (OSPAR). As a member of the European Community, Belgium also executes the Directives of the European Commission (EC). Other Treaties concerning nature conservation ratified by Belgium and relevant for the marine environment are ASCOBANS (Agreement on the Conservation of Small Cetaceans of Baltic and North Seas; concluded under the Bonn Convention) and the Ramsar Convention.

Under the Ramsar Convention the coastal sandbanks west of Oostende are protected as 'Wetland of International Importance for Bird Species'. In accordance with the EC Habitats Directive, Belgium proposed a large part of the western part of the coast to be included in the NATURA 2000 network as a 'Special Area for Conservation' (Fig. 5.4.: shaded area). As a consequence of the NSC and ASCOBANS, an intervention network for scientific research on cetaceans washed ashore on Belgian beaches has been established. For live stranded animals emergency equipment is available at Oostende. The intervention network is also dealing with scientific research on seals and stranded seabirds.

Fig. 5.4. Location of the Special Area of Conservation (shaded area) proposed by Belgium for the NATURA 2000 network (MUMM).

5.4.2. Marien Milieu Marin

The international framework forms the basis of a new law concerning the protection of the North Sea which is being prepared by the federal ministry responsible for marine environmental protection. This ‘Marien Milieu Marin' (MMM) bill was approved by the Cabinet on 25 July 1997. The new law will provide for:

• the obligation for all users of the marine environment to take account of the principles of prevention, precautionary approach, sustainable management, compensation for damage and the pollutant pays-principle;
• the creation of marine protected areas of five possible types;
• the effective protection of a number of species;
• the prohibition of introduction of 'alien' species or genetically modified organisms;
• ship traffic schemes to preserve protected areas;
• contingency planning for accidental pollution as well as a regime of compensation and restoration;
• a procedure of environmental impact statements and studies for activities subject to a licence or authorisation;
• enforcement through a reinforced control and high penalties.

5.5. Strategy and Action plan

5.5.1. Fisheries management

Belgian fisheries are regulated through the EC's ‘Common Fisheries Policy' (CFP). Despite a lot of measures in force, the exploitation rate on some fish stocks is still too high. Besides the management measures taken by the EC, some additional regulations are in force in Belgium, the most important one being the prohibition of directed fishery on 'sessile species', such as bivalve molluscs. In spite of this, research is being carried out for the economical and ecological viability of a fishery directed at trough shell. If this fishery is practised, it will have to be managed appropriately in order to avoid adverse effects to the environment as much as possible (applying the precautionary principle).

Concern is growing about the impact of fisheries on the ecosystem of the North Sea as a whole. Therefore it was decided at the fourth NSC to hold a Ministerial Meeting on fisheries and the environment. Ministers responsible for both fisheries and environmental policies sat together at this meeting in March 1997 and made commitments to the integration of fishery management and environmental policy.

5.5.2. Management of mineral extraction

Mineral extraction is subject to a system of licensing, following the 'Code of Practice for the Commercial Extraction of Marine Minerals' (ICES, 1991). OSPAR as well pays attention to marine aggregate extraction.

Each ship needs to be equipped with a 'black box', an automatic registration system which makes it possible for the authorities to control the amount of sand and gravel extracted, and the location of the extraction site. Mineral extraction is only allowed in two zones off the Belgian coast. These are carefully monitored for the morphological and sedimentological effects of the extraction activities, and the effects on fish species and benthic organisms. Because of the granulometry and the instability of sand banks, these exploitation zones are faunistically poor compared to the surrounding seabed. If severe adverse effects on the environment were to become apparent, the Belgian authorities have the possibility to react immediately.

5.5.3. Environmental management of dredging activities

Environmental effects of dredging activities are carefully assessed. Possibilities for the reduction of the impact of dredging and the dumping of dredge spoil are being examined. These include technical and geographical (choosing of the dump-site) measures and alternative uses for dredge spoil. The use of the best available technology is promoted and further investigated in an international framework.

Dredging in harbours and navigational channels is a competence of the Flemish Region. In order to do everything possible in protecting the marine area from adverse effects of dredging activities, a co-operation agreement was signed between the federal and regional authorities. The policy of the Flemish Region concerning the pollution of rivers and harbours is leading to an improvement of the quality of the sediments in ports. This will lead to a lower level of pollution present in dredge spoil. National and regional authorities have decided in concert not to continue the direct dumping into the sea of dredge spoil heavily contaminated with TBT and polyaromatic hydrocarbons. Feasibility studies of physical, chemical and biological treatment of heavily polluted dredge spoil are being carried out.

5.5.4. Management of pollution

5.5.4.1.

Belgium signed and ratified the 'International Convention for the Prevention of Pollution from Ships' (MARPOL 73/78). This convention contains five Annexes, each dealing with a different type of cargo or waste, and establishes rules and levels for their discharge. It also contains technical measures to prevent accidental and intentional pollution. Under Annex V of MARPOL, the North Sea has been indicated as a 'Special Area'. This means that the discharge of garbage, except for food remains, is not allowed. Also for Annex I and II (oil and chemicals) the North Sea may in the future become a Special Area.

The policy of the regional government concerning litter, is first of all aimed at a reduction at the source. Following the designation of the North Sea as a Special Area under Annex V of MARPOL, all ports have facilities to deal with garbage generated on board ships.

Since 1990, the Management Unit of the North Sea Mathematical Models (MUMM) carries out an intensive programme of aerial surveillance of the Belgian zone of interest in the North Sea (according to the Bonn Agreement) to monitor illegal discharges of oil and other harmful substances by ships. In the marine area controlled by Belgium, illegal operational discharges probably still occur every day (Fig. 5.5.). By means of the national MARPOL - Law of 1995, it has been made easier to legally charge any ship caught redhanded, but it is clear that control alone is insufficient. An increased international co-operation between port authorities is vital to prevent illegal discharge of used oil, or the cleaning of oil tanks at sea. In Belgian ports, reception facilities are available for ships to deposit used oil. Encouraging ships to make use of these facilities might reduce illegal discharge.

Fig. 5.5. Number of oil slicks observed by Belgium and number of slicks per flight hour from 1991 to 1995 (Schallier et al., 1996).

5.5.4.2.Pollution from land-based sources

Guidelines for the reduction of sea pollution through discharges coming from rivers are set in the framework of OSPAR. The Regions have legal competency for dealing with land-based activities indirectly causing marine pollution. This is why a consultative process was set up between the competent federal and regional authorities. In this process problems concerning certain emissions, mainly of harmful substances and nutrients, are identified. A programme for the reduction by 50% of inputs of 36 hazardous substances (metals, solvents, pesticides, dioxines) in the North Sea was drawn up (1985-1995). Efforts to reduce pollution are persued. Marine pollution from land-based sources is assessed through monitoring and mathematical modeling. Data are stored in an extensive database, held by MUMM.

5.5.5. Management of recreation

One part of a project co-funded by the EC LIFE-Nature programme consists in the assessment of human activities and their impact on the environment in the proposed Special Area of Conservation. Based on these assessments, possible management measures will be proposed for the conservation of this site, and where necessary and feasible, for the restoration of the natural values of this site, and possibly for the larger part of the marine area.

Due to the economic importance of tourism at the Belgian coast the restoration of beaches to their original ecological function is difficult. Animals which require undisturbed beaches, such as some bird species and seals, have virtually disappeared. Possibilities to establish an integral nature reserve, including both the terrestrial and marine part of the environment, are investigated.

Marina's are well equipped to deal with garbage and used oil. The main negative impact on the environment to be feared from yachting, is the disturbance of wintering birds. It is not allowed to use a jetski in Belgian waters.

5.6. Monitoring

5.6.1. Indicators

Seabirds are the most conspicuous victims of oil pollution. Each year some two thousand birds wash ashore on Belgian beaches. A large proportion of these are victims of oil pollution. Some oiled birds found alive are taken to a rehabilitation centre. To assess the level of oil pollution at sea, the Institute for Nature Conservation, in co-operation with numerous volunteers, has been organising for several years regular counts of beached seabirds and is as such contributing to the 'International Beached Bird Surveys'. These counts have been carried out since the 1960's and are essential to provide us with data on trends of oil pollution.

Marine mammals and seabirds are at the top of the foodchain, so toxic substances such as heavy metals and PCB's are concentrated in their tissues. Tissues of all marine mammals washed ashore dead, and a lot of seabirds, are analysed to determine the level of toxic substances. Pathological research is also being done, providing in some cases useful indicators of the ecosystem's health. Various types of litter can cause illness or even death of marine mammals and seabirds, a negative impact which is also carefully monitored.

The research of the benthic communities (macro-, meio- and hyper-) is perhaps even a better way to identify problems. Benthic animals are abundant and their sampling is very easy. Because most do not migrate very far, they show a picture of long-term pollution. In the research programme on sustainable management of the North Sea, a selection will be made of individual species that can be used as indicators for ecosystem health.

5.6.2. Monitoring of alien species

More than 20 plant and animal species now living in our marine waters have been identified as being introduced by human activities. Some of these 'alien species' were introduced hundreds of years ago, such as the sand-gaper Mya arenaria. Alien species living on hard substrates include the Pacific oyster Crassostrea gigas and the ascidian Styela clava. The American razor clam Ensis directus is a very recent introduction, yet it has become very abundant. Another very recent introduction is the blue crab Callinectes sapidus, but it is still unclear if this animal can reproduce in our waters. A research project confirmed that alien species, including potentially toxic phytoplankton, are still transported to Europe in ballast water.

5.6.3. Programmes

To investigate the human activities and their possible negative impact on the environment of the ecologically most valuable part of the marine area, a LIFE-Nature project (covering also the terrestrial part of this area) was set up in 1997. The project, co-funded by the EC, is carried out by Flemish and Federal administrations and two NGO's (‘World Wide Fund for Nature' and ‘Natuurreservaten vzw').

The Federal Government funds a number of research and monitoring projects dealing with the sustainable management and the conservation of natural values of the marine environment. These programmes last for two to five years (1997-2001) and form a scientific support for the environmental policy of the government.

Thanks to the Federal Government an oceanographic vessel ('BELGICA') is available for research and monitoring projects of universities and other institutions.

Annex 5.1. Species mentioned in chapter 5

 

J. Haelters & Th. Jacques
Management Unit of the Mathematical Models
of the North Sea and the Scheldt Estuary
Gulledelle 100
1200 Brussels