5. The North Sea
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.
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
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.
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
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
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
Fig. 5.2. Marine mineral extraction
in Belgium from 1979 to 1996 (MUMM).
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
- Change in the sediment composition, not limited to the dredge site or
- Increase in turbidity of the water column.
- Spreading of pollution, when present in the dredge spoil.
- Increase of pollutant content of the seawater through mobilisation of
- Impact on the benthic community (especially sedentary) and spawning
- Ecotoxicological impact on species.
Fig. 5.3. Amount of dredge spoil
dumped at sea in Belgium from 1975 to 1996 (MUMM).
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, ...).
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.
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
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
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
- 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
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
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
184.108.40.206. Pollution from ships
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).
220.127.116.11. 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
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
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
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
Thanks to the Federal Government an oceanographic vessel ('BELGICA') is
available for research and monitoring projects of universities and other
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