Pressures, impacts and policy responses in European coastal zones

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Pressures, impacts and policy responses have been identified for 18 coastal sites in Europe. These sites were selected as study sites for the SPICOSA project, as they constitute together a representative sample of the diversity of European coastal environments. A comparative analysis reveals striking similarities between coastal sites in spite of widely different physical, environmental, social and economic conditions. It therefore makes sense to share experience on policies and practices for defining the best policy responses in each particular case. A generic framework for analysis is under construction in the SPICOSA project, based on the systems approach. This framework of analysis enables the transfer of knowledge and experience among coastal sites, with full consideration of site-specific conditions.

Table 1: The set of 18 SPICOSA study sites (Map) is representative for the diversity of European coastal environments. They all host valuable ecosystems and most of them have a NATURA2000 status. Dark blue = entirely NATURA2000, light blue = partly NATURA2000.

Coastal zones provide society with a great wealth of goods and services. They support numerous different functions and uses; coastal zones are typically multifunctional areas. However, resources and space in coastal zones are limited. When exploiting one resource, it is difficult to avoid a negative impact on other goods and services. The best exploitation strategy for an individual user is probably not the best strategy for a user group and the best exploitation strategy for one particular user group is probably not the best strategy for all different user groups together. So is it possible to define an optimum exploitation strategy? Are there objective criteria? These are key questions of ICZM. Different uses mutually interact and they are affected by natural and anthropogenic feedback. Cause-effect chains are generally not straightforward; this explains the need for an integrated assessment framework, which was developed in the SPICOSA project.


Table 2 provides an overview of the human activities that in the present situation have a major impact on different coastal zones in Europe.

Table 2. Human activities presently regarded as most urgent pressures in the SPICOSA study sites.

Urban development – the extension of cities, industries, road infrastructure, railways, airports, the sprawl of second homes, the construction of tourist resorts and marinas – is a widespread phenomenon along the European coasts. It conflicts spatially with the preservation or restoration of valuable habitats and it entails many other pressures, such as an increase of urban and industrial effluents. Increased pressure may also result from recreational activities, for instance through disturbance, pollution and deterioration of habitats.

Many coastal sites still suffer from poor water quality and soil quality due to insufficient treatment of urban and industrial effluents. The situation has improved in the past decade, but in many cases additional investments remain necessary. This holds in particular for cleaning up the legacy of past soil contamination.

Agricultural practices have strongly evolved during the pas decades in order to increase productivity. Widespread use of fertilizers has caused a tremendous increase of the nitrogen concentration in agricultural effluents that are discharged via rivers into the coastal waters. Throughout Europe, coastal waters suffer from eutrophication, primarily as a consequence of agricultural practices.

Next to urbanization (including effluents and tourism) and agriculture, the third major pressure on European coastal zones results from fishery. The use of advanced fishing techniques (e.g. fish finding sonar devices) and large sophisticated vessels has greatly reduced the stocks of many species of commercially interesting finfish. The decline of fish stocks and the increasing food demand has promoted the development of mariculture, both for finfish and shellfish. Mariculture relieves the direct pressure on fish stocks, but it may have indirectly negative impacts on the marine environment.

Other pressures, such as resulting from shipping and engineering works (especially river dams) are in some cases quite serious, but less widespread among the coastal sites considered in the SPICOSA project. It is remarkable that sea level rise and climate change are not yet ranked among the most urgent pressures.

For a more general discussion of pressures, see Threats to the coastal zone.


The impacts experienced in the different coastal sites are listed in table 3. There is a clear correspondence with the pressures identified in table 2, but there is no one-to-one relationship – different pressures may give rise to similar impacts.

Nutrient loading (or eutrophication) is the most frequently occurring impact. Agricultural effluents (containing e.g. natural or chemical manure residuals) are in most cases the primary cause, but sewage from households and industry are also non-negligible sources, as well as atmospheric deposition of traffic emissions. In the neighbourhood of fish farms nutrient concentrations can be considerably raised by faeces and uneaten food. Nutrient loading has important secondary effects on the trophic food web, leading to change and loss of biodiversity, to increased turbidity, to oxygen depletion and to more frequent harmful algae blooms. Fish farmers strongly apprehend harmful algae blooms, which can destroy the yield of one year.

Table 3. Major impacts experienced in the SPICOSA study sites.

Loss and degradation of habitats is another widespread impact in European coastal zones. Some estimates [1] range up to 80% loss of coastal wetlands in Europe. The loss of coastal wetlands, such as salt marshes, seagrass fields and shellfish reefs, results in declining food resources, loss of breeding and nursery grounds and in extinction of species. Moreover, valuable ecosystem services are lost, such as the fixation of fine sediments, denitrification and protection against storm waves and erosion.

Many European coastal zones are still suffering from biochemical pollution. Most pollution (microbes, organic and metallic compounds) originates from land-based sources (households, industry, traffic, agriculture) and enters the marine environment via rivers or via the atmosphere. Platforms and ships also contribute substantially, in particular hydrocarbons, such as oil and PAH’s, and other highly toxic substances such as antifoulants. Several large accidental oil spills have had a devastating impact on maricultures and on recreational coastal activities; the impact of oil pollution can be very persistent in sheltered coastal environments. Maricultures are another source of chemicals, such as antibiotics, pesticides, desinfectants and hormones.

Many pollutants easily adsorb to fine sediments and tend to accumulate in estuaries and lagoons. Pollutants entering at low concentrations the lower levels of the food chain, accumulate in predators, causing diseases of fish, birds and marine mammals and affecting their reproduction. Bioaccumulation also presents a risk to human consumers.

Nutrient loading, biochemical pollution and loss of habitats are three major causes of biodiversity degradation. Fishery is a fourth major cause. It is estimated that in the North Atlantic region the biomass of large predatory fish species has decreased by almost 90% during the 20th century[2]; from the North Sea, 1/3 of the fish biomass is taken out each year. Selective fishing of predator species has important consequences for lower trophic levels in the food web and finally may shift the entire ecosystem. Another direct effect of fishing is the physical disturbance by scraping, scouring and resuspension of the substratum. The fishery impacts favour short-living species over long-living species and tend to a genetic shift in the fish population towards early maturation.

Invasive species are also a real treat to biodiversity, especially through competition with native species for vital food sources. A dramatic example is the introduction of the comb jellyfish into the Black Sea through ship ballast water in the early 1980s; by 1994, the area’s anchovy fishery had almost disappeared [3]. Transport by ship ballast water is the most common translocation mechanism, but intentional introduction also occurs. The Pacific oyster was introduced in the Eastern Scheldt in the sixties, after the disease that decimated the indigenous oyster population. Now it has colonized the Wadden Sea, with a biomass exceeding 50 thousand tons. Global climate change has probably accelerated this colonization. Accidental escape from maricultures is another cause of non-native species invasion.

Flooding is a major risk in many low-lying coastal areas. The vulnerability to flooding has increased by coastal urbanization over the past decades, because of urban development in areas prone to flooding and because of increase of population and capital investments in zones at risk. It is to be expected that flood risks will dramatically increase over the next century as a consequence of sea level rise related to global warming.

Coastal erosion is a natural phenomenon along the European sedimentary shores. Erosion caused by extreme storm waves can cause serious damage, but it has often a temporary character. Beaches and dunes tend to be restored (at least partially) during subsequent calm-weather conditions. Structural coastal erosion also occurs at many places, especially where the coastline consists of mud, sand, gravel or soft-cliffs. The relative rise of sea level is a major driving force for structural erosion, but it is a slow process, currently counting for typically less than 1m/year coastal retreat. More rapid structural coastal retreat is generally caused by human interventions, for instance the construction of sediment trapping coastal structures, such as jetties, groynes, breakwaters, harbours and navigation channels. Upstream retention of sediment behind river dams is another important cause of coastal erosion.

Some coastal regions suffer from fresh water shortage and salt intrusion. Upstream fresh water demand is one of the causes, but also an increased fresh water demand in the coastal zone, especially for agricultural use.

The overall picture reveals the great stress experienced by coastal zones due to a multitude of natural and human pressures. In the foregoing, many of these stresses are described in terms of environmental impacts. These environmental impacts have important societal consequences; they affect the coastal economy as well as social and cultural values of coastal communities. It is generally recognized that “do nothing” is not a viable option. Several types of policy responses are studied in the SPICOSA site studies.


The policy responses considered in the different SPICOSA study sites are summarized in table 4. Many of these policy responses are developed and implemented in the framework of European policy directives agreed by the European Union Member States, in particular:

The Birds Directive: commits Member States to maintain the existing habitats, to restore destroyed biotopes and to create protection zones and biotopes, in order to maintain or restore the diversity and the area of habitats for all species of naturally occurring birds in the wild state.

The Habitats Directive: commits Member States to designate sites hosting natural habitats and wild fauna and flora, as special areas of conservation, and to establish an enforceable plan in order to maintain or restore the special protection area to a favourable conservation status. Such plans or projects must take into account the economic, social or cultural requirements of the area in question. The designated special areas form together the European NATURA2000 network.

Table 4. Policy responses in the SPICOSA study sites.

The Water Framework Directive: commits Member States to achieve good qualitative and quantitative status of inland surface waters, transitional waters, coastal waters (up to 1 km from the shore) and groundwater by 2015. For the implementation each Member State develops River Basin Management Plans in concert with other Member States sharing a same river basin; these plans take into account and extend measures prescribed under the Urban Waste Water Treatment Directive, the Nitrates Directive and the Integrated Pollution Prevention and Control Directive.

The Strategic Assessment Directive: commits Member States to ensure that environmental consequences of plans and programmes are identified and assessed during their preparation and before their adoption.

The Marine Strategy Framework Directive: commits Member States to achieve good environmental status of the EU's marine waters by 2021 and to protect the resource base upon which marine-related economic and social activities depend. For the implementation each Member State develops a marine strategy plan in concert with other Member States bordering on the same regional sea; these plans contain a detailed assessment of the state of the environment, a definition of "good environmental status" at regional level and the establishment of clear environmental targets and monitoring programmes.

The European ICZM Recommendation in which Member States agree to implement, on a voluntary basis, principles of Integrated Coastal Zone Management.

Besides, Member States are committed to the Common Fisheries Policy, which aims at ensuring the sustainable development of fishing activities from an environmental, economic and social point of view, based on sound and transparent scientific advice and on participation of stakeholders.

Almost all the SPICOSA study sites contain NATURA2000 areas that are protected under the Habitats and Birds Directives. They also have to comply with either the Water Framework Directive or the Marine Strategy Framework Directive. Most of the policy responses of table 4 therefore have to be coordinated on the national and European levels, where targets are defined and financial means are allocated.

Detailed implementation plans have to be elaborated at the local level by the responsible authorities. The involvement of local stakeholders and experts is important for creating public support and for defining measures that fit local circumstances. Many study sites therefore aim at a strategy based on the ICZM principles. Implementation of the EU directives provides opportunities to better exploit local coastal resources. A few examples are given below.

Spatial planning: Mitigating conflicts, by considering mutually compatible and incompatible uses. Optimising space allocation, such that different uses can take advantage of each other.

Conservation of coastal wetlands: Goes often hand in hand with coastal protection and with water management. The water buffering capacity of coastal wetlands mitigates the impacts of exceptional droughts and floods.

Coastal protection: Artificial beach or shore nourishment is not only in many cases an effective strategy for combating coastal retreat and for stimulating dune growth, but it also preserves the environmental quality of the coast and it serves beach recreation.

Urbanisation: Building in low-lying areas should be avoided, but flood risks can also be mitigated by constructing floating homes. The environmental quality of urban environments can be strengthened by creating water spaces, which also serve as water buffers for reducing flood risk.

Agriculture: Pairing agriculture with wetland restoration can contribute to reduce eutrophication of coastal waters, thanks to the denitrification capacity of wetlands.

Tourism: Sustainable tourism can benefit from the neighbourhood of marine protected areas. Sustainable tourism strengthens the benefits of tourism through protection or rehabilitation of environmental and cultural assets, while limiting negative environmental impacts.

Fishery: New mariculture techniques, such as Integrated Multi-trophic Aquaculture, produce less harmful waste than traditional techniques. Moving mariculture to land is also an option for a better process control and for avoiding spatial conflicts with other uses.

Social measures: Reconversion of employment towards new technology branches, for instance, innovative aquaculture techniques or the industry of renewable energies.

Many studies stress that coastal policies should already take into consideration the predictable consequences of climate change. Adapative management, the iterative process of optimal decision making in the face of uncertainty, is generally advocated as the most adequate response strategy. The Coastal-SAF site SPICOSA systems framework of analysis is specifically tailored to support adaptive coastal management.


  1. Airoldi, L., Beck, W.M. 2007. Loss, status and trends for coastal marine habitats of Europe. Oceanogr. Marine Biology Annual Review 45, 345–405.
  2. Christensen, V., Guénette, S., Heymans, J.J. et al. 2003. Hundred-year decline of North Atlantic predatory fishes. Fish and Fisheries 4: 1-24
  3. Marine invasive species

See also

Integrated Coastal Zone Management (ICZM)
Sustainability indicators
Threats to the coastal zone
Climate adaptation policies for the coastal zone
Climate adaptation measures for the coastal zone

Useful links

Further reading

The main author of this article is Job Dronkers
Please note that others may also have edited the contents of this article.

Citation: Job Dronkers (2022): Pressures, impacts and policy responses in European coastal zones. Available from,_impacts_and_policy_responses_in_European_coastal_zones [accessed on 18-07-2024]