The European Environment Agency is producing a series of '10 messages for 2010', aimed at providing a short assessment on a specific ecosystem or issue related to biodiversity in Europe. This is a timely campaign, seeing that it’s the International Year of Biodiversity. Four of the “messages” are currently available to download on the EEA website, and deal with “climate change and biodiversity”, “protected areas”, “freshwater systems” and, most recently, “marine ecosystems”.

Shrimp trawlers at the North Sea coast of Holland. Photo by Jerker Lokrantz/Azote

The document dealing with marine ecosystems starts with the almost compulsory description of the goods and services produced by marine ecosystems at global scales (e.g. production of oxygen, nutrient cycling and carbon sequestration) and regional and local scales (e.g. hosting crucial commercial fisheries, stabilizing coastlines, filtering waste and pollutants, providing  aesthetic/cultural values and tourism appeal). It’s worth reiterating the role of marine ecosystems in supporting societal development through this flow of goods and services. However, future research must begin applying a more critical approach to this. For example, how does the suite (or bundle) of ecosystems services look like with regards to the characteristics of the human community that receives them (e.g. level of economic development and management approaches). Ecosystem goods and services could also radically change when marine ecosystems undergo dramatic changes such as regime-shifts.

It continues by reviewing the major pressures on European marine ecosystems. Overexploitation of commercial fish stocks is a widespread problem. For example, Atlantic cod has declined dramatically throughout European waters and is struggling to recover. The reasons behind these recovery failures are disputed, but seem to be linked to increases in the biomass of other fish, such as sprat in the Baltic Sea, and climate change. Climate change is having other negative impacts on the biodiversity and structure of European marine ecosystems. For instance, the type of fish species found in the North Sea has changed from 1985 to 2006, and this has been related to higher water temperatures. In essence, small-sized species of southerly origin have increased while large northerly species decreased, but these changes could also partly be explained by commercial overexploitation of large predatory fish species.

One tool that can help European marine ecosystems is a region-wide network of marine protected areas (MPA’s).  For example, a large study of Mediterranean MPA’s has shown that they can increase the abundance and biomass of important fish, enhanced the fisheries yield outside protected areas, and increased the dominance of large predatory species. Unfortunately the use of MPAs in marine environments is lagging behind their terrestrial counterparts, particularly in offshore areas. This difference between marine and terrestrial may have a historical explanation in the sense that the marine environment was long regarded and managed as a resource, rather than as a habitat supporting biodiversity that should be conserved. An even tougher problem to solve is the issue of 88% percent of EU waters currently being overfished. Slashing the overcapacity of the EU-fishing fleet should be an immediate priority, but navigating such a transition is a precarious undertaking. Huge subsidies, currently at €4.3bn per year, exacerbate the problem and create vested interests in keeping the status-quo. Direct profits related to fishing are low, and thus there are continued incentives for fishing fleets to break existing rules. Thus it is clear, as in all cases of creating platforms for the sustainable management of natural resources, that solutions need to not only consider ecological aspects but the socio-economic context in which they preside.