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Final Report Summary - MARBEF (Marine biodiversity and ecosystem functioning)

The marine ecosystems have distinct characteristics in comparison to terrestrial systems, are crucial for almost all biogeochemical processes that sustain the biosphere and provide a variety of goods and services that are essential for human welfare. Marine biodiversity describes the total variation among living organisms in the marine realm and its loss is among the major consequences of the unsustainable use of Earth resources. The observed impact could be mitigated only through increased awareness on the relevant processes.

The MARBEF project aimed to establish a European network on marine biodiversity and ecosystem functioning in order to enhance understanding of the ongoing large-scale, long-term changes in marine biodiversity. A bottom-up approach was utilised, enabling the exchange of expertise between numerous scientists that represented different disciplines. Three research themes were identified, namely the patterns of species' diversity, the structures of diversity and the socioeconomic consequences of the observed changes.

Firstly, a baseline to detect trends in biodiversity change was created. Moreover, MARBEF employed recent advances in molecular technology to indicate the variety of organisms that were contained within a single water sample. The key microbes participating in biogeochemical cycles in different areas were also identified. These results, accompanied by findings of necessary future studies, were anticipated to enable the determination of linkages between biodiversity and ecosystem functioning.

In addition, the importance of cold-water caves and vents was highlighted and ways of bacteria communication were defined. The results were anticipated to improve fisheries' management, assist in defining possible species' decline and improve understanding of the role of secondary metabolites in marine biodiversity. Distinct and potentially vulnerable populations were identified for the first time as part of this process.

The extent in which human activities affected biodiversity could not be directly determined; however, some factors were pinpointed since they evidently imposed heavy pressures. Such critical factors were resources' overexploitation, pollution and eutrophication, introduction of invasive alien species, habitat destruction, anthropogenic climatic change and acidification of the sea.

It was observed that, contrary to expectations, warming effects led to higher biodiversity in the Arctic and to simultaneous food shortages for the top predators. Furthermore, rising temperatures and climatic change contributed to an increase in fish diversity in the North Sea, changes in phytoplankton assemblages in the Mediterranean and modifications in the deep sea-bed communities of the North Atlantic. The possible increase in river inputs, due to climate change, could result in alteration of the existing food webs and fisheries. Moreover, fish populations were vulnerable to fishing habits and invasive alien species, while accidents such as oil spills imposed significant pressures on numerous organisms. On the other hand, protection schemes appeared to have notable results in population recovery. Finally, the alterations of key species' abundance affected ecosystems more than changes in species diversity, while human activities had limited effects on the stability of rocky shore assemblages.

The implementation of a goods and services method was of major importance for the application of an ecosystem approach to environmental management. Maps were prepared under this context, to serve as a basis for future spatial planning in the marine environment. A decision support system (MarDSS) was also developed, using representative indicators and criteria, in order to identify and evaluate alternative solutions for the protection of marine biodiversity. Assessment was performed in biological, economic, social and cultural terms.

Furthermore, the project pinpointed uncertainties in existing biodiversity information that had to be clarified in prospective research projects. The uncertainties were related to impacts of global climate change, synergies of anthropogenic and climatic factors, coastal management practices and alternative stable states, habitat diversity and ecosystem functions, genetic information on biodiversity, microorganism diversity and, finally, marine biotechnology. The importance of performing long lasting research to derive accurate conclusions was indisputable; therefore the established network was planned continue its activities after the project completion. Finally, the acquired knowledge was disseminated to scientists, students and the general public via a series of targeted activities, publications and educational programmes.