Coralligenous based indicators to evaluate and monitor the "good ecological status" of the Me-diterranean coastal waters

Informations

Funding country

France

Acronym

CIGESMED

URL

-

Start date

3/1/2013

End date

-

Budget

361,320 EUR

Fundings

Abstract

Biodiversity is influenced by a wide range of external environmental pressures. Some direct impacts are easy to observe, whereas others are far less obvious and therefore more difficult to understand. In 2008, the EC estab-lished a framework for community action in the field of marine environmental policy regarding biodiversity: the Marine Strategy Framework Directive, MSFD, which defines a series of 11 qualitative descriptors of Good Envi-ronmental Status (GES). A range of specific pressures are treated within these separate descriptors but most also impact biodiversity in some way. A knowledge-based monitoring strategy is then recommended. Targets for ac-ceptable status, or “GES”, must be set according to the conditions relevant to each area. The overall aim of the Marine Directive is to achieve a sustainable balance between human needs and the natural environment across the European seas. Monitoring all aspects of biodiversity across the whole European seas is neither possible nor an acceptable use of resources. The ecological, socio-economical and patrimonial importance of the Mediter-ranenan coralligenous ecosystem and its variability all around the Mediterranean Sea give the highest priority to its knowledge, understanding and protection for a sustainable use. Moreover, as a coastal system, it is under endlessly increasing pressures. Its complexity and richness of the associated fauna are potential sources for numerous indicators. CIGESMED will design some new tools based on coralligenous for this perspective. Biologically mediated habitats are structured formations on a seafloor provided by marine living organisms alone (often engineer species) or incrusted by inorganic materials of biogenic origin. These habitats can be built by multi-layered aggregations of organisms to form meadows, colonies, banks or beds, mosaics and patches or accumulations of hard structural elements. These complex biological habitats offer a range of favorable hiding places, are vital reproduction and nursery areas, have protein-rich and easily accessible food resources for ben-thic invertebrates and fish, and are easily exploited by humans due to their high biodiversity and species richness. In the Mediterranean Sea, coralligenous and Posidonia meadows are the most important biologically me-diated habitats. They are the main milieu to generate the structural complexity and biodiversity, as well as for the functioning of these ecosystems. Posidonia meadows were extensively studied whereas coralligenous which is a typical hard bottom Mediterranean underwater seascape is comparatively less so. Feldmann (1937) was the first to unequivocally describe the algal composition of the coralligenous and identify the main calcareous algae mak-ing the coralligenous assemblages. Two main different morphologies are traditionally described: banks, over more or less horizontal substrates, and rims, in the outer parts of marine caves and vertical cliffs (Natura 2000 – sheet 1170.14, Barcelona Convention 2007, IV.3.1). This typical coastal benthic Mediterranean environment lies, de-pending of light conditions, from ca. 15 to 130 m depth. It expands in the circalittoral zone and also develops in the infralittoral zone. These assemblages are one of the most important hot-spots of species diversity in the Mediterranean, together with Posidonia oceanica meadows but which are by far more studied. As mentioned by a recent Mediterranean Action Plan-MAP’ working group13, even if an overall knowledge about its composition and distribution in the NW-Mediterranean basin, the distribution of coralligenous populations (lack of maps), their structuring, functioning and threats are important lacunae from the conservation point of view.