Marine biodiversity

Biodiversity studies at ISMAR focus on pelagic and benthic community structures of the open sea, coastal areas and transitional systems, especially considering that a good taxonomic analysis of communities supplies important information on the state of the sea and evidences its biodiversity and functioning.

The signs of good health of an ecosystem can be described in terms of vigour, organization and resilience. The organization of a system refers to the number and the diversity of the interactions among its components, and depends on the number of species and the relationships between species. A good healthy ecosystem shows a high biological diversity in relation to its structural characters. The recent WFD (2000/60) agrees with this idea, imposing diversity as the biological quality element.

Biodiversity of an ecosystem evaluates also the sizes and the role of the organisms in the trophic chain. For the transitional ecosystems, biodiversity depends strictly on the basin structure. The research of the ratio between abiotic stressors and biological communities is very important because it permits to distinguish between natural signs and anthropogenic disturbance. In coastal areas, the impact from pollution, eutrophication and overfishing is considered a serious threat, but even there the loss in biodiversity is often perceived to be low or not existing.

ISMAR proposes to evaluate the effects of human impact on marine biodiversity for these categories: i) overexploitation of resources, ii) introduction of exotic species iii) pollution and eutrophication, iv) physical alteration of the habitats v) global climate change. Keeping in mind that the species richness represents a guaranty for the ecosystems, all these categories are to be considered, because their high biodiversity improves the response to every kind of change.