Trade-off between conservation and exploitation of the transitional water ecosystems of the northern Adriatic Sea

Transitional Waters (TWs) provide ecosystem goods and services essential for human well being. These unpredictable aquatic systems, characterised by large environmental fluctuations, are under severe stress due to human activities. The increasing pressures (e.g. over-harvesting, eutrophication, habitat loss) inevitably lead to degradation of these ecosystems. Analysis of the complexity of species distribution patterns within and among TW habitats is relevant to understand the underlain processes, and to promote appropriate management strategies. Assessment of the trophic status is among the most critical aspect of TWs. Untangling relevance of anthropogenic nutrient inputs from internal biogeochemical processes is of primary importance to define appropriate restoration strategies. Biotic indices have been suggested as an operational tool to assess TWs environmental quality. However, application of indices developed for coastal waters in TWs can give distorted indication (e.g. low species diversity and high abundance are natural features). The BITS approach provides a rapid assessment of ecological quality, while its sensitivity in reflecting the field conditions remains to be assessed. The major challenge to TWs management is to couple long-term conservation with the productive activities. This goal can be achieved by an integrated approach, forecasting conservation of TW ecosystem functioning together with a sustainable economic development. North-western Adriatic TW habitats have been exploited for centuries and major shifts in ecological processes occurred. In this study knowledge on ecological features of these habitats have been summarised and analysed using recent ecological tools. Based on these findings possible strategies for a conservative management have been suggested.