Assessing the health of coastal marine ecosystems: A holistic approach based on sediment micro and meio-benthic measures

We applied a thermodynamic and network analysis on the micro and meio-benthic community in a wide coastal area of the southern Adriatic Sea in order to assess ecosystem health and to identify useful descriptors of environmental quality. The analysis of the micro and meio-benthic system in terms of organic matter, bacteria, microphytobenthos and meiofauna reflected changes occurring in the trophic state of benthic ecosystems and provided a tool for comparison between different environments. The biopolymeric carbon load never reached very high concentrations. Within these trophic conditions, ascendency, exergy and specific exergy resulted strictly related to each other and an increase of all the goal functions was observed at increasing resource availability. The analysis of trophic efficiency was particularly sensitive to assess the environmental state in term of sustaining complex structure and resource exploitation. In particular, specific exergy, ascendency/capacity and Finn's cycling index showed lowest values in more anthropogenic areas and can be proposed as candidate indices for the health assessment of coastal ecosystems.