Microbial communities as indicators of marine ecosystem health: Insights from coastal sediments in the eastern Adriatic Sea.

Considering the adaptability and responsiveness of microorganisms to environmental changes, their indicator potential is still not acknowledged in European directives. This comprehensive study examined the changes of microbial communities in sediments and a range of geochemical parameters from pristine and anthropogenically impacted coastal areas in the eastern Adriatic Sea. Various analytical methods found evidence of sediment contamination (high toxicity level, enrichments of metals, tributyltin) in certain areas, leading to the categorization of sediments based on the level of anthropogenic disturbance. Prokaryotes were identified as the most promising group of microbes for further research, with specific bacterial families (Rhodobacteraceae, Ectothiorhodospiraceae, Cyclobacteriaceae) and genera (Boseongicola, B2M28, Subgroup 23, Sva0485, Thiogranum) proposed as potential indicators of environmental status. Finally, predictive models were developed to identify key indicator variables for assessing anthropogenic impact in sediments. This research represents an essential step toward incorporating microbial communities into assessments of benthic environmental health.

Ecological quality status of the Adriatic coastal waters evaluated by the organotin pollution biomonitoring.

The aim of this study was to evaluate the post-legislation change in tributyltin (TBT) pollution at Croatian Adriatic coast. Gastropod Hexaplex trunculus and sediments were collected, nearly 10years after TBT based antifouling paints were banned, at 12 locations along the coast where a previous study was conducted in 2005. The study showed a decline of TBT levels over the investigated period, although all gastropods populations were highly affected by imposex meaning that prohibition did not result in the recovery of populations. The further aim was to propose the Ecological Quality Ratio (EQR) boundaries for potential use of H. trunculus as a principal bioindicator in the assessment of the ecological status of the Mediterranean regarding TBT pollution, under the Water Framework Directive (WFD). According to the proposed EQR classes, the WFD target for achieving the Good ecological status of the marine environment by 2015 was not reached.