Assessment of biological effects of chemical warfare agents (CWAs) dumped in the Baltic Sea has been one of the tasks of the Chemical Munitions Search & Assessment (CHEMSEA) project. Three sites have been selected for investigation: Bornholm Deep, Gotland Deep and Gdansk Deep. Fauna collected from these locations were compared with the reference area located between the studied regions at similar depths below 70 m. In total, four scientific cruises occurred in different seasons between 2011 and 2013. The total lack of any representatives of macrozoobenthos in all of the investigated dumping sites was noted. As a practical matter, the Baltic deeps were inhabited by nematodes as the only meiofauna representatives. Therefore, nematodes were used as a key group to explore the faunal communities inhabiting chemical dumping sites in the Baltic deeps. In total, 42 nematode genera belonging to 18 families were identified, and the dominant genus was Sabatieria (Comesomatidae), which constituted 37.6% of the overall nematode community. There were significant differences in nematode community structure (abundance and taxa composition) between the dumping areas and the reference site (Kruskal–Wallis H=30.96, p<0.0001). Such clear differences suggest that nematode assemblages could mirror the environmental conditions. |