Морфометрические характеристики черноморских мидий Mytilus galloprovincialis Lam. как биоиндикатор антропогенного воздействия на прибрежные биоценозы Черного моря на территориях рекреационно-туристской специализации

Abstract

The study assessed the ecological state of the marine environment in the Black Sea coastal zone on the territory of the popular Mayak public beach, located in the central part of Sochi and exposed to complex anthropogenic impact, using morphometric parameters of the Black Sea mussels Mytilus galloprovincialis L. as biomarkers. The studied parameters were compared with those of mollusks selected on a provisionally clean area of the Black Sea coast. In this paper morphometric parameters related to the size characteristics of the mussel shell — its length, width, and thickness — were used as the main biomarkers. On their basis we calculated two indices — the ratio of the shell height to its length (H/L) and the ratio of its width to its length (D/L) — which describe the relationship among morphometric parameters and determine the shell geometry formed under the impact of various environmental factors. As additional indicators, we recorded the colour, the characteristics of the mollusk shell surface, the sexual structure of the studied populations, and the ratio of the mussel raw body weight to the total weight of the mollusk with its shell. It was determined that the values of the main identified indices were significantly lower in the mussels from the clean zone, which can be explained by the fact that in the absence of negative effects mollusks do not need a strong and tightly closed shell to the same extent as animals from polluted areas. Moreover, the results revealed that the two studied mollusk populations from different habitat conditions demonstrated differences in practically all additional parameters. Thus, the studied biomarkers showing the state of biological communities in recreational zones indicate the presence of a systematic or repeated negative impact on marine aquatic organisms in the coastal waters of the Mayak public beach caused by anthropogenic activity.