Biodiversity effects of the interaction between installed artificial reefs and seagrass meadows along the Sinop coasts of the Black Sea

Abstract

This study was conducted within the scope of the MS-MPAs project to map seagrass meadows and monitor the seasonal effects of habitats supported by artificial reefs on biodiversity along the Karakum coast of Sinop. The study aims to provide scientific evidence for zoning strategies of potential Marine Protected Areas (MPAs) and decision-making processes in fishery management in the Black Sea. Fieldwork was carried out across two distinct stations, with the deployment date of the artificial reefs designated as T0 (baseline):  ARs: a station with both artificial reefs and seagrass meadows (0–6 m), and SG (Control): a control station with seagrass meadows but no artificial reefs (0–6 m). To collect data on fish, arthropod, and crustacean species, gillnets and trammel nets with mesh sizes of 36 mm and 40 mm, alongside baited traps with six circular entries and a 40 mm mesh size, were deployed. Stations were evaluated and compared based on species composition, number of individuals (N), and catch amount (kg). The highest biodiversity was recorded at the ARs station—where artificial reefs and seagrass were integrated—yielding a total of 35 taxa comprising fish, arthropods, and crustaceans. The seagrass-only control station (SG) hosted 28 taxa. At the ARs station, Scorpaena porcus (black scorpionfish) was the most abundant species, accounting for 27.530 kg (710 individuals). Conversely, at the control station, scorpion fish (Scorpaena porcus) ranked first in terms of the number of individuals with 540 specimens, whereas Atlantic stargazer (Uranoscopus scaber) was the most caught species in terms of weight, reaching 25.345 kg. The findings demonstrate that artificial reefs play a crucial "nature-based and adaptation-oriented" supportive role in enhancing seagrass habitats and boosting coastal biodiversity.