Expansion of the Distribution Range and Size of the Invasive Blue Crab on the Turkish Coast of the Black Sea

Aydın M., Karadurmuş U., Verep B., Gözler A. M.

Journal of Anatolian Environmental and Animal Sciences, cilt.9, sa.1, ss.132-136, 2024 (Hakemli Dergi)

Özet

The blue crab Callinectes sapidus (Rathbun, 1896) is an endemic species with broad salinity tolerance specific to the Western Atlantic Ocean, including a wide distribution range extending to the Black Sea, including the coastal waters of Turkey. This study encompasses a monitoring effort where blue crab specimens were collected in a region stretching from Taskana Cape (Ünye, Ordu) to the Georgian border along the coast of the Black Sea in Turkey. The study period spans from 2017 to 2024. According to the analysis results, the carapace width of 16 blue crab samples ranged from 14.8 to 20.3 cm, with male individuals observed to have larger sizes compared to females. Notably, among the examined females, it was observed that two individuals carried eggs, supporting reproductive success in the region. Additionally, the study reports the discovery of the largest blue crab recorded so far on the Turkish Black Sea coast, with a carapace width of 20.3 cm and a weight of 565.1 g. A male specimen sampled from the Rize region indicates the expansion of the species distribution to the easternmost part of the Black Sea. These findings significantly contribute to our understanding of the distribution and size increase of blue crabs in the Black Sea. The presence of larger sizes in males and the occurrence of excessively large females suggests the potential existence of a successful adaptation and a self-sustaining population. Consequently, this study highlights the importance of a cautious approach in fisheries biology and ecosystem management, emphasizing that the blue crab could impact the Black Sea ecosystem as an invasive species. Thus, it contributes to providing information and conservation strategies.