First Record and Geographic Expansion of the Sebastes schlegelii in the Sea of Marmara

Abstract

This study reports the first-recorded presence of the Korean rockfish (Sebastes schlegelii) in the Sea of Marmara, signifying a notable geographical expansion beyond its natural range. The sampled male specimen, with a total length of 27.5 cm and a weight of 459.20 g, aligns with known size patterns observed in the Black Sea, suggesting a consistent trend. The unexpected presence of the species in the Sea of Marmara raises intriguing questions about its potential spread in the broader Mediterranean Sea basin. The adaptability of the Sebastes schlegelii to diverse environmental conditions underscores its ecological resilience. The study emphasizes the need for careful monitoring and management due to potential threats posed by invasive species, especially considering the vulnerabilities of the Sea of Marmara to climate change

Prebosphoric occurrence of Korean rockfish, Sebastes schlegelii Hilgendorf, 1880 in southwestern Black Sea with notes on its morphometry and dispersal potential

“…The above description of the examined specimen is coincided with those given in Karpova et al (2021), Froese and Pauly (2023), Bilecenoğlu et al (2023), Yağlıoğlu et al (2023 andKaradurmuş et al (2024). The morphometric distances of the examined specimen of S. schlegelii are also coincided with those reported in the literature (Karpova et al, 2021;Bilecenoğlu et al, 2023;Yağlıoğlu et al, 2023;Karadurmuş et al, 2024), and the slight differences between the examined and published ratios (as % SL), all of which are in the safe limits for the Korean rockfish, may be arised because of intraspecific allopatry (Moyle and Cech Jr., 1988).…”

“…Based on Google Maps measure distance function result, the distance between Giresun (southeastern Black Sea), where S. schlegelii sighted in Turkish waters for first time on 6 March 2023, and Şile (prebosphoric Black Sea), where the present specimen captured on 21 December 2023, is about 833 km and just a few weeks later, on 7 March 2024 the Korean rockfish finally occurred in the Gulf of İzmit, where it has been reported for the first time in the Sea of Marmara (Karadurmuş et al, 2024). Regarding the above mentioned dates, dispersal of S. schlegelii along this distance just took 10 months, suggesting a remarkable dispersal speed (83.3 km per month) from east to west, from southeastern Black Sea to the Sea of Marmara.…”

“…The above description of the examined specimen is coincided with those given in Karpova et al (2021), Froese and Pauly (2023), Bilecenoğlu et al (2023), Yağlıoğlu et al (2023 andKaradurmuş et al (2024). The morphometric distances of the examined specimen of S. schlegelii are also coincided with those reported in the literature (Karpova et al, 2021;Bilecenoğlu et al, 2023;Yağlıoğlu et al, 2023;Karadurmuş et al, 2024), and the slight differences between the examined and published ratios (as % SL), all of which are in the safe limits for the Korean rockfish, may be arised because of intraspecific allopatry (Moyle and Cech Jr., 1988). The number of observed lachrymal spines (3) in the examined specimen, one of the main descriptive characteristic of S. schlegelii, as well as the number preopercular (5) and opercular (2) spines are also coincided with the numbers reported by Karpova et al (2021), Bilecenoğlu et al (2023) and Yağlıoğlu et al (2023), also confirm the identification of the examined specimen.…”

“…beds, is now considered an important economic resource in the Black Sea (Öztürk, 2021). Based on our previous ecological experience with R. venosa in the Black Sea, Sea of Marmara and Aegean Sea, the occurrence and dispersal of S. schlegelii far from its natural distribution range (nortwestern Pacific), arise several questions, such as whether the Korean rockfish brings with ecological problems or economic opportunities as it moves towards the Sea of Marmara, where it has been recently reported (Karadurmuş et al, 2024). Although Sebastes species were previously classified in the same family with closely related species of scorpion fish (Scorpaenidae) in the past (Hureau and Litvinenko, 1986), are today divided into the Sebastidae family (Froese and Pauly, 2023).…”

“…S. schlegelii reported from Turkish Black Sea coast for first time by Bilecenoğlu et al (2023) based on specimens previously sighted (and photographed) or captured from several localities in the region, which followed by another recent capture of the species off the coast of Akçakoca (southwestern Black Sea; Yağlıoğlu et al, 2023) and the first record of the Korean rockfish in the Sea of Marmara (Karadurmuş et al, 2024). In the present article authors report on a prebosphoric capture of S. schlegelii, provide detailed morphometric and meristic characteristics of the examined specimen, as well as make a projection of its dispersal potential along Turkish coasts.…”