A young individual of Isurus oxyrinchus was caught by a commercial longline off Dana Island (Mersin Bay, northeastern Mediterranean Sea) at a depth of 72 m on May 18th 2020. Morphometric measurements ...of the specimen were recorded and its photographs were taken. The examined specimen is now being preserved in the Museum of Systematics at Faculty of Fisheries of Mersin University, under the reference number MEUFC-20-11-132. This occurrence of a young female specimen reported in this study is adding a new location (Mersin Bay) from the Mediterranean's Turkish waters.
Isurus oxyrinchus'un genç bir bireyi, 18 Mayıs 2020 tarihinde Dana Adası açıklarında (Mersin Körfezi, Kuzeydoğu Akdeniz) 72 m derinlikte ticari balıkçılık sırasında pareketa ile yakalanmıştır. Örneğin morfometrik ölçümleri kaydedildi ve fotoğrafları çekildi. İncelenen örnek şu anda Mersin Üniversitesi Su Ürünleri Fakültesi Sistematik Müzesi'nde MEUFC-20-11-132 örnek numarasıyla muhafaza edilmektedir. I. oxyrinchus'un Doğu Akdeniz ve Türkiye sularında nadir görüldüğü aşikardır. Bu çalışmada bildirilen genç bir dişi bireyin bu bölgedeki varlığı Türkiye’nin Akdeniz sularına yeni bir lokalite (Mersin Körfezi) eklemektir.
Seasonal aggregations of batoids were observed in Güllük Bay (souteastern Aegean Sea) based on opportunistic underwater observations between the years of 2014–2022. Torpedo marmorata, Glaucostegus ...cemiculus, Dasyatis pastinaca, Gymnura altavela and Aetomylaeus bovinus were observed in the study area. The most observed species is G. altavela (n=65) and it constitutes 51.18 percent of the whole sample, and followed by A. bovinus (n=31, 24.4%), D. pastinaca (n=12, 9.44%), G. cemiculus (n=8, 6.29%) and T. marmorata (n=2, 1.57%). Based on the seasonal occurrence data of batoids observed during the research, it is seen that the species that occurred in the region from mid-spring to mid-autumn, and the aggregations peaked in July. Seasonal aggregations of batoids may have important implications for the conservation of these species. Among the observed batoids in the present study, only G. cemiculus is currently under protection in Turkey. According to EU Regulation 1343/2011 and Annex II of the Barcelona Convention, G. altavela is a prohibited species; thus, it should not be retained on board, transhipped, landed, transferred, stored, sold or displayed or offered for sale, and masters of fishing vessels shall record in the fishing logbook any event of incidental catch and release. Therefore, as an urgent measure, at least G. altavela and A. bovinus, which are considered as “critically endangered”, should be added to the list of protected species in Turkish waters, and the aggregation site in Güllük Bay should be declared as a no-take-zone during mid-spring and throughout the summer.
Oxynotus centrina is considered a rare or uncommon shark species throughout its distribution range. Because of this reason, it is one of the 46 uncommon elasmobranchs in the Mediterranean Sea, which ...requires filling the knowledge gaps, such as length-weight relations. Based on the analysis of 34 angular rough sharks, the length-weight relations (LWR) of males, females and combined sexes of O. centrina were described as W = 0.216L2.686, W = 0.134L3.041 and W=0.102L3.173, respectively. Total lengths (TL) of females and combined sexes were strongly correlated with total weights (TW); while TL of males was moderately correlated with TW. The b values of LWRs of females and combined sexes (3.041 and 3.173, respectively) were not significantly different from 3.0 (t-test, p>0.10) and indicated positive allometric growth for the examined TL and TW range of O. centrina in the Mediterranean Sea.
Forty-six individuals of Carcharodon carcharias were either recorded or sighted in Turkey's waters during a period from February 1881 to 28 September 2011. Total lengths (TLs) of the recorded great ...white sharks ranged from 85 cm TL to ~800 cm TL, and mass ranged between 12 kg and ~4500 kg. Three non-fatal shark attacks on boats of tuna hand-liners were also recorded. A North Aegean Sea specimen (85 cm TL; sp No. 45; Table 1) caught by a coastal trammel netter in Edremit Bay on July 6, 2011, is possibly the smallest neonate white shark from Mediterranean waters to date. Due to intensification of tuna fishing and the resulting decline or extinction of tuna stocks, C. carcharias is now apparently extinct from marmaric and bosphoric waters. Capture of 6 neonate great white sharks between 2008 and 2011, in the same period of the year (from late June to early July), in the waters of Edremit Bay (northern Aegean Sea, Turkey) suggests the possibility of a breeding ground in the region. The growing tuna farm industry offers a new possibility for encounters between humans and great white sharks off the Turkish coast.
On 21 December 2023 one specimen of Sebastes schlegelii Hilgendorf, 1880 have been captured by means of a commercial bottom trawler towed at a depth of 30 m off Şile coast. Following its first ...occurrence in Turkish Black Sea waters off Giresun coast on 6 March 2023, it has recently reported from the Sea of Marmara (Gulf of İzmit) on 7 January 2024, exhibiting a noteworthy dispersal speed which required less than one year to migrate across nearly a 1,000 km. Therefore, the dispersal and potential interactions with indigenous species of this invasive teleostean along theTurkish coast should be monitored carefully. In the present article, authors provide full morphometric and meristic characters of S. schlegelii, as well.
Sharks are one of the most threatened groups of marine animals because of high exploitation rates coupled with low resilience to fishing pressure. We provide information on the current status of the ...young sharks caught in fishing nets in Iskenderun and Mersin Bays in the eastern Mediterranean, based on fishery-dependent surveys conducted between 2010 and 2021. Sharks were found in bycatches in trawling nets, trammel nets, bottom longlines and fishing lines. Incidental captures of young-of-the-year or juvenile specimens (n=269) included 15 species and the data indicate that İskenderun and Mersin Bays may serve as a nursery ground for the new-born and young individuals especially for the Blackmouth Catshark (Galeus melastomus), the Lesser Spotted Dogfish (Scyliorhinus canicula), and the Velvet Belly (Etmopterus spinax). If necessary measures are taken, bycatch can be reduced to a certain limit, or even eliminated for shark species in the Mediterranean Sea.
Review of the available literature and the results of the present study revealed that 17 specimens of Isurus oxyrinchus were caught between 1950 and 2013. Nine (52.9%) of these verified 17 catches ...were recorded after 2000. Catches of I. oxyrinchus off Turkey's coast include specimens ranging from new-borns (65 cm total length) to huge adults (585 cm total length). A new-born female caught off the coast of Foça on 19 May 2015 represents the smallest free-swimming specimen of I. oxyrinchus ever recorded in Turkish waters. The occurrence of a new-born shortfin mako shark off Foça's coast provides new evidence to support the possibility of a mating region of lamniform sharks, including I. oxyrinchus, in the northern Aegean Sea. The seasonal occurrence of both young and adult shortfin mako sharks off Turkey's Aegean and Mediterranean coasts should be monitored to clarify whether the shortfin mako shark is a resident or a vagrant species along the aforementioned coastline.
Our current knowledge on the carcharhinid sharks occurring in Turkey's seas comprises rudimentary data. Recently discovered photographic evidence suggests that Carcharhinus spp. have been present in ...the Sea of Marmara since the 1950s. This evidence also extends the known historical distributional range of Carcharhinus spp. into Marmaric waters, a northern extension of the Mediterranean basin. The results of previous and recent ichthyological inventories of the Sea of Marmara suggest that, currently, no species of the Carcharhinidae family occur in Marmaric waters. Further studies could provide an answer to the question: do any species of the Carcharhinidae family inhabit the Sea of Marmara?
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