Stomach contents of by-caught striped dolphins (Stenella coeruleoalba) in the eastern Mediterranean Sea

Abstract

Stomach contents of six striped dolphins taken as by-catch in the swordfish fishery in the eastern Mediterranean Sea off the Turkish coast were examined. In total, 29 taxa were identified to species or family and 1777 individual food items (1394 bony fishes, 289 cephalopods, 94 crustaceans) were counted.Diaphusspp. andCeratoscopelus maderensiswere the most remarkable ones, as they accounted for 70.45% of the total number of fishes.Onychoteuthis banksii, on the other hand, was the only cephalopod species found in all stomach content analyses and represented 38.06% of the total number of cephalopods. Bony fish species:Myctophum punctatum, Notoscopelus elongatus, Electrona risso, Sudis hyalina,Moridae sp., Phycidae sp., Sternoptychidae sp. and cephalopods:Pterygioteuthis giardiandChtenopteryx siculawere reported the first time in the stomach contents of striped dolphin in the Mediterranean Sea.

Assessment of cetacean–fishery interactions in the marine food web of the Gulf of Taranto (Northern Ionian Sea, Central Mediterranean Sea)

“…This difference is probably due to the more opportunistic behaviour of this flexible predator possibly allowing it to exploit the discard from trawling (Broadhurst 1998). In contrast, the striped dolphin is characterized by more specialist feeding, mostly based on mesopelagic fishes as observed in the Eastern Mediterranean areas (Dede et al 2016). The Risso's dolphin and sperm whale showed the highest TLs in the Gulf of Taranto trophicweb due to their preferential predation on the medium and large squids, which occupy the TLs [ 3.…”

“…A partial niche overlap was observed between S. coeruleoalba with P. macrocephalus and G. griseus. In fact, although the striped dolphin shares different bathyal squids as food items with both the sperm whale and Risso's dolphin, it preferentially exploits the mesopelagic fishes (Dede et al 2016). Finally, the slight niche overlap between T. truncatus and the other odontocetes in the Gulf of Taranto is due to its spatial segregation in the shallower portion of the investigated area exploited for its feeding (Carlucci et al 2016(Carlucci et al , 2018c.…”

Cetacean stranding and diet analyses in the North Aegean Sea (Greece)

“…Bycaught striped dolphins from the eastern Mediterranean Sea off the Turkish coast presented in their stomachs a large number of fish of the Myctophydae family, mainly Diaphus spp. and Ceratoscopelus maderensis and several cephalopod species, among them Onychoteuthis banksii , which was the only cephalopod species found in all the stomachs analysed (Dede et al ., 2016).…”

Modelling dolphin distribution within an Important Marine Mammal Area in Greece to support spatial management planning

“…Cañadas, Sagarminaga, & Garcia-Tíscar, 2002;Carlucci, Fanizza, Cipriano, Paoli, & Russo, 2016;Panigada et al, 2008), and with a diet based on pelagic and bathypelagic prey species living in the water column (including bony fishes of the families Gadidae, Sparidae, and Gonostomiatidae, and perhaps more importantly cephalopods of the families Histiotheuthidae, Ommastrephidae, Enoploteuthidaea, and Onychoteuthidaea; Aguilar, 2000). For instance, the stomach contents of striped dolphins bycaught in fishing gear off Turkey suggest that oceanic and bioluminiscent cephalopods with wide vertical distribution and diurnal movements are important prey (Dede, Salman, & Tonay, 2016;Öztürk, Salman, Öztürk, & Tonay, 2007). Although studies of striped dolphin diet were not conducted in the Gulf of Corinth, repeated findings of fresh and wounded dead specimens of the long-armed squid Chiroteuthys veranyi occurred while tracking striped dolphins, suggesting that these squids could have been killed by them .…”