This contribution forms part of a series of collective articles published regularly in Mediterranean Marine Science that report on new biodiversity records from the Mediterranean basin. The current article presents 51 geographically distinct records for 21 taxa belonging to 6 Phyla, extending from the western Mediterranean to the Levantine. The new records, per country, are as follows: Spain: the cryptogenic calcareous sponge Paraleucilla magna is reported from a new location in the Alicante region. Algeria: the rare Atlanto-Mediterranean bivalve Cardium indicum is reported from Annaba. Tunisia: new distribution records for the Indo-Pacific lionfish Pterois miles from Zembra Island and Cape Bon. Italy: the ark clam Anadara transversa is reported from mussel cultures in the Gulf of Naples, while the amphipod Caprella scaura and the isopods Paracerceis sculpta and Paranthura japonica are reported as associated to the -also allochthonous-bryozoan Amathia verticillata in the Adriatic Sea; in the latter region, the cosmopolitan Atlantic tripletail Lobotes surinamensis is also reported, a rare finding for the Mediterranean. Slovenia: a new record of the non-indigenous nudibranch Polycera hedgpethi in the Adriatic. Greece: several new reports of the introduced scleractinian Oculina patagonica, the fangtooth moray Enchelycore anatina, the blunthead puffer Sphoeroides pachygaster (all Atlantic), and the lionfish Pterois miles (Indo-Pacific) suggest their ongoing establishment in the Aegean Sea; the deepest bathymetric record of the invasive alga Caulerpa cylindracea in the Mediterranean Sea is also registered in the Kyklades, at depths exceeding 70 m. Turkey: new distribution records for two non-indigenous crustaceans, the blue crab Callinectes sapidus (Atlantic origin) and the moon crab Matuta victor (Indo-Pacific origin) from the Bay of Izmir and Antalya, respectively; in the latter region, the Red Sea goatfish Parupeneus forsskali, is also reported. Lebanon: an array of records of 5 alien and one native Mediterranean species is reported by citizen-scientists; the Pacific jellyfish Phyllorhiza punctata and the Indo-Pacific teleosteans Tylerius spinosissimus, Ostracion cubicus, and Lutjanus argentimaculatus are reported from the Lebanese coast, the latter notably being the second record for the species in the Mediterranean Sea since 1977; the native sand snake-eel Ophisurus serpens, rare in the eastern Mediterranean, is reported for the first time from Lebanon, this being its easternmost distribution range; finally, a substantial number of sightings of the lionfish Pterois miles further confirm the current establishment of this lessepsian species in the Levantine.
This study aimed to determine the survival rates of three fish species, the brown comber (Serranus hepatus), black goby (Gobius niger) and annular seabream (Diplodus annularis), after their escape from a 40 mm stretched diamond mesh polyethylene (PE) codend. Experiments were carried out in the eastern Mediterranean in September 2007 using a conventional bottom trawl with 600 meshes around the mouth. A constant 15 min towing duration was used for all hauls. The towing speed varied between 2.0 and 2.5 knots. Codend covers, supported by two hoops, were used to retain escaping fish. At the end of each haul, these covers were detached from the codend, fixed to the sea floor at depths of 19 to 28 m, and then observed by the divers for a period of seven days. On the eighth day, all of the covers were lifted up and the survivors and mortalities were counted and measured. The mean survival percentages of open codend and experimental cages were found to be 97.1% and 98.3% for brown comber, 69.0% and 77.2% for black goby, and 97.5% and 98.6% for annular seabream respectively. Keywords: survival rate, escapes, trawl codend, discard and by-catch, Aegean Sea. RESUMEN: Supervivencia de peces después de escapar de una red de arrastre con copo de 40 mm de malla romboidal en el mar Egeo.-Este estudio tuvo como objetivo determinar las tasas de supervivencia de tres especies de peces, cherna afanecada o merillo (Serranus hepatus), chaparrudo (Gobius niger) y raspallón (Diplodus annularis), después de escapar de un copo con mallas de 40 mm romboidales de polietileno (PE). Los experimentos fueron realizados en el Me-diterráneo Oriental, en septiembre de 2007 utilizando una red de arrastre de fondo convencional con 600 mallas alrededor de la boca. La duración estándar fue de 15 minutos de arrastre para todos los lances. La velocidad de arrastre varió entre 2.0 y 2.5 nudos. Los peces que escapaban del copo eran retenidos por un sobrecojo, el cual quedaba separado del copo mediante aros que facilitan el escape en buenas condiciones entre ambos paños. Al final de cada lance, las cubiertas del sobrecopo se separaban del copo y se fijaban al fondo del mar a profundidades entre 19 y 28 m y fueron observados por buceadores durante los siete días siguinetes. Al octavo día se contaron y midieron los sobrevivientes. Los porcentajes de supervivencia medios de control y en las jaulas experimentales resultaron ser del 97.1% y 98.3% para la cherna afanecada; 69.0% y 77.2% para el chaparrudo y 97.5% y 98.6% para el raspallón. Palabras clave: tasa de supervivencia, escapes, red de arrastre, descartes y capturas acompañantes, mar Egeo.
Summary:This study was performed off the southern coast of Yassıca Island in the İzmir Bay on the Turkish coast of the Aegean Sea to investigate the mortality of red mullet (Mullus barbatus, Mullidae) escaping through 40-mm square-mesh and 44-and 50-mm diamond-mesh codends attached to a conventional demersal trawl net. In total, 48 replicate experimental hauls were performed in the summer and winter of 2011 and 2012. Mean escape mortality for all hauls in winter (33.2%±6.51) was significantly higher (p<0.0001) than that in summer (26.5%±6.19). Furthermore, mortality was also highest among the smallest fish, particularly during winter. Irrespective of season, the escape mortality of red mullet was lowest from the 40-mm square-mesh codend (mean, 25.5%±4.58). These observations emphasize the importance of investigating the survival potential of escaping fish when considering the benefits of different selective devices in the management of a fishery.Keywords: escape mortality, bottom trawl, size-related mortality, seasonal variation, mesh size, mesh shape, Aegean Sea.Variación estacional en la mortalidad post pesca del salmonete (Mullus barbatus), capturado con arrastre de fondo en el mar Egeo Resumen: El estudio se llevó a cabo frente a la costa sur de la isla de Yassica en la Bahía de Izmir, costa turca del mar Egeo para investigar la mortalidad post captura del salmonete (Mullus barbatus, Mullidae) que escapa de las redes de pesca con copos de malla cuadrada de 40 mm, y romboidales de 44 y 50 mm acoplados a una red tradicional de arrastre demersal. En total, se realizaron 48 lances experimentales durante el verano e invierno de 2011 y 2012. La media de la mortalidad post captura para todos los lances en invierno (33.2%±6.51) fue significativamente mayor (p<0.0001) que en verano (26.5%±6.19). Además, la mortalidad fue más alta entre los individuos más pequeños, especialmente en invierno. Independientemente de la estación, la mortalidad post captura del salmonete fue inferior con el copo de luz de malla cuadrada de 40 mm (media, 25.5%±4.58). Estas observaciones ponen de manifiesto la importancia de la investigación de la supervivencia potencial de los peces que escapan de las redes de pesca a la hora de considerar los beneficios de distintos dispositivos selectivos en la gestión de una pesquería.Palabras clave: mortalidad post captura, arrastre de fondo, mortalidad dependiente de la talla, variación estacional, luz de malla, forma de la malla, mar Egeo.Citation/Como citar este artículo: Düzbastilar F.O., Breen M., Aydin C., Özbilgin H., Özgül A., Ulaş A., Metin G., Gül B., Lök A. 2017. Seasonal variation in mortality of red mullet (Mullus barbatus) escaping from codends of three different sizes in the Aegean Sea. Sci. Mar. 81(3): 339-349. doi: http://dx
Fish farm structures attract a variety of fish species by providing solid structure, and 'free meals' in the form of uneaten feed and feces that fall from the cages. In this study, we compared the composition and abundances of wild fish populations around 2 fish farms in the Red Sea and at nearby reference locations. Fish assemblages were evaluated by SCUBA divers carrying out rapid visual censuses in August, September and October 2007. A total of 87 238 fishes, representing 39 species and 25 families and a number of trophic levels, were observed. Overall, the abundance, biomass, and diversity of wild fish were much greater at the sea cages than at the open-water reference sites, at both fish farms. It is noteworthy that 35 out of the 39 species observed at the farms were juveniles and adults of coral-reef fish species. This finding is especially interesting, considering that the nearest coral reefs were > 4 km away and reef fishes generally have small home ranges, typically <1 km. Among these, the Carangidae (5 species), Sparidae (3 species), and Pomacentridae (3 species) contributed the most to species richness. In light of strong fishing pressures in many areas, the large populations of wild fishes at the fish farms, the high availability of nourishment from artificial food pellets, and restrictions on fishing within farm lease areas, we suggest that coastal net-cage fish farms may serve as small marine protected areas.
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