MEDLEM database, a data collection on large elasmobranchs in the Mediterranean and Black Seas

The Mediterranean Large Elasmobranchs Monitoring (MEDLEM) database contains more than 3,000 records (with more than 4,000 individuals) of large elasmobranch species from 21 different countries around the Mediterranean and Black seas, observed from 1666 to 2017. The principal species included in the archive are the devil ray (1,868 individuals), the basking shark (935 individuals), the blue shark (622 individuals), and the great white shark (342 individuals). In the last decades, other species such as the thresher shark (187 individuals), the shortfin mako (180 individuals), and the spiny butterfly ray (138) were reported with increasing frequency. This was possibly due to increased public awareness on the conservation status of sharks, and the consequent development of new monitoring programs. MEDLEM does not have homogeneous reporting coverage throughout the Mediterranean and Black seas and it should be considered as a database of observed species presence. Scientific monitoring efforts in the south-eastern Mediterranean and Black seas are generally lower than in the northern sectors and the absence of some species in our database does not imply their actual absence in these regions. However, the available data allowed us to analyse the frequency and spatial distribution of records, the size frequencies for a few selected the available data allowed us to analyse the frequency and spatial distribution of records, the size frequencies for a few selected species, the overall area coverage, and which species are involved as bycatch by different fishing gears

Length-weight relationships of 10 fish species found off Antalya Bay, eastern Mediterranean

Length-weight relationships (LWRs) are presented for eight teleost and two elasmobranch fish species representing ten families that were captured in deep water (from 400 to 1000 m, except for the stingray Dipturus centrura) in Antalya Bay. This study represents the first LWR references for eight of these species. © 2013 Blackwell Verlag GmbH

Grouper fishery in the Northeastern Mediterranean: An assessment based on interviews on resource users

Groupers are important components of coastal ecosystems as well as a valuable resource for fisheries. Their populations are known to be decreasing throughout the world primarily due to over-exploitation. However, even the basic data for an effective management strategy is lacking. Interviews of a representative sample of 113 fishers in Turkey in the northeastern Mediterranean were conducted with specific questions regarding fishing gears, periods and areas as well as best day's catch and the sizes of fishes caught. Fishermen recognized Epinephelus marginatus, E. aeneus, E. costae, Hyporthodus haifensis, Mycteroperca rubra and Polyprion americanus distributed in the area. “Endangered” E. marginatus and “Near Threatened” E. aeneus were the dominant species of the grouper fishery. Based on best days’ catch values and reported lengths of fish caught, the northern coasts of Iskenderun Bay were found to be important for both species. Demersal longliners, spearguns, traps, anglers and demersal trawlers were reported catching groupers in the study area. Artisanal fishermen, especially demersal longliners contributed the most to the grouper fishery. Fishing pressure were subject to seasonal fluctuations, with decreasing reported catches during summer when threatened groupers spawn. Finally, some critical aspects of fishery pressure were related to the removal of juveniles which may lead to reproduction loss. © 2017 Elsevier LtdRufford Foundation: 20449-1This study was performed as a part of the project “Strongholds for Groupers in Iskenderun Bay: Defining Conservation Hotspots for Sustainability” granted by The Rufford Foundation with the grant number 20449-1 . We would like to thank Ayla Yıldırım for English proofreading. Appendix

The importance of alien species to the food web and bottom trawl fisheries of the Northeastern Mediterranean, a modelling approach

Alien species and bottom trawl fisheries are of significant concern in the Eastern Mediterranean as both can put pressure on coastal systems whilst some alien species also constitute an important component of the trawl catches. Using an Ecopath model representing the Gulf of Mersin (Northeastern Mediterranean) for the period September 2009 to September 2013, this study describes the impacts of alien species and bottom trawl fisheries on the structure and functioning of this Northeastern Mediterranean food web. Our results show that the increase in alien species has had an important ecological impact on ecosystem structure and function. The alien species have had mostly negative impacts on native taxa, and trawl fisheries may have helped some alien species gain an advantage over native species, particularly at lower trophic levels. The Mixed Trophic Impact analysis showed that trawling and trawl discards had a noticeable direct and indirect impact on the food web, to the extent that trawling now affects the ecological role of the alien species. The cumulative overall impact of alien demersal functional groups on the pelagic domain, and vice versa suggest that alien species now play a role in benthic-pelagic coupling, and that this role is mediated by the fisheries. These results support the idea that alien species and trawling are now both important factors in structuring the Northeastern Mediterranean food web. It will thus be critical to consider both factors, as well as their interactions, when developing ecosystem-based management approaches for the region. © 2019 Elsevier B.V.2014-2 Türkiye Bilimsel ve Teknolojik Araştirma KurumuHere we present a part of the PhD thesis of Ismet SAYGU, funded by the Scientific and Technological Research Council of Turkey (TUBITAK) on the TUBITAK 2214-A Programme ( 2014-2 ) and supported by the Scottish Association for Marine Science (SAMS) as host institution. In addition, the main data of this study was obtained from the project 109O684 financed by TUBITAK . Ismet Saygu would like to address a special thanks to Barış Salihoğlu, Ekin Akoğlu, Nazlı Demirel, Xavier Corrales, Sinan Mavruk, Marieke Steuben and Sam Jones for their advice. Appendix

The effect of codend circumference on selectivity of hand-woven slack knotted codend in the north eastern mediterranean demersal trawl fishery [Kuzey doğu akdeniz demersal trol balıkçılığında torba çevresinin El örmesi gevşek düğümlü torba seçiciliğine etkisi]

Poor selectivity and high discard rate of hand-woven slack knotted codend is a serious problem for north eastern Mediterranean demersal fish stocks. This study investigates the effect of codend circumference on bottom trawl selectivity for red mullet (Mullus barbatus), bogue (Boops boops), goldband goatfish (Upeneus moluccensis), Randall's threadfin bream (Nemipterus randalli) and picarel (Spicara smaris). A total of 18 valid hauls were conducted using covered codend method between 08 October and 26 December 2012 in Mersin Bay. Results show that selectivity of commercially used standard codend (300 meshes around its circumference) is rather poor and the narrow codend (150 meshes around its circumference) significantly increases selectivity for tested species. However, it is not selective enough to avoid the individuals of five commercial species under the MLS or FMS. © Published by Central Fisheries Research Institute (CFRI) Trabzon, Turkey

MEDLEM database, a data collection on large elasmobranchs in the Mediterranean and Black Seas

The Mediterranean Large Elasmobranchs Monitoring (MEDLEM) database contains more than 3,000 records (with more than 4,000 individuals) of large elasmobranch species from 21 different countries around the Mediterranean and Black seas, observed from 1666 to 2017. The principal species included in the archive are the devil ray (1,868 individuals), the basking shark (935 individuals), the blue shark (622 individuals), and the great white shark (342 individuals). In the last decades, other species such as the thresher shark (187 individuals), the shortfin mako (180 individuals), and the spiny butterfly ray (138) were reported with increasing frequency. This was possibly due to increased public awareness on the conservation status of sharks, and the consequent development of new monitoring programs. MEDLEM does not have homogeneous reporting coverage throughout the Mediterranean and Black seas and it should be considered as a database of observed species presence. Scientific monitoring efforts in the south-eastern Mediterranean and Black seas are generally lower than in the northern sectors and the absence of some species in our database does not imply their actual absence in these regions. However, the available data allowed us to analyse the frequency and spatial distribution of records, the size frequencies for a few selected the available data allowed us to analyse the frequency and spatial distribution of records, the size frequencies for a few selected species, the overall area coverage, and which species are involved as bycatch by different fishing gears. © 2020 Mediterranean Marine Science

MEDLEM database, a data collection on large Elasmobranchs in the Mediterranean and Black seas

The Mediterranean Large Elasmobranchs Monitoring (MEDLEM) database contains more than 3,000 records (with more than 4,000 individuals) of large elasmobranch species from 21 different countries around the Mediterranean and Black seas, observed from 1666 to 2017. The principal species included in the archive are the devil ray (1,868 individuals), the basking shark (935 individuals), the blue shark (622 individuals), and the great white shark (342 individuals). In the last decades, other species such as the thresher shark (187 individuals), the shortfin mako (180 individuals), and the spiny butterfly ray (138) were reported with increasing frequency. This was possibly due to increased public awareness on the conservation status of sharks, and the consequent development of new monitoring programs. MEDLEM does not have homo-geneous reporting coverage throughout the Mediterranean and Black seas and it should be considered as a database of observed species presence. Scientific monitoring efforts in the south-eastern Mediterranean and Black seas arc generally lower than in the northern sectors and the absence of some species in our database does not imply their actual absence in these regions. However, the available data allowed us to analyse the frequency and spatial distribution of records, the size frequencies for a few selected the available data allowed us to analyse the frequency and spatial distribution of records, the size frequencies for a few selected species, the overall area coverage, and which species are involved as bycatch by different fishing gears