The garfish Belone belone euxini (Gu¨nther, 1866) is a commercially important pelagic fish species in Sinop artisanal fishery, which is showing a decreasing trend in catch results. As a basis for fisheries management a sampling program was carried out between October 2000 and September 2001 along the Turkish coast of the Black Sea, to study the population structure, growth, and reproduction cycle of garfish in the area, and to achieve a rough estimate of exploitation. The length-weight relationship and von Bertalanffy growth parameters were estimated as W ¼ 0.00076 L 3.137 , L ¥ ¼ 74.64 cm, K ¼ 0.13 year )1 , t o ¼ )3.67, respectively. First sexual maturity was estimated at age 2 and at a total length of 38.8 cm for females. The spawning period was from May to September. The total fecundity-length relationship was estimated as F ¼ 0.0041 L 4.1086 (r 2 ¼ 0.92). Mortality rates were Z ¼ 1.24 year )1 , M ¼ 0.23 year )1 and F ¼ 1.01 year )1 for total, natural, and fishing mortality, respectively. The exploitation ratio E ¼ 0.81 indicates that the population is heavily exploited.

The purpose of this study is to determine the amount of bycatch and discardfish caught by bottom trawlers used in the Black Sea coasts of Turkey anddiscard changes depending on the depth. The study was conducted during theSeptember 2009 – April 2010 fishing season. Twenty-one bottom trawleroperations were sampled and the catch composition was determined. A total of 26species were caught, which included 22 species of fish, 2 species of arthropods,1 species of gastropods and 1 species of bivalves. Two of these were targetspecies (Mullusbarbatus, Merlangius merlangus), while 25 species werediscarded including trash fish and specimens below the legal size. A total of2142.76 kg of biomass was caught during the operations, of which 53.99 % bycatch.The weighted discard rate was determined as 42.06% and two different groupswere identified in discards (T1: 10-57 m, T2: 72-118 m) based on the depth. Significantdifferences were identified between these depth groups (p<0.05). It was determined that the biomass (kg h-1),the evenness index (J) (p<0.05),the average species number and the species richness (D) (p<0.01) of the discards showed significant differences, but thatthe difference between species diversity (H) was negligible. No difference wasfound (p>0.05) between theecological parameters of landings.

This study was carried out to determine the effects of harvesting method and refrigerated storage on biochemical composition of Atlantic Bonito. Samples were fish caught with a surround trammel net and a drift net in the Middle Black Sea region by fisherman and were brought to the laboratory. Quality control analyses for soluble solid, protein, fat and ashes were performed. On the 10th day after refrigerated storage (4C), pH, total volatile base nitrogen (TVB‐N), trimethylamine (TMA‐N) and thiobarbituric acid (TBA) values were found in the drift net. In the fresh fish samples caught by surround trammel net and drift net, fat, proteins, soluble solids and ash contents were calculated. PRACTICAL APPLICATIONS The results of the proximate content of Atlantic bonito caught with a trammel net and drift net showed that fat contents were 5.76; protein contents were 20.35; dry matter contents were about 30.5% and ash contents was 1–1.2%. After 10 days of storage at 4C, pH, TVB‐N, TMA‐N and TBA values were 6.17, 34.46 mg/100 g, 7.34 mg/100 g and 7.72 mg malonaldehyde/kg, respectively, in the surround trammel net, and 5.98, 40.60 mg/100 g, 8.02 mg/100 g and 8.03 mg malonaldehyde/kg in the drift net, respectively. Based on these results, there were significant differences between surround trammel net fishing and drift net fishing in terms of meat quality.

In this study, factors (depth, season and mesh size) influencing the catch and discards of whiting (Merlangius merlangus euxinus) gillnet fishery on the Black Sea coasts of Turkey were investigated. A total of 19 species were identified and the target species, whiting (Merlangius merlangus euxinus), dominated 87.56% of the total catch and followed by red mullet (Mullus barbatus) with 6.32%. While 82.02% of the total catch had commercial value, 17.98% was discarded. The percentage of the discarded red mullet and whiting under MLS (<13 cm) were found to be 16.03% and 13.27%, respectively. The highest discard amount was observed in winter and the lowest one in summer. The discard rate was highest in the 55-74 m depth group and the 32 mm mesh size. One-way analysis of similarity (ANOSIM) showed that there were significant differences in the discard species compositions between spring and summer, as well as 32 and 40 mm, 32 and 44 mm mesh sizes (P<0.05). These results on the discard information in gillnet fishery can contribute to the literature on ecosystem-based sustainable fisheries management by highlighting relevant results on the protection of species and ecosystem.

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