One specimen of the Indo‐Pacific silverstripe blaasop Lagocephalus sceleratus(Gmelin, 1789)(Tetraodontidae) is recorded from the Aegean coast of Turkey and is confirmed for the Mediterranean. Dispersal of the species to the Mediterranean is due to migration from the Red Sea via the Suez Canal.

An ecological niche modelling (ENM) approach was used to predict the potential feeding and spawning habitats of small (5-25 kg, only feeding) and large (>25 kg) Atlantic bluefin tuna (ABFT), Thunnus thynnus, in the Mediterranean Sea, the North Atlantic and the Gulf of Mexico. The ENM was built bridging knowledge on ecological traits of ABFT (e.g. temperature tolerance, mobility, feeding and spawning strategy) with patterns of selected environmental variables (chlorophyll-a fronts and concentration, sea surface current and temperature, sea surface height anomaly) that were identified using an extensive set of precisely geo-located presence data. The results highlight a wider temperature tolerance for larger fish allowing them to feed in the northern - high chlorophyll levels - latitudes up to the Norwegian Sea in the eastern Atlantic and to the Gulf of Saint Lawrence in the western basin. Permanent suitable feeding habitat for small ABFT was predicted to be mostly located in temperate latitudes in the North Atlantic and in the Mediterranean Sea, as well as in subtropical waters off north-west Africa, while summer potential habitat in the Gulf of Mexico was found to be unsuitable for both small and large ABFTs. Potential spawning grounds were found to occur in the Gulf of Mexico from March-April in the south-east to April-May in the north, while favourable conditions evolve in the Mediterranean Sea from mid-May in the eastern to mid-July in the western basin. Other secondary potential spawning grounds not supported by observations were predicted in the Azores area and off Morocco to Senegal during July and August when extrapolating the model settings from the Gulf of Mexico into the North Atlantic. The presence of large ABFT off Florida and the Bahamas in spring was not explained by the model as is, however the environmental variables other than the sea surface height anomaly appeared to be favourable for spawning in part of this area. Defining key spatial and temporal habitats should further help in building spatially-explicit stock assessment models, thus improving the spatial management of bluefin tuna fisheries

spanning most of the known Atlantic and Mediterranean Atlantic bluefin tuna fisheries dating from 1605 to 2011, give L values ranging from L min = 20 cm and L max = 330 cm. The results indicate that the parameter L ∞ = 318.85 cm of the growth equation used by ICCAT's Standing Committee on Research and Statistics Atlantic bluefin tuna assessment group for the eastern stock (Lt = 318.85 [1 -e −0.093 (t + 0.97) ]) lies within the confidence limits of the maximum Ls presented in the study: L max = 319.93 ± 11.3 cm, confirming that this equation perfectly fits the biology of the growth of this species. These conclusions are also valid for the equation for the western stock ]). The ICCAT Atlantic bluefin tuna database contains numerous records of Atlantic bluefin tuna L outside the biological feasibility, and solutions are provided to recognize and remove these outliers based on the application of fixed values of Fulton's condition factor (K) between 1.4 and 2.6 and appropriate L-W relationships to correct this situation in the future.

Ceyhan, T., Akyol, O., Ayaz, A., and Juanes, F. 2007. Age, growth, and reproductive season of bluefish (Pomatomus saltatrix) in the Marmara region, Turkey. – ICES Journal of Marine Science, 64: 531–536. Bluefish (Pomatomus saltatrix) are distributed widely along the Turkish coasts, and are regularly captured, especially in the Sea of Marmara during their spawning migration to the Black Sea from the Mediterranean in spring and during their return migration south in early autumn. Age, growth, and reproductive season are reported. The ages of 1114 bluefish were determined from otoliths. The age groups ranged from 0 to III, and mean fork lengths (and weights) were 14.4 ± 0.12 cm (38.2 ± 1.02 g), 19.5 ± 0.06 cm (93.7 ± 0.86 g), 27.5 ± 0.48 cm (238.5 ± 11.3 g), and 33.3 ± 0.50 cm (431.9 ± 17.08 g) for each age group, respectively. The von Bertalanffy growth parameters were L∞ = 51 cm, K = 0.228, and t0 = −1.26 y. The reproductive period, evaluated from gonadosomatic indices, began in early spring and extended until August.

This study reports length-weight relationships (LWRs) of the 11 fish species in the Central Black Sea. The values of b ranged from 2.523 (±0.62) for Liza aurata to 3.445 (±0.56) for Sarda sarda. The median value of b was 2.933. The information about the length-weight relationships of fish species in the Black Sea is still very scarce and incomplete. The LWR for Sparus aurata was not recorded before for the Black Sea. Consequently, this paper contributes the LWR of some Black Sea fishes, especially with S. aurata and Diplodus annularis, which are given for the first time.

Age, growth, reproduction and mortality of Red Mullet (Mullus barbatus ponticus Essipov, 1927) from the Turkish coasts of the Black Sea Türkiye'nin Karadeniz kıyılarından avlanan barbunya (Mullus barbatus ponticus Essipov, 1927) balığında yaş, büyüme, üreme ve ölüm oranları

size selectivity of small-scale fishing gear for the smooth-hound shark Mustelus mustelus (Linnaeus, 1758) AbstractCatch rate, CPUE, biomass ratios and size selectivity from traditional longline and trammel nets of Turkish coastal small-scale fisheries were investigated in order to describe the smooth-hound shark (Mustelus mustelus) fishery. The SELECT method was used to estimate the selectivity parameters of a variety of models for the trammel nets inner panel of 150 and 170 mm mesh sizes. Catch composition and proportion of the species were significantly different in longline and trammel nets. While mean CPUE of longline was 119.2±14.3 kg/1000 hooks, these values for 150 and 170 mm trammel nets were 5.3±1.2 kg/1000 m of net and 12.7±3.9 kg/1000 m of net, respectively. Biomass ratios of the by catch to smooth-hound catch were found to be 1:0.32 for 150 mm trammel net, 1:0.65 for longline and 1:0.73 for 170 mm trammel net. The estimated modal lengths and spreads were found to be 91.1 and 16.2 cm for 150 mm and 103.2 and 18.4 cm for 170 mm, respectively. The modal lengths of the species as well as the spread values increased with mesh size.

Specimens of twaite shad, Alosa fallax were sampled from commercial purse seiners and trammel netters in Izmir Bay during November and December 2007. A total of 287 prey items from 14 taxa from 208 stomachs were recorded. The primary food of twaite shad was found to be fish, especially anchovy Engraulis encrasicolus, which was the most frequent (%F ¼ 66.11) and abundant (%N ¼ 63.64) prey item, and also had the highest percentage by weight (%W ¼ 81.91). Decapoda, Isopoda, Ostracoda and Copepoda (Calanus spp., Candocia armata, Temora stylifera from Calanoida and Corycaeus spp. from Cyclopodia), were recorded occasionally with low values for all indices. The study showed that in the Aegean Sea Alosa fallax is a predator of small pelagic fish, E. encrasicolus, A. boyeri, S. pilchardus, and some crustaceans. Benthopelagic P. acarne and demersal S. hepatus were first recorded in diet of twaite shad.