SummaryAge, growth and reproduction of the black scorpionfish, Scorpaena porcus were studied in specimens from the coast of the Sinop Peninsula (Black Sea) between March 2002 and April 2003 in order to characterize these population parameters in comparison to specimens from populations of nearby regions. A total of 1086 specimens was captured by beam trawl at the depths between 0 and 30 m. The total number of females (510) was significantly higher than that of males (373). Total length of males and females ranged between 5.7 and 23.6 cm, and 4.9 and 31.7 cm, respectively. The length-weight relationship showed a positive allometric growth. Females grew faster and reached a larger size at age than males (L ¥ = 111.9 cm, K = 0.035 year , u¢ = 2.49 for males). The age range estimated was up to 8 years for females and 5 years for males. Reproduction likely occurs between June and September. Sex ratio varied greatly with season, perhaps indicating different seasonal migratory patterns in adults of different sex. An inverse correlation between gonadosomatic index (GSI) and hepatosomatic index (HSI) was evident during the reproduction seasons. The mean size at first sexual maturity was 17.5 cm TL for females, and 16.7 cm TL for males.

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.

Seasonal growth pattern and reproductive biology of the Baltic prawn, Palaemon adspersus, were studied in the southern Black Sea between February 2002 and January 2004. The seasonal von Bertalanffy growth parameters, computed from monthly length -frequency distributions, were estimated as L 1 ¼ 62.99 mm TL, K ¼ 1.190 year 21 , C ¼ 0.815, and WP ¼ 0.847 for females and as L 1 ¼ 49.63 mm TL, K ¼ 1.085 year 21 , C ¼ 0.011, and WP ¼ 0.407 for males. Growth performance index of females (F 0 ¼ 3.67) was greater than it was for males (F 0 ¼ 3.43). Based on latitudinal gradients, water temperature negatively affected F 0 of P. adspersus. Sexual dimorphism in size was evident, females being larger than males. This typically shallow water species was observed in water depths as deep as 30 m. Compared to shallower water depths, larger individuals were observed in deeper water depths. The size at sexual maturity for females (TL 50 ) was estimated as 53.60 mm TL. Ovigerous females were recorded from March to August and juveniles appeared in the benthic population in August. Ovary development was related to photoperiod and occurrence of ovigerous females was linked to increased water temperature.

To describe the age, growth, mortality and distribution of the garfish, Belone euxini and differences in these parameters from other populations, monthly samplings were conducted between December 2011 and July 2013 in the south-east Black Sea. Garfish catch decreased to its lowest levels in spring months, especially after May, and it was completely finished by the summer months. The mean total length (TL) of the female was significantly greater than the mean TL of the male (P < 0.05). The sex-ratio of female:male with size was skewed towards males up to 38 cm length-class, and skewed towards females above the 38 cm class (P < 0.05). The growth pattern of garfish was described by goodness of fit of the data and biological interpretation of growth parameters. The exponential (females: L∞ = 88.3 cm TL, K = 0.108 yr−1, males: L∞ = 71.9 cm TL, K = 0.151 yr−1) and von Bertalanffy (females: L∞ = 81.6 cm TL, K = 0.125 yr−1, t0 = −2.25 year, males: L∞ = 81.6 cm TL, K = 0.125 yr−1, t0 = −2.13 year) models were considered the most suitable growth models. Total instantaneous mortality rate, Z, was estimated as 1.04 yr−1 for females and 1.24 yr−1 for males. Instantaneous natural mortality ratio, M, was estimated higher for males than for females. The exploitation rate of both sexes was also higher than the optimum exploitation (E = 0.5) criterion, which is indicative of overfishing of the garfish population.

No abstract

No abstract

Seasonal growth pattern and reproductive biology of the black goby, Gobius niger (n= 568; 2.1-14.6 cm TL), were monthly studied in southern Black Sea between December 2012 and November 2013. The seasonal von Bertalanffy growth parameters, computed from ELEFAN, were estimated as L∞= 11.9 cm TL, K= 0.701 year -1 , C= 0.633, and WP= 0.492 for the Hoenig seasonal model and as L∞= 12.1 cm TL, K= 0.680 year -1 for non-seasonal von Bertalanffy model. The size at sexual maturity (Lm) was estimated as 8.9 cm TL. The Gonadosomatic index (GSI) ranged between 0.60 in December and 8.57 in April 2013 (mean 3.82±0.82) for females and 0.61 in October 2013 and 2.90 in May 2013 (mean 1.70±0.26) for males. The seasonal growth was pronounced probably due to reproduction activity which extended investment of energy in reproduction causing slower growth. The GSI development was related to photoperiod and the monthly variations of GSI values indicating that the intensive spawning occurred between April 2013 and August 2013. During spawning time, the mean GSI value of females (6.04±1.18) was 2.9 times higher than the mean GSI values of males (2.08±0.42) (P< 0.05). The results of this study were offered as biological input parameters regarded as a reference for the conservation and management of the Black Sea stocks of the black goby.

Özet:Şubat -Nisan 2007 ve Ocak -Nisan 2008 tarihleri arasındaki av döneminde gerçekleştirilen bu çalışmada her trol çekiminde ortalama 0.1359±0.0013 km 2 olmak üzere toplam 80.07 km 2 lik alan taranmıştır. Sinop-İnceburun bölgesinde yapılan alan çalışmasında mezgit (Gadus merlangus euxinus), barbunya (Mullus barbatus ponticus), kalkan (Psetta maxima maeotica), iskorpit (Scorpaena porcus), tirsi (Alosa sp.), izmarit (Spicara maena), istavrit (Trachurus mediterraneus), mahmuzlu camgöz (Squalus acanthias), dikenli vatoz (Raja clavata) ve kaya balıklarının (Gobius sp.) yıllık, aylık ve günlük av miktarları belirlenerek türlerin avlanabilir biyokütleleri ve bölgedeki stok büyüklükleri incelenmiştir. 2007 ve 2008 yılı olmak üzere her iki av sezonu için ayrı yapılan araştırmada elde edilen bulgulara göre avlama bölgesinde ortalama 619.44± 13.71 kg/km 2 mezgit; 22.45±1.20 kg/km 2 barbunya; 40.78±1.11 kg/km 2 kalkan; 0.75±0.11 kg/km 2 iskorpit; 7.26±0.82 kg/km 2 tirsi; 2.98±0.24 kg/km 2 izmarit; 1.10±0.38 kg/km 2 istavrit; 13.05±3.00 kg/km 2 mahmuzlu camgöz; 2.42±0.36 kg/km 2 dikenli vatoz ve 1.30±0.18 kg/km 2 kayabalığı bulunmaktadır. 2007-2008 yılı av sezonlarında avlama bölgesindeki ortalama stok büyüklükleri mezgit için 451.59±9.89 ton; barbunya 15.96±0.81 ton; kalkan 30.05±0.83 ton; iskorpit 0.55±0.77 ton; tirsi 5.07±0.52 ton; izmarit 2.19±0.17 ton; istavrit 0.81±0.27 ton, mahmuzlu camgöz 9.54±2.30 ton; dikenli vatoz 1.60±0.24 ton; kayabalığı 0.97±0.12 ton olarak belirlenmiştir. fishing periods, a total of 80.07 km 2 areas has swept and mean swept area is 0.1359±0.0013 km 2 per trawl haul. On the swept area surveys performed at the Sinop-İnceburun region; annual, monthly and daily catch amounts of whiting (Gadus merlangus euxinus), red mullet(Mullus barbatus ponticus), turbot (Psetta maxima maeotica), black scorpion fish (Scorpaena porcus), shad (Alosa sp.), picarel (Spicara maena), horse mackerel (Trachurus mediterraneus), picked dogfish (Squalis achantias), thomback ray (Raja clavata) and goby (Gobius sp.) has determined and, catchable fish biomass and stock size on the region has examined. According to results of the study, separately practiced for both of 2007 and 2008 fishing periods, distribution of whiting, red mullet, turbot, scorpion fish, shad, picarel, horse mackerel, shark, ray and goby has calculated 614.44 ± 13.71 kg/km 2 , 22.45 ± 1.20 kg/km 2 , 40.78 ± 1.11 kg/km 2 , 0.75 ± 0.11 kg/km 2 , 7.26 ± 0.82 kg/km 2 , 2.98 ± 0.24 kg/km 2 , 1.10 ± 0.38 kg/km 2 , 13.05 ± 3.00 kg/km 2 , 2.42 ± 0.36 kg/km 2 and 1.30 ± 0.18 kg/km 2 respectively. Stock sizes of the species in 2007 and 2008 fishing periods has calculated as 451.59 ± 0.89 tons for whiting, 15.96 ± 0.81 tons for red mullet, 30.05 ± 0.83 tons for turbot, 0.55 ± 0.77 tons for black scorpion fish, 5.07 ± 0.52 tons for shad, 2.19 ± 0.17 tons for picarel, 0.81 ± 0.27 tons for horse mackerel, 9.54 ± 2.30 tons for picked dogfish, 1.60 ± 0.24 tons for thomback ray and 0.97 ± 0.12 tons for goby. Journal of FisheriesSciences.com Gönener ve Bilgin, 4(3): 195-208...