Population structure, growth, mortality and estimated stock size of the introduced tench,Tinca tinca(L.), population in Lake Beyşehir, Turkey

Abstract

Population structure, growth, length-weight relationship, mortality and stock size of tench, Tinca tinca (L.), was studied in Lake Beys¸ehir, Turkey in 2005. Totals of 3360 tench (1865 males; 1795 females) were captured with gill-and trammel-nets of various mesh sizes. Male to female ratio was 1.04 : 1. The study covered length year classes. Fork lengths and total weights ranged from 9 to 37 cm and 13 to 815 g. For all individuals, the von Bertalanffy growth equation and lengthweight relationship were L t = 54.2[1)exp()0.1350(t + 1.0281)] and W = 0.0151 L 2.9993 , respectively. Growth performance index and mean condition factor of the tench population were 2.598 and 1.513, respectively. Mortality rates were Z = 1.97 year )1 , M = 0.29 year )1 and F = 1.68 year )1 for total, natural, and fishing mortality, respectively. The exploitation rate was E = 0.85, and the percentage of surviving fish was 13.9%. Tench stock was assessed as about 6-7 million individuals and 1450-1500 tonnes in biomass. It was determined that maximum sustainable yield could be obtained with an 80% level of the current fishing effort.

Growth and reproductive properties of Tench,Tinca tincaLinnaeus, 1758 in Trasimeno Lake (Umbria, Italy)

“…(Gandolfi et al, 1991). However, the maximum age found in Trasimeno Lake was well higher than those reported in literature for other environments (Wright and Giles, 1991;Altindag et al, 2002;Benzer and Yılmaz, 2007;Balık et al, 2009;Gürbüz, 2011;Erguden and Goksu, 2010;Vetlugina, 1992). As regard the wellbeing of fishes, females proved to be in better condition than males, but this result seemed to be affected by the ovary mass; indeed, when the somatic weight was considered in the calculation of condition factor, it was greater in males than females with statistically significant differences.…”

“…07p7 the value calculated for the whole sample was similar to (Altindag et al, 2002), or higher than those reported in the literature (O'maoileidigh and Bracken, 1989;Wright and Giles, 1991;Altindag et al, 1998;Sinis et al, 1999;Miranda et al, 2006;Alaş and Ak, 2007;Balık et al, 2009;Erguden and Goksu, 2009;Erguden and Goksu, 2010;Innal, 2010). The tench in Trasimeno Lake can reach the length of 50.54 cm and the rate of growth was high (0.27 yr −1 ); also the growth performance index testifies the quality of the growth, being its value the higher reported in literature for other populations (Wright and Giles, 1991;Balık et al, 2009;Froese and Pauly, 2011).…”

“…The tench in Trasimeno Lake can reach the length of 50.54 cm and the rate of growth was high (0.27 yr −1 ); also the growth performance index testifies the quality of the growth, being its value the higher reported in literature for other populations (Wright and Giles, 1991;Balık et al, 2009;Froese and Pauly, 2011). Although biased in favor of younger age classes, the population structure is though continuous and life span proved to be over 11 years, according to the typical species longevity 07p8…”

Population structures and some growth properties of tench (Tinca tinca L., 1758) in Mogan Lake, Ankara, Turkey

“…Variations in fish growth in terms of length and weight can be explained as an adaptive response to different ecological conditions (17 (1, 4), other studies were different (3,6,7,11,18,25). This variation may be due to different stages in ontogenetic development, as well as differences in condition, length, age, sex and gonadal development of fish (21).…”

Yeniçağa Gölü’ndeki (Bolu) Kadife Balığı (Tinca tinca L., 1758) Popülasyonunun Ölüm Oranları ve Stok Büyüklüğünün Tahmini

“…Yeniçağa Gölü kadife stokundaki işletme oranı 0,5'ten küçük hesaplanmıştır. Diğer göllerdeki kadife balığı popülasyonu üzerinde aşırı avcılık baskısı olduğu bildirilmesine rağmen (Balık vd., 2004;2009) (% 11,76) olarak değiştiği belirlenmiştir. Çalışma sonucunda bu balık türleri üzerinde av baskısı olmadığı ve yeterince avlanılmadığı sonucuna varılmıştır (Kılıç ve Becer Özvarol, 2008).…”