Population Structure of Pagellus Acarne (Risso, 1927) in the North Aegean Sea

Abstract

Sparidae family is one of the most important demersal group for Turkish fisheries. When considering the importance of Turkey fisheries, population parameters of Pagellus acarne Risso, 1827 give basic information for future fisheries studies. Studies of biology and population parameters of this species are very limited in the Aegean Sea; therefore we aimed to determine population parameters (length-weight relationship, age and growth parameters, mortality rates and, reproductive season) in order to obtain data for the future studies. We caught 2673 Pagellus acarne specimens between September 2006 to September 2008 from monthly samples at depths ranging from 20 to 500 m in the Saros Bay using a commercial bottom trawl net. Total length and weight range from 3.5 to 27.1 cm, 1.93 to 314.5 g, mean length and weight were 14.0±0.05 cm, 35.6±0.46 g respectively. The length-weight relationship was detected W=0.001*L3.054, which indicated positive allometric growth. The high GSI value was in September. The data on maturity stages indicated that length at 50% maturity (L50) for females 18.1 cm TL for males 15.3 cm TL. The age data derived from sagitta otoliths reading were used to estimate the growth parameters and ranged from 1-4 aged. The von Bertalanffy growth parameters of the total were L∞=30.63 cm, K=0.26 year-1, to=-0.95. The instantaneous total mortality was Z= 0.72 year-1, the natural mortality M = 0.54 year-1, the fishing mortality F=0.19 year-1 respectively. The exploitation ratio (E) of the stock was found as 0.26. Pagellus acarne is the most important marine fish species with high commercial value for both the Turkey coast and the Mediterranean basin. This study aims to define basic population parameters which should be needed for further fisheries studies and management strategies in Saros Bay, the North Aegean Sea.