Determination of bioecological characteristics of striped red mullet (Mullus surmuletus Linnaeus, 1758) in Saros Bay (North Aegean Sea)

In this study, age composition, growth characteristics, length at first maturity, reproduction, stock densities and feeding habits of Mullus surmuletus were studied in the Saros Bay, North Aegean Sea between September 2006 - September 2008. Samples were collected monthly at depths ranging from 0-50m, 50-100m, 100-200m and 200-500m by trawling.The total length and weight ranged from 11.0cm-26.8cm and 15.3g-235.1g, respectively. The average length were 14.6cm and weight were 38.5g. The female male ratio was 1.6:1. The age data derived from otoliths readings were used to estimate the growth parameters, and ranged from 0-7 age. The length weight relationship for male, female and total were W=0,0075*L3,162, W=0,0114*L3,009, W=0,0084*L3,116 respectively. According to growth equations males have isometric growth while the females have positive allometric growth.The von Bertalanffy growth parameters of totals were L?=27.82cm, K=0,20year-1, t0=-2.16year. Exponential coefficients of natural mortality (M), total mortality (Z), and fishing mortality (F) of Mullus surmuletus was estimated 0.31yıl-1, 0.62year-1, 0.32yıl-1 respectively. The exploitation rate (E) of population calculated that 0.52year-1. The minimum value of GSI in June and the maximum GSI value was found in February. The breeding period of Mullus surmuletus were calculated of between March to June. Stomach content analysis indicated that the most preferred prey were Crustacea.The average catch per unit effort (kg/h) and biomass index (kg/km2) values of the M. surmuletus were 0.8kg/h and 15.7kg/km2 respectively. According to depts, biomass values were determined as 38,3kg/km2 in 0-50m, 13,7kg/km2 in 50-100m, 2,3kg/km2 in 100-200m, and catch per unit effort (CPUE) values were determined 1,95kg/h in 0-50m, 0,70kg/h in 50-100m and 0,12kg/h in 100-200m.