Population ecology parameters and biomass of golden grey mullet (Liza aurata) in Iranian waters of the Caspian Sea

摘要

This paper examines the changes in the population ecology parameters and biomass of golden grey mullet (Liza aurata) in Iranian waters of the Caspian Sea from 1991 to 2005. For most years during this 14-year period, we estimated the age structure of the catch, length-weight relationship, von Bertalanffy growth parameters, condition factor, natural and fishing mortality and biomass. Growth parameters were estimated as L sub(~)=62.7cm, K=0.15year super(-) super(1), t sub(0)=-0.23year super(-) super(1). The instantaneous coefficient of natural mortality was estimated as 0.350year super(-) super(1) and the instantaneous coefficient of fishing mortality varied during the 14-year period between 0.111 to 0.539year super(-) super(1). Biomass estimates of golden grey mullet, from the biomass-based cohort analysis were increased from 13,527mt in 1991-1992 to 23,992mt in 2002-2003. In 2004-2005, it was estimated to be 23,658mt. We concluded that at the present time, the stock of golden grey mullet is not being over-fished.