A trophic model of the coastal fisheries ecosystem of the northern Persian Gulf using a mass balance Ecopath model

Abstract

An Ecopath ecosystem modeling was applied to describe the trophic model of coastal fisheries ecosystem of the northern Persian Gulf. A total of 32 functional groups and species were used to determine the key features of the aquatic system. We also examined the stability and developmental stage of the Persian Gulf ecosystem. Total primary production/total respiration was calculated to be >1 indicating that more energy is produced than respired within the system. Indicators of ecosystem stability and development were estimated as follows: ominivory index = 0.29; connectance index = 0.14; Path length = 1.005; relative low biomass to throughput ratio = 0.0008; ascendency = 12.26; Finn’s cycling index = 2.01; high primary production to biomass ratio = 81.57 and ratio of total primary production to total respiration = 23.92. The trophic levels of the groups varied from 1 for primary producers and detritus to 4.42 for piscivorous fish in the coastal system. These indicators show that the coastal system of the Persian Gulf are in their developing stage with high exploitation pressure, especially on demersal fish resources.