Evaluation of the “fishing down marine food web” process in the north-west of Persian Gulf (Khuzestan Province) during the period of 2002–2011

Abstract

The worldwide increase in commercial fisheries and its impact on ecosystems as well as inefficient fishery management have led to overfishing and frequent breakdown of traditional fish stocks. In this context, an analysis of Khuzestan inshore fisheries data covering the years 2002–2011, was conducted in reliance on testing for occurrence of the fishing down marine food webs (FDMFW) phenomenon in the North of Persian Gulf Large Marine Ecosystem (LME). In this study, the mean trophic level (mTL) and the fishing-in-balance (FIB)-index of Khuzestan landings during this period of time were estimated using the trophic level of 47 fishery resources. Increase in total landings (Y) was observed, which explained the high fishing yield in major fishery resources (especially demersal). Moreover, the moderates decreasing trend in mTL per decade, and the increasing trend in FIB-index were observed. The status of fishery resources in Khuzestan inshore waters (under exploited but not overexploited), the rise in Y, FIB and slightly drop in mTL can be considered as indirect indicators of the fishing impacts on the trophic structure of marine communities. Based on this result, probability occurrence of FDMFW process in Khuzestan inshore waters is low to some extent. However, we suggest that the goal of management programs in Khuzestan inshore waters should prevent the continuance of this trend in the long-term using an ecosystem-based approach.