Fisheries impact on trophic levels: North of the Persian Gulf case study, 2002-2011

Abstract

There are few documented reports about the trophic structure and catch composition of trawl fishery in the Persian Gulf. In this study, the changes in the marine food webs in the North of Persian Gulf along the Bushehr province coastal water of Iran was determined based on the estimates of the two indicators, mean trophic level (MTI) and Fishing in Balanced (FiB) index for the last decade (2002-2011). The data indicated an increase in total landings (of 49 exploited species), and moderate increasing trend in both MTL and FiB-index was observed. Even though the Iranian coastal fishing has increased over time, it has a low impact on the trophic structure of marine communities in this region. The study suggested that it may be due to occurrence of ‘‘fishing up’’ phenomenon in this area and there is a need to expand fishing to offshore and deep waters for discovery of new and high-TL species.