Identification and estimation of macrofauna in low tides of Bushehr province, Persian Gulf

The present investigation was undertaken to determine temporal and spatial distribution of macrofauna in low tide regions of Bushehr province in the northern Persian Gulf. Sampling was seasonally carried out by a box corer of 0.0225 m2 in six stations including Genaveh, Farakeh, Shif, Bandargah, Rostami and Asalouyeh from summer 2008 until spring 2009. In this study, 752 specimens belonging to 29 genera were collected. Polychaetes were dominant both in terms of genus number (22) and relative abundance (77.1% of total macrofaunal abundance). The other dominant groups were crustaceans, bivalves and turbellaria. The highest number of Prinospio and Solen specimens were found in Genaveh, Farakeh, Bandargah, Rostami and Asalouyeh stations with sandy substratum; however Capitella sp. and Nicomache specimens were collected only in silt–clay substratum of Shif station. The highest (888.89 ind. m-2) and lowest (37.03 ind. m-2) annual average density of macrofauna were found in Farakeh and Asalouyeh regions, respectively. R- square in quadratic Regression equation between temperature and macrofauna density and Shannon wiener species diversity index were assessed to be 0.988 (P= 0.044) and 0.992 (P= 0.09), respectively. The annual Principal Component Analysis indicated that in stations 1- 5, the organic matter content, sediment texture and temperature have had the most influence on the macrofauna assemblage, but comparison of species composition, density and Shannon wiener species diversity index of macrofauna in Asalouyeh with previous recorded data of the region showed that manmade factors such as gas and petrochemical industries have had the most effect on the macrofauna community structure during sampling period.