Investigation of physicochemical factors, chl-a and primary production in Mahshahr Creeks (Northwest Persian Gulf)

Abstract

The study on physiochemical factors and primary production of the aquatic ecosystems is important to know the characteristic of environment and capacity of recharge. Mahshahr creeks are the most important creeks in Khuzestan, Iran. In this study, variations in physiochemical factors, chl-a and primary production in 3 regions (Mahshahr, Zangi, and Moussa entrance creeks) were evaluated in 2 months of every season of 2014 in different depths (1m and 8m). The following variable has been analyzed: nitrate, phosphate, nitrite, silicate, temperature, salinity, DO, pH, conductivity, turbidity, light, chl-a, primary production and phytoplankton abundance. The maximum amount of chl-a (1.6 mg m-3) was observed in the shallow region of Mahshahr creek in April while the minimum amount (0.08 mg m-3) was seen in the depth region of Zangi in July. The highest (1.59 gc m-2 day-1) and lowest (0.02gc m-2 day-1) amount of primary production were observed in the shallow region of Moussa entrance in April and the depth region of Zangi creek in Nov, respectively. The maximum abundance of shallow and depth phytoplankton was observed in April and the minimum was observed in July in all of the three creeks. The results of correlation test between the studied factors revealed that primary production has a significant relationship with nitrite, chl-a, phytoplankton abundance and light. Primary production in these creeks is relatively high in April, but in other months the production is low.