Using meiobenthos for biomonitoring of ecological health in southern Caspian Sea shores, Mazandaran, Iran

摘要

Human activities, including industry, agriculture, mining, dredging, and dumping introduce large amounts of pollutants into marine areas, causing permanent and significant disturbance to and a major impact on ecosystems. For assaying ecological health of south of Caspian Sea shores (Mazandaran) biodiversity and distribution of meiobenthos was measured as a bioindicator. From 12 stations (ranging in depths from 5, 10, 20 and 50 meters), sediment samples were gathered for four seasons (2012). Temperature, salinity, dissolved oxygen and pH were measured during sampling with CTD (conductivity, temperature and depth). Percentage grain size and total organic matter and calcium carbonate were measured. The average water temperature ranged from 9.52 to 23.93 C, dissolved oxygen from 7.71 to 10.53 mg/L, salinity from 10.57 -0.07 to 10.75 -0.04 ppt, pH from 7.44 -0.29 to 7.41 -0.22, EC from 17.97 -0.12 to 18.30 -0.04 us/cm2, TDS from 8.92 -0.04 to 9.14 -0.02 mg/L, total organic matter from 5.83 -1.43 to 6.25 -0.97% and calcium carbonate fluctuated from 2.36 -0.36 to 1.68 -0.19%. From 4 groups of animals (Foraminifera, Crustacea, Worms and Mollusca), the results indicate that following Foraminifera, the worms had the maximum density in the present region. In particular, benthic foraminifera have been demonstrated to be particularly sensitive microorganisms and they have been successfully utilized for their value as bioindicators of environmental change in a wide range of marine environments. Account of Shannon index (below less than 1) showed that this area is under pressure. In Bandar Amirabad (Behshahr) station we observed lowest Shannon index and the west of study area had been better condition compare with east of study area. Account of Pielou index showed that the distribution in this area was not steady.