Ecological health analysis of Caspian marine environment based on the diversity and distribution pattern of meiofauna in the Mazandaran Province, Caspian Sea

Biodiversity and distribution of benthic meiofauna in the sediments of the Southern Caspian Sea (Mazandaran) was studied in order to introducing and determining of their relationship with the environmental factors. From 12 stations (ranging in depths 5, 10, 20 and 50 meters), sediment samples were gathered in 6 months (2012). Environmental factors of water near the bottom including temperature, salinity, dissolved oxygen and pH were measured during sampling with CTD and grain size and total organic matter percentage and calcium carbonate were measured in laboratory. In different months, the average water temperature (9.52-23.93), dissolved oxygen (7.71-10.53 mg/L), salinity (10.57±0/07 and 10.75±0/04 ppt), pH (7.44±0/29 and 7.41±0/22), EC (17.97±0/12 and 18.30±0/04μs/cm2), TDS (8.92±0/04 and 9.14±0/02 mg/L), total organic matter (5.83±1/43 and 6.25±0/97%) and calcium carbonate (2.36±0/36 and 1.68±0/19%) were measured respectively. Structure of the sediment samples mostly consisted of fine sand; very fine sand, silt and clay. From the 4 group animals (Foraminifera, Crustacea, Worms and Mollusca), there were identified 40species belong to 29 genera of 25 families. The cosmopolitan foraminifer, Ammonia beccarii caspica, was common in all sampling stations. Result showed that depth was important factor on distribution of meiofauna. Most density of foraminifera and crustacean was observed in depth of 20m and for mollusca and worms observed in 5m. Shannon diversity index decreased with depth that showed in shallow water diversity was higher than deep water. Mean of maximum and minimum Shannon index was obsorvers in depth of 5m and 50 m that was measured in order 0.93 and 0.43. Account of Shannon index showed that this area is under pressure. Account of peioleo index showed distribution in this area was not steady.

Studies on diversity of Hara's Laft - Khamir and Sout Beaches of the Gheshm polychaetes

One of the most important marine ecologic phenomenon, is the study of animal community among the bed or benthic fauna. Macrobenthoses are the great part of the benthic fauna that are more biomass than meiofauna and microfauna. To study polychaetes diversity of mangroves, located in Khoore-Khooran, sampling was conducted on a bimonthly and carried out from December 2001 to October 2002. Bottom samples were collected by Van Veen grab (0.025 m2) at 6 station from 2 transect in situ measurement of temperature, pH, DO and salinity were done. A total of polychaetes were identified within study 32 Family and 43 Genus. Cirriphormia and Nephtys were the most dominant genus in the studies. The range numerical abundance of polychaetes was between 3006 per m2 in the station A3 to 559 individual per m2 in the station A1 and the variation was done to different bottom, texture the variable environment conditions governing the different parts of each creeks as well as within creeks. Application of diversity indices (Shannon H') on the dominant polychaetes assemblages has higher H' in the Azar and lower H' in the Mehr and the stations B3 has the highest H' and the station A2 has the lowest H' Application of diversity and Richness, Evennes were studied and showed that the station A3 has the lowest evenness and the most individual, and station A I has the middle pollution.