Survey on ecological characteristicsof Horolazim wetland in Khouzestan (2012-2013)

Rregarding the potential and capabilities of different socio-economic, ecological and recreational, Hurolazim wetland is allocated as a special place in the collection of ecosystems and environment and the study of existing ecological conditions is necessary to protect and restoring management. In this study, monthly Samples of four stations (stations north of the road, Imam Reza (1) and south of the road, Imam Reza (2), in the Rofayeh area and stations Tabor (3) and the Shatt Ali (4), in the Shatt Ali area) were taken during the year from April to March 2012. Samples included physical and chemical parameters, phyto and zoo planktons, benthos, fish, and fishing status. Phytoplankton samples using sampling bottles from 0.5 meters below the surface were taken and counted based on alive unit. Zooplankton samples were collected by 100 micron mesh size plankton net from a depth of 1.5-2 meters. Benthic animals and sediment were sampled by Van Vin grab(0.125 square meters). One sample for benthos and one sample for grain size analysis and percentage of organic matter were sampled from each stations. In order to estimate the monthly depleted catches, data collected from the census in place and sampling was done at the time. Three fishing area has inspected randomly once every 15 days and active fishermen and caches were recorded in the prepared forms during the day. In this way, the number of observed boats, the average boat per day, the catches of the boats and CPUE were registered and total fishing effort was calculated monthly. In this study, 194 species of phytoplankton were identified. Diatoms with 85 species, Cyanophyta with 59 species, Chlorophyta with 31 species, Euglenophyta and Dinophyta with 18 and one species were observed respectively. The highest abundance frequency of phytoplanktons with 38.96 percent were observed in Tabar station (3), Diatoms with 46% has shown the highest frequency and then Cyanophyta (34.17%), Chlorophyta (16.39%), Euglenophyta (1.6 %) and Dinophta (1.58%) were included of the total abundance respectively. In the summer colonies of Cyanophyta were in high density. A total of 35 species of zooplankton have been identified. from Rizopoda, the species of Arcellidae and Centripyxidae families, from Rotifera, the species of Brachionidae, Lecanidae, Asplanchnidae and Philodinidae families, from Cladocera ,the species of Daphnidae, Sisidae and Chydoridae families and from copepods, Cyclopoda families have been observed that included about 98 percent of identified zooplankton. Respectively, Copepoda (39.9 %), Rotifera (34.71 %), Cladocera (22.38 %) and Rizopoda (0.843 %) were dominant groups. The species Brachionus urceolaris with average density of 7.29 individual per liter, is the most abundant species that included 17 % of total abundance frequency in the wetland. The higher frequency of crustacean zooplankton such as Copepoda and Cladocera could be indicated an environment more favorable conditions and expected to be good status of food in the Horolazim wetland. Among the known benthic groups, families, Tephritidae (85%) and Chironomidae (7 %) of the order Diptera and Ostracoda (2 %) from crustacean, were the dominant macrobentic groups Among the studied stations, Station South Road Imam Reza (2), and the station Shatt Ali (4), were the highest and the lowest abundance respectively. The mean abundance of macrobenthos in different seasons showed the lowest and the highest abundance frequency in summer and winter respectively. According to diversity indices, The stations Tabar (3) was the highest and the Station South Road Imam Reza (2), was the lowest value of diversity index. The results showed the higher than 71.84 % of Silt-Clay percentage in all stations, The highest value of sediments TOM in the Station South of the Road Imam Reza(2) in the winter and the lowest in station Shat Ali(4) in summer were recorded. Based on HFBI index the stations north of the road Imam Reza (1) and the station Shatt Ali (4) in moderate status and the stations south of the road Imam Reza (2) and Tabar (3) in good status were classified. In this study, 15 species of fishes belonging to 8 genera and 3 families were identified. It was noticed that 87.4 percent of all identified species in the wetland belonged to the Cyprinidae family. The results of previous studies in 2006 and 2008 in the Iraqi part of Hawizeh wetland showed that the most common fish species belonged to Biah, Karas, Hemry and Shelej that included 89.3 percent of total fishing in the current study .Finally, It is evaluated that changes in water regime of freshwater wetlands, controlled the environmental characteristics and conditions. That means water plays a decisive role in the vital characteristics of wetlands. Changes of quantity and quality of water may be associated with changing the quantity and quality of biotic fauna in wetland system. In the management and protection of a wetland system, it is necessary to adopt measures based on scientific principles and reasonable methods in order to protect water quality.