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Without industrial and urban development and their effects on marine ecosystem, due to high biotic potential, Khure-Mussa would be one of the productive coastal areas. Because of sensitivity and vulnerability to environmental changes this area are classified in sensitive ecologic area. This study was conducted to evaluation ecological health status in Khure-Mussa in the Northwest of Persian Gulf by using benthic indices. Twenty creeks in Khure-Mussa area were set up for study and sampling in four seasons from winter 2008 to autumn 2009. Monthly water sampling for physico-chemical parameters was done by bottle sampler and seasonal samples of surface sediment were collected by Peterson grab sampler (0.125m^2) .At each station three samples for macrobenthic study and one sample for grain size analysis and organic matter determination were obtain. Totally, 187589 macrobenthic individual were collected and separated. Among identified groups, Polychaetes with total number108906, Crustacean with total number 46561, Bivalve with total number 14156 and seapen with total number 9841 were the dominant groups and were included 58, 25, 8 and 5 percentage of total number respectively. The highest abundance in the spring and the lowest abundance in the summer were observed. According to mean abundance, Somaily creek and Khure-mussa (3) station showed the highest and the lowest abundance respectively. Seapen is included more than 90 % of total biomass. The range of Shannon diversity index was (1.95-3.58) which the minimum and the maximum values were found in Shipping and Patil station respectively. Significance benthic biological parameters (abundance and richness) in different creeks explained the variation of benthic community structure in studied creeks. In addition, seasonal significant differences were found in these parameters due to seasonal changes in benthic animal s succession. The results of grain size analysis showed that the range of siltclay was (63.6-95.59). According to AMBI index values, all of the studied creeks are classified in slightly pollution level and disturbed condition except for Petrochemical station that placed in moderate pollution level. The BOPA index values in all stations showed more than threshold level (0.19) that means bad and weak ecological condition. The highest and the lowest ITI index values were observed in Oil exporting port station (64.92) and Ghazaleh creek (29.53) respectively. The others were grouped in 30-60 range that means moderate pollution level and disturbed ecological status. The values of ABC (Abundance Biomass Curve) that explained the relation between macrobenthic biomass and abundance, were calculated near zero from 0.1 to -0.1 in all studied creeks that show moderate condition for living animals. In general the studied creeks showed pollution potential and benthic biological parameters indicated downward trend in ecological quality and health status.

In recent years MPAs (Marine Protected Areas) have been known as a flexible tool to improve fishery management as well as to preserve biodiversity in valuable coastal waters habitats. This study was conducted to selecting the sensitive and high potential area that are impacted by several environmental stress and associated habitats are being damaged in Mahshahr creeks in Northwest of Persian Gulf. Study was done in eight creeks from October 2005 to September 2006. Different biotic parameters such as phytoplanktons, zooplankton, macro zooplankton, benthic animals and fishes (trawled species) communities and also physico-chemical parameters and sediments heavy metals were investigated. Different parameters were sampled monthly or seasonal from each creek. Water samples with bottle sampler and sediment were collected by Peterson grab. Several ecological and biological indices based on heavy metals and benthic communities were used. Concentrations of heavy metals were measured by using voltammetric plarography method (Methrom 797). The range and mean concentrations obtained in mg/kg were 35.16-15.03 (27.01) for Cu, 171.41-65.57 (102.672) for Ni, 20.06-4.63 (13.22) for Co, 0.78-0.093 (0.22) for Hg, 379-65.07 (113.7) for Zn, 1.00-0.27 (0.559) for Cd and 29.72-7.09 (14.66) for Pb. To evaluate the levels of sediment contaminations, the background values of the different heavy metals were calculated and contamination factor for each metals and degree of contamination for each creek determined as well. Measured concentrations were compared with International standards. Ultimately the heavy metals contamination factors (Cf) can be arranged as follows: Hg> Zn> Cu≥ Ni> Pb≥ Co > Cd and according to contamination degree (Cd), different creeks can be arranged as follows too: Ghannam> Ahmady≥ Zangy> Doragh≥ Darvish> ghazaleh> Patil> Bihad Regarding the results some elements such as Hg, Zn and Ni, are at risk level and all of the studied creeks are classified in moderate degree of pollution except Ghannam showing considerable degree of pollution. The benthic invertebrates are a well-established target in evaluations of environmental quality status. The AMBI (AZTI,s Marine Biotic Index) was developed to determine the impacts and the quality status in softbottom marine benthic communities. All creeks are characterized by muddy bottom. Macrobenthic animals, according to their sensitivity to an increasing stress gradient, classified in five ecological groups. In present study due to appearance of dominant species such as Capitella sp and nematodes (as opportunist species), diversity values was reduced. Two way ANOVAs showed only seasonal significant differences in mean abundance (P

In regarding to study the fecundity and feeding behaviour of Barbus xanthopterus in Karkheh river and Hoor-al-Azim marsh, 393 specimens of this species were collected monthly by drift gillnet, set net and castnet from October 1996 to September 1997. The bottom substrate of marsh was silty-clay and in some points it was sandy. Seventeen types of benthic invertebrates from 6 orders were identified, among which insects had the highest density and diversity. Maximum and minimum absolute fecundity was 549211±7295 and 136924±652 and for relative fecundity they were 142.53±1.95 and 18.886±0.O9 for each gram of body weight, respectively. Absolute and relative fecundity showed the highest correlation with girth and fork length, respectively. Feeding intensity did not show a regular trend and intestine fullness in river fishes is more than that of Hoor-al-Azim which was an indicative of active feeding in Hoor-al-Azim and migration to the Karkheh river for spawning. Main food item was invertebrates and plants and relative index of intestine and its contents showed that B. xanthopterus is an omnivorous species.

In summer 1994, 30 grass carp (Ctenopharyngodon idella) were caught from a pond culture and blood sampling was done, while the fish were alive, for ichthyohaernatologicall examination. The fish and blood were brought to the laboratory, the digestive tract and internal organs of fish were examined for parasitological investigation. Eleven fishes were infected by a tape worm (Bothriocephalus) seriously. Number of parasites in intestine of each fish specimen was between 70 -80 and they cause intestinal obstipation. Amount of haemoglobin, haematocrit value and erythrocyte in infected fishes was lower than healthy fishes.