JOURNAL OF WETLAND ECOBIOLOGY
Year:2010 | Volume:1 | Issue:4|Papers Count:11

In this research, study of catch, biomass and production of fish species take place in the Shadegan wetland. Samples were collected from landing at six station: Mahshar, Rogabe, Khorosy, Kanal, Atish and Abadan.During one years study (from 2008 to 2009) more than 2000 specimen were measured and used of assessing depletion method for the fish stock assessment and also random sampling in station landing was done to determinate fishing effort. Number of active fishermen was 2370 persons and maximum fishing effort was in the January, February and March.Maximum and minimum fish biomass was in the autumn (337.17 kg/ha/year) and summer (83.19 kg/ha/year), and mean fish biomass was 197.57 kg/ha/year. Cyprinus carpio and Thrssa ilisha were maximum and minimum fish species biomass in the Shadegan wetland. The mean of catch landing during the year was near 303 t. and the maximum catch landing observation was in the March (997t). Fish biomass and production in wetland shadegan were 20 g./m2/year.

Intensity of precipitation is presented by its quantity in which precipitation more than 30 mm is called heavy rainfall.Number of raining days determines frequency of increasing factor. In present survey in order to study daily quantity of precipitation and determining number of days with precipitation more than 1 mm in Anzali wetland watershed 5 year meteorological data of Gilan water organization was utilized. The research method was obtained from descriptive analyzing with statistical software and Geographic Information System for map zoning with Kriging method. Results of study have shown that maximum number of precipitation days in Masuleh uplands.In south area of watershed number of precipitation days in 181-246 and in north parts is 246-311 days. Maximum precipitation days were located from north to east parts of watershed with precipitation of 30 mm per day.

Shadegan wetland, the largest Iranian wetland is among the important international wetlands of 537700 area located in the furthermost jarahi river route at ontset of the Persian Gulf in the south western Iran.It’s basin area is 24310 km3 located in Khuzestan plain lands. This study intends to compare procedure of variations in shadegan wetland conservative values using the world standard method daring 1360s, 1370sand 1380s, in this study it is a empted to deal with considering procedure of variation in shadegan wetland conservative values daring 1360s, 1370s and 1380s and presenting a comparision of their conservative values during this period with respect to sources and feasibilities present in the wetland range and using IUCN conservative valuation criteria. Criteria inserted in these methods include 14 major criteria and 22 minor criteria. That at the end shadegan wetland achieved the potentials and capabilities of assignment either as a conservated coastal-marine area or costal – marine wild shelter achieving 101 scores (out of 140 scores) in 1360s, 110 scores in 1370s and 111 scores in 1380s (out of 150 scores).

The Anzali wetland is an international wetland on the southern coast of Caspian Sea at north of Iran country. Nowadays this wetland is degraded and utrification is done in many part of it. The destructive process from the out to inside the wetland is more sensible so it is important to determine the wetland buffer zones accord to the scientific and systematic approachs. In order to determine wetland buffer zone in the year 2008 around to 500 meters from the wetland five buffer zones with 100, 200, 300, 400 and 500 m width were considered. The Anzali wetlands include east part. Water body, Siahkashim, Selke and Sorkhankol divided to 13 regions and by hierarchical cluster analysis base on bird number, threatened bird and fish species number, COD, T-P and T-N concentration in water and total area of agricultural and residential land uses in each buffer zone, those regions divided to five homogenous classes. Classes were compared together and base on the sensitivity of each class the buffer zone proposed between 100 up to 500 m. The proposed buffer zones around the Housainbekande and Selke is 500 m, south of the western part, central and eastern part of the wetland and Anzali port is 400m, Siahkeshim 300m, Sourkhankol 200m and north of the western part of the wetland is 100m.

In recent years due to drought and reduced rainfall in the Khuzestan province, water salinity in some fish culture reached to 9 ppt and grass carp mortality increased and many damages entered to province aquaculture, so the aim of the present study was to evaluate the effect of salinity on growth and survival of fingerlings of grass carp (Ctenopharyngodon idella). For this reason grass carps (13.55±0.726 g, 11.04±0.093 cm) were placed in 250 l-tank (15 grass carp /tank) at 24.16±1.35 °C in salinity groups: 3, 6, 9 and 12‰, and fresh water as the control for 21 days. Each treatment was repeated in three replicates (from September 2009 to November 2009). In trial, fish were fed twice daily with a 3% body weight ration of powder feed (Beta). After 21 days the results indicate that Salinities up to 3‰ did not affect weight gain, specific growth rate and length but higher salinities (6 and 9‰) had adverse effects on survival. In 12‰ all fishes died during the 14 days trails. Growth was significantly reduced at salinities greater than 3‰. Grass carp is a freshwater stenohaline fish that exhibited good growth and no signs of stress in saline waters up to 3‰ salinity. These results demonstrate that the grass carp could be cultured successfully in brackish water with salinity up to 3%.

In this study, Total number of 181 Rudd (75 male and 106 female) using gill net were caught in the Anzali wetland from April 2008 to March 2009. Fishes were measured using biometry board and caliper. To measure fork length of small samples, it was utilized regular or digital calipers and digital scale with precision 0.01 g was used to weight samples. The age range of samples was between 0+ to 2+ years. SPSS, One Way ANOVA and regression were used to analyze data and Excel was utilized to draw curves. Average fork length and weight of samples were determined 133.99±20.5 mm and 46.02±23.4 g, respectively. Tukey's test showed significant difference in fork length in both sexes. The fork length-total weight relationship and correlations were determined W=0.0000087 FL3.145 and r2=96% respectively.Regression equation in male was W=0.00000979 FL3.119 with r2=97.2% while in females, it was W=0.00000655 FL3.205 with r2=94.1%.

This survey was carried out to study biometric and morphometric characteristics of Capoeta fusca in its main ecosystem in Birjand. Sampling was done monthly and the specimens were under biometry after collection and transferring to laboratory. The result of this study revealed that the average of total weight of this species was 21.85 ± 9.23 gr in males and 27.27 ± 18.47 gr in females, and also the average of standard length was determined 10.54 ±1.324 cm in males and 11.05±2.179 cm in females. The number of scales on the lateral line was 42-49 and the number of branched rays of dorsal fin and anal fin were 7-9 and 5-6 respectively. The average of head length 2.41 ± 0.2 cm, eye diameter 4 mm and body height were 2.59±0.515 cm respectively. There was a significant difference between data of some of morphometric characteristics male and female, the minimum total length for adult males was 8.1 cm and adult females was 8.3 cm and the maximum total length were measured 15.4 mm for males and 18.6 for females. According to this result, the (CV) in this species was calculated 25 and the food preference (FP) of weeds and benthoses for that were calculated 86.6 and 13 respectively. The relative gut length was also calculated in this study 6.64 ± 23.1. The pharyngeal teeth of Capoet fusca were in 3 rows with the formula of 2.3.4 - 4.3.2.The generic relation of female to male totally was 1.6 female of 1 male and according to k-square test there was a significant difference between 2 sex. (p<0.005).Also the survey during 6 month on 800 specimens of Capoeta fusca since 2006 October until 2007 April, revealed that the Gonadosomatic index (GSI), Hepatic index (HSI) and nutrition index were maximum in march and minimum in December for both of sexes .Thus according to these results it can be understood that Capoeta fusca spawns in December. But it was a considerable point that there was a variety of Capoeta fries in different lengths and during all time of sampling, so this species may spawn more than one time during the year.

Biological parameters are one of the new methods to study water quality. Aquatic insects, due to richness of species and different sensitivity to many biotic and abiotic factors in their environment, are used as an useful indexe to water quality measurments. This study was carried out to determine biotic index and water quality of three important rivers (Karimchay, Lavandavil and Chalvand) of Astara region. Sampling was carried out monthly and regularly. In this survey, 27 families from 7 orders of benthic insects including the orders of Coleoptera, Ephemeroptera, Odonota, Diptera, Hemiptera, Trichoptera and Collembla were collected and identified. Diptera and Coleoptera ordres were dominant. In 2008 the Biotic index of Krimchay and Lavandavil rivers were 6.11 and 5.79 respectively and water quality of both rivers was fairly poor (Substantial Pollution likely) and the biotic index of Chalvand river was 5.33 with Fair (Fairly substantial Pollution likely) quality.

The objective of the present study was to compare cadmium and lead levels in muscle and liver of Barbus grypus in Dez River. In summer of 2009, randomly 48 fish samples were caught in random size by gill net from Dez River after Dezful city (Ali abad village). At first the tissues were extracted and then the elements were determined by using atomic absorption spectrophotometer and the results were given as mg/kg dry weight. The levels of cadmium and lead in muscles of Barbus grypus were 1.0997 and 1.2944 mg/kg dry wt and in liver 1.3497 and 1.5525 mg/kg dry wt, respectively. The concentration of lead had statistically significant difference (P£0.05) in muscle and liver but did not showed significant difference for cadmium in muscle and liver. Our study showed that the concentrations of cadmium and lead were higher than world health organization (WHO) limit in the muscle tissue of Barbus grypus in Dez River.