JOURNAL OF MARINE BIOLOGY
Year:2009 | Volume:1 | Issue:3|Papers Count:9

In this study, the composition and diversity of the invertebrates of Bamdezh Wetland were studied for determining biotic index. According to the result of this research, 6 class of the freshwater benthic invertebrates were recorded in this region. The most abundant class during two period of sampling was the gastropoda ( 69.30%). For evaluating biodiversity of macrobenthics in this region, Shanon and Sympson Index were used.The maximum value of Shanon and Sympson index were recorded 2.37 & 0.97 and the minimum value were recorded 0.45 & 0.11 respectively. For indentification, separation and diversity determination of Macrobenthics, 3 samples of sediment were gathered by 0.025m2 Van Veen garb.

Diversity of benthic Foraminifera in the offshore sediments of the continental shelf in the Oman Sea was studied. The main aim of the recent research was to discover the structure of benthic foraminiferal communities in the studied area (for the first time) and for further understanding of sedimental condition of the Oman Sea and its comparison with the coastal waters and other marine ecosystems. Sediment samples were gathered in the winter 2006 by a 0/1m2 Van Veen grab, from 12 stations ranging in depth from 30 to 103 meters. The composition of foraminiferal communities was different in northern and southern regions. From the overall 57 benthic foram species, 52 species belonging to 25 genera of 16 families were identified. The suborder ROTALIINA was dominant in the northern region, while LAGENINA, MILIOLINA and TEXTULARIINA were abundant in the northwest region too. TEXTULARIINA were more abundant in the southern region in comparison with the northern. Ammonia beccarii was common in the whole studied region.

This study was conducted in order to consider the effect of water soluble fraction of crude oil on the accumulation of heavy metals (Ni, Pb, Cd & V) in muscle tissue of Pelates quadrilineatus from the Persian Gulf. The study was carried out in spring 2006 in the Ecology Research Center of the Persian Gulf. Two solutions with 0ppm (Control) and 12 ppm dosages of crude oil were prepared. Then 24 fish from this species that were caught from 6 stations in the northern part of the Persian Gulf were exposed to 12 ppm dosage of crude oil for 8 days in long-term bioassay examination. After 8 days exposed fish were freezed and packed seprately and sent to the laboratory for determination of heavy metals accumulated in their muscle. Heavy metals concenteration measurment was done with Atomic Absorbtion model Philips PU 3400. The result of data analysis shows that the mean (x¯±STD) accumulation amounts of V, Ni, Cd & Pb in tissues of control fish were 0.15±0.02 ppm, 0.36±0.03ppm, 0.02±0.01 ppm and 1.1±0.04 ppm respectively. The mean (x¯±STD) accumulation amounts of V, Ni, Cd & Pb in tissues of fish which were exposed to 12 ppm dosage of crude oil were 0.25±0.04 ppm, 0.57±0.03 ppm, 0.09±0.05 ppm and 1.57±0.11 ppm respectively. According to T-test we concluded that there is a significant difference (p< 0.05) between two mentioned dosages of crude oil in muscle tissues of this fish. Also in the fish of both treatments the order of heavy metals accumulation was Pb> Ni> V> Cd that was significant according to T-test experiment. On the other hand, the high amount of heavy metals in the control fish is due to pollution of Persian Gulf. Also, the mean concentrations of Pb, V & Cd in muscle tissue of control fish were below the international guidelines for human consumption.

In this study (2007), 170 samples of Vimba vimba persa were caught from the coast of Tonekabon, Astara and Bandartorkman in the autumn 2008. In this research, 22 morphological and 6 numeral characteristics were studied. Morphological characteristics were standardized before statistical analysis to reduce the error of the allometric growth. In morphological characteristics, 4 factors were indicators of 74% characteristics diversity and in numeral characteristics 3 factors were indicators of 65% characteristics diversity between people of three populations. The method of analyzing to main factors showed that migratory population of Vimba vimba persa to three ecosystem were not completely distinctive but possibly are from different populations which according to different ecological conditions, annually migrate to these areas. In this study according to differences in the size of samples from different areas, morphological characteristics were almost the best characteristics to show the differences between three populations.

In order to study the content of the digestive system in the Barbus grypus, samples were caught from Dalaki and Helleh rivers (982 & 1512 samples, respectively) . The maximum and minimum total length of fish were 750 mm and 45 mm respectively. Relative gut length in 1 and 7 years old fishes, were calculated 2 and 1.16 respectively. Highest frequency percentage of food items was related to Ephmeroptra in Dalaki river but, Plecoptra and Odonata were the food preference of this fish in both rivers. Diversity of benthic species in the Dalaki River was higher than Helleh River and also this index was higher in spring and summer. According to the result of this sudy, Barbus grypus has omnivorous diet that by increasing in its age, shows carnivorous diet.

Seasonal samples of bivalves and gastropods were collected during the period from March 2008 to April 2008 from the Tis rocky coast of the Chabahar Gulf.Samples were collected form three following stations: Supra littoral, Littoral and Sub littoral. According to the result, 34 species of gastropods and bivalves were identified and their frequency in the population were calculated 23.6% & 39.3% for bivalves and gastropods.

In this research, time and spatial changes ofphytoplankton abundance as well as chemical and physical parameters were assessed and measured in Tajan estuary during a year.The amount of chl-a concentration showed significant seasonal changes which were 0.6 - 94 mg/m3. Diatoms (Bacillariophyta) were dominant groups in Tajan estuary region. The reduction of river flow in summer and the amount of water stability in this region were of effective and important agents in phytoplanktonic density in Tajan estuary. In addition, the amount of dissolved inorganic nitrogen was one of the remarkable factors in restricting the growth of phytoplankton.

The manual sorter is appropriate for using in all of farms around the world. It has been used at least 3 times along rearing period. Its simple structure made it easy to construct in farms. Many of these constructed sorters have some applied problems such as heavy weight, low accuracy and high mortality. This research was conducted to construct an appropriate sorter without these malfunctions. 4 manual sorters with variable characteristics in frame, Tubs and table was made and tested in 3 replicates for assessing accuracy, broken opercula, mortality, and sorter weight, using with bench and saving working human power. Results showed that for constructing a sorter frame, PVC was more appropriate than wood, aluminum and fiber glass. Using tubes with 30 mm in diameter showed more significant variation (p< 0.05). Fixed tubs were more accurate than wheeling tubs and aluminum tubs was more appropriate than PVC tubs. Using bench with a sink can support sorter frame and decreased human work power from 2 people to 1.