ALBERT

Description: The effects of aquaculture industry on the environment were evaluated by studying the water quality of Bushehr costal water during culture season 2005 and 2006. The variations of selected parameters such as total phosphorus, ammonia, chlorophyll a, pH, salinity and... Were monitored in effluent canal, influent canal and open sea in Helleh and Mond regions as monthly. Following occurrence of White Spot Disease (W.S.D) in the shrimp ponds of Bushehr province, shrimp culture suspended and entrance of effluent waters completely were blocked since August 2005, despite the absence of aquaculture sewage evaluation of environment and sampling were continued. During releasing of sewage of shrimp ponds to the coastal waters of Bushehr in Jun 2005, the average amount of ammonia in Helleh and Mond were obtained to be 0.161 mg/l and 0.194 mg/l, however the average amount of total phosphorus in Helleh and Mond regions were 0.149 mg/l and 0.043 mg/l, respectively. Although effluent water suspension, amount of ammonia and total phosphorus were increased in both region especially in June 2006. Comparing present data in Jun 2005 and recorded data from culture period 1997-2003 with permitable range of municipal and aquaculture waste show that; aquaculture industry on both regions have not had any obvious negative effect on the coastal waters of Bushehr but it seems if other sources of pollutions in the region is not controlled, then the aquaculture industry can contribute to occurrence of environmental problems.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: We determined the LC50 of copper (as CUSO4) and it's Maximum Allowable Concentration (MAC) for Litopenaeus vannamei. The study was performed in 2003 for which bioassays were used for acute toxicity tests in a period of 96 hours during which water parameters such as water temperature, pH, dissolved oxygen, hardness, alkalinity were also measured. Ten treatments and three replicates for each treatment were used. A LC50 of 86.71, 27.28, 7.98 and 3.90mgi1 and also Maximum Allowable Concentration of 8.671, 2.728, 0.798 and 0.390mgi1 were determined at 24, 48, 72 and 96 hours post exposure. Results showed that L. vannamei is relatively resistant to copper. Hence, short period application of copper to white shrimp farms for controlling algal bloom is judged harmless to the fish.

Description: Published

Description: The influence of different dietary levels of plant protein (30, 50 and 70%) on growth indices of White Leg Shrimp (Litopenaeus vannamei) fed with an original 38 percent protein was assessed and compared with that of the commercial shrimp diet. The average weight gain at the end of the culture period in treatment 1 (30% plant protein and 70% animal protein), was 5.89 plus or minus 0.06 grams, for treatment 2 (50% plant protein and 50% animal protein), was 6.22 plus or minus 0.25 grams, for treatment 3 (70% plant protein and 30% animal protein), was 6.19 plus or minus 0.24 grams and for the control treatment (20% plant protein and 80% animal protein), was 6.42 plus or minus 0.40 grams. Our study of the influence of experimental and control diets on growth indices including growth rate (GR), food conversion ratio (FCR), protein efficiency ratio (PER), specific growth rate (SGR), and average daily gain (ADG), demonstrated that the indices were better in the control compared to the treatments. No significant difference was found among the treatments and between the treatments and the control for the indices (P〉0.05). The percent of net protein utilization (NPU) in treatment 1 was significantly more than other treatments (P0.05). We also found that the application of diets containing 50% plant protein (with 20% soybean meal), and 70% plant protein (with 41.72% soybean meal), can decrease diet costs. Cost of one kilogram of pellet, in treatments 1, 2, 3 were, 83.3%, 68.3% and 53.3% lower than the control diet respectively. Decrease of cost in treatment 2 and 3, in comparison to control in terms of lowering shrimp production cost is very important.

Description: Published

Description: In order to investigate some ecological condition of the waters of Bushehr province in the Persian gulf between 50~'-01 E to 52~'-47 E and 26~'-39 N to 29~'-03 N , 18 major and 16 minor stations have been studied from Nayband bay to Kharg Island, using R.V. Ferdows 1. There have been a preliminary survey in winter 2001, 4 seasonal surveys in 2001-2 and a complementary one in summer 2002. During this period the seasonal environmental conditions, physico-chemical parameters, zoo and phytoplankton concentrations in water layers, macrobenthoses and sediments were studied. Sea bed swelling in the Motaf region has resulted in division of the area in two parts and in a such away that the climatic and chemico-physical conditions in the southeast area are different from the northwest area. In the southeast area the termocline, halocline, picnocline and oxycline are generated in spring, increased in summer, moved down to the deeper layers in fall and disappeared in the winter. In the Northwest area the clines are only formed in spring and summer but disappear in fall and winter due to almost perfect water column mixing resulted from climatological conditions. During survey period the water temperature ranged from 18 34.1~'C, salinity 37.9 41.3 ppt, conductivity 51.3 70.4 ms/cm, sigma〈sub〉T〈/sub〉 23.1 30.2 g/cm〈super〉3〈/super〉, dissolved oxygen 0.2 8 ppm, and chlorophyll a 0.1 3.6 mg/m〈super〉3〈/super〉. It is observed that salinity, conductivity and sigma〈sub〉T〈/sub〉 have increased from surface to depeer layer, while oxygen and chlorophyll a had a pick in mean layers but temperature have decreased from surface to the depth. Temperature and conductivity decreased from southeast to the northwest and from costal to offshore. Salinity and sigma〈sub〉T〈/sub〉 increased from southeast to the northwest. Dissolved oxygen and chlorophyll-a did not show any trend. The concentration of nutrients including ortho silicate (Si-SiO〈sub〉4〈/sub〉〈super〉- 4〈/super〉), ortho phosphosphate (P PO〈sub〉4〈/sub〉〈super〉-4〈/super〉), nitrate (N NO〈sub〉3〈/sub〉〈super〉-〈/super〉 ) and nitrite (N NO〈sub〉2〈/sub〉〈super〉-〈/super〉 ) varied between 0.4 13.3, 0.05 1.6, 0.1 12.3 and 0.1 1.4 ~kmol/l, respectively. The overall nutrient concentrations increased from surface to depth. 61 genuses of 5 phytoplankton groups and 8 branches, 12 classes of zooplankton were identified. The identified phytoplanktons included 42 Diatom, 16 Dinophyceae, 3 Cyanophyceae, one Chrysophyceae and one Euglenaphyceae geneses. The highest intensity of phytoplanktons was recorded in summer, while in the case of zooplankton, was recorded in spring. Diatoms had the highest variety in all seasons and the maximum abundance in fall and winter. Cyanophyceaes were predominant group in the spring and summer. On the contrary to zooplanktons, the intensity of phytoplanktons decreased from coastal to the offshore waters. The highest intensity of all planktons (zoo and phyto) was in 10-20 m layer. The intensity of phyto plankton increased from southeast towards northwest. The zooplankton concentration didn t follow any particular trend. The identified macrobenthoses were 69 families including 34 polychaets, 22 gastropods, 10 of bivalvs, 1 crustacean, 1 scaphopoda, 1 foraminifera, 5 classes and 6 orders of crustacea, 1 order of echinodermata, 1 fish larva and 6 branches of other benthoses. Intensity and biomass of all groups were determined. The polychaets and malacostraca had the most abundance in contrast to the other groups. Macrobenthosis intensity decreased from coast to the offshore in southeast of Motaf region, while the middle stations of northwest of Motaf had a better intensity. The mean abundance and biomass of total area decreased from coast to the offshore, and the slope of decrease in biomass was more than abundance. Seasonal minimum and maximum abundance ranged from 1457 to 1903 per square meter in spring and winter, and the biomass ranged between 7.8-10.8 g/m〈super〉2〈/super〉 in summer and spring, respectively. In spite of high abundance of macrobenthose in the transect no: 13, the estimated biomass was lower than other transects. This might be due to prolonged exposition to more pollutant. The grain size of sediments was classified as gravel, sand, silt and clay. The organic mater of sediments ranged from 1.12 3.3% with annual average of 1.6%. The grain size of sediments in southeastern point was coarser than other areas. The middle stations of northwestern area had fine grain and more organic mater in contrast to the offshore and coastal stations.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: The influence of different percents of plant protein (30, 50 and 70) in the diet of white leg shrimp (Litopenaeus vannamei) with 38 percent protein, in comparison with a commercial shrimp diet (Fenneropenaeus indicus) with 39 percent protein (contain20 percent plant protein) was studied. Initial weight of shrimp was 10±1 gram. The average increase of shrimp weight in the end of culture period in experimental treatment 1 (contain 30 percent plant protein and 70 percent animal protein), 5.89±0.06 gram, experimental treatment 2 (contain 50 percent plant protein and 50 percent animal protein), 6.22±0.25 gram, experimental treatment 3 (contain 70 percent plant protein and 30 percent animal protein) 6/19±0/24 gram and in the control treatment (contain 20 percent plant protein and 80 percent animal protein) 6/42±0/40 were measured. Generally in the study of influence of experimental diets and control diet on the growth rate(GR), food conversion rate (FCR), protein efficiency ratio (PER), specific growth rate (SGR), average daily gain (ADG), demonstrate that, mentioned parameters in the control treatment is better than experimental treatments. But no significant difference measured between them (p〉0/05). Also results showed that, application of diets contain 50 percent of plant protein (with 22 percent soybean meal), and 70 percent of plant protein (with 72 percent soybean meal), can decrease costs of diet preparation and therefore shrimp production.

Description: Iranian Fisheries Science Research Institute

Description: Published