Hydrology and hydrobiology data analysis collected during 1998-2007

Annually, many data of hydrology and hydrobiology of the southern Caspian Sea at Iran's coasts were collected by Caspian Sea Research Institute of Ecology. The data which had been collected by researchers submitted annually in several reports but has not been processed all at once. Fluctuations of various parameters were surveyed and the relationships between them were analyzed. The main goal of this research is to analysis the data were obtained from 1994 to 2006 and show changes the concentration of various parameters in the Caspian Sea. Physicochemical data indicated that the average trend of transparency and salinity was decreased from 1994 to 2006 annually, where the salinity value was decreased from 12.37 ppt (part per thousand) to 11.5 ppt. The average of dissolved oxygen was increased from 6.4 to 8.6mg/l. pH has slightly fluctuated from 8.15 to 8.31. However, with increasing depth from surface to bottom, the average of dissolved oxygen was sharply decreased (DO concentration in surface and 800 m was 7.18 and 1.45 mg/l, respectively). The trend of salinity and pH fluctuation was very slow with depth but the salinity has an increasing with incrementing of depth but pH has a decreased trend. The average of organic and inorganic phosphorus and TP was nearly increased. The average of Nitrate and Silica sharply increased comparing to depth but the average of Nitrite and organic Nitrogen decreased. The results showed that the temperature fluctuation in different water layers was low in winter but the dramatic decreasing of temperature was occurred at 10-20 m (in spring), 20-50 m (in winter) and 50-100 m (in autumn). With increasing of depth (Slope of the Sea), transparency and salinity values have an increasing while DO and pH showed decreased. As a whole, 335 species of phytoplankton were identified, there are 70 species in advance as these species were not seen in this period but 96 of novel's species have been recorded. The lowest and the most of phytoplankton biomass was recorded in 2006 and 2001 while the biomass was 59 and 1034 mg/m^3, respectively. Albet, the lowest biomass was recorded at the depth of 100 m (24.1 mg/m^3) but the maximum was observed in surface layer (1344.1 mg/m^3). The average of phytoplankton biomass was increased after arrival of the ctenophore. There was a significant difference between the average of biomass in different seasons before and after of the ctenophore invasion (P0.137, P>0.782). Before the presence of ctenophore, the worms had been constituted a dominate group with an approximately %45 of total abundance and also %20 of their biomass. After this period, their frequency was sharply increased (more than %85) but the maximum value pertains to Cardidae (more than %90). The species diversity, evenness and richness were varied between .69-2.51, 0.23-0.63 and .011-3.79, respectively. AMBI software, Shanon-Viner parameter was moderate in all seasons from 1994 to 1996 but this parameter was reduced in a bad limit (boundary) in the most seasons from 2002 to 2005. The main parameter of M-AMBI consists of several parameters and also approximately showed similar changes such as Shanon -viner parameter. On basis of this parameter, the ecological quality condition of Caspian Sea was superior limit in all seasons from 1994 to 1996 but after the following years were decreased from good to moderate limits (After the presence of ctenophore). Relationship between abiotic variants and phytoplankton indicated that there was a direct relationship between transparency and salinity while there was a powerful and reversal significant relationship between transparency water temperature, transparency in organic Nitrate, phytoplankton number and transparency phytoplankton biomass. The comparison between different variants average in two periods (before and after the ctenophore invasion) indicated that the average of Kilka catch was decreased, the relative frequency of clupeonella engrauliformis and clupenoella grimmi was sharply reduced but the relative frequency of Clupeonella cultriventris was sharply increased, the species diversity, evenness and richness and the number of zooplankton species were sharply decreased, the average of biomass and transparency was sharply reduced, the average of dissolved oxygen and liza saliens or liza auratus catch were increased. These difference were often significant (P<0.05). Therefore, with the ctenophore invasion into the Caspian Sea, the primary production was increased, the biomass value of zooplankton and specially Kilka which fed on zooplankton were sharply decreased while the fish such as Rutilus frisii kutum and mullet (Liza salins or Liza aurratus) which fed on benthic were increased

Bester (beluga ♀ × starlet ♂) production and comparing their growth with beluga in Iran

Aquaculture for human consuming species is being considered as the first substitution of catching aquatic species due to increase of human population and decrease of wild aquatic stocks. In this study, the hybrid sturgeon Bester (female beluga x male sterlet) was produced for the first time in Iran. Sperm of 1.35 kg male Acipenser ruthenus was used to fertilize the eggs of 125 kg female Huso huso in Shahid Marjani Sturgeon propagation center (Agh Ghala, Golestan province). The fries of bester and control treatment of beluga were transported to International Sturgeon Research Institute (Rasht) after about one month by reaching to 490 mg and 377 mg of weight respectively. All fishes fed by artificial concentrated food (48-50% protein and 15-17% fat) after a period of feeding with Artemia and Daphnia. Sorting was carried out according to increase of fish weight for both fishes. Results showed that the imported sterlet spawners were not at the high maturation stages and especially the males had not suitable sperm quality. It showed that up to 2 months of age , these was no significant difference between bester and beluga weight but from this age up to 2 months of age the weight of beluga was greater. Meanwhile from 2 months old up to the end of the study (21 months) the weight of bester sample was significantly greater than beluga. The comparison of FCR for the whole rearing period showed no difference between bester and beluga (2.4 and 2.3 respectively). In general, the increase and decrease pattern of GR and SGR were coincided to each other, but showed monthly differences. Growth rate (GR) and specific growth rate (SGR) of bester were greater than beluga from 4th and 3rd month of rearing period respectively

Study of physico-chemical Characteristics of water in the southern of Caspian Sea

This study was conducted to physico-chemical characteristics of water in the Iranian coastal of southern Caspian Sea during four seasons at 8 transects (Astra, Anzali, Sefidrud, Tonekabon, Nowshahr, Babolsar, Amirabad and Bandar Turkman) during 2009-2010. 480 samples were collected at different layers of water and then analyzed based on standard methods. Results showed that the mean of water temperature were 18.67±0.32 and 17.82±0.43 ◦C at the surface and euphotic layer, respectively. Minimum and maximum of water temperature were recorded in winter (6.40) and summertime (27.60). In addition, temperature gradient was ranged between 12 to 15 ◦C at 20 to 50 layers in 50 and 100m depths. Mean of salinity was 11.04±0.17 g/l at euphotic layer. Pearson correlation between temperature and salinity was positively significant. Therefore, maximum salinity was recorded in summer and minimum in winter. Mean of transparency (SD) in the present study was 4.35±0.21 m which compared to the pervious sampling period (2008) showed small decrease, but the mean of pH was observed 8.43±0.01 which was higher than the previous sampling period (2008). The mean of DO and DO% were observed 5.72±0.06 ml/l and 130±1 percent at euphotic layer during sampling period. The mean of DO% was recorded 104±5 at euphotic layer in 1996 (before introduction of Mnemeiopsis leidyi), but the study in the years 2004, 2008 and present (one decade after introduction of Mnemeiopsis leidyi) this value was registered higher than 120% at euphotic layer. This shows that trophic status of Caspian ecosystem shifted from oligotrophy (before introduction of Mnemeiopsis leidyi) to meso-eutrophy (after introduction of Mnemiopsis leidyi). Annual concentration of inorganic nitrogen (DIN= NH^4 +, NO^2-, NO^3-) has a fairly wide variation. Percentage of nitrogen components out of DIN were varied 9-98, 0.2-28.2 and 0.0-90.0 respectively. In this study, percentage of DIN was lower than 15% and organic nitrogen (DON) was higher than 80%. Overall, results showed that water temperature, salinity, transparency and DON were recorded lower than the previous study (2008), but DO, DO%, pH, NH^4+, NO^3- and DSi were higher than the previous sampling period. Inorganic phosphorous (DIP) and NO^2- have not changed substantially. N/P ratio of Caspian Sea has a narrow range which order of magnificent lower than other seas. The results of the present study showed that Caspian ecosystem was nitrogen limitation before introduction of Mnemiopsis leidyi, while it seems that after introduction of Mnemiopsis leidyi the system has been shifted to the phosphorous limitation

Rearing of common carp (Cyprinus carpio) in fiber glass tanks with pellet feeding

The intensive culture of common carp (Cyprinus carpio) evaluated in fibreglass tanks (2*2m) with feeding on pellet during 8 weeks. The fish (n=201)of common carp selected from three treatments along with three replicates as the average of fish weight was less than 100(g )which divided into 0.05).The common pellet food was chosen for feeding from market as fish were fed by the mean of 4% of their body weight a day. The result indicated that the mean of particular growth ratio at first treatment (0.54) has higher than second treatment (0.34) but in comparison with third treatment (0.46), there was no statistically significant difference (P<0.05).Also, the conversion ratio at first treatment (5.28) and third treatment (6.09) was lower than second treatment (35.66) and third treatment (20.91) was lower than second treatment (24.24), (P<0.05). This study showed that monoculture in small scale is feasible by utilizing artificial diet, if the water quality is exposed to change. In this survey, the conversion ratio of the fish was relatively high whereas the growth rate was low

Feasibility study of rainbow trout (Oncorhynchus mykiss ) culture in brackish water in earthen fish pond in North Khorasan province

The use correct of non-agricultural land due to saline and waternon fresh for rearing of aquatic animals, especially fish, in good seasons, can generate for employment and provide fertile ground . This study aimed to assess the ability of Rainbow Trout reared in earthen ponds potential using brackish water stub area south of North Khorasan province in cold seasons (autumn and winter) have been conducted. Farming operations in three earthen ponds, each with an area of 3,000 square meters and two water wells within 160 days of the initial electric Bahdayt 8400 and 18100 µs was conducted. Average initial weight of juveniles when introduced into soil ponds 32.0±1.0 and 22.7±1/7 grams and density drop in the of ponds 5 and 7 number per cubic meters . Feeding on pond done recipes nutrition standards Related to fish size and water temperature was during the period culture . To help improve the water quality during the breeding ponds of cyclic change in volume of pond water (20-15%) and two aeration SPLASH with errive fresh water to form rain fall in each pond was used. The results obtained during the period of measurement water physico-chemical parameters (temperature, electrical conductivity, dissolved oxygen, nutrients, total dissolved substances, acidity) shows changes in the mean amplitude of these factors has been tolerated for raising trout The results showed that children reared trout have been introduced since the introduction of nteroperability with brackish water in the pond also grown to over 14 thousand have salt and water changes physical and chemical factors have endured. The results showed that fish farming in addition to works by adapting the environment had to foster the growth of the pond water . So in 5 months, with a mean survival of 87 percent hindrance develop marketable size with an average weight of 340±12-390±13and 470 ±17grams and have a total production of more than 20 tonnes. All of it has been confirmed, the study area (SFRAIEN)is very suitable for the breeding Rainbow trout of pond during the fall and winter seasons

Survey of diversity, distribution, abundance and biomass of macrobenthic fauna in the southern Caspian Sea

Sediments samples were collected using Veen Grab Sampler (0.1 square meter) at 8 transects namely Astara, Anzali, Sefidroud, Tonekabon, Noshahr, Babolsar, Amirabad, Torkman in the southern of Caspian Sea. Five stations were selected at 5, 10, 20, 50 and 100 meter depths in each transect. Sediments were sampled triplicate at each station. Samples also were collected during four seasons (spring (May), summer (July), fall (November) and winter (January)) in 2009. Results of this study showed that species composition of Macrobenthos consisted of 32 species which belonged to 7 families of Polychaeta, Crustacea and Bivalvia at studied area. In addition, Oligochaeta identified in “Class”, Chironomidae considered in Insecta categories “Family” and Streblospio spp. (Polychaeta) was recognized in “Genus”. Gammaridae and Pseudocumidae of Crustacea with 12 and 10 species had the highest species diversity compared to other groups, respectively. Polychaeta was consisted 75.5 percent of total abundance of macrobenthos which the major abundance (equal 62.4% of total abundance) were belong to Streblospio spp. from Spionidae family, while its biomass was equals 5.11% of total macrobenthos. In contrast, Cerastoderma lamarcki species from Bivalvia Class with only 1.7% of total abundance of macrobenthos allocated 69 percent of total biomass. In the southern of Caspian Sea, average total abundance was significantly less at 4 western transects (Astara, Anzali, Sefidroud, Tonekabon) compared to 4 eastern transects (Noshahr, Babolsar, Amirabad, Torkman) (p<0.05). The highest average abundance of macrobenthos (10655±1246SE ind/m^2) was observed at transect of Torkman, and lowest value (4032 ± 686SE ind/m^2) was recorded at transect of Sefidroud (p< 0.05). Generally, minimum species diversity were obtained at 20 m depth in all transects and the maximum value was observed at 5 m depth in most of transects (p<0.05). In contrary, maximum average abundance of Macrobenthoses was at 20 m depth in transects of Anzali, Sefidroud, Tonekabon, Nowshahr and Amirabad compared to other depths. Macrobenthoses abundance average in 5 m depth (except Astara and Torkman) was less than other depths in 6 transect (p < 0.05). Total average abundance and biomass of macrobenthos was 5976±583SE ind/m^2 and 43.675 ± 11.402SE gr/ m^2, respectively. Maximum and minimum of abundance of macrobenthos were observed in summer (7714±778 ind/m^2) and winter (4071 ± 340 ind/m^2), respectively. Maximum and minimum of biomass of macrobenthos were obtained in fall (50.271±13.258SE gr/ m^2) and in summer (35.123 ± 8.903SE gr/ m^2), respectively (p< 0.05). Percent of total organic matter (TOM) were low in 5 and 10 m depths and increased toward offshore depths. TOM percent was 2.06±0.11SE at 10 m depth and increased to 4.62 ±0.17SE in 100 m depth. Percent of silt and clay (grains size less than 63 micron) had positive significantly correlation with percent of TOM (p<0.01).While they had negative significantly correlation with percent of sand (grains size between 63 and 1000 micron) (p<0.01). Percent of silt and clay like organic matter, had ascending trend toward to depth increased and varied from 44.4 ± 4.06SE percent in 5 m depth to 96.5 ± 0.59SE percent in 100 m depth. In contrast, percent of sand decreased toward depth and varied from 54.5 ± 4.13SE percent in 5 m depth to 2.8 ± 0.53SE percent in 100 m depth. Result of current study showed that total abundance of macrobenthoses had positive significantly correlation with TOM percent (p<0.01) and silt/clay percent (p<0.05). Abundance of Oligochaeta had positive significantly correlation (p< 0.01) with TOM and silt/clay percent. Two groups of Polychaeta, Gammaridae and Cerastoderma lamarcki had negative significantly correlation with TOM and silt/clay percent (p< 0.01), and every four aforementioned groups had positive significantly correlation with sand percent (p< 0.01). Overall, different correlation between abundance of various macrobenthos groups and TOM percent and type of grain size of sediment could be related to fluctuation of abundance of various macrobenthos groups at difference transects and depths. On the other hand, in study area were occurred simultaneously some phenomena such as increased abundance of Oligochaeta and Polychaeta, dominance of Streblospio Genuse (Polychaeta group), and decreases abundance of Bivalvia and appearance of Menemiopsis leidyi which need to study more and monitoring of this area

Production of bacterial probiotic from trout (Oncorhynchus mykiss) for improvement of immune system and challenge to streptococcosis

This study was conducted for the first time and the effects of probiotic bacteria isolated from the gut of Rainbow trout (Oncorhynchus mykiss). In the first step, after the purification of the isolated bacteria, probiotic properties in vitro was assessed with injection to healthy fish and challenge with three species of pathogenic bacteria in culture media. The second phase of the bacteria isolated in 5 treatments (log 7, 8 and 9 of the lactic bacteria (LAB), Vibrio sp and Pseudomonas sp) and a control treatment on growth and survival, hematological parameters (RBC and WBC cells), immunology and physiology parameters tested during the 60 days of the above parameters after 30 and 60 days and finally at the end, the final assessment was Streptococcosis resistance in fish. The results showed that the isolated bacteria were able to enhance the growth parameters (weight, feed conversion, feed fat, protein efficiency ratio and specific growth rate) and survival. The results showed that log 8 LAB was significant difference with other treatments and control. When using log 8 LAB and Vibrio, the MCV, MCH and MCHC were decreased with no significant difference. The log 8 has the greatest effect on the amount of liver enzyme (AST), IgM and complement component C3, and had significant difference with other treatments. The challenge examination to Streptococcus iniae showed the highest survival in treatments with log 8 (96.66%), and Vibrio (93.33%) and then subjected to other treatments and control are also the least survival (25.38%). The conclusion of that study is the first probiotic properties of bacteria isolated from trout to changes in quality indicators are in particular the LAB bacteria and the second log 8 of LAB had significant positive of changes development and safety, and the fish are resistanted against Streptococcosis

Stock assessment of the bony fishes in Iranian coastal waters of the Caspian Sea (2007-2010)

In the years 2007-2007, 2008-2009 and 2009-2010 the exploitation of bony fishes resources (by 131 beach seines) started on 12 October but finished on 9 April, 9 April and 13 April, respectively. During these periods the total catch of bony fishes were 23537.8, 20045.5 and 18664.8 tonnes, respevtively. During these periods, kutum predominated and represented the highest proportion of total catch at 73.1, 74.0 and 66.9% , followed by golden grey mullet at 18.3, 13.9 and 18.7%, respectively. K values calculated 0.22, 0.15 and 0.14 year-1 and L∞ were 66.0, 62.7 and 70.0 cm for kuttum, golden grey mullet and common carp, respectively. The instantaneous coefficient natural mortality were estimated as 0.386 and 0.35 year-1 for kutum and golden grey mullet, respectively. During three periods, the exploitation rates were 0.789, 0.584 and 0.614 for kutum and 0.71, 0.75 and 0.61 for golden grey mullet, respectively. In the years 2007-2007, 2008-2009 and 2009-2010, the total biomass, from the biomass-based cohort analysis were 56600, 62090 and 61590 tonnes for kutum and and MSY estimated about 24733.7 and 8550.4 tones for kuttum and 11040, 11900 and 14460 tonnes for golden grey mullet, respectively. The ABC (acceptable biological catch) were estimated as 8000 and 2200 tonnes