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This study was conducted for investigation on algae bloom monitoring and oscillations of biotic and non-biotic parameters in coastal waters of Bandar Abbas from October 2013 to Septembre 2014. In this project, planktonic distribution and environmental data were collected from five stations, every 10 days. Four order and 45 genus of phytoplankton (Bacilliarophycea 29 genous, Dinophycea 13 genus, Cyanophycea 2 genus, Raphidophycea 1 genus) were identified, as well as , 10 order of zooplanckton consisted of Copepoda, Mollusca, Chaetognatha, Sarcomastigophora, Urochordata, Annalida, Nematoda, Echinodermata, Ciliophora and Granuloretica. Results showed that Bacillariophycea were dominate among phytoplankton species in all season. So that, Leptocylindrus, Chaetoceros and Nitzschia from Bacillarriophycea, Protoperidinium and Gymnodinium belong to Dinophycea, and Oscillatoria belong to Cyanophycea were dominate genus in Bandar Abbas coastal waters. The maximum and minimum density and frequency for phytoplankton were recorded respectively from Shilat Jety and Airport Stations. Based on ANOVA analysis on phytoplankton density no significant were observed seasonally (p>0.05), but significant differences were observed between stations (p

This study was conducted to determine water quality and sediment of Aras River based on environmental parameters, metals (Mo, Cu, As, Hg) and determine of heavy metals in fish species at four stations (From Julfa to 25km after Nourdos border) during four seasons from 2015 to 2016. All samples were carried out standard methods using titration and spectrophotometer instruments. Result showed that range of water and weather temperature, DO, BOD5, COD, EC, Turbidity, TA, CO2, pH, DIP, NH4/N, NO2/N, NO3/N and IRWQI were observed 200-24.00, 3.00-28.00 C, 8.90-15.01, 1.77-13.41, 2.00-86.00 mg/l, 1.00-1.34 ms/cm, 2.4-638.0 NTU, 116-247 mg/ CaCO3 l, 0.20-2.20 mg/l, 8.06-8.79, 0.026-0.195, 0.330-0.575, 0.005-0.026, 3.640-6.474 mg/l, and 31.10-48.02, respectively. Mean of whole parameters (TA, NO2 - and NO3 - ) were significant between seasons and (p0.05). Result showed that range of Mo, Cu, As, Hg in water and sediment were observed 0.10-23.01, 3.0-40.0, 0.02-0.81, 23.7-104.6 µg/l, 0.1-111.6, 17.5-482.5, 0.001-0.145, 46.8-303.6 µg/g.dw, respectively.As a conclusion, water quality of Aras River was classified in class III (moderate pollution) based on mean concentration of Cu and As concentration was observed less than threshold level. Water quality of Aras River was classified in class IV and II based on mean value of Hg and As, respectively. Maximum value of Mo and Cu at surface sediment was registered at stations 3 and 4 during all seasons which it is because of effluent of sewage from Mo, gold and other metals mines in Armenia country. Mean concentration of As at surface sediment was higher than standard value, but concentration of Hg was lower than threshold value. Bioaccumulation factor was also calculated for each species.The amount of Bioaccumulation factor for molybdenum is the highest and the arsenic metal has the lowest amount. The highest concentration of copper in Barbus lacerta with a mean of 13.6 ± 11.3 μg / g dry weight and for the molybdenum, Alburnoides bipunctatus had the highest mean concentration (11.7 ± 4.9) μg / g dry weight. The average concentration of mercury (13.1 ± 1.5 μg / kg dry weight) was highest in Alburnus alburnus. Regarding the arsenic element, as it was analyzed in a small number of specimens, the highest concentrations were recorded in Alburnoides bipunctatus . According to ANOVA, there is a significant difference between mean concentration of copper in different species (p

Nutrient enrichment is followed by excessive algal growth (possible in toxic and hamful species); in Caspian Sea in recent decades. So aims of the present study were 1-study on potentional of algal bloom at different transects and seasons, 2- determine correlation between potentional of algal bloom and environmental parameters using statistical model, and 3- the role of sediment nutrients on algal bloom in the southern Caspian Sea in 2013-2014. The samples of water were collected from four transests (Bandar Anzali, Tonekabon, Bandar Nowshahr and Bandar Amirabad) and three depths (5, 10 and 20 meter) during four seasons. Surface sediments samples were collected at same depths and transects as well. Result showed that organic phosphorous and nitrogen of water were more than inorganic phophorous and nitrogen. Also, maximum and minimum water temperature was obtained at summer and winter, respectively. The values of DO and salinity were more than 5 ml/l and 12 g/l, respectively and pH of water were ranged from weak alkaline to alkaline. Maximum organic and inorganic phosphorous and nitrogen of water were distributed at different transects and seasons. The nitrogen was limiting factor accomponing with phosphorous during spring, summer and fall, but during winter shift to more nitrogen limitation. In addition, the ecosystem was experienced sillicon limitation during winter. Result of sediments showed that inorganic phophorous was maximum during different seasons, however, percent mean of residue-P which contain organic compounds and non-degrediable compounds, was less that 5 percent. Percent of Ca-P was higher than 90, whereas Bioava.-P was less that 10 percent. The order of different forms of phosphorous were registered Ca-P>Org-P>Fe-P>Al-P>Loosely-P. The mian role of adsorbed and desorbed of Loosely-P, Fe-P and Al-P were due to temperature, Eh and pH, respectively. Annual percent of TON was two folds than TIN and NH4/N was also three times than NO3/N. Minimun and maximum of phytoplankton abundance were obserbed in summer (73±31 million cells/m3) and winter (505±55 million cells/m3), respectively. Statiscal analysis (ANOVA) showed that phytoplankton abundance significantly increased in winter compared to the other seasons (P1000 cells/ml) during spring. Maximum abundance of phytoplankton was mainly registered at Anzali and Amirabad transects.The re-existence of Thalassionema nitzschioides (as valuble food in food chain) in dominant species list (same as the stability year of ecosystem) and decreasing of percent abundance of harmful species to the dewell and native species are good sign of good quality of the Caspian Sea water. However, Pseudonitzschia seriata expansion of the cold season to other seasons (even in summer) is important point. Pseudonitzschia seriata as harmful algae and its ability to produce toxin and potential bloom, high percent frequency and abundance during the study has important role in environmental issues of the Caspian Sea.It seems that temperature changes in different parts of the Caspian Sea in each season (except fall season) was obtained in the range of dominant species needed, therefore, it had less importance compared to nutrients. Trophic status was meso-eutroph during fall and winter seasons which was higher level than spring and summer (mesotroph). The Stephanodiscus abundance increased at Anzali transet due to nutrients enrichment of water in spring. Excessive use of silica in the spring, summer caused dominant of non Diatoms species (Binuclearia lauterbornii) and low content of Diatoms species (Chaetoceros throndsenii). In fall, high abundance of Bacillariophyta (Thalassionema nitzschioides) accompanied with consuming of silicon and ammonium. The statistical analysis also showed significant correlation between Bacillariophyta and Thalassionema nitzschioides abundance and Si/N ratio. Subsequently, the excessive use of silica in autumn and winter (due to high abundance Bacillariophyta and dominant species including Pseudonitzschia seriata and Dactyliosolen fragilissima) cause severely declined dissolved silica, and for the first time in winter, silicon was limited factor for phytoplankton growth. In addition, the results showed that there were positive correlations between abundance of dominant species and nutrients of sediments in all seasons. This is shows that some species of phytoplankton, even though the limitation of nitrogen and phosphorus in the water, are able to supply the nutrients required from the surface sediments. It would be more importance in the present study, which higher concentration of different forms of phosphorus and nitrogen in sediments as compared to the deep water, provide transport of nitrogen and phosphorus from sediment to water column. Iranian Fisheries Science Research Institute Published

This study was conducted to spatio-temporal fluctuation and distribution of phosphorous and nitrogen species, total organic carbone and some environmental parameters at suface sediments in the southern of Caspian Sea. In current study, 48 samples were collected from four stations (Bandar Anzali, Tonekabon, Bandar Nowshahr and Bandar Amirabad) and three dephths (5, 10 and 20 meter) during four seasons in 2013-2014. Results of this study showed that annual mean of Adsorbed-P, Fe-P, Al-P, Bioava.-P, Ca-P, TIP, Rese.-P and TP were obtained 6.68±0.63, 60.90±2.44, 24.94±2.39, 94.52±3.62, 1868±36, 1963±37, 87.51±9.52 and 2050±38 µg/g.dw, respectively. Result also showed that inorganic phophotous was maximum during different seasons, however, percent mean of residue-P which containe organic compounds and non-degrediable compounds, was less that 5 percent. Percent of Ca-P was higher than 90, whereas Bioava.-P was less that 10 percent. The order of different forms of phosphorous were registered Ca-P>Org-P>Fe-P>Al-P>Adsorbed-P.Annual mean of NH4/N, NO3/N, TIN, TON and TN were observed 2.56±0.27, 0.89±0.12, 3.52±0.26, 6.06±0.27 and 9.57±0.32µg/g.dw respectively. Annual percent of TON was two folds than TIN and NH4/N was also three times than NO3/N. In addition, mean of Fe, Al, Ca, Eh and TOC% were obtained 25.39±0.65, 18.76±0.68, 60.15±1.50 mg/g.dw and 67.02±0.68, 1.11±0.09, respectively. Maximum mean of carbon (1152±171), nitrogen (0.87±0.05) and phoporous (74±23) µM/g were observed in fall, winter and summer, recpectively. Also, maximum ratios of TOC:TP (16.8±2.3) and TOC:TN (2378±363) were obtained in fall season. As a conclusion, mian role of Adsorbed-P, Fe-P and Al-P adsorbed and desorbed were temperature, Eh and pH, respectively. Results of this study showed that TOC:TN was very high which represented to excitance of organic matter with almost non-degrediable. Whereas, TOC:TP was low which showed that organic phophoros was not related to proteins and phospholipids therefore sources of org-P were belong to other compounds.

The project investigates the relationship between the biological parameters (phytoplankton, zooplankton, Macrobenthic and ctenophore- Mnemiopsis leidyi) and environmental parameters, nutrients and environmental pollutants (oil, pesticides, heavy metals, and detergents) in water and sediment, at the southern of Caspian Sea in 2010-2011. Sampling was carried out in four seasons (spring, summer, autumn and winter) and in eight transects perpendicular to the coast (Astara, Anzali, Sefidroud, Tonekabon, Noshahr, Babolsar, Amir Abad and Bandar Turkmen). Samples were collected from the different layers at depths of 5, 10, 20, 50 and 100 meters. The relationship between biological and environmental parameters surveyed through parametric and multivariate statistical methods. Result showed that the annual mean of environmental parameters and nutrients concentration such as water temperature, pH, transparency, DO, ammonium, nitrate, inorganic nitrogen (DIN), organic nitrogen (DON), inorganic phosphorus (DIP), organic phosphorus (DOP) and soluble silicon (DSi) at euphotic layer were 16.70±0.43 (ºC), 8.38±0.01 (m), 5.48±0.05 (ml/l), 1.52±0.06 (µM), 1.80±0.08 (µM), 3.41±0.10 (µM), 43.3±0.9 (µM), 0.32±0.01 (µM), 0.52±0.02 (µM), 8.88±0.22 (µM), respectively. Meanwhile, annual mean of environmental pollutant such as PAHs and OCPs in sediment were recorded 0.88±0.16 (µg/g.dw) and 9.78±2.20 (µg/g.dw), respectively. In addition, annual mean of heavy metals such as Zn, Cu, Ni, Pb and Hg in sediment were obtained 247±46 (µg/g.dw), 29.5±1.5 (µg/g.dw), 49.9±4.9 (µg/g.dw) and 0.179±0.800 (µg/g.dw), respectively. Annual mean abundance of biological parameters namely phytoplankton, zooplankton and M. leidyi (0-20m) at photic layer were 238±17 (million cells/m3), 4808±362 (individuals/m3) and 26±3 (individuals /m3) respectively, and for biomass were 747±60 (mg/m3), 44.3±5.0 (mg/m3), 2.15±0.31 (g/m3). Annual mean abundance of those biological parameters at below of photic layer (50-100m) were 104±35 (million cells/m3), 843±92 (individuals/m3) and 2±1 (individuals /m3) respectively, and for biomass were 412±93 (mg/m3), 9.1±1.0 (mg/m3), 0.15±0.05 (g/m3). Annual mean abundance and biomass of macrobenthic were 5073±1225 (individuals /m2) and 144±73 (g/m2), respectively. Annual mean annual percentage of TOM, Gravel, Sand and Silt-clay were recorded 3.74±0.26, 0.92±0.32 , 22.51±4.97 and 76.67±5.01, respectively. The stratification of water column was strongly based on gradient of water temperature and the phenomenon (difference of temperature between water layers) was more clear in this study compared to previous years. Temperature and biological factors (phytoplankton) were effected on changes of dissolved oxygen at warm and cold seasons summer and winter), but coefficient factor of temperature was higher than biological factors in winter. The nutrients concentration (with the exception of inorganic phosphorus) in different years 2008-2009, 2009-2010 and 2010-2011 increased compared to 1995-1996 (the year of stability of ecosystem). One of the reason attribute to the presence of the ctenophore (M. leidyi) in Caspian Sea after 1999. The annual correlation of phytoplankton abundance and temperature was reversed but seasonal pattern was varied at each season (within a year). In this study, the Caspian Sea contained the conditions of nitrogen limitation (55%) and nitrogenphosphorus limitation (6-43%) as well as phosphate limitation (2-39%) (DIN/DIP>20) . Inspite of no silica limitation (sufficient concentration of silica) in the Caspian ecosystem, Bacillariophyta was not dominance phylum at whole seasons.It seems that other factors such as the temperature changes of seasons, the effects of predation and feeding of the next chains of the food chain, the difference of the ability in the growth and reproduction, competition (uptake of nutrients) in dfferent groups of phytoplankton and stoichiometry of the nutrients (nitrogen and phosphorus) were caused of non-diatoms dominance at most seasons. As, Pyrrophyta and Bacillariophyta were dominant at spring and winter, respectively and Cyanophyta was pre-dominant at summer and autumn. Multivariate analysis showed the significant correlation between Coppepoda and oxygen and water temperature only. The other gropus of zooplankton did not show any significant correlation with environmental parameters. It might be due to stronger effects of other parameters such as food and predators on different groups of zooplankton at each season and abundance of zooplankton groups indirectly affected by environmental parameters. In this study, Shannon diversity indices of zooplankton and phytoplankton were closer to 1995-96 values and showed diferent trend compared to 2009-2010. However it is not enough reason for recovery of ecosystem in to the stability of Caspian Sea. It is because of other negative evidiance such as strong increasing trend of phytoplankton to zooplankton biomass ratio in all seasons and regions particularly the 2009-2010 and 2010-2011 years compared to 1995-96 (the year of stable ecosystem). In the other word, the balance between the biomass of the first and second of the food chain has been disturbed and the value was much much higher than the year of stable ecosystem in 1995-96. Based on multivariate analyses, there was not significant correlation between zooplankton groups and some edible phytoplankton species, vise versa zooplankton groups consumed some unsuitable species of phytoplankton (based on size, nutritional value, difficulty of digestion and absorption, the potential of toxicity and harmfulness). The lack of expected relationship and routine rules of nutritional between zooplankton and phytoplankton are the more resons of instability in the ecosystem. In current study, dominant group of macrobenthos (polychaeta) observed in depths less than 20 meters which the percentage of silt-clay and sand were 74 and 26, respectively. It seems that this ratio of silt-caly and sand was suitable for their living and accumulation. PCA analysis showed that increasing the percentage of TOM and siltclay accompanied to the decreasing of macrobenthos abundance while increasing the temperature, dissolved oxygen and pH had a positive effect on macrobenthos abundance in most seasons. Increasing the abundance of macrobenthos at all seasons (except spring) would not be a strong indication of improvement of Caspian ecosystem after the ctenophore introduction stress and unfavorable evidence such as low Shannon diversity index observe in the results. Meanwhile, in the present study, Streblospio and oligochaeta (invasive growth and advantage to the food uptake and habitat and sediment seeding) similar to the years of 2008-2009, 2009-2010 still were dominant groups insteade of Gammaridae family (feeding on suspended solids). This means that sediment has a noteworthy amount of organic matter which indicate to the trophic level of ecosystem tend to eutrophy level. The comparison of results on this study to previous studies on biological parameters (phytoplankton, zooplankton and macrobenthos) indicating to the persistence of stress (such as biological and anthropogenic) on their changing population patterns (quantitative relationships between species) and structural patterns (species composition and seasonal succession of dominant species). In other words, many species (both macroscopic and microscopic) of the Caspian Sea are still vulnerable to complications of stressor factors. In order to protection and sustainable exploitation of this worth ecosystem it is necessary to look more serious studies and practical techniques from the relevant organizations in this area. Iranian Fisheries Science Research Institute Published

Harmful algal blooms resulting in red discoloration of coastal waters in the Persian Gulf, Iran were first observed in January 2007. The species responsible for the bloom, which was identified as Cochlodinium polykrikoides, coincided with massive aquatic organisms’ mortalities in the Persian Gulf. In order to provide optimum growth and bloom forming, C. polykrikoides cells were sampled during the bloom conditions in the coastal waters of Persian Gulf. After adaptation in filtered seawater, they isolated by positive phototropism characteristic of this species to light. They were grown in modified media culture at different salinity (30, 32 and 35ppt), temperature (20, 23, 26 and 28ºC) and intensity (35, 70 and 90 µmol m^-2 s^-1) with an initial cell density of 50 cell mL^−1. The results of the present study clearly showed that the highest alga biomass was obtained following culture by using A^2 medium under the 32ppt salinity, 26°C temperature, and under a 11h light:13h dark photoperiod regime at a light intensity of 90 µmol m^-2 s^-1 provided by cool white fluorescent tubes. Mean cell density of C. polykrikoides in a 60 liter tank for ten days reached to 32 × 10^6 cell L^−1. Moreover, individual C. polykrikoides chain with 18 cells was observed for the first time in cultures. Based on the results from the present study, as mentioned above, providing suitable media culture and physical condition (light intensity and temperature), bloom forming of C. polykrikoides start from day 8 to 10 and will be continued until day 24 t0 28. In the other hand, C. polykrikoide cells immediately crashed and destroyed.

The project investigates the relationship between the biological parameters (phytoplankton, zooplankton, Macrobenthic and the comb jelly Mnemiopsis leidyi) and environmental parameters, nutrients and environmental pollutant (oil, pesticides, heavy metals, and detergents) in water and sediment, at the southern part of Caspian Sea in 2009-2010. Sampling was performed in four seasons (spring, summer, autumn and winter) and in eight transects perpendicular to the coast in Astara, Anzali, Sefidroud, Tonekabon, Noshahr, Babolsar, Amir Abad and Turkmen. Samples were collected from depths of 5, 10, 20, 50 and 100 meters and the different layers. The relationship between biological and environmental parameters surveyed through parametric and multivariate methods. Based on the result, the annual mean of environmental parameters and nutrients concentration at euphotic layer such as water temperature, salinity, pH, transparency, DO%, ammonium, nitrate, inorganic nitrogen (DIN), organic nitrogen (DON), inorganic phosphorus (DIP), organic phosphorus (DOP) and soluble silicon (DSi) were 17.82±0.32 (ºC), 11.35±0.10 (g/l), 8.43±0.01 (m), 126±1 (%), 3.76±0.19 (µM), 1.55±0.07 (µM), 4.81±0.13 (µM), 29.88±0.66 (µM), 0.24±0.01 (µM), 0.62±0.02 (µM), 8.22±0.22 (µM), respectively. Meanwhile, annual mean of environmental pollutant such as TPH, OCPs and LAS in water were 12.33±1.76 (µg/l), 2.85.0.90 (µg/l), 0.048±0.003 (mg/l), respectively and for TPH and OCPS in sediment were recorded 33.07±9.36 (µg/g) and 2.64±0.34 (µg/g), respectively. In addition, annual mean of heavy metals such as Ni, Hg, Pb and Cd at water were 4.01±0.01 (µg/l), 0.64±0.01 (µg/l), 15.0±0.1 (µg/l) and ND respectively, and in sediment were obtained 43.77±3.55 (µg/g), 0.13±0.29 (µg/g), 14.14±1.07 (µg/g) and 0.07±0.06 (µg/g), respectively. Abundance annual mean of biological parameters such as phytoplankton, zooplankton and M. leidyi were 143±12 (million cells/m3), 6548±700 (individuals/m3) and 86±10 (individuals /m3) respectively, and for biomass were 548±41 (mg/m3), 60±9 (mg/m3), 5.06±0.65 (g/m3). Abundance and biomass annual mean of macrobenthic were 5970±460 (individuals /m2) and 44±10 (g/m2), respectively. The stratification of water column was strongly based on gradient of water temperature and the rule of salinity was low in this area. According to mono and multivariate statistical analysis, the southern of Caspian Sea experienced four seasons without any overlapping based on environmental parameters and nutrients. In 2009-10, the nitrogen concentration was higher than previous years and showed a decrease in the amount of inorganic phosphorus in the study area. Therefore, the system has been lead to phosphorus limitation. No limitations of the DSi in the Caspian ecosystem had caused the dominance of bacillriophyta phylum during spring, autumn and winter. However in summer (highest seasonal mean temperature) which held the most DIP, the cyanophyta was dominant phylum. During spring and winter, the abundance of zooplankton was maximized and conversely the minimum values observed during summer and autumn with growth increasing of M. leidyi. By now, M.leidyi has been preferred the time with highest temperature or salinity during year. However with considering PCA analysis result and high ability of the organism to adaptation, the M.leidyi will probably to growth and reproduce at lower temperature and salinity than now in this area. Result showed that during summer and autumn only abundance of two of six main zooplankton groups namely Copepoda and Cirripedia were noticeable. The other zooplankton groups were low due to high consumption by different predators or were influenced by environmental factors. The dynamics population of M.leidiy is used to consider as first explanation of the Caspian ecosystem happening, however the interaction of different factors such as temperature, salinity, nutrients and predators determine the dynamic of biological parameters. Based on statistical analysis, feeding behavior of zooplankton species was not same in different seasons and was strongly dependent on the phytoplankton structure (species diversity and population). In other words, the classical boundary of phytoplankton species to, edible and suppressed, non-edible and unaffected and finally non-edible, enhanced species was not possible. Copepoda can act as filter-feeder and raptorial-feeder. So Copepoda compare to Cladocera (generally filter- feeder and sometimes raptorial feeder) and Rotifera (mostly suspension feeding and sometimes raptorial feeder) had more chances and opportunities for the achievement food and it support them for dominanane in all seasons. Anthropogenic and eutrophication affect on the structure and function of plankton community and it reflected on ratio of phyto/zoo biomass. Seasonal increasing of different groups of zooplankton were done through their life cycles in 2009-10, but mostly phytoplankton abundance increased several folds than zooplankton populations. This trend made the ratio of phyto/zoo biomass at 10, 4, and14 during spring, summer and autumn, respectively. In summer, with stratification of water column and dominant of Cyanophyta, grazing pressure by herbivores zooplankton was low. However in winter due to the zooplankton population growth, the ratios reached to 11, and declined with 1.3 folds compare to autumn. Because of severe decreasing of zooplankton biomass in 2009-10 compare to years before introduction of M.leidiy in to the Caspian Sea, the ratio of phyto/zoo biomass increased from "less than" 5 "to more than 10" Top-down control of zooplankton grazing on phytoplankton populations was clear in the years before the introduction of M.leidyi in to the Caspian Sea. But in 2009-10 zooplankton Shannon index reduced and phytoplankton Shannon index increased. In other word higher functional diversity at the lower trophic level (phytoplankton) increased the probability of successful defense against top-down control from zooplankton and phytoplankton abundance controled mainly by nutrients materials (down-top control). Seasonal macrobenthos abundance showed the maximum values in summer and minimum in the cold season (winter). The polychaeta had the highest proportion of abundance compare to others main orders (oligochaeta and crustacea). The dominance of deposit feeder species of polychaeta indicates to high level of organic matter in sediment and trophic status of ecosystem. Result of CCA analysis showed that three dominant orders had different behavior respect to environmental and sediments characteristics. The oligochaeta order was directly related to sediments characteristics (TOM) and inverse relationship with environmental parameters at most seasons. In contrast, polychaeta order was linked with environmental parameters in most seasons.Crustacea order was related to the both of them. Two orders of oligochaeta and crustacea were also related directly to OCPs and inverse relationship with TPH and heavy metals. In the other words, the two orders were more affected by TPH and heavy metals in this area. As a last point, increasing of trophic level from oligotrophic to the meso–eutrophic status, an increase of DO% from 105 percent to 120 percent, phytoplankton Shannon index increasing, zooplankton Shannon index decreasing, entrance of the potentially invasive species to the list of dominant phytoplankton species, increasing of phyto/zooplankton biomass ratio from less than 5 to more than 10 and also increasing of deposit feeder species abundance of macrobenthos are some evidences that indicate to disturbance and stress condition of the Caspian Sea. Iranian Fisheries Science Research Institute Published

Seasonal variation and vertical distribution of water temperature, pH, electrical conductivity, dissolved oxygen and chlorophyll-a from the Iranian waters of Hormozgan province in the Persian Gulf were studied from February 2001 to February 2002. All parameters were measured by using CTD multi parameter probes at 30 sampling stations. Data obtain revealed that seasonal thermocline appears in the survey area during spring, extended in summer, diminishes in autumn and gradually eliminate during winter season. Variation in electrical conductivity follows the changes in winter temperature throughout the year except in winter. Dissolved oxygen was recorded to be higher in the depth layer of 10-25 meters and decreases by increasing depth. Vertical pH of water indicated a decreasing pattern from surface to bottom throughout the year, with highest decrease in autumn, when the dissolved oxygen decreases as well. The maximum concentration of chlorophyll-a was recorded at depth layers of 20-40m and 10-20m during first and second half of the year, respectively.

The brine shrimp is used as a worth food source in aquaculture today..... Iranian Fisheries Science Research Institute Published

Iranian Fisheries Science Research Institute Published