ALBERT

Description: Concentration of chlorophyll-a and quantitative feature of phytoplankton are major concern in primary production estimation and prediction of probably algal blooms in aquatic ecosystems. The subject has important role in development and sustainable exploitation of marine culture. The goals of the project are study of chlorophyll-a concentration changes and its relations to variations of phytoplankton community structure parameters and abiotic factors (environmental and nutrients matters) in the costal waters of the Caspian Sea- Goharbaran region during 2013-2014. Monthly water samples were collected from different layers (surface, 5 and 10m) and depths (5, 10 and 15 m). The minimum mean (±SE) of abundance and biomass reported in spring (39± 9 million cells/m3) and summer (94± 40 mg/m3) respectively. The results showed maximum abundance (553± 58 million cells/m3) and biomass (1209± 106 mg/m3) in winter season. The minimum and maximum mean (±SE) values of chlorophyll-a recorded in spring (0.60± 0.05) and autumn (4.56± 0.23) mg/m3, respectively. The changes trend of field chlorophyll-a concentration was confirmed by satelit data. Bacillariophyta showed the highest percent abundance in all seasons except in summer which it was for chlorophyta phylum. Pyrrophyta was the second dominant phylum in winter as well as spring; however its contribution in phytoplankton abundance of winter was low. The first dominant abundance species in spring, summer, fall and winter were Prorocentrum cordatum, Binuclearia lauterbornii, Thalassionema nitzschioides and Pseudonitzschia seriata respectively. Based on the results the species of Prorocentrum (scutellum+ proximum+obtusum) in spring and fall seasons, Cyclotella menenghiniana in summer and Pseudonitzschia seriata in winter showed the highest role in phytoplankton biomass forming. chlorophyll-a concentration showed significant Pearson correlations with biomass of total phytoplankton, bacillariophyta, pyrrophyta and chlorophyta phyla, dominant species, size cells of dominant species, water temperature, clearancy, nutrients matters. The study showed that chlorophyll-a cells content of winter dominant species was lower than fall dominant species. The Change of seasonal taxonomic phytoplankton pattern showed important role in relationship between chlorophyll-a cells content with biotic and abiotic factors. Meanwhile the values of temperature, nutrient matters, pH, pattern of dominant phytoplankton species showed significant roles on decoupling between chlorophyll-a and biomass changes pattern. The critical time of algal bloom recorde from September to January and March based on chlorophyll-a concentration. Spatial critical algal bloom was more obvious on surface water from October to December based on chlorophyll-a concentration. Pseudonitzschia seriata and Binuclearia lauterbornii species classified in medium bloom threshold (in winter and summer respectively) in all sampling depths. However Thalassionema nitzschioides (in fall) was in medium bloom threshold in 10 and 15m depths. As conclusion, in order to estimate logic primary production and predict algal blooms in the cage and pen culture sites it is necessary that all phytoplankton parameters such as chlorophyll-a concentration, biomass, abundance, shape, size, biological and ecological chracterstics of dominant species are considered. Because changes in the chlorophyll-biomass relationship could lead to obviouse errors interpretation of results and as well as unexpected field observations.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: The survey sampled during the fourth stage of the season was in 1387. Sampling in eight directions perpendicular (transect) to the beach and 480 samples was performed. In each transect from Astara to the Turkmen 5 stations at depths of 5, 10, 20, 50 and 100 m were selected for sampling. The total number of 191 species was identified; Bacillariophyta category species number was 97, equivalent to %50.8, category of Chlorophyta 28 species, equivalent to %14.7, category of Pyrrophyta 26 species, equivalent to 13.6 %, category of Cyanophyta 25 species, equivalent to 13.1% and category of Euglenaphyta 15 species, equivalent to 7.9% of all species formed. Average abundance of phytoplankton was 27947500(SD=2465184) n/m3 . The average biomass was 125.51(SD=8.84) mg/m3 . Abundance and biomass in spring and summer, autumn and winter have been significant differences (p 〈0.05). The highest frequency was in winter, autumn, summer respectively and spring was (p 〈0.05) and The highest biomass in winter, fall, spring and summer was respectively (p 〈0.05). Bacillariophyta category has the highest abundance equal to 14390833 ± 16262.35 n/m3 (mean ± standard error) were equivalent to %51.49 of the total abundance, Euglenophyta category has the least density equal to 109791 ± 16262.14 n/m3 (mean ± standard error), which is equivalent to % 0.39 of total abundance were included. Also Pyrrophyta category has the highest biomass equal to 69.66 ± 5.53 mg/m3 (standard error ± mean) were equivalent to %53.14 of the total biomass and Chlorophyta category with an average of 0.68 ± 0.11 mg/m3 (mean ± standard error) have the lowest biomass, were equivalent to %0.54 of the total. Phytoplankton Categories in every season, with biomass and abundance have been different (p 〈0.05). Abundance and phytoplankton biomass in the upper layer and lower layer varies with depth of 50 meters (p 〈0.05). With distance from shore and depth increases, reducing the mean abundance and biomass were observed (p 〈0.05). The highest and lowest abundance of phytoplankton was observed at depths of 10 and 100 meters respectively. The maximum amount of phytoplankton biomass in surface areas of deep stations 20 m and the lowest biomass sampled at the deepest point of the station was 100 meters. Abundance and biomass of phytoplankton in the deep layers of the sample with significant difference (p〈0.05) . So that the highest abundance layers of 10 m, the surface layer of 5 m, 20 m, 50 m and 100 m, respectively(p 〈0.05), and the most biomass in the surface layers of 5 m, 20 m, 10 m, 50 and 100 meters, respectively (p 〈0.05). Abundance and biomass of phytoplankton in transects was significant difference (p 〈0.05). Most phytoplankton respectively transect Astara, Babolsar, Anzali Amirabad, Turkmen, Sefidrud, Noshahr, Branch was observed (p 〈0.05) and in terms of biomass, respectively transects Astara, Anzali, Sefidrud, Babolsar, Noushahr, Branch, Amirabad and Turkmen values were higher (p 〈0.05). Species diversity indexe (Shannon – Wiener) phytoplankton was equivalent to 2.92. Environmental conditions and nutrients in different seasons on these parameters influenced the way that species diversity was lowest in summer and in autumn, winter, and spring, respectively, species diversity increased.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: 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.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: Comb jelly Mnemiopsis leidyi investigation was conducted in the southern region of the Iranian coast of the Caspian Sea during the 2010 in the seasons of spring, summer, autumn and winter at 8 transect with depths of 5, 10, 20, 50 and 100m. Sampling was done at 0–5, 0-10, 0-20, 20-50 and 50–1000 m using a 500 µ and 50 cm mouth opening area. During 2010, a total of 757 samples of comb jelly were collected by the size length of smaller than 5 mm to a maximum of 35 mm. Mean annually Mnemiopsis abundance and biomass was 11±2 ind.m3 and 0.6±0.1 g.m3 . Maximum abundance was recorded in autumn with 25.7±4.8 ind.m3 and maximum biomass was observed in summer of 1.2±0.1 g.m3 . Minimum abundance was found in spring with 2.3±0.4 ind.m3 and minimum biomass was in winter of 0.1±0.3 g.m3 . Statistical comparison showed that the density of comb jelly were not significantly different in spring and summer (P〉0.05, Tukey test), and winter and summer with the same density, while having the highest density of autumn compared to other seasons which showed a significant difference (P〈0.01, Tukey test). Comb jelly biomass showed summer and spring with higher than winter and autumn, compared to the statistical comparison showed no significant difference in biomass between seasons of summer- spring and fall – winter (P〉0.05). Fluctuations of comb jelly abundance and biomass in different seasons showed that the water level of 20 m had a higher value than other layers. In the spring, more than 98 percent of the comb jelly was recorded in the upper layer (less than 20 m), and only 2 percent of the animals living in layers of 20-50 m. In the summer and autumn, about 93 percent of Mnemiopsis was found in the layers above 20 m and 7 percent of those in the lower layers (maximum 50 meters). In the winter, more comb jelly were observed in layers from 20 to 50 m (about 14 percent) and about 87 percent of them were collected in layers less than 20 meters. As a whole, the total maximum annual average abundance was recorded in the autumn of layer 0-5 m with 94.0± 33.8 ind.m3 and the highest average biomass in the 0-5 m layer of summer with 3.1±1.0 g.m3 . Frequency of group length (size) of the population M. leidyi showed that comb jellies of less than 15 mm (prior to adult) consisted of 85.8%, in which at less than 20 m, group length (size) of 15 mm included of 82-92% and at the depth of more than 50 m, these group was 8-18%. Also comb jelly adults (greater than 16 mm) in the surface layers (less than 20 m) were included of approximately 73 to 100% and below 20 m, 0-27 % of the population. Data of the 8 transect showed that the highest density and biomass of Mnemiopsis were recorded in Torkaman with 16.4± 6.5 ind.m3 , and 0.8±0.2 g.m3 , respectively. Statistical comparison of the mean abundance and biomass of comb jelly showed that there were a significant differences between Turkmen and Amirabad transect compared to other transects (P〈0.05). Regional distribution of M. leidyi in the southern Caspian Sea showed aggressive area in terms of density and biomass are areas with significant differences (P〈0.05). Comb jelly population showed that both West and East in terms of abundance and biomass were similar but different with the central region. Eastern and western regions compared to the central region have the higher abundance. Based on the study looks at the rise and persistence parameters of comb jelly, it seems two main factors such as water temperature to the desired value, especially in summer (22-30°C), and food availability (zooplankton) have more roles in the southern of the Caspian Sea. After the invasion of M. leidyi into the Caspian Sea, not only the abundance and biomass of zooplankton decreased but also the species diversity decreased from 36 to 15 species. Hence, it seems the decline in the South Caspian comb jelly was due to decreased of fecundity for lack of zooplankton feeding resources.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: Region South East of the Caspian Sea (area Goharbaran) having valuable resources biological flora and fauna, the diversity of commercial fishes, especially reserves the exclusive sturgeon as well as reserves abiotic such as oil and gas resources and transit of goods through Bandar Amirabad to Central Asia , the ecological conditions for the implementation of the project is very necessary.The aim of this study was to determine species composition, spatial and temporal distribution of plankton and fish of this region.Plankton sampled from different depths (5, 10 and 15 m) were carried out.Sampling of phytoplankton did by Ruttner and sampling of zooplankton did by net with mesh size 100 microns.The fish were sampled monthly from December 2013 to July 2014 and within months was carried out. From livestock gill Monofilament.. In this study, a total of 130 species of phytoplankton of 7 filums Bacillariophyta (60 species), Pyrrophyta (23 species), Cyanophyta (22 species), Chlorophyta (14 species), Euglnophyta (9 species), Haptophyta (1 species) and Chrysophyta (1 species )and 24 species of zooplankton branch of Copepoda (5 species), Rotatoria (7 species), porotozoa (3 species), Cladocera (9 species), and Meroplankton (2 species) of larvae of Cypris Balanus and bivalves Lamellibranchiate larvae and 256 fish Acipenser persicus at 5, Alosa braschnikowi 71 number, Alosa caspia 40 number, Benthophilius lipidus 1 number, Cluponella cultriventris 72 number, Cyprinus carpio 1 number, Liza saliens 15 number, Neogobius bathybius 1 number, Neogobius caspia 5 pcs, Neogobius flauviatilis 19 number, Neogobius gorlab 6 number, Rutilus kutum 14 number, Rutilus rutilus 2 pcs, vimba vimba 4 number was observed.Different ecological conditions appointment dietary needs and relationships of organisms and their adaptations to the environment, the density and distribution of different species of phytoplankton, zooplankton and fish specifies.Also the Caspian Sea due to the type of biological species and number of endemic species (42%) in addition to comb jelly invasion, were force of the effects some species like Gloeotrichia Echinulata and as a result, now or in the future, more species will be observed and recognized will be of most interest. Also Psedonitzschia seriata ability to produce Domick acid that can be hazardous to aquatic animals and even human, was in Goharbaran area. This was considered for fishes of the southern Caspian Sea and ecological distribution of most species depends on the region. The abundance of two species of whitefish and pelagic fish in Ghahrebaran region is more than the whole Caspian Sea. On the other hand, the dominant phytoplankton of this region is Bacillariophyta and dominant zooplankton is Copepoda, which shows the goodness of these plankton branches, and by changing the various factors as the different terms of receiving solar energy and resulting in temperature and water currents can cause seasonal differences in the density of the Bacillariophyta branch and also the Copepoda, therefore one of the most important factors is season, and in the winter, when the aquatic rotation of this ecosystem increases, it increases the nutrients and moves it from the floor to the water column, and as a result, increasing the amount of silica in various levels of water can affect the nutrition of fish.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: Region South East of the Caspian Sea (area Goharbaran) having valuable resources biological flora and fauna, the diversity of commercial fishes, especially reserves the exclusive sturgeon as well as reserves abiotic such as oil and gas resources and transit of goods through Bandar Amirabad to Central Asia , the ecological conditions for the implementation of the project is very necessary. The aim of this study was to determine species composition, spatial and temporal distribution of plankton and fish of this region. Plankton sampled from different depths (5, 10 and 15 m) were carried out. Sampling of phytoplankton did by Ruttner and sampling of zooplankton did by net with mesh size 100 microns. The fish were sampled monthly from December 2013 to July 2014 and within months was carried out. From livestock gill Monofilament.. In this study, a total of 130 species of phytoplankton of 7 filums Bacillariophyta (60 species), Pyrrophyta (23 species), Cyanophyta (22 species), Chlorophyta (14 species), Euglnophyta (9 species), Haptophyta (1 species) and Chrysophyta (1 species )and 24 species of zooplankton branch of Copepoda (5 species), Rotatoria (7 species), porotozoa (3 species), Cladocera (9 species), and Meroplankton (2 species) of larvae of Cypris Balanus and bivalves Lamellibranchiate larvae and 256 fish Acipenser persicus at 5, Alosa braschnikowi 71 number, Alosa caspia 40 number, Benthophilius lipidus 1 number, Cluponella cultriventris 72 number, Cyprinus carpio 1 number, Liza saliens 15 number, Neogobius bathybius 1 number, Neogobius caspia 5 pcs, Neogobius flauviatilis 19 number, Neogobius gorlab 6 number, Rutilus kutum 14 number, Rutilus rutilus 2 pcs, vimba vimba 4 number was observed.Different ecological conditions appointment dietary needs and relationships of organisms and their adaptations to the environment, the density and distribution of different species of phytoplankton, zooplankton and fish specifies.Also the Caspian Sea due to the type of biological species and number of endemic species (42%) in addition to comb jelly invasion, were force of the effects some species like Gloeotrichia Echinulata and as a result, now or in the future, more species will be observed and recognized will be of most interest. Also Psedonitzschia seriata ability to produce Domick acid that can be hazardous to aquatic animals and even human, was in Goharbaran area. This was considered for fishes of the southern Caspian Sea and ecological distribution of most species depends on the region. The abundance of two species of whitefish and pelagic fish in Ghahrebaran region is more than the whole Caspian Sea. On the other hand, the dominant phytoplankton of this region is Bacillariophyta and dominant zooplankton is Copepoda, which shows the goodness of these plankton branches, and by changing the various factors as the different terms of receiving solar energy and resulting in temperature and water currents can cause seasonal differences in the density of the Bacillariophyta branch and also the Copepoda, therefore one of the most important factors is season, and in the winter, when the aquatic rotation of this ecosystem increases, it increases the nutrients and moves it from the floor to the water column, and as a result, increasing the amount of silica in various levels of water can affect the nutrition of fish.

Description: 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.

Description: Comb jelly Mnemiopsis leidyi investigation was conducted in the southern region of the Iranian coast of the Caspian Sea during the 2010 in the seasons of spring, summer, autumn and winter at 8 transect with depths of 5, 10, 20, 50 and 100m. Sampling was done at 0–5, 0-10, 0-20, 20-50 and 50–1000 m using a 500 µ and 50 cm mouth opening area. During 2010, a total of 757 samples of comb jelly were collected by the size length of smaller than 5 mm to a maximum of 35 mm. Mean annually Mnemiopsis abundance and biomass was 11±2 ind.m3 and 0.6±0.1 g.m^3 . Maximum abundance was recorded in autumn with 25.7±4.8 ind.m3 and maximum biomass was observed in summer of 1.2±0.1 g.m^3. Minimum abundance was found in spring with 2.3±0.4 ind.m3 and minimum biomass was in winter of 0.1±0.3 g.m^3. Statistical comparison showed that the density of comb jelly were not significantly different in spring and summer (P〉0.05, Tukey test), and winter and summer with the same density, while having the highest density of autumn compared to other seasons which showed a significant difference (P〈0.01, Tukey test). Comb jelly biomass showed summer and spring with higher than winter and autumn, compared to the statistical comparison showed no significant difference in biomass between seasons of summer- spring and fall – winter (P〉0.05). Fluctuations of comb jelly abundance and biomass in different seasons showed that the water level of 20 m had a higher value than other layers. In the spring, more than 98 percent of the comb jelly was recorded in the upper layer (less than 20 m), and only 2 percent of the animals living in layers of 20-50 m. In the summer and autumn, about 93 percent of Mnemiopsis was found in the layers above 20 m and 7 percent of those in the lower layers (maximum 50 meters). In the winter, more comb jelly were observed in layers from 20 to 50 m (about 14 percent) and about 87 percent of them were collected in layers less than 20 meters. As a whole, the total maximum annual average abundance was recorded in the autumn of layer 0-5 m with 94.0± 33.8 ind.m3 and the highest average biomass in the 0-5 m layer of summer with 3.1±1.0 g.m^3 . Frequency of group length (size) of the population M. leidyi showed that comb jellies of less than 15 mm (prior to adult) consisted of 85.8%, in which at less than 20 m, group length (size) of 15 mm included of 82-92% and at the depth of more than 50 m, these group was 8-18%. Also comb jelly adults (greater than 16 mm) in the surface layers (less than 20 m) were included of approximately 73 to 100% and below 20 m, 0-27 % of the population. Data of the 8 transect showed that the highest density and biomass of Mnemiopsis were recorded in Torkaman with 16.4± 6.5 ind.m^3 , and 0.8±0.2 g.m^3 , respectively. Statistical comparison of the mean abundance and biomass of comb jelly showed that there were a significant differences between Turkmen and Amirabad transect compared to other transects (P〈0.05). Regional distribution of M. leidyi in the southern Caspian Sea showed aggressive area in terms of density and biomass are areas with significant differences (P〈0.05). Comb jelly population showed that both West and East in terms of abundance and biomass were similar but different with the central region. Eastern and western regions compared to the central region have the higher abundance. Based on the study looks at the rise and persistence parameters of comb jelly, it seems two main factors such as water temperature to the desired value, especially in summer (22-30°C), and food availability (zooplankton) have more roles in the southern of the Caspian Sea. After the invasion of M. leidyi into the Caspian Sea, not only the abundance and biomass of zooplankton decreased but also the species diversity decreased from 36 to 15 species. Hence, it seems the decline in the South Caspian comb jelly was due to decreased of fecundity for lack of zooplankton feeding resources.

Description: The survey sampled during the fourth stage of the season was in 1387. Sampling in eight directions perpendicular (transect) to the beach and 480 samples was performed. In each transect from Astara to the Turkmen 5 stations at depths of 5, 10, 20, 50 and 100 m were selected for sampling. The total number of 191 species was identified; Bacillariophyta category species number was 97, equivalent to %50.8, category of Chlorophyta 28 species, equivalent to %14.7, category of Pyrrophyta 26 species, equivalent to 13.6 %, category of Cyanophyta 25 species, equivalent to 13.1% and category of Euglenophyta 15 species, equivalent to 7.9% of all species formed. Average abundance of phytoplankton was 27947500(SD=2465184) n/m^3. The average biomass was 125.51(SD=8.84) mg/m^3. Abundance and biomass in spring and summer, autumn and winter have been significant differences (p 〈0.05). The highest frequency was in winter, autumn, summer respectively and spring was (p 〈0.05) and the highest biomass in winter, fall, spring and summer was respectively (p 〈0.05). Bacillariophyta category has the highest abundance equal to 14390833 ± 16262.35 n/m^3 (mean ± standard error) were equivalent to %51.49 of the total abundance, Euglenophyta category has the least density equal to 109791 ± 16262.14 n/m^3 (mean ± standard error), which is equivalent to % 0.39 of total abundance were included. Also Pyrrophyta category has the highest biomass equal to 69.66 ± 5.53 mg/m^3 (standard error ± mean) were equivalent to %53.14 of the total biomass and Chlorophyta category with an average of 0.68 ± 0.11 mg/m^3 (mean ± standard error) have the lowest biomass, were equivalent to %0.54 of the total. Phytoplankton Categories in every season, with biomass and abundance have been different (p 〈0.05). Abundance and phytoplankton biomass in the upper layer and lower layer varies with depth of 50 meters (p 〈0.05). With distance from shore and depth increases, reducing the mean abundance and biomass were observed (p 〈0.05). The highest and lowest abundance of phytoplankton was observed at depths of 10 and 100 meters respectively. The maximum amount of phytoplankton biomass in surface areas of deep stations 20 m and the lowest biomass sampled at the deepest point of the station was 100 meters. Abundance and biomass of phytoplankton in the deep layers of the sample with significant difference (p〈0.05). So that the highest abundance layers of 10 m, the surface layer of 5 m, 20 m, 50 m and 100 m, respectively(p 〈0.05), and the most biomass in the surface layers of 5 m, 20 m, 10 m, 50 and 100 meters, respectively (p 〈0.05). Abundance and biomass of phytoplankton in transects was significant difference (p 〈0.05). Most phytoplankton respectively transect Astara, Babolsar, Anzali Amirabad, Turkmen, Sefidrud, Noshahr, Branch was observed (p 〈0.05) and in terms of biomass, respectively transects Astara, Anzali, Sefidrud, Babolsar, Noushahr, Branch, Amirabad and Turkmen values were higher (p 〈0.05). Species diversity indexe (Shannon – Wiener) phytoplankton was equivalent to 2.92. Environmental conditions and nutrients in different seasons on these parameters influenced the way that species diversity was lowest in summer and in autumn, winter, and spring, respectively, species diversity increased.

Description: Concentration of chlorophyll-a and quantitative feature of phytoplankton are major concern in primary production estimation and prediction of probably algal blooms in aquatic ecosystems. The subject has important role in development and sustainable exploitation of marine culture. The goals of the project are study of chlorophyll-a concentration changes and its relations to variations of phytoplankton community structure parameters and abiotic factors (environmental and nutrients matters) in the costal waters of the Caspian Sea- Goharbaran region during 2013-2014. Monthly water samples were collected from different layers (surface, 5 and 10m) and depths (5, 10 and 15 m). The minimum mean (±SE) of abundance and biomass reported in spring (39± 9 million cells/m^3) and summer (94± 40 mg/m^3) respectively. The results showed maximum abundance (553± 58 million cells/m^3) and biomass (1209± 106 mg/m^3) in winter season. The minimum and maximum mean (±SE) values of chlorophyll-a recorded in spring (0.60± 0.05) and autumn (4.56± 0.23) mg/m^3, respectively. The changes trend of field chlorophyll-a concentration was confirmed by satelit data. Bacillariophyta showed the highest percent abundance in all seasons except in summer which it was for chlorophyta phylum. Pyrrophyta was the second dominant phylum in winter as well as spring; however its contribution in phytoplankton abundance of winter was low. The first dominant abundance species in spring, summer, fall and winter were Prorocentrum cordatum, Binuclearia lauterbornii, Thalassionema nitzschioides and Pseudonitzschia seriata respectively. Based on the results the species of Prorocentrum (scutellum+ proximum+obtusum) in spring and fall seasons, Cyclotella menenghiniana in summer and Pseudonitzschia seriata in winter showed the highest role in phytoplankton biomass forming. chlorophyll-a concentration showed significant Pearson correlations with biomass of total phytoplankton, bacillariophyta, pyrrophyta and chlorophyta phyla, dominant species, size cells of dominant species, water temperature, clearancy, nutrients matters. The study showed that chlorophyll-a cells content of winter dominant species was lower than fall dominant species. The Change of seasonal taxonomic phytoplankton pattern showed important role in relationship between chlorophyll-a cells content with biotic and abiotic factors. Meanwhile the values of temperature, nutrient matters, pH, pattern of dominant phytoplankton species showed significant roles on decoupling between chlorophyll-a and biomass changes pattern. The critical time of algal bloom recorded from September to January and March based on chlorophyll-a concentration. Spatial critical algal bloom was more obvious on surface water from October to December based on chlorophyll-a concentration. Pseudonitzschia seriata and Binuclearia lauterbornii species classified in medium bloom threshold (in winter and summer respectively) in all sampling depths. However Thalassionema nitzschioides (in fall) was in medium bloom threshold in 10 and 15m depths. As conclusion, in order to estimate logic primary production and predict algal blooms in the cage and pen culture sites it is necessary that all phytoplankton parameters such as chlorophyll-a concentration, biomass, abundance, shape, size, biological and ecological chracterstics of dominant species are considered. Because changes in the chlorophyll-biomass relationship could lead to obviouse errors interpretation of results and as well as unexpected field observations.