فهرست مطالب javid imanpour namin

Marine ecosystems are under serious threat from climate change, which can alter species distributions, biodiversity patterns, community structure, and ecosystem functioning by affecting temperature, acidification, and current patterns. Species distribution models (SDMs) are a useful tool for ecologists to link species’ fundamental niches with environmental conditions and project potential distribution shifts under climate change scenarios. This study modeled current and future habitat suitability for the black pomfret (Parastromateus niger) using an ensemble SDM with 1,396 occurrence records and environmental data layers (depth, temperature, salinity, currents). Six algorithms (MAXENT, GAM, GLM, RF, ANN, MARS) with ensemble approach modeled species distribution under current and future semi-optimistic (RCP 4.5) and pessimistic (RCP 8.5) scenarios for both 2050s and 2100s. Models were evaluated by AUC, TSS and Cohen’s Kappa indices. According to the results, future range changes under all optimistic and pessimistic scenarios were negative. These results reveal prospective climate change impacts on the geographic range of P. niger, providing a valuable basis for science-based adaptation initiatives aimed at ensuring long-term sustainability of populations. Localized conservation and global mitigation policies are urgently needed to sustain P. nigerand reliant human communities into the future. Habitat modeling supports climate-resilient management strategies for threatened marine species

Species diversity of macrobenthos in Fusheh River, in Guilan Province, North Iran was studied and biological indices developed based on macroinvertebrates were used to evaluate the health status of the river. Macrobenthos sampling in the river was carried out at 4 stations on a monthly basis beginning from May to December 2016 using a Sorber sampler (mesh size of 300 μm and surface area of 900 cm2) with three repetitions. The sampled macrobenthos were preserved in 96% ethanol and transported to the laboratory for identification. A total of 4928 individuals from two phyla of Arthropoda and Annelida, three classes of insects (Insecta), crustaceans (Crustacea) and Clitellata as well as 8 orders (including Ephemeroptera, Trichoptera, Plecoptera, Diptera, Coleoptera and Haplotaxida) along with 25 families and 31 genera were identified. The most abundant genera were Simulium sp. (35.84-46.65%), Hydropsychae sp. (15.79-33.36%) and Baetis sp. (7.87-17.66%). Parameters of total abundance, EPT richness, EPT percentage and EPT/CHIR ratio were also calculated. The EPT richness showed a significant difference in monthly samplings (p<0.05). The presence of species sensitive to pollution such as Perla sp., Isoperla sp., Chloroperla sp., Oligoneuriella sp., Heptagenia sp., Rithrogena sp., Epeorus sp., Rhyacophila sp. and Philorus sp. belonging to orders Trichoptera, Plecoptera and Ephemeroptera exhibits both the good quality of river water and the desirability of species and genera as natural food for the river fish species.

The amount of lysine required in the diet of juvenile Beluga Huso huso with an average initial weight of 2.45 g was evaluated based on growth response in 12 aerated aquariums in four treatments each with three replications for 40 days. Four diets were prepared based on fish meal with the same protein (39.32%), fat (15.78%) and carbohydrate (21.19%) with different levels of lysine (0, 0.75, 1.5 and 2.25% of dry weight). The diet without lysine was considered as the control diet. Each ration was given in proportion to 4% of body weight, in three equal portions, to groups of three with 10 fish in each replicate. The mean water temperature, dissolved oxygen and pH during the test period were 23.8 ºC, 6.27 mg/L and 7.32, respectively. The results showed a significant difference in the growth performance between the treatments. The maximum weight obtained (31.95 ± 0.84 g) and specific growth rate (7.01 ± 0.09%/day) were observed in the treatment with 2.25% lysine. Apart from the decreased growth in the fish fed the lysine-deficient diet, no signs of growth deficiency were observed in the other fish. Codition factor, food conversion ratio, protein efficiency ratio and survival rate were not significantly different among treatments. Finally, the optimal amount of lysine for this weight group of juvenile Beluga was estimated to be 2.25 g per 100 g of the dry weight of the diet.

Rivers are vital ecosystems and their protection is of outmost importance. In this study effects of physicochemical parameters of water on the population structure of Ephemeroptera in three sampling locations e.g. upstream, middle and downstream of the Tajan River were examined. Sampling was carried out on monthly bases from April to March 2019. One-way analysis of variance was used to evaluate the qualitative status of the sampling stations, Principal component analysis was utilized to determine the effect of environmental factors on separation or overlap of the studied stations and comparative conventional analysis was used to determine the relationship between environmental variables with presence and absence of Ephemeroptera families. Results showed that physicochemical factors varied significantly during the study period. The average of factors such as the flow rate (68.3 m3/sec), dissolved oxygen (9.53 mg/lit) and pH (8.31) were at highest levels in February and March while average of EC (1181µm/cm) and TDS (815 mg/lit) were at their lowest values in in September. Significant differences were observed in physicochemical factors at different stations. The differences were apparent between Mohammadabad station with other two sampling stations in terms of temperature and dissolved oxygen and Tajan station varied significantly with others in terms of EC, TDS and Debi. Significant relationship was observed between frequency and presence of some families of Ephemeroptera including Baetidae with EC and TDS and Oligoneuridae with pH and dissolved oxygen which allows considering these groups as qualitative indicator or indicator species of surface water resources.

In the last few decades, the construction of fish farms on the banks of rivers has increased significantly. The purpose of this study was to investigate the quality of the inlet and outlet water of the rainbow trout farm and also to investigate the effects of the effluent on the water quality parameters of the Masouleh River located in Guilan Province. To perform this study, three stations including the control station at the entrance of the farm, the second station at the outlet of the farm effluent and the third station at a distance of less than 100 m after the outlet of the farm were sampled once every fifteen days for three months (November, December, and January 2019). The results of the study showed that the farm output water had a significant effect on water quality indices such as temperature, acidity (pH), dissolved oxygen (DO), nitrite (NO2-), nitrate (NO3-) and ammonia. The level of dissolved oxygen in the outlet water in the first two months of the sampling (5.75 ± 0.18 mg/L) had a significant decrease (P<0.05) compared to the inlet water and the acidity, nitrate, nitrite and water hardness values ​​in the outlet water (8.23 ± 0.09, 4.83 ± 0.15, 0.09 ± 0.07, 7.55 ± 0.18, respectively) showed a significant increase compared to the input water (P<0.05). Also, the comparison between the stations showed that the third station was more polluted than the other stations and the degree of water pollution decreased as the distance from the outlet increased. According to the results of this study, it can be concluded that the output of the fish farming farm has the highest level of pollution compared to other stations due to the use of low-quality commercial feed, high density, and high rearing activity in the farm and as the distance from the farm increases, the level of water pollution decreases due to the process of self-purification of the river.

In recent years, the construction of fish farms along the Qaleh Roudkhan river has increased significantly. The aim of this study was to investigate the effects of effluent from these farms on benthic communities and their population structure in river water. A total of 6 study stations were selected, of which 2 stations are from Fusheh (Shahed) branch and 4 stations are from Qaleh Roudkhan branch. Among the stations, Station 2 of Qaleh Roudkhan is located at the exit of the effluent of the fish farm. The results of analysis of variance using SPSS for all biological indicators indicate that there is a significant difference between the stations. Also, according to Duncan's test at 5% level in Shannon-Wiener index between stations 1 and 2 of Fosheh and stations 1 and 2 of Qaleh Roudkhan, in Margalf index between stations 1 and 2 of Qaleh Roudkhan with other stations, in Simpson dominance index between all stations except station 1 Fusheh and 4 Qaleh Roudkhan, in Helsinghof and EPT index between all stations and in BMWP / ASPT index between 2 Qaleh Roudkhan stations and other stations, there are significant differences. Based on the results, the fish pond workshop has caused changes in the groups of benthic invertebrates during the study period, which indicates a sharp decline in water quality at the effluent outlet.

Gashtrudkhan River is located in the western drainage basin of Guilan Province. Monthly sampling of macroinvertebrates was carried out in five stations by using a surber sampler with Dimensions of 30.5 cm ×30.5 cm and 360 micron mesh size for eight months in different seasons from autumn 2019 to spring 2020. Moreover, some physicochemical parameters of water, i.e., pH, EC, TDS, DO, temperature and salinity were measured, so that these parameters showed significant differences in different seasons. In addition, diversity indices (Simpson and Shannon), species richness, EPT, EPT/Chir, biological indices (Hilsenhoff and BMWP) and the WQI index were studied and calculated. During the sampling period, a total of 1017 macroinvertebrates were isolated and identified from different stations, belonging to one Phylum, one Kingdom, four orders, 19 families and 22 genera in this river. EPT and EPT/CHIR indices were the highest in spring and the lowest in winter. Also, the highest and lowest values of Shannon's diversity and species richness indices were observed in autumn and spring, respectively. The water quality status in the studied period was classified as good to excellent based on the Hilsenhof biological index. Furthermore, the water quality status was evaluated based on the BMWP and WQI indicators as clean and average, respectively. According to the investigated area in Gashtroudkhan River, located in a forest area with gravel and stone beds, no significant differences were observed in many of the studied indicators.

The environmental effects of fish cage culture have poorly been studied in reservoirs. Since this activity is increasingly practiced, investigations on the impacts of cage culture on physicochemical parameters and biodiversity of the reservoir is imperative. The aim of this study was to study the effects of rainbow trout cage culture on water quality, as well as plankton population structure and communities in a reservoir (Golestan Reservoir 1, Gorgan, Iran). Four sampling stations were selected in the following manner: sampling station immediately below the cages, stations some distances including 50 m, 150 m and 1000 m (control station) away from the cages. Phytoplankton, zooplankton and water samples were obtained on a monthly basis for 4 months (December, January, February and March 2016). The depths of the stations were the same. Water temperature, pH, dissolved oxygen, EC, transparency, TDS and TSS did not exhibit statistically significant differences among the stations. Significant increases were detected in the ammonium, nitrate, phosphate and chlorophyll α concentrations at the cage station (P˂0.05). Five phytoplankton phyla including Bacillariophyta, Chlorophyta, Cyanophyta, Euglenophyta and Dinophyta and also four zooplankton phyla including Protozoa, Rotatoria, Cladocera and Copepoda were identified in the reservoir. The obtained results revealed that cage culture exerts significant effect on the population and communities of planktonic organisms. Increase

The presence of microplastics (less than 5 mm) in marine environments, owing to their persistence and risk imposed to marine communities has become a growing global concern. Considering the hazardous nature of microplastic particles to benthic communities and commercial species of the Caspian Sea, the study was conducted to investigate the distribution of microplastics in sediments of the southern shores of the Caspian Sea. Sediment samples were taken by a Van Ween grab as sampling sites located in Astara, Bandar Anzali, Kiashahr, Rudsar, Sari and Turkmen port during the winter 2018. Sari station with an average of (340±20 items/kg dry sediment) had the highest and Turkmen port station with (156.66±75.71 items/kg dry sediment) had the lowest microplastic frequency. The size of the microplastics varied from 0.2-9.2 mm and most of the microplastics found (35.54%) were 1-2 mm in size. The extracted microplastics were mainly filamentous although fragment microplastics and films were also observed. In the studied samples, high color diversity was observed and blue (63.85%) and brown (20.31%) had the highest frequency. Using ATR-FTIR analysis, 4 types of polymers including cellophane, polyethylene, polypropylene and polyvinyl acetate were identified. The most abundant microplastics identified were cellophane. This study is among very few studies on microplastic contamination in the sediments of the southern Caspian Sea and the obtained results vital for further studies.

The aim of this study was to investigate body shape variations of Alosa braschnikowi populations in three localities of the Caspian Sea using geometric morphometric method. So that, 216 specimens were caught from three regions from west to east, including Guilan (Anzali), Mazandaran (Sari) and Golestan (Miankaleh). Shape data was extracted using 15 landmark points on 2-D pictures of specimens. The PCA, DFA analyses and cluster analysis based on Euclidean square distances were used to examine shape differences among the three populations. The results showed that there was a significant difference between the studied populations in terms of body shape (p<0.05). The population in Guilan had a longer head and snout, short and depth caudal peduncle and longer dorsal fin base that was different from the populations in Mazandaran and Golestan regions. Differences in head and snout shapes of the Guilan population with other populations, can be considered as a reflect of differences in feeding resources and selection of food items. Body shape differences may also be due to geographical distance and other environmental parameters. Specifications obtained on the basis of the body shape of A. braschnikowi can provide an identification key that is useful to distinguish species.

Determining the age and growth of fish is vital in fisheries management and biology. This information is the foundation for modeling aquatic population dynamics and is employed to analyze fishing data. The relationship between length and weight and some other growth indices of Caspian Vimba persa was studied from autumn 1996 through spring 1997 on the southwestern coasts of the Caspian Sea (Astara, Anzali and Kiashahr).

Sampling was carried out seasonally using beach seine net at three fishing regions e.g., Kiashahr, Astara and Anzali. Each season 8 samples were taken at designated sampling stations (a total of 24 fish each season) except for 9 samples at Anzali stations in the autumn (25 samples in total). In total 73 specimens of Caspian Vimba persa were collected from the sampling stations.

Fish age varied in the range of 0+- 3+ in both females and males. The highest length frequency was observed in the length group of 14-25cm. Mean total length in the whole population, females and males were 18.05± 2.38; 18.61± 2.73 and 17.14±1.29 respectively. Mean total weight in the whole population, female and male were 65.62 ±33.98; 73.89± 39.43 and 52.32±15.78 respectively. Mean fork lengths in the whole population, female and male were 16.05± 2.66; 16.68±2.49 and 15.46± 1.17 respectively. Mean gonadosomatic index was 6.88 ± 4.23. Mean hepatosomatic index and obesity coefficient were 0.98±0.51 and 1.04±0.10 respectively.

Analysis of the obesity coefficient showed that the species upholds ‘good’ growth rate.  The Length-weight relationship for the whole population was W = 0.3403L3.403, female W= 0. 003 L3.365 and male W= 0.0047L3.2719. The t test showed that the obtained bvalue was greater than 3 thus the species has a positive allometric growth pattern. Since within the whole sampled fish the W> L3 and CF = K> 1 (obesity coefficient was greater than 1) relationship was applied, it can be concluded that the Caspian Vimba persa are more obese than usual which indicates good feeding condition of fish in the southwestern part of the Caspian Sea.

The anesthetic effects of Valeriana officinalis (valerian) and Cymbopogon citratus (lemongrass) extracts and Eugenia caryophyllata (clove) powder were examined on juvenile sterlet sturgeon, Acipenser ruthenus to determine their optimal concentration to evaluate the possibility of these extracts as a potential replacement for clove tree flowers. In this study sterlet juveniles averaged 86.2±11.7g in weight and 29.7±1.05cm in length were exposed to 45, 60, 75 and 90 mL/L valerian extract, 3, 5, 7 and 10 mL/L lemongrass extract and also 2000, 3500 and 5000 mg/L clove powder by immersion method. The Results revealed anesthetic effects of all three compounds on sterlet sturgeon. Considering the time required for anesthesia and recovery, the 60mL/L, 5mL/L and 3500mg/L doses were determined as optimum concentrations for valerian and lemongrass extracts and clove powder, respectively. Since the valerian and lemongrass extracts were very effective in inducing anesthesia in this study, their use as an anesthetic agent in aquaculture activities is recommended.

The Caspian Sea is the largest water body in the world. It is surrounded by five states – Azerbaijan, Iran, Turkmenistan, Kazakhstan and Russia. Caspian kutum, Rutilus kutum Kamensky 1901, is a commercially important fish species in the southern part of the Caspian Sea, but little data available on trace element (TE) concentrations in its skin. In this study 51 R. kutum in the south shoreline of the Caspian Sea (including Astara, Anzali and Kiashahr) were caught during September 2017 to June 2018 and inductively coupled plasma optical emission spectrometry (ICP-OES) was used to measure TE concentrations in their skin. The trace element concentrations (TECs) measured in the skin (except for potassium) did not exhibit significant differences between the study areas. So that, only concentration of potassium was higher in Kiashahr than other areas.

Growth pattern and some biological characteristics of Leuciscus aspius Linnaeus 1758, in the southern parts of the Caspian Sea were studied. Some 96 fish specimens were caught at Guilan, Mazandaran and Golestan provinces from October 2018 to September 2019. Fish were at the age classes of 1+ to 4+ years. The highest percentage of fish were at the age class of 2+ (33.72%), while the lowest at 4+ years (11.62%). Male/female age ratio was 0.68-1. Total length varied between 29-54 cm, fork length between 25-49 cm and the body weight was 213- 985 g. The mean total length was 38.91±5.57 cm, fork length 35.06±5.23 cm and mean weight was 639.74±87.27 g. The lowest growth coefficient rate was observed at the ages of 1-2, while the highest at 3-4 years. The mean condition factor (CF) was 0.87±0.22, hepatosomatic index (HSI) was 0.41±0.17 and gonadosomatic index (GSI) was 0.56±0.17. The length- weight relationship of all specimens was W= 0.0204 L2.7361, in males was W= 0.0189 L2.7648 and in females W= 0.0217 L2.8867. According to the obtained b values, the growth pattern of L. aspius was negative allometric meaning that weight and length growth did not follow similar rate. Length growth was faster which resulted in thin fish specimens. Moreover, condition factor below 1 (CF<1) reflects that L. aspius did not have favorable feeding ground in the study area which has led to lower growth. Factors like pollution, destruction of rivers, scarcity of food sources and overfishing could be responsible for these problems.

The relationship between length and weight and some biological characteristics of Tinca tinca (Linnaeus, 1758) in the Anzali Wetland was investigated. A total of 102 specimens of T. tinca were collected on monthly sampling intervals from spring to winter 2019. The mean total length of fish was 15.97±1.51, minimum 13 and maximum 22.5 cm. The fork length was 15.58±1.55, minimum 12.7 and maximum 22.3 cm. Mean fish weight was 62.64±21.15 g with minimum 30 and maximum 174 g. The obesity factor index was 1.49±0.18 in the whole population and 1.41±0.11 in males and 1.55±0.20 in females with minimum values in autumn and maximum in spring. Mean hepatic index was 1.05±0.76 for the whole population, 1.29±0.89 in males and 0.90±0.63 in females with minimum values in spring and maximum in autumn. The mean gonadosomatic index was 5.62±4.58 for the whole population and 3.35±2.1 in males and 7.02±5.12 in females with the minimum in winter and maximum in spring. The relationship between total length and weight for all fish was W=0.025 L2.8123, female W=0.0363 L2.6907 and male, W=0.0066 L3 .2724. According to the b value of the length-to-weight relationship, T. tinca in the Anzali Wetland has an isometric growth pattern indicating similar growth and length growth rate. In the present study, the obtained CF>1 was obtained indicating a proper feeding conditions of the species in the Anzali Wetland.

Algae are the most important group of organisms which considerably affect the water quality. Although algae constitute one of the fundamental parts of the aquatic food chains, only few researches deal with the freshwater algae of Iran. Filamentous algae are important components of the river vegetation. The Balikhlou River is utilized as a source to obtain drinking water for the city of Ardabil, therefore, the algae flora of this river was studied and a total number of 18 taxa of filamentous algae were determined, of which nine species were belonged to the Cyanophyceae class of Cyanobacteriae, while five speciesof which were belonged to the Chlorophyta. In addition, four species were recorded for the first time from Iran, i.e., Audouinella eugenea, Arthrospira gigantea, Homoeothrix janthina and Tychonema bourrellyi.

Occurrence and abundance of Microplastics (MPs) were studied in sediments of the Anzali wetland for the first time in spring 2018. Sediment samplings were carried out using Van Ween Grab. After density separation in saline solution, MPs were counted by a stereomicroscope. The number of MPs was at the range of 14-282 items/100g dry sediment (140-2820 items/kg dry sediment). Stations 10 and 9 with 282 ± 171.14 and 14 ± 3 items/100g dry sediment exhibited the highest and lowest contaminations, respectively. The MPs gathered during the survey varied in size from 0.3 to 5 mm, and those with 1–2 mm in size had the highest frequency (37.3%). The dominant shape of MPs was fiber; Followed by fragments and films. Red, black, and blue were the most abundant colors by 34.1%, 30.8% and 26.4%, respectively. In total, 5 microplastic polymers including polystyrene (PS), polypropylene (PP), polyester (PEST), polyethylene (PE) and poly acrylonitrile (PAN) were identified. This first work provides original data on the presence of MPs, determining their bioavailability to organisms as seafood, and then possible transfer to human. The results provide useful information for further studies.

In this study, 34 different elements, including toxic and non-toxic heavy metals in the liver, muscle, gonad, kidney and skin of the Alosa braschnikowi were investigated. also, the relationship between aggregation of these elements with growth parameters (age and length) and physiological indices (Condition Factor, relative weight and Hepatosomatic index) were investigated. Some 74 specimens of fish were caught during fishing season (2017-2018) were prepared from three stations Astara, Anzali and Kiashahr on the south-west coastlines of the Caspian Sea. trace elements detection was performed by Inductively Coupled Plasma Mass Spectrometry (ICP-OES). The difference between the tissues was significant in terms of concentration of metals, so that the maximum mean of chromium, molybdenum and Strontium metals in muscle, aluminum, arsenic, barium, manganese, vanadium and nickel in skin, cadmium, cobalt, lithium and lead in the kidney, copper and iron were found in liver and zinc metal in gonad tissue. In all five tissues of muscle, skin, kidney, liver and gonad, the highest concentrations of metals were iron and the lowest concentrations of metals were barium, nickel and cadmium. Investigation of the association of metals concentration in tissues with growth parameters (length and age) showed that there is a significant positive correlation between arsenic, cadmium, cobalt, chromium, copper, iron, manganese, Strontium and zinc metals with the growth parameters, and the strongest positive relationship and significant between copper with age (p<0.05, r = 0.40). also, there was a positive correlation between arsenic, iron, aluminum, barium, chromium, copper, lithium, molybdenum, manganese, nickel, lead and strontium with the physiological indices, which had the strongest positive and significant relation between lithium metal and liver index (p<0.05, r = 0.57).

Bio-indicators is a method for assessing water quality. The responses of benthic macroinvertebrates to pollution are more reliable. These organisms vary in their sensitivity to environmental pollution. The objectives of the present study were evaluation of health status and pollution of the Ghale Rudkhan River using macro benthos richness, Hilsenhoff biotic index and Shannon- Wiener diversity index. Five sampling sites were selected. Samples were taken from May to November 2017. A Surber sampler (area 900 cm2, 300μ pore size)was used for sampling with three replicates in each site. Samples were preserved in ethanol 96% and transported to the laboratory. Total of 5134 specimens of macroinvertebrates belonging to 35 genera, 30 families, 10 orders, 4 classes and 3 phyla were identified. Aquatic insect larvae dominated the samples. The highest abundance belonged to Diptera, Ephemeroptera, Trichoptera and Plecoptera in a descending order. The highest and lowest Shannon diversity index (2.28 and 0.42) were observed in May (site 4) and September (site 3) respectively. Based on Hilsenhoff (HFBI) index the water quality at sampling site 1 (upstream), site 3 (before trout fish farm), site 4 (immediately after fish farm) and site 5 (downstream) was “Good” and at sampling sites 2 (in vicinity of the tourist complex) was “Fair”. Based on monthly assessments of these indexes the water quality state in May and October were Excellent and Fair respectively.

Fish stock assessment in the Caspian Sea requires employing some growth indicators such as length-weight relationship (LWR). Size determination in fish is more biologically relevant than age, because several ecological and physiological indicators are more size-dependent compared to age-dependent. This study aims to examine the length-weight relationship and condition factor of Rutilus kutum (Kamensky) from the southern Caspian Sea. 218 fish samples were caught using a gill net from Anzali, Astara, Kiashahr, Sari and Torkaman Port from September 2018 to February 2019. Negative allometric growth patterns were observed in Sari and Torkaman Port and positive allometric growth patterns were found in Anzali, Kiashahr and Astara stations. The fish caught from Anzali displayed the maximum condition factor. LWRs are not continuous over the year and LWR indices may vary significantly due to biological, food availability, temporal and sampling factors, and also by fish health and sex. Relative weights in fisheries studies can be used for comparing condition across different populations and species. Investigations carried out indicate that growth of R. kutum in recent years has decreased.

Water quality of Fusheh River (Guilan province) was examined using macrobenthose density, Hilsenhoff Biotic index and Shannon Winner diversity indices. Four sampling sites were selected and monthly sampling was conducted from May to December 2017 with a surber sampler (area of 900 cm2, mesh size of 300 µ) with 3 replicates in each sampling site. The collected macroinvertebrate samples were preserved in ethanol 96% and transferred to the laboratory for enumeration identification. In Total 4928 macrobenthoses specimens were identified belonging to 2 phyla, 3 classes, 8 orders, 25 families and 31 genera. Insect larvae dominated the samples. The most abundant groups of macrobenthoses were Diptera (53.09%) and family Simuliidae. Trichoptera (28.44%) with dominant family of Hydropsychidae and Ephemeroptera (16.24%) and the dominant family of Baetidae. Based on tolerance scores assigned to each family considering their resistance or sensitivity to pollution the Hilsenhoff Biotic Index was calculated. The results obtained from this Index categorized the Fusheh River in GOOD (some organic pollution) water quality class.BMWP/ASPT Biotic indices categorized site 1 and 2 (upstream) in suspected to pollution, site 3 and 4 (downstream) in moderately pollution classes. According to the Shannon wiener index the sampling sites 1, 2 and 4 were relatively polluted and sampling site 3 was polluted (P≤0.05).

Length-weight relationship, growth pattern, condition factor and age composition of Alburnus chalcoides in the southwest coasts of the Caspian Sea (Astara, Anzali and Kiashar) were examined from September 2017 to October 2018. A total of 77 fish were caught using beach seine. The mean length and weight of fish were 19.25±5.17 cm and 76.78±83.92 g, respectively. Fish age ranged from 0-4 years and age class 0-1 accounted for 81.8% of the examined specimens. Considering the growth pattern, the regression coefficient (b) was bigger than 3. The figure obtained from Pauly equation was 5.28 which is larger than the t value of Pauly table (1.66), suggesting a heterogeneous or alometric growth pattern for the species under question. The CF values were 0.83±0.14 and 0.82±0.11 in males and females, respectively. Mean gonadosomatic index was higher in females and significantly varied in females (8.04±4.82) as compared to males (3.05±1.47). Mean hepatosomatic index was 0.79±0.49 in males and 0.75±0.44 in females.

This study aimed to investigate morphological differences of western and eastern populations of Caspian kutum Rutilus kutum in the southern Caspian Sea and its providing length-weight relationships and condition factor (CF). A 13-landmark based morphometric truss network system was used to investigate the hypothesis of population fragmentation of western and eastern populations of this species. The studied populations were differentmorphologically based on pre anal, body height, distance from pectoral fin to ventral fin, distance from pectoral fin to anal fin, caudal peduncle length, head length, pre orbital, pre ventral, and dorsal length. The results also revealed a negative allometry (b<3) of length-weight relationships for both sexes. Maximum condition factors was found in March. The results suggest distinct stocks in the western and eastern of Caspian Sea for fisheries management.

Land and water pollution by heavy metals is a universal issue. Although the pollution affects all countries, but its range and severity vary hugely. The pollution of the marine environment by heavy metals is a worldwide problem. Marine sediments can be sensitive indicators for monitoring contaminants in aquatic environments. The concentration of 10 elements (As, Cd, Cr, Cu, Al, Fe, Ni, Pb, Sb, and Zn) was determined in the sediments of four shoreline stations including Imam Hassan port, Ameri port, Bushehr port, and Nayband Bay at the west Persian Gulf from March to December 2017. The elements were measured by
inductively coupled plasma mass spectrometry (ICP-MS). Data were analyzed using SPSS version 16. The contamination of the sediments was assessed based on the geoaccumulation index (Igeo) and enrichment factor (EF). Spearman correlation matrix was calculated between all the trace metals and major elements as well as corresponding sampling regions. Statistically significant inter-elemental correlations (e.g., Cr-Fe, Cr-Al, Cr-Ni, Cr-Zn, and Cr-Cu) were found between some metals. High EF levels for Fe, Al, and Pb suggest that metals in the sediments of the northern Persian Gulf could have originated from anthropogenic sources. The contamination pattern of sediments is affected by factors such as sedimentation patterns, physical and chemical properties of the sediments. For example, sediments with fine-grained and high surface area-to-volume ratio can act as good absorbents for many pollutants

This study aimed to investigate the effect of Tiyab shrimp farms effluent (Hormozgan Province) on the physicochemical parameters of water, sediment and on the structure of macrobenthic assemblages in areas receiving effluents was conducted during one-year period (from April 2014-April 2015). According to the area of the region and water depth, 3 plots selected (sea water inflow to the creek, before the sea water inlet channel into shrimp farms and after output channel of shrimp farms) and samples were taken. During the study, 24 families of benthic macroinvertebrates were identified in the Tiyab creek, which contains 6 orders belonging to 3 phyla. In total, the highest number of families and species of benthic macroinvertebrates were belonging to Annelida, Arthropoda and Mollusca, respectively. The results of the ecological classification of studied plots based on BENTIX index in different seasons indicated that the plots located before the shrimp farms classified in classes "no pollution" to "moderately polluted" and plots that located after and on-site effluent output from shrimp farms were classified in the categories of "slightly polluted" to "heavily polluted". The most important factors influencing the distribution of benthic macroinvertebrates in this study were: salinity, nitrate, biochemical oxygen demand (BOD), total soil phosphorus (TP) and total organic matter (TOM), respectively. Also in this study Capitella capitata and Clymene robusta species as a species resistant to pollution and species Assiminea sp. And Littorina intermedia were introduced as species sensitive to disturbance and pollution.