جستجوی مقالات مرتبط با کلیدواژه « macrobenthos » در نشریات گروه « شیلات »

This study was conducted in order to compare the presence of polycyclic aromatic hydrocarbons in sediments and to compare them in four groups of macrobenthic communities, including gastropods, bivalves, crustaceans, and polychaetes in the north of Persian Golf. Sampling was carried out at 9 stations using a van veen grab along the coastline of Bandar Abbas in March 2018 and August 2019. The average concentration of total PAHs in two sampling periods, regardless of time distribution by station, showed that the refinery has the highest concentration of these compounds, followed by Posht-e-Shahr and Soro. The highest average concentration of polycyclic aromatic hydrocarbons in gastropods belonged to the 3-ring compound Acenaphthene with an average (ppb) of 1117 and the lowest value belonged to the 6-ring compound Benzopyrylene with an average (ppb) of 2. In bivalves, the highest average concentration of the 3-ring compound Acenaphthene with an average (ppb) of 1261 and the lowest value of the 6-ring compound Benzopyrylene with an average (ppb) of 32 was obtained. The highest average concentration belonging to the 4-ring compound Fluranthene with an average (ppb) of 1551 and the lowest value belonging to the 6-ring compound Benzopyrylene with an average (ppb) of 0 were obtained in crustacean tissue. Studies showed that sediments absorb 5-ring compounds, molluscs absorb 3-ring compounds, crabs absorb 4-ring compounds, and reptiles absorb 5-ring compounds more easily.

In this study, due to the importance of Doiraj Dam Lake, which supplies an important part of agricultural water of Dehloran and Mosian, the assessment of the lake water was carried out in order to develop aquaculture activities and investigate the possibility of fish farming in the lake behind the dam. For this, 4 stations selected, the entrance, before and ater the lake and sampling were done in three seasons by using Van veen grab with with 0.0625 m2. The results of this study were determined based on the biological indicators. In benthic indices, the quality of water was evaluated by determining the species composition and biological value of different species using Shannon-Wiener diversity indices and Hilsenhoff Family Biotic Index (HFBI). The HFBI index in the studied stations ranged from 3.07 to 6.07. In general, based on the biological indicators, in most of the stations and seasons, moderate pollution was observed, which was more evident in the stations before the dam due to its without move nature than the entry and after stations.

Spiny lobster is one of the most valuable crustaceans in the Gulf of Oman. Overfishing in recent decades has reduced the stocks of this aquatic resource. Therefore, accurate knowledge and study of ecological parameters of lobster habitats are very important because the seabed structure and ecological parameters in these habitats are widely associated with the presence, absence and distribution of lobsters. The current study was conducted to investigate the relationship between the classification of sediments, the abundance of macrobenthos and environmental factors on a seasonal basis along seven transects and 28 stations. It was carried out in the rocky areas of the coast of Ramin in the east of Chabahar port. The mean values of temperature, salinity, turbidity, acidity and chlorophyll a in the study area were 26.38 ° C, 36.65 PSU, 2.59 FTU, 8.1, 86 µg / L, 0.86, respectively. Almost similar environmental parameters were observed between similar points between the depth of 5 and 15 meters. The macrobenthos results in the studied stations showed that foraminifera and Polychaeta are the most prevalent macrobenthos groups and in the deepest stations in transect T3. Percentages of sand, silt and clay for the sediment samples were 93%, 5% and 2%, respectively. The sedimentary texture of the bed plays an important role in the movement of the lobster in the habitat, and the rocky and sandy bed is a suitable habitat for the lobster. According to the results of this study, the highest percentage of sediment sand was observed in the eastern part of Ramin port. There were similar environmental parameters for equal depths of water. Furthermore, Macrobenthos were most abundant in the eastern region of Ramin port in spring and autumn and agreed with pre-Manson and post-Manson conditions. Therefore, the stations in the eastern part of Ramin port are suitable places for the establishment of artificial reefs.

The current research was conducted in 2021 in 5 stations in order to investigate the quality of water before the operation of Javeh Dam in Kurdistan Province. Sampling of fish and Macrobenthos was done using an electrofishing device and Surber sampler, respectively. A total of 13 fish species were identified, which belonged to 3 families: Cyprinidae, Mastacembelidae and Nemachielidae. Out of the total of 2003 fish caught in all the stations, more than 96.6% belonged to the Cyprinidae family. The highest relative frequency of 32.4% belonged to Capoeta damascina species. In addition, 2 exotic species, Carrasius auratus and Carrasius gibelio had an abundance percentage of 1.4. The diversity of fish species decreased from station 1 (upstream) to stations 2 and 3, which was probably influenced by human activities such as various types of pollution, but in station 5 of It had the maximum amount, which is due to the change in habitat conditions, such as the increase in flow rate and water depth. The results showed that the species diversity of fish had changes in different seasons, so that its minimum was estimated at 0.91 in winter and its maximum at 1.29 in summer. Macrobenthos included 10 families Chironomidae, Lumbriculidae, Simulidae, Baetidae, Hydropsychidae, Erpobdelidae, Glosiphonidae, Gamphidae, :union:idae and Potamidae. The classification of water quality based on the Karr ecological integrity showed that stations 1 and 4 were placed in the good quality class with a numerical value of 40 and 42, respectively, and stations 3 and 5 were placed in the very low and medium water quality classes with a numerical value of 9 and 34, respectively. In this way, it is necessary to manage and organize all sources of point and non-point pollutants in Gheshlagh and Gavehroud tributaries.

Water pollution is a major global problem that affects plants and living organisms. Factors affecting water pollution include industrial, agricultural, and human pollutants. Qarasu river is very important in terms of pollution due to the use of river water in the agriculture and aquaculture sectors. In this research, the effect of intensive fish farms and the riverbed material was investigated on the abundance of macrobenthic communities. For this purpose, four stations 1) the station upstream and before the fish farms (as control station), 2) the station between the fish farms, 3) the last station of the farms, and 4) the downstream station at a distance of 4 km from the last farm were selected. A sampling of the macrobenthos and riverbeds was done in two seasons, winter and spring, and their frequency was calculated in the sampling stations and months. The highest abundance was related to the family’s Chironomidae (1456 numbers per m2) and Simolidae (2737 numbers per m2) from the Diptera order, which were observed in the effluent of station 2 and station 4 in the winter season, respectively. In addition, the type of the river bed was determined to find the correlation with macrobenthic species. The identified macrobenthos was classified into trophic groups and the relationship with the type of substrate was determined using the Pearson correlation. The correlation of different macrobenthic species with sampling stations and months was found using Canoco software and CCA statistical analysis. The present study showed that the effluent from intensive fish farms had an effect on the abundance of macrobenthos in the Qarasu River, which could be due to the increase in nutrients in the river water from the release of the effluent, and decrease in temperature and decrease in the decomposition of nutrients in the winter season. Therefore, based on the findings, the presence of different functional macrobenthic groups is affected by the type of riverbed and different seasons of the year.

The role and importance of benthic organisms in the food chain and ecological pyramid of aquatic ecosystems is highly recognized. This study was conducted to investigate the benthic population and water quality of Karaj River, located in Alborz Province. In this study, a total of four stations along the river were selected and their benthic fauna were sampled seasonally. Samples were fixed with 4% formalin, isolated, identified, and counted in the laboratory. In the sampling procedure, 24 families, 5 categories and 5 orders were identified. The highest benthic density with 177 specimens (number per square meter) was reported in summer and the lowest benthic density with 105 specimens reported in winter. The benthic population and composition of Karaj River benthic was consisted of two classes of Oligocheata, Platyhelminthes and Coleoptera order and these groups had the highest density in all stations. During this study, the average Shannon-Wiener diversity index was 1.61. The highest Shannon-Wiener diversity index in the first station was 1.92, Based on the Hilsenhof Biological Index (HFBI), resulting that the water quality of Karaj River classified at the levels of good to desirable.

This study was conducted to investigate the possible effects of cages culture Asian sea bass fish (Lates calcarifer) on the population structure of macrobenthos in the Rigo area of Qeshm Island in Hormozgan province during a breeding period in 1397 were investigated. The average abundance of macrobenthos at the location of the cages culture and the refrences site in this study was equal to (52765 ± 19154 in m2) and (50642 ± 21002 in m2), respectively.The results showed that at the time of the study among the identified the genus of Ammonia sp. With a relative abundance of 73.41 percent at the location of the cages compared to the control station and Archasterope sp., Spirolochulina sp. and Nephtys sp. with a relative abundance of 63.9%, 49.1% and 12.6%, respectively, were more dominant in the control station compared to the location of the cages.The loading rate of organic matter in the bed of the cages was significantly affected by fish farming activities and in some times showed a significant difference with the control station (P<0.05). In general, at the time of the study, activities related to fish farming in cages had no effect on the population structure of macrobenthos in the study area.

The aim of this research conducted in the lower zone (or estuary) of Gharesou River was to study biodiversity of the macrobenthos and changes in sedimentary organic matter in river litter. No sample collected in summer 2018 due to drying river. Sampling was undertaken over five surveys, (May, June, November, and December 2018 and March 2019), in four sites (with two replications). The results of split plot analysis showed that sedimentary organic matter in river litter reduced significantly in autumn 2018 and winter 2019 (P<0.05). Whilst, biodiversity indices like species abundance, species richness, and evenness showed significant differences among surveys, Shannon, Simpson, and Berger-Parker indices had no significant differences (P>0.05). Species abundance reduced to -0.87 in autumn, and also species richness reduced to 3 species in autumn, including Tubificidae, Chironomidae, and Spionidae (Streblospio sp.). In addition, Species abundance was the only biodiversity index which had significant difference among sampling sites (P<0.05), as species abundance reached to the highest level (i.e., -0.7) in the fourth site. Thus, river drying in summer reduced species abundance and richness in autumn. But, when water reflowed in river in autumn, two species belonging to Tuificidae and Shironomidae were emerged first in river, which might be associated to the higher resistance of these two families to the rigid environmental conditions, like river drying.

Macrobenthos are known as biological indicators of their living environments and can be used as index of water pollution in different water resources. Achiroud River located in Gillan province and its macrofauna has not been studied yet. So, in the present study, the macrofauna of the Achiroud River in the winter 2015 and spring 2016 was examined. Sampling was performed in two seasons of winter 2015 and spring 2016. Five stations were selected based on geographical characteristics of the river and each station using GPS system. Sampling was quadratic and seasonal. The Hilsenhoff index was determined based on the presence of benthos at each station. The water pollution was determined using the Hilsenhoff index in each station in spring and winter. The macrobenthos classified into 3 classes, 12 families and 14 species and identified. The most frequency was related to insects and the lowest frequency belonged to Malacostraca. The highest frequency in the winter belongs to the Gammaridae (Gammarus sp.) and in the spring belonged to the two families Gammaridae and Heptageniidae (Gammarus sp. and Ecdyonurus venosus). Species of Gammarus sp. and Ecdyonurus venosus were present at the most stations in two seasons. The highest value of Hillsenhof index was (5.22) observed in winter and the lowest value of this index was related to spring (0.71). According to the HFBI bio-index, water quality in stations 3 and 5 was excellent, in stations 4 was very good and in station 2 was intermediate.

Aquatic ecosystems have changed dramatically over the last decades. For example, by reducing the water flow in the rivers, organic material would increase in the lower zone of rivers resulted in fluctuating biodiversity of macro-benthic communities. The aim of this study was to determine the changes in macrobenthic diversity in the lower zone (or estuary) of Gharesou river - southeastern Caspian Sea, in where hatchery-reared juvenile fish like Rutilus rutilus (Linnaeus, 1758) and Sturgeon fish (Acipenser sp.) are released for stock enhancement. Sampling was undertaken over five surveys in four sites in the lower zone (or estuary) of river to study the abundance, species richness, and biodiversity indices of macrobenthos. The results of split plot analysis showed that sedimentary organic matter in river litter reduced significantly in the second survey, due to relatively heavy rain fall occurred before second sampling. Whilst, biodiversity indices had no significant differences among surveys (p>0.05), these indices showed significant differences among sampling sites. Species abundance in the third survey increased significantly (p<0.05), related in sharp increment of Tubifex abundance in the fifth site. Rising abundance of Tubifex in the fifth site resulted in significant reduction of diversity indices like Shannon index and inverse-Simpson, and also significant increment of Berger-Parker index, which was probably associated with higher resistance of this species to the hard environmental condition like reduction of water flow in the river. Whilst, diversity indices in the release site for hatchery-reared juvenile was not significantly more (diverse) than the other sites(p>0.05), and also dissolved oxygen and NO3, and NH4 in the release timing had the higher and lower rates, respectively; higher fluctuations of salinity and total dissolved solids in the release site could impact survival of released hatchery reared juvenile. Thus, it is recommended that hatchery reared juveniles being released more far from the estuary towards the upstream.

Karaj River, as one of main source of drinking and agriculture water for Tehran and Alborz provinces, has biological potentials, and is one of the protected rivers in Iran. The main purpose of this study was to investigate the concentrations of heavy metals: cadmium, chromium and zinc in the water and sediment samples of Karaj River in order to evaluate the quality of water, using biological value index (Z). Sampling of water, benthos and sediments was carried out from January 2018 to July 2018 from 7 point stations along the river. Preparation of water and sediment samples was performed by evaporation and the studied metals concentrations were measured by ICP device. The obtained results demonstrated that both in water and sediment samples, studied metals showed significant differences from upstream to downstream stations. Also, the concentration of all metals in water and sediment was lower in January than in July. The results of the Z biological value index revealed a significant difference in both seasons between the sampling stations, and the highest value of in both seasons belonged to the downstream stations. Contamination by heavy metals, especially in downstream, is due to human interventions such as agricultural, urban and industrial wastewaters. In the cold season, because of declining population density in the river vicinity area, pollution levels have been decreased. Also, in terms of quality, in general, Karaj River can be classified in saprobe class II and III.

In order to qualitative evaluation of the sediment samples, the samples were seasonally taken in the Tiab basin for one year from autumn 1994 to summer 1995. Four stations were considered to be sampled that the first was between the south and north Tibet, the second station is located to the south Tiab and the third station located at the subbranch of the canal and the station 4 at the branch of estuary. Two ecological indicators based on macrobenthos community were used to calculate ABC and w-statistic indices. Spatial distribution of macrobenthos density at four stations showed that station 4 with an average of 1467 individual per square meters had the highest density, followed by station 3, 1 and 2, respectively, with 652, 393 and 223 individual per square meters in ranking are next. Amount of weight-based indices showed that the frequency curve in the ABC index is located on the top of the weight curve at all four stations and the w-statistic index with the lowest value is -0.433 at station 2. The results of this study showed that, although at stations far from shrimp breeding grounds, the diversity is more than those are close to shrimp farms, but biodiversity figures indicate that all areas are affected by effluent from shrimp pools.

In this investigation, the amounts of organic matter, types of sediment and distribution of macrobenthic species in the Boojagh Marine National Park (BMNP) were studied. Sampling was conducted in six transects perpendicular to the beach using a Van Veen grab sampler using cross section of 20 cm with five replications. Samples were collected in five seasons (from summer 2015 to summer 2016). Each transect include three stations at various depths of 1, 5 and 10 meters. Samples were washed and fixed in formalin. Then, they were transferred to a laboratory for sorting and identification of different groups of macrobenthic taxons. The identified species were as follows; Cerastoderma glaucum, Mytilaster lineatus, Pyrgula grimmi, Anisus kolesnikovi, Stenogammarus carusui, Paraniphargoides motasi, Onisimus caspius, Pterocuma pectinatum, Pterocuma sowinskyi, Pseudocuma (Stenocuma) gracile, Naiss sp., Hypania invalida, Manayunkia caspica, Streblospio gynobranchiata, Hediste diversicolor and Amphibalanus improvisus. Evaluation of sediment composition indicated that the highest proportions belonged to sand with an average amount of 89/25%, whereas the lowest proportions belonged to clay with an average amount of 0/26%. with highly significant difference among sand identified with other particles (p<0/01). The average percentage of organic matter in the summer 2015 in the fourth transect at the depth of five meters was significantly lower than that of the others (p<0/01). The highest density of macrobenthos was at the depth of 10 meters. Macrobenthos density was the highest in the summer 2015 and was the lowest in the spring 2016 as compared to the other seasons.

This study was carried out at the southeast of the Caspian Sea on the shores of the Goharbaran region during 2013-2014. Sampling was repeated monthly in eight stations. A total of 157 species of phytoplankton, 10 species of zooplankton and 24 species from macro invertebrate were identified. There were significant differences based on abundance and biomass among different biological groups in various stations (p<0.05). Comparing the abundance and density of phytoplankton in different seasons showed that there was an increasing trend in phytoplankton from spring to winter, whereas the abundance and biomass of zooplankton showed a decreasing trend. The results of the multivariate statistical analysis, Pearson correlation coefficient and Principal Component Analysis (PCA) in different months showed that the biomass of phytoplankton and zooplankton had the highest correlation (0.943), whereas the abundance of zooplankton and jelly comb had the highest correlation which could be due to their physiological structure and ecobiological conditions. In conclusion, ecological relationships among biological groups can be due to the abundance and biomass changes, species diversity, environmental parameters, predator, seasonal changes, feeding habits and environmental pollutions.

The study is part of a research project on the southern shores of the Caspian Sea (Mazandaran waters- Kelarabad) was conducted in 2012. The aim of this study was to evaluate the effects of fish farming in cages on the distribution, abundance and biomass of macrobenthos organisms in the water at a depth of 20 meters Kelarabad. Sampling was monthly at three stations including 1(seating cage), 2 (control with a distance of 500 m) and 3 (50 meters after the cage) using a grab with 30 cm diameter. A total of 6 groups of benthic organisms, including 2 branches, 2classes, 4 families and 6 species were identified. Overall, 23442 specimens of large benthic organisms were counted, the lowest and highest frequency at stations 1 (23.4%) and 2 (46.8%), respectively. The results showed that the highest abundance at station 2 with an average of 646.00±1230.43 N/m2 and biomass with 0.526±1.00 g/m2 in station 3, in which can be due to the lack of cage fish farming activity and the presence of big species to depend Cerastoderma lamarki, respectively. The highest abundance and biomass was in autumn with mean 888.3±1371.58 N/m2 and 0.524±0.887 g/m2 and lowest was in winter with mean 143.33±138.22 N/m2 and 0.070±0.078 g/m2. This could be related to activity fish cage culture and wintering season. The Streblospio gynobranchiata of polychaeta dominant benthic organisms with large population accounted 93.3%. This could be due to exotic species, high power compatibility and suitability related to environmental conditions. The conclusion is that the abundance and biomass of macrobenthos organisms in station 1 was less than other stations in which can be duo to concerned fish cage activity and its effects on organisms’ infauna. Therefore, it is suggested that any activity in the Caspian Sea offshore aquaculture should maintain environmental considerations and implementation of detailed environmental impact assessment (EIA) projects.

Macrobenthos were performed the main group of the Caspian Sea funa while they have not completely attentived espacilly in estuaries environoments. In this survey were studied eghiteen river estuaries in Guilan province off Caspian Sea southwest. The macroinvertebrate sampling was conductedseasonally at egith station during winter 2009 to summer 2009. The macrobenthos organisms were sorted and identified as possible level in genus or species. The results presented fifteen orders including thirty six families. The most presentation of genus belongs to Chironomidae family with twenty six genus while others were included forthy three genus. The Stenogammarus genus had the normally distribution between seasons while the most abundance was linked to Eukifferiella and Cricotopus during winter and spring 2009 nearly same as Streblospio and Limnodrilus. The Cerastoderma was showed a high percentage with decresing of others especially during summer 2009. In this paper have been described the fluctuation of benthic aboundance according to biological characteristic and the environoment degradation.