Asghar Abdoli; Fahimeh Rashidabadi
Abstract
Quantitative assessment of fish abundance is the basis of scientific research and management of their population. Demographic studies of stream-dwelling salmonids have shown that variation in their abundance s on a spatio-temporal scale is common, and brown trout populations are no exception. Understanding ...
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Quantitative assessment of fish abundance is the basis of scientific research and management of their population. Demographic studies of stream-dwelling salmonids have shown that variation in their abundance s on a spatio-temporal scale is common, and brown trout populations are no exception. Understanding this variation is crucial for several reasons, including designing and interpreting environmental impact assessment studies and monitoring fishery management strategies. The present study aimed to estimate the spatial and temporal variations in the density of brown trout in some of the Lar National Park streams and investigate the relationship between the density of fish in these streams and the density of benthic invertebrates as their primary food sources. In general, the purpose of this study was to assess the status of trout for conservation planning and better management of its populations in the future against human impacts and climate change. Since the Lar National Park streams are small, fish densities were calculated using the Le Cren depletion method to achieve reliable population estimates. After two removal steps, the total number of fish caught was standardized and expressed as density per 100 m2 of the river channel. To investigate the temporal changes of fish abundance, the study results in 2009 were qualitatively compared with the results of another study in 2017.According to the 2009 results, the highest brown trout density was recorded in the Delichay (44 per 100 m2), Lar (43.2 per 100 m2), and Siah Palas sites (33.4 per 100 m2), respectively, and the lowest density were recorded in the Lar (Kharsang, 10.5 per 100 m2) and Lar (Sorkhak, 11.5 per 100 m2). In 2017, the highest density of trout was documented to Siah Palas (175 per 100 m2), Delichay (Vararo, 118 per 100 m2), and Elam (112 per 100 m2) streams, and the lowest density was recorded in the Delichay (downstream, 48 per 100 m2) and Absefid (49 per 100 m2) streams.The distribution and abundance of stream-dwelling salmons are primarily regulated by food and space. The abundance of brown trout on a local scale indicates variety in quality and habitat access for brown trout in the Lar National Park. We speculated that habitat diversity has influenced the density of brown trout in various streams in the region by affecting the abundance of aquatic invertebrates, which are the main source of prey. However, the results of regression (R2= 0.02, p value = 0.72) and correlation (Spearman, r = 0.24) analyses showed no significant relationship between the density of fish and benthic invertebrates in the Lar National Park streams. Despite the enough abundance of prey in the Lar streams, the fish were low in density. The cause of this incongruence is probably related to the salmon fishing in Lar National Park in the past.Comparing fish densities in 2009 and 2017 showed that the trout density in 2017 had a better condition than the trout density in 2009. Considering that in 2014, the Department of Environment stopped issuing fishing licenses in this area, one of the reasons for the increase in fish density is probably a positive effect of the fishing prohibition on this species.Since brown trout abundances in the Lar National Park streams are spatially-temporally variable, it is necessary to provide reasonable management strategies and continuous monitoring to prevent them from global warming and conserve them in the streams of the Lar National Park. Furthermore, due to climate change and being at risk of other populations of brown trout in different habitats in Iran, this population should be protected as a support population.
Saleh Mahmoudi; Asghar Abdoli
Abstract
Introduction: Finding habitat requirements for fish in fluvial water ecosystems is a key factor in conservation and decision making for their management, which unfortunately does not have enough scientific information in this field. The purpose of this study is to identify the optimal range of habitat ...
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Introduction: Finding habitat requirements for fish in fluvial water ecosystems is a key factor in conservation and decision making for their management, which unfortunately does not have enough scientific information in this field. The purpose of this study is to identify the optimal range of habitat variables for Alburnus atropatenae in the Jajroud protected river and compare different composite approaches in the modeling of this species.Material and methods: In this study, the habitat of A. atropatenae sampled in the form of 71 points in the Jajroud river. Physical variables of habitat measured including depth, water velocity and substrate type. After sampling the fish by electrofishing, the total length of the fish measured. Habitat suitability curves developed by univariate method then combined habitat suitability calculated by multiplication, minimum, arithmetic mean and geometric mean methods. To validate the results, two statistical metrics of mean absolute error (MAE) and root mean square error (RMSE) used.Results and discussion: Overall, 235 individual of A. atropatenae caught including 221 adults and 14 juveniles whose total body length varied from 23 mm to 148 mm. Physical habitat variables included a depth of 6-56 cm, a flow velocity of 4-29 cm / s, and a riverbed with a particle size of "very fine gravel" to "small cobble". The preferred and optimal range habitat for this species included a depth of 16-25 cm, a flow velocity of 5-10 cm / s and a bed with small cobble structure. Among univariate models, the riverbed-based model had the lowest error. Among the models of combined habitat suitability, multiplication method had the lowest values of MAE and RMSE measures, and was low-error model. The arithmetic mean method had the highest values of these measures and had detected as the high-error model.Conclusion: This is the first study related to the ecology of A. atropatenae in Iran, which has identified the optimal habitat of this species. The variable of bed structure is determinative more than two variables of depth and flow velocity in habitat selection by this species. Also in combined habitat suitability modeling, the multiplication method has priority and importance.
Maryam Peymani; Asghar Abdoli; Seyed Daryoush Moghaddas
Abstract
Introduction: The introduction of invasive fish species into aquatic ecosystems causes various adverse ecological and socio-economic impacts. The first step in analyzing the effects of these species is to identify the risk. Then, different tools have been developed to identify potential invasive ...
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Introduction: The introduction of invasive fish species into aquatic ecosystems causes various adverse ecological and socio-economic impacts. The first step in analyzing the effects of these species is to identify the risk. Then, different tools have been developed to identify potential invasive species and evaluate the potential degree of their invasiveness to support decision-makers in analyzing the invasive risk of these species. This study aimed to assess the invasive potential of the non-native species redbelly tilapia (Coptodon zillii, Gervais 1848) in the Shadegan Wetland basin (the Karun and Jarahi catchments) using some of these tools.Material and methods: The level of risk for C. zillii in the trinational risk assessment protocol was determined based on the results of the two components "Probability of Establishment" and "Consequences of Establishment". In the German-Austrian Blacklist Information System (GABLIS), the invasive potential of the species was evaluated according to the distribution in the study area. The non-native species were screened by the Aquatic Species Invasiveness Screening Kit (AS-ISK) model according to the threshold of the assessment area; and the rank of species invasion was calculated based on the probability of species establishment, expansion, and environmental effects, using the Harmonia+ method. Also, the climate matching between the introduced and native range of the species was carried out with the Köppen-Geiger climate classification system.Results and discussion: The results of trinational risk assessment indicated that the species posed a high potential rank of placing at each step of introduction, establishment, and expansion potential and the possibility of economic and environmental impacts in the study area. The results of the GABLIS protocol showed that the non-native species C. zillii has been widely distributed in the risk assessment area and was placed on the blacklist and the subset management list (b3). In the AS-ISK risk assessment, the risk score of the species was 44, which was higher than the tool threshold (22.5) for the study area. This score indicates that this species has a high invasive risk in the wetland. The overall risk score in the Harmonia+ method, which is a function of invasiveness and species impacts, was assessed as high for the redbelly tilapia. Based on the results, the risk of establishment and dispersal of this species in the study area is high, and its environmental impacts are significant. Also, there was a high climate match between the risk assessment area and the native range of the species in the Köppen-Geiger climate classification system. Conclusions: The trinational risk assessment methods, GABLIS, AS-ISK, and Harmonia+ models were able to show the invasiveness of the non-native C. zillii in Shadegan Wetland basin as literature and field evidence demonstrate that the species has exerted strong and adverse impacts on native fishes and local people livelihood in the risk assessment area. Given the results of risk assessment methods and the risks posed by this species, it is highly recommended that large-scale control and management measures should be seriously implemented.
Seyedeh Narjes Tabatabaei; Asghar Abdoli; Iraj Hashemzade Segherloo; Faraham Ahmadzadeh; Louis Bernatchez
Abstract
Introduction: Lar National Park is the best habitat of Salmo caspius in Iran. In other habitats located in Iran, the species has been threatened by different factors including habitat destruction, pollution, sand removal from the river bed, dam construction, introduction of exotic species, over-fishing, ...
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Introduction: Lar National Park is the best habitat of Salmo caspius in Iran. In other habitats located in Iran, the species has been threatened by different factors including habitat destruction, pollution, sand removal from the river bed, dam construction, introduction of exotic species, over-fishing, and other human mediated changes. Dalicahy River, as one of the major habitats of S. caspius, is ecologically different from other rivers in the Lar National Park. In this study, we assessed genetic differences (applying next-generation sequencing) of S. caspius in Dalichay River and Lar Lake; considering an impassable barrier in the mouth of Dalichay River. Material and methods: in this study fin clips from fish electrofished in the river and fin clips collected via angling in the lake were used. DNA extraction was performed using salt extraction method with an additional treatment with RNAse to degrade RNA molecules. To compare fish from Dalichay River and the Lar Lake, next generation sequencing was used. Analyses including principal components analysis (PCA) and Admixture, plus calculation of genetic differentiation (Fst) were used to compare the studied populations. Results and discussion: According to the results of principal components analysis (PCA) fish from the Dalichay River and the Lake were separated clearly along the first PC (25.11% of variation). But they were overlapped along other PCs. The results of Admixture analysis showed that Dalichay and Lake fish were always represented with different admixture clusters with little contribution from one another. Additionally, the genetic differentiation between the Dalichay and the Lake was significant. The reason for this differentiation can be the existence of a physical barrier in the moth of Dalichay that blocks the path for migration from Dalichay to the Lake and vice versa. On the other hand, it is possible that the fish in Dalichay are resident and do not show any preference for migration to the Lake. The residency behavior forms in result of low density of fish and satisfaction of biological and habitat related needs of the fish and hence no need for migration. Conclusion: overall, the results of this study showed that the fish in Dalichay River and in the Lake differ in their genetic composition and were significantly differentiated from one another. In any case, high differentiation of the fish in the Dalichay River and their isolation in addition to inability of fish from the Lake and other rivers in the Lar National Park to Dalichay, necessitates revision and taking better management approaches.
Seyed Daryoush Moghaddas; Asghar Abdoli; Bahram Hassanzade Kiabi; Hossein Rahmani
Abstract
Introduction: The intentional and unintentional introduction of non-native fish species to the aquatic ecosystems of Iran has occurred with purposes such as enhancing aquaculture, ornamentation, biological control, and research. Some of them cause or have the potential to cause, significant environmental ...
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Introduction: The intentional and unintentional introduction of non-native fish species to the aquatic ecosystems of Iran has occurred with purposes such as enhancing aquaculture, ornamentation, biological control, and research. Some of them cause or have the potential to cause, significant environmental and socio-economic impacts on aquatic ecosystems and/or fish farms. The eradication of non-native fishes is impossible or very costly, especially in large areas. Screening and identifying the potential invasiveness of species are being increasingly used all over the world. The main aim of the present research was to assess the potential invasiveness of redbelly Tilapia Coptodon zillii in Anzali international wetland. Material and methods: Aquatic Species Invasiveness Screening Kit (AS-ISK) was used to identify redbelly Tilapia Coptodon zillii as a non-native fish that may pose a high potential risk of becoming invasion in Anzali Wetland. The model is able to discriminate between invasive and non-invasive aquatic organisms including non-native fishes by risk area-related threshold value. Also, the Köppen-Geiger climate system and Climatch software were used to match the climate between the native range of redbelly Tilapia and Anzali Wetland. The projected future climate change scenario was taken from relevant studies to carry out Climate Change Assessment (CCA) of the AS-ISK. Results and discussion: The output of the AS-ISK was 44 for redbelly Tilapia that was higher than the AS-ISK threshold value of the risk assessment area, which meant that the species pose a potential risk of becoming invasive in Anzali wetland. There was a high climate-mating between the native range of redbelly Tilapia and the assessed area when the Köppen-Geiger climate system was used. At least one native habitat of redbelly Tilapia in the system was in the same climate category as the studied area. Also, the Climatch model output was 0.87 that shows a high climate matching for the non-native fish. The CCA had an increasing effect on the total score of the AS-ISK. The factors that increased the AS-ISK score were climate-mating, probable climate change, biological attributes, and invasiveness history of other places that the species was introduced. The comparison of the results of this study and other relevant studies that used AS-ISK to assess potential invasiveness of redbelly Tilapia showed that the species had the potential of becoming an invader in Anzali Wetland as well as some other areas around the country. Conclusion: While non-native fishes are frequently used to enhance aquaculture in the country, a rapid assessment tool is required to avoid nuisance environmental impacts. The AS-ISK can be reliably used as a tool to predict the potential risk of becoming invasive in Anzali Wetland and elsewhere to be used by conservation managers, decision-makers, and policymakers in the aquaculture development plans.
Kamal Khezri; Asghar Abdoli; Bahram Hasanzadeh Kiabi; Hussein Valikhani; Jaber Aazami
Abstract
Introduction: Nowadays, many indicators have been developed to assess water quality and ecological classification of rivers based on variations in ecological structure. The goals of the study were assessing the ecological status, the effects of human land use, and the performance of the most common ecological ...
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Introduction: Nowadays, many indicators have been developed to assess water quality and ecological classification of rivers based on variations in ecological structure. The goals of the study were assessing the ecological status, the effects of human land use, and the performance of the most common ecological indices for fishes and macroinvertebrates as biological evaluation of the Jajrood River. Material and methods: In the present study, sampling of water, macroinvertebrates, and fishes was done at 10 stations in November 2015. The physical, chemical, and biological parameters including temperature, turbidity, velocity and depth of water, acidity, electrical conductivity, BOD5, nitrate, ammonium, phosphate, dissolved oxygen, and fecal coliform were measured on-site or after the sampling. Macroinvertebrates sampling was performed using a Surber sampler with three replications at each station and fishes were sampled using an electrofishing apparatus. Different physicochemical, macroinvertebrates, and fish indices were used to evaluate the integrity of the Jajrood River. The Canonical Correspondence Analysis (CCA) test was also used to analyze the relationship between macroinvertebrates and fishes with physical, chemical, and biological variables. Results and discussion: Overall, 481 specimens belonging to eight species of fishes and 2435 macroinvertebrates belonging to 15 families were collected. Among all sampled fishes, Oxynoemacheilus bergianus and Paracobitis malapterura had the highest and lowest abundance, respectively. The highest total percentage of macroinvertebrates abundance belonged to the Baetidae family of the order Ephemeroptera and the lowest percentage belonged to the Polycentropodidae of the order Trichoptera. The results of Canonical Correspondence Analysis (CCA) showed that the efficiency of the EPT/CHIR index for macroinvertebrates was better than others. The Karr Biotic Integrity (KBI) that was used for fishes as a water quality index was suitable for the river. Conclusions: The present study was the first one that used both fishes and macroinvertebrates indices with physicochemical parameters for ecological integrity assessment. From the findings of this study, it can be concluded that the urban-rural and agriculture wastewaters and the Latyan dam had the most negative impact on the ecological structure of the river.
Hussein Valikhani; Asghar Abdoli; Bahram HassanzadehKiabi; Farshad Nejat; Mohammad Sadeghsaba; Milad Khosravi
Volume 15, Issue 4 , January 2018, , Pages 29-44
Abstract
Introduction: Invasive fishes are a major threat to biodiversity of aquatic ecosystems. Tilapia species are invasive due to reproductive, diet and behavioral characteristics and high resistance to environmental conditions, pollution and diseases. So far, two exotic species Coptodon zillii and Oreochromis ...
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Introduction: Invasive fishes are a major threat to biodiversity of aquatic ecosystems. Tilapia species are invasive due to reproductive, diet and behavioral characteristics and high resistance to environmental conditions, pollution and diseases. So far, two exotic species Coptodon zillii and Oreochromis aureus and also a native species Iranocichla hormuzensis of these species were reported from Iran. In recent years, exotic tilapia species invaded Iran and its neighboring countries inland waters and have had significant ecological and economic impacts. The aim of this study is to do a preliminary survey on the status of exotic tilapia species in Khuzestan province, Iran. Material and methods: The present study was carried out from November 2014 to September 2015 to determine the abundance of tilapia species (C. zillii and O. aureus) in the Shadegan wetland and some local fishery markets in Khuzestan province. In addition to, we evaluated presence or absence of the species in some cyprinid fish farms in the province. Results and discussion: The results showed that the catchment and supply of C. zillii is high and the species is one of the dominated fish in the Shadegan Wetland. In this study, O. aureus was not caught from the Shadegan wetland but observations show that the species is dispersed to other areas, especially in rivers and its abundance is increased. The tilapia species especially C. zillii are pests in some fish farms and the reduction of fish production was noted. The presence of the species in some fish hatcheries is increased the possibility of their transfer to other regions. Conclusions: At the moment, it seems that the best course of action to take action against tilapia is to prevent them from entering to other bodies of water (especially by aquaculture). The continuous studies to determine various aspects of the introductions, potential range prediction, and regular monitoring should be also considered. Overall, a compilation method and also ecologically sustainable water management, reduction of water contaminants and decrease of fishing pressure on native species should be adopted for controlling and reducing of these species.
Shafagh Kamal; Asghara Abdoli; Majid Bakhtiary; Mahmoud Karami
Volume 6, Issue 3 , April 2009
Abstract
Some biological traits of Killifish (Aphanius sophiae)of CheshmeAli Damghan such as age and growth frequencies, condition factor, von Bertalanfy growth parameter, Gonadosomatic index, fecundity and egg diameter were studied monthly from October 2004 to November 2005. During the study 535 specimens were ...
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Some biological traits of Killifish (Aphanius sophiae)of CheshmeAli Damghan such as age and growth frequencies, condition factor, von Bertalanfy growth parameter, Gonadosomatic index, fecundity and egg diameter were studied monthly from October 2004 to November 2005. During the study 535 specimens were sampled with a net which bears a mesh size of 1mm. Sex ratio of Cheshme Ali population was 1 :♂ 1.367♀.There was significant difference between male and female (χ2=12.877, p=0.000)). Length and age frequency studies showed that female fishes were longer and older than male fishes. Male fishes had higher condition factor than females (F=40.037, p=0.000). Reproduction cycles of these fishes were estimated to be about 6 month and the peak of GonadoSomatic Index of females was in May. Eggs diameters were from 0.53 to 2.73 mm.
Roohallah Mirzaei; Mahmud Krami; Afshin Danehkar; Asghar Abdoli
Volume 6, Issue 2 , January 2009
Abstract
The Eurasian otter (Lutra lutra) is a semi-aquatic mammal from Mustelidae family. It is recognized as one of the top predators in freshwater systems, and thus has the potential to play an important role in the functioning of these systems. There are only 2 otter species in Iran .Information about this ...
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The Eurasian otter (Lutra lutra) is a semi-aquatic mammal from Mustelidae family. It is recognized as one of the top predators in freshwater systems, and thus has the potential to play an important role in the functioning of these systems. There are only 2 otter species in Iran .Information about this species in Iran is absent. River ecosystems are one of the important habitats for otters. Jajrood River with 140 km length in the east of Tehran is one of these habitats that were selected for this study. To study otter distribution standard method was used. This method is a systematic sample survey for field signs of otters. 16 survey sites at about 5 km intervals were selected and Otter signs, habitat parameters such as vegetation cover, river width and fish of river were recorded for each 600m stretch by walking the entire it (both banks) of all river, wading in the river wherever possible. A total of 599 signs (spraints, tracks, holst,rolling places and passes) were identified over the whole study period, the most common being spraints. Otter spraints were found in 6 of the sites of river Surveyed and in the study area, three core areas could be identified.
Ahmad Reza Mehrabian; Asghar Abdoli; Hossein Mostafavi; Abdol Rasool Salman Mahini; Faraham Ahmadzadeh; Mehregan Ebrahimi
Volume 5, Issue 1 , October 2007
Abstract
The habitats are the most basis of plants diversity and the study of habitats are the most important studies in the ecosystem. Qom province Due to ecotonical conditions (the connection between Zagros mountain ecosystem in west and south of province and central desert ecosystem in east of province, ecosystems ...
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The habitats are the most basis of plants diversity and the study of habitats are the most important studies in the ecosystem. Qom province Due to ecotonical conditions (the connection between Zagros mountain ecosystem in west and south of province and central desert ecosystem in east of province, ecosystems and habitats diversity is high. this research has been carried out on the natural habitats and effected by human. The former Nature habiatats includes desertic, alpine and wetland zones and the later are includes the marginal of agricultural lands and Ruderal habitats . Moreover in the present survey diversity of plant habitats has been investigated in order to height, temperature and perception gradient. the different habitats by accessed With quadratic sampling in different habitat of province based on Braun-Blanquet . The highest diversity is includes Palang-darreh Valley (south west of province) and the lowest diversity is in relevant to Massileh plain (East of province).
Mehdi Naderi Jelodar; Abbas Esmaeili Sari; Mohammad Reza Ahmadi; Seyed Jafar Seifabadi; Asghar Abdoli
Volume 4, Issue 2 , January 2007
Hossein Mostafavi; Asghar Abdoli
Volume 2, Issue 7 , April 2005
Hossein Mostafavi; Asghar Abdoli
Volume 2, Issue 6 , January 2005
Hossein Mostafavi; Asghar Abdoli
Volume 1, Issue 1 , October 2003
