- Pars, Tehran, Iran, Islamic Republic of
Hasan Fazli
Caspian Sea research institue of ecology, Marine Biology & Stock Assessment, Department Member
One of the major sources of impacts on marine resources comes from climate variability and regime shifts. In this context, the present study pinpoints the role of climatic and environmental parameters on the dynamic of kilka in the... more
One of the major sources of impacts on marine resources comes from climate variability and regime shifts. In this context, the present study pinpoints the role of climatic and environmental parameters on the dynamic of kilka in the Caspian Sea. During the last decades, landings and stocks of the main pelagic species of kilka had been changed dramatically in the Caspian Sea. This study focuses on the last three decades of the climate regime and tries to explain the part of the changes in the recruitment (R) and spawning stock biomass (SSB) of three kilka species. Based on the statistical analysis of data series, it is found that regime changes in the global and regional environmental variables started in the mid-1995s, however, the shift of the late 1990s (1998) was more strong in the Caspian Sea. The study further reveals that the global climatic indices changes in the late 1990s are triggering the regional and local indices induced regime shifts in the late 1990s and 2000s. The stu...
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This study aimed to investigate the impact of fishing in Iranian part of the Caspian Sea during 1991-2017 years using fishing-in-balance (FiB), mean trophic level (MTI), ratio of pelagic and demersal fish landings (P/D) and piscivory (PI)... more
This study aimed to investigate the impact of fishing in Iranian part of the Caspian Sea during 1991-2017 years using fishing-in-balance (FiB), mean trophic level (MTI), ratio of pelagic and demersal fish landings (P/D) and piscivory (PI) indices. The mean (±S.D) of MTI were 2.91±0.38 (95% C.I =3.14-2.67). Its value is first reduced and then increase happened and ultimately stays constant. The mean of FiB was 0.13 (95% C.I=0.28-(-0.02)) and its trend was similar to that of total landing. The mean of Pi index, P/D index, pelagic fish and demersal fish were 0.04±0.02 (95% C.I=0.09-(-0.012)), 3.16±2.31 (95% C.I = 0.6-(-0.52)), 38529±22883 (95% C.I=38585-38472) and 13380±3314 (95% C.I= 3401-13358), respectively. The results revealed that the fish stock in the Iranian waters of the Caspian Sea have been over-exploited. Considering that fishing impacts on the trophic level, we suggest that the fishery management should not continue this trend.
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Measurements of bioavailability responses in frogs from contaminated sites could provide valuable data for environmental risk assessment. Biomarkers are sensitive to both e nvironmental pollution and confounding factors that are not... more
Measurements of bioavailability responses in frogs from contaminated sites could provide valuable data for environmental risk assessment. Biomarkers are sensitive to both e nvironmental pollution and confounding factors that are not related to pollution. The specimens were collected on a monthl y basis from the Babol-River from July to September 2010 to determine if monthly changes exist in condition, he patosomatic index (HSI) and frogs. Fulton condition factor (FCF range: 1.513±0.431 ‐ 1.638±0.473), hepatosomatic index ( HSI range: 3.901±0.504-5.231±1.206), Bioaccumulation factor (BAF), the highest level of copper was observed. Liver wei ght was seen to increase from July to August/Septem ber, most probably as a result of accumulation of metabolites, especia lly fat and glycogen. Furthermore, the concentratio ns of the metals found in the liver of the frog were in the order: Cu>Cr>C d>Pb>Ni. On the other hand, the concentrations of t he metals found in the water were in the order: Cu>Pb>Cd> Ni >Cr.
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Some reproduction characteristics of the Caspian Vimba, Vimba vimba persa, were studied from Oct. 2008 to Sep. 2009 in coastal waters of the Caspian Sea (Mazandaran province). 994 specimens were monthly collected from 6 fish landing sites... more
Some reproduction characteristics of the Caspian Vimba, Vimba vimba persa, were studied from Oct. 2008 to Sep. 2009 in coastal waters of the Caspian Sea (Mazandaran province). 994 specimens were monthly collected from 6 fish landing sites of Ramsar, Tonekabon, Chalus, Mahmood Abad, Sari and Behshahr. The fecundity was measured using 92 specimens. This species was found to have more abundance in spring (especially April and May). The samples composed of 397(42.6%) male, 537(57.4%) female; the sex ratio was M: F = 1:1.35. The advanced stages of maturity (4th & 5th) were found in April and May. The highest Gonadosomatic Index in females was in May and the lowest one was in July. The average of absolute and relative fecundities was 17198±7710 and 171.85±48.8, respectively.
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The Caspian Sea, which is known as the largest lake in the world, is located in the northern part of Iran. Caspian Sea Sprat or Clupeidae are pelagic fish and play an important role in the food chain. In Iran, clupeid fish are caught by a... more
The Caspian Sea, which is known as the largest lake in the world, is located in the northern part of Iran. Caspian Sea Sprat or Clupeidae are pelagic fish and play an important role in the food chain. In Iran, clupeid fish are caught by a conical lift net with artificial light and at night. The color of artificial light used in the conical lift net is white or sunny. In a study conducted from May 2018 to January 2019 in the fishing port of Amirabad, the effect of two types of artificial light (blue and red light) was investigated. For this purpose, two lamps with a color of blue and red with the same Volt and Ampere of white light were used in the depth of 40 – 50 meters. The results show a significant difference in the average length of sprat fish caught in each of the lights used (p <0.05). In blue light, the fish caught had a longer length and a heavier weight, while the fish caught in red light had a shorter length and a lighter weight.
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Research Interests: Ichthyology, Biology, Heavy metals, Black Sea, Mariculture, and 4 moreFishery, Cadmium, Gill, and Gonad
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Research Interests: Earth Sciences, Biology, Neural Networks, Biological Sciences, Environmental Sciences, and 15 moreActinopterygii, Habitat, Cypriniformes, Fishery, Caspian Sea, Pacific ocean, Water Quality, Habitat Modeling, River Management, Habitat preferences, Essential Fish Habitat, Cyprinidae, Eastern Mediterranean Sea, Anzali Wetland, and Caspian kutum
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Abstract Monitoring for 6 years (20012006) showed that the population explosion of the alien ctenophore Mnemiopsis leidyi in the southern Caspian Sea coincided with a decline in the abundance and species number of mesozooplankton. While... more
Abstract Monitoring for 6 years (20012006) showed that the population explosion of the alien ctenophore Mnemiopsis leidyi in the southern Caspian Sea coincided with a decline in the abundance and species number of mesozooplankton. While this decline appeared to have reduced ...
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The objective of this study was to compare the biological parameters such as length, weight, age, caviar production indices, caviar/weight, condition factor and sex ratio of Persian sturgeon (Acipenser persicus Borodin, 1897) and Russian... more
The objective of this study was to compare the biological parameters such as length, weight, age, caviar production indices, caviar/weight, condition factor and sex ratio of Persian sturgeon (Acipenser persicus Borodin, 1897) and Russian sturgeon (A. gueldenstaedtii Brandt & Ratzeburg, 1833) in the Caspian Sea during 1990-2014. All these characteristics (except condition factor) of Persian sturgeon were greater than the Russian sturgeon. In the long period, annually average (±SD) fork length ranged from 129.3 (±11.87) to 140.9 (±15.99) cm for Russian sturgeon and 145.7 (±17.61) to 157.4 (±19.31) cm for the Persian sturgeon. The annually caviar harvest for the Russian sturgeon ranged from 3.86 (±1.05) to 5.02 (±1.82) kg with a caviar/weight ratio were ranged from 16.9 (±4.12) to 20.1% (±5.12), while comparatively for the Persian sturgeon was greater and ranged from 4.84 (±1.62) and 7.04 (±2.58) kg with a caviar/weight ratio of 16.2 (±3.99) to 21.1% (±5.20). The age of both species ra...
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The aim of the present study was to estimate the population parameters including length weight relationship (LWR), condition factor (KF), relation condition factor (Kn), age, growth and mortality of Alburnus mossulensis in Azad dam and... more
The aim of the present study was to estimate the population parameters including length weight relationship (LWR), condition factor (KF), relation condition factor (Kn), age, growth and mortality of Alburnus mossulensis in Azad dam and Komasi river from Kordestan province, Iran. Of 522 specimens, the fork length, total length and weight of A. mossulensis ranged from 70 to 164, 75-175 mm, and 4.3 to 48.1 g and averaged (±SD) 114.0 (±15.97), 127.5 (±25.29) mm and 18.2 (±5.61) g, respectively. The length-weight regression was W=0.0003×FL2.7434 indicating a negative allometric growth. The sex ratio (M:F) was 1:0.49, for adult A. mossulensis (n=134) which differed significantly from the expected 1:1 (P<0.001). The von Bertalanffy growth parameters were estimated as L∞ = 170.3 mm, K = 0.46 yr-1, t0 = -0.59 yr. The instantaneous coefficient of natural mortality was estimated as 0.85 yr-1. The average of condition factor (KF) was 1.27±0.161. Statistically significant differences were fou...
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Population structure of three kilka fishes (Clupeonella spp.), particularly anchovy kilka (C. engrauliformis), in Iranian waters of the Caspian Sea was surveyed in 2003. A total of 3230 biweekly samples were collected from commercially... more
Population structure of three kilka fishes (Clupeonella spp.), particularly anchovy kilka (C. engrauliformis), in Iranian waters of the Caspian Sea was surveyed in 2003. A total of 3230 biweekly samples were collected from commercially landed kilka at 3 stations in Mazandaran and Guilan provinces. Catch and effort statistics were obtained from the relevant organization. Results showed a great decline in the commercial kilka catch from 95000 tons in 1999 to 15497 tons in 2003. The contribution of anchovy kilka to the total kilka fishery also showed a decline from 71% in 1999 to 52.5% in 2003, while common kilka (C. cultriventris) increased from 13.7% in 1999 to 48.9% in 2003. Fork length range of anchovy kilka showed an increase from 89.2±12mm in 1999 to 100.4±4.9mm in 2003. The age composition of anchovy ranged between 1+ to 7+ years and the dominant group was 5+ years old (age group of 4+ and 5+ comprised 84.6% of population). The K value and L∞ calculated 0.598/year and 110.13 mm ...
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The invasive ctenophore Mnemiopsis leidyi was first recorded in the Caspian Sea in 1995 in the southern part of the sea (Iranian waters). This study assesses the magnitude of the M. leidyi bioinvasion impacts on the region’s ecosystem... more
The invasive ctenophore Mnemiopsis leidyi was first recorded in the Caspian Sea in 1995 in the southern part of the sea (Iranian waters). This study assesses the magnitude of the M. leidyi bioinvasion impacts on the region’s ecosystem using the biopollution level (BPL) index. For this purpose, biomass and distribution range of the invasive ctenophore were analyzed for the period 1996–2010. In addition, the impacts of the IAS on native species, communities, habitats and ecosystem functioning were assessed. The BPL for the period of our study remained relatively stable at the level 4 (massive). The BPLs caused by M. Leidyi in the southern Caspian Sea were compared with those of the Black and Baltic Seas. The method used in this study seems to be applicable for evaluating spatial and temporal variations of the invasive impacts of gelatinous zooplankton in other marine regions.
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The present study was conducted to evaluate the status of the parasite fauna in Acipenser persicus at different development stages, in order to find prevention protocols for parasitic diseases in this valuable species. For this purpose,... more
The present study was conducted to evaluate the status of the parasite fauna in Acipenser persicus at different development stages, in order to find prevention protocols for parasitic diseases in this valuable species. For this purpose, sampling from each sex breeder, 10 egg samples, 5-day-old larvae (n = 20), 20-day-old larvae (n = 80) and fingerling of A. persicus (n = 60) released in earthen ponds were done. After the bioassay and preparing wet mount from the internal and external organs, identification was done according to the keys. According to the results, no fauna parasites were isolated from egg samples and 5-day-old larvae; but Trichodina spp. was isolated from 20-day-old larvae. Also, the same protozoan was isolated from fingerling released in earthen ponds, the mean intensity, prevalence and range of contamination by fingerling were higher with compared to 20-day-old larvae. Trichodina sp. and Diplostomum spathaceum were isolated from skin and eyes of females, respective...
Research Interests: Biology, Medicine, Pubmed, Fauna, Larva, and 3 moreAcipenser, Trichodina, and Ichthyophthirius multifiliis
Research Interests: Pediatrics, Health Informatics, Pakistan, Public Health, Health Services Research, and 15 moreHealth Policy, Health Administration, Medicine, Nursing Research, Library and Information Studies, Humans, Female, Male, Obstetrics and gynecology, Newborn Infant, Adult, Public health systems and services research, Health Services Administration, Postnatal Care, and Costs and Cost Analysis
(English) In the present research expriments were conducted to evaluate the Sturgeons Stocks insouth part of the Caspian Sea (Iranian side) by measuring different populationparameters such asCPUE, length, age, weight, sex, caviar wieght.... more
(English) In the present research expriments were conducted to evaluate the Sturgeons Stocks insouth part of the Caspian Sea (Iranian side) by measuring different populationparameters such asCPUE, length, age, weight, sex, caviar wieght. The ...
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In the last three decades, several ecological factors were changed and affected the most important commercial fish stocks in the Caspian Sea. This paper aims to assess the effects of these pressures on the population structure, stock... more
In the last three decades, several ecological factors were changed and affected the most important commercial fish stocks in the Caspian Sea. This paper aims to assess the effects of these pressures on the population structure, stock status and the vulnerability risk of stock extinction of the stellate sturgeon ( Acipenser stellatus Pallas, 1771) in the Southern Caspian Sea, in the years 1990-2011. For this period, we estimated growth parameters, the age structure of catch, sexual maturity, age at first capture, natural and fishing mortality, biomass and risk of stock extinction of stellate sturgeon by IUCN Red List categories. Fork lengths of individuals ranged from 82 to 206 cm and ages from 4 to 29 years. The growth parameters were L ∞ =215.0 cm, K = 0.064 year −1 , t 0 =−3.2 years. The majority of the catch (67.4-90.1%, averaged 80.0%) belonged to 9-13 years old. The biomass had a descending trend from 4983.5 mt in 1990-91 declined to 10.6 mt in 2011-12. The generation length wa...
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Seasonal variations of phytoplankton abundance, species composition, and their interaction with environmental parameters were investigated in the Azad Dam Lake, in the West of Iran during 2015–2016. Sampling was conducted seasonally at... more
Seasonal variations of phytoplankton abundance, species composition, and their interaction with environmental parameters were investigated in the Azad Dam Lake, in the West of Iran during 2015–2016. Sampling was conducted seasonally at five stations in the lake. Multivariate statistical analyses were carried out to define the abiotic variables influencing phytoplankton community composition. A total of 51 taxa of phytoplankton belonging to six phyla were identified. Bacillariophyta (diatoms) were most diverse with 22 taxa, comprised more than 90% of the total density. Despite the low Shannon–Wiener index (H ′) diversity (0.10–1.54), pointing out the dominant density of Bacillariophyta resulted in high water quality. Statistical analysis showed seasonal phytoplankton assemblages differences indicating a biogeographical gradient. Distance-based Linear Model (DisTLM) analysis displayed six environmental variables showing significant relationships with the phytoplankton abundance in the...
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Through most of the last century, three endemic kilka species supported major commercial species in the Caspian Sea. It is clear that catches and abundance of all species have changed. Recent changes in the Caspian Sea ecosystem have... more
Through most of the last century, three endemic kilka species supported major commercial species in the Caspian Sea. It is clear that catches and abundance of all species have changed. Recent changes in the Caspian Sea ecosystem have occurred as a consequence of ecological change caused by the invasive ctenophore (Mnemiopsis leidyi). In this investigation which had been done in commercial catch regions during 2002-2004, in addition of biological characteristics survey such as species composition, length, weight, age, sex ratios and maturity stages; catch and catch per unit effort also were analyzed. During the years 2002-2004 the annual catches of kilka varied between 15000-25000 mt and CPUE varied between 1.077-1.474 mt (vessel×night). The frequency of anchovy kilka declined from 69.5% in 2002 to 26.9% in 2004. During the years 2002, 2003 and 2004 the frequency of common kilka were 30.4%, 48.9% and 71.9%, respectively. During this period the frequency of bigeye kilka was negligible...