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  • 1
    Publication Date: 2021-05-19
    Description: 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. The average fork length of anchovy kilka increased from 100.4 mm in 2002 to 105.0 mm in 2004 and the average weight were 6.4 g and 8.4 g, respectively. The average fork length of common kilka increased from 87.0 mm in 2002 to 93.8 mm in 2004 and the average weight were 5.2 g and 7.4 g, respectively. Anchovy kilka spawn in spring and autumn but mass spawning anchovy occurred in autumn. Spawning of common kilka occurred in spring and early summer. In the age compositions of anchovy kilka, age 3 was the largest age group during 2002 and 2003 (55.3% and 52.1%, respectively). In 2004, age 4 predominated (42.5%). For common kilka, ages 3 and 4 predominated (representing 67.2, 62.0 and 69.1% of catches, respectively). According to CPUE and biological characteristics, after the appearance of ctenophore in the Caspian Sea, the abundance and biomass of bigeye and anchovy kilka collapsed.
    Description: Iranian Fisheries Science Research Institute
    Description: Published
    Keywords: Commercial ; Ecological ; Biological ; kilka ; Species ; Ecosystem ; Mnemiopsis leidyi ; Survey ; Length ; Age ; Sex ratios ; Weight ; Maturity ; CPUE ; Anchovy Kilka ; Spawning ; Bigeye kilka
    Repository Name: AquaDocs
    Type: Report , Refereed
    Format: 49pp.
    Location Call Number Expected Availability
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  • 2
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    Iranian Fisheries Science Research Institute | Tehran, Iran
    In:  http://aquaticcommons.org/id/eprint/25627 | 18721 | 2018-10-07 16:48:29 | 25627 | Iranian Fisheries Science Research Institute
    Publication Date: 2021-07-16
    Description: This study have been conducted entitle biological and statistical sturgeon in the southern Caspian Sea (Mazandaran waters)” from 2009 to 2013. Sampling was manthly. Overal, 1859 specimens of different species of sturgeon was caught including Acipenserpersicus (69%), A. stellatus (19%), Husohuso (6%), A. nudiventris (4%) and A. guldenstaedtii (2%). Totally, the meat and caviar of five species were found 53263.6 kg and 5633 kg respectively and caviar to meat ratio was 10.6%. The results show that ration of meat and caviar whole species reduced from 2009 to 2012 in which the meat and caviar of A. persicus was declined from 12146 to 4465 kg in meat and caviar from 1358 to 487 kg were extremely reduced respectively. The CPUE (catch per unit effort) of sturgeon has fluctuated from 2009 to 2012. Totally, the CPUE of A. persicus was decreased from 0.150 (2009) to 0.130 (2012) kg boat per day, A. stellatue from 0.009 (2009) to 0.021 (2012) kg boat/day, A. guldenstaedtii from 0.002 (2009) to 0.003 (2012) kg boat/day, A. nudiventris from 0.027 (2009) to 0.001 (2012) kg boat/day and H. huso from 0.123 (2009) to 0.018 (2012) kg boat /day. 1061 specimens of fish has been caviar including A. persicus with 69%, A. stellatus (18.1%), H. huso (5.5%), A. guldenstaedtii (2.7%). The frequency of caviar categorize was included 1 , 2, 3 and massive with 49.6%, 38%), 10.6% and 1.9%, respectively. The highest of meat and caviar belong to A. persicus with 31414 kg and 3515.7 kg, respectively were found and the lowest was 841kg and 105.9 kg pertain to A. guldenstaedtii. The results show that 65.9% of sturgeon was caught by legal catch (landing) and 34.1% by beach seine remained. 391 individuals was age determined that the minimum and maximum age was 9 and 41 year comprised to H.huso and A. stellatus, respectively. A. persicus and A. stellatus were majority caught compare to other species. A. persicus has the highest frequency in 14-15 year age groups with 50% and 57% in 2009 and 2011, respectively and 15-16 year age group with 41% and 56% in 2010 and 2012, respectively. The results show that mean of fork length, body weight, caviar weight of A. persicus was declined because the FL and weight average (±SD) obtained from 152.4±16.7cm and 25.8±9.2 kg in 2009 to 146.5± 18.7cm and 22.1±9.2kg in 2012, respectively. In contrast, the average (±SD) FL and weight of H. huso was increased from 218.8±41.1cm and 137.3±96.6kg in 2009 to 231.3±45.2cm in FL and 146.2±78.5kg body weight in 2012, respectively. Consequently, the results show that stocks of sturgeon in the Caspian Sea has a trend declined because of some species in IUCN categorize list was Endangered in 2006 but at this moment lie in Critically Endangered list of IUCN categorize were down which could be a serious alarm for the valuable sturgeon fish in the Caspian Sea. Therefore, recommendation that trade catch of sturgeon in the Caspian Sea must be forbidden and continue legal catch for spawner fish that needede to artificial propagation only.
    Keywords: Biology ; Iran ; Caspian Sea ; Biology ; Sturgeons ; A. persicus ; A. stellatus ; A. guldenstaedtii ; A. nudiventris ; H. huso ; CPUE
    Repository Name: AquaDocs
    Type: monograph
    Format: application/pdf
    Format: application/pdf
    Format: 98
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  • 3
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    Unknown
    Iranian Fisheries Science Research Institute | Tehran, Iran
    In:  http://aquaticcommons.org/id/eprint/25084 | 18721 | 2018-08-22 07:18:57 | 25084 | Iranian Fisheries Science Research Institute
    Publication Date: 2021-07-16
    Description: 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. The average fork length of anchovy kilka increased from 100.4 mm in 2002 to 105.0 mm in 2004 and the average weight were 6.4 g and 8.4 g, respectively. The average fork length of common kilka increased from 87.0 mm in 2002 to 93.8 mm in 2004 and the average weight were 5.2 g and 7.4 g, respectively. Anchovy kilka spawn in spring and autumn but mass spawning anchovy occurred in autumn. Spawning of common kilka occurred in spring and early summer. In the age compositions of anchovy kilka, age 3 was the largest age group during 2002 and 2003 (55.3% and 52.1%, respectively). In 2004, age 4 predominated (42.5%). For common kilka, ages 3 and 4 predominated (representing 67.2, 62.0 and 69.1% of catches, respectively). According to CPUE and biological characteristics, after the appearance of ctenophore in the Caspian Sea, the abundance and biomass of bigeye and anchovy kilka collapsed.
    Keywords: Biology ; Fisheries ; Iran ; Caspian Sea ; kilka ; Species ; Ecosystem ; Mnemiopsis leidyi ; Survey ; Length ; Age ; Sex ratios ; Weight ; Maturity ; CPUE ; Anchovy Kilka ; Spawning ; Bigeye kilka
    Repository Name: AquaDocs
    Type: monograph
    Format: application/pdf
    Format: application/pdf
    Format: 49
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2021-05-19
    Description: This study have been conducted entitle biological and statistical sturgeon in the southern Caspian Sea (Mazandaran waters)” from 2009 to 2013. Sampling was manthly. Overal, 1859 specimens of different species of sturgeon was caught including Acipenserpersicus (69%), A. stellatus (19%), Husohuso (6%), A. nudiventris (4%) and A. guldenstaedtii (2%). Totally, the meat and caviar of five species were found 53263.6 kg and 5633 kg respectively and caviar to meat ratio was 10.6%. The results show that ration of meat and caviar whole species reduced from 2009 to 2012 in which the meat and caviar of A. persicus was declined from 12146 to 4465 kg in meat and caviar from 1358 to 487 kg were extremely reduced respectively. The CPUE (catch per unit effort) of sturgeon has fluctuated from 2009 to 2012. Totally, the CPUE of A. persicus was decreased from 0.150 (2009) to 0.130 (2012) kg boat per day, A. stellatue from 0.009 (2009) to 0.021 (2012) kg boat/day, A. guldenstaedtii from 0.002 (2009) to 0.003 (2012) kg boat/day, A. nudiventris from 0.027 (2009) to 0.001 (2012) kg boat/day and H. huso from 0.123 (2009) to 0.018 (2012) kg boat /day. 1061 specimens of fish has been caviar including A. persicus with 69%, A. stellatus (18.1%), H. huso (5.5%), A. guldenstaedtii (2.7%). The frequency of caviar categorize was included 1 , 2, 3 and massive with 49.6%, 38%), 10.6% and 1.9% , respectively. The highest of meat and caviar belong to A. persicus with 31414 kg and 3515.7 kg, respectively were found and the lowest was 841kg and 105.9 kg pertain to A. guldenstaedtii. The results show that 65.9% of sturgeon was caught by legal catch (landing) and 34.1% by beach seine remained. 391 individuals was age determined that the minimum and maximum age was 9 and 41 year comprised to H.huso and A. stellatus, respectively. A. persicus and A. stellatus were majority caught compare to other species. A. persicus has the highest frequency in 14-15 year age groups with 50% and 57% in 2009 and 2011, respectively and 15-16 year age group with 41% and 56% in 2010 and 2012, respectively. The results show that mean of fork length, body weight, caviar weight of A. persicus was declined because the FL and weight average (±SD) obtained from 152.4±16.7cm and 25.8±9.2 kg in 2009 to 146.5± 18.7cm and 22.1±9.2kg in 2012, respectively. In contrast, the average (±SD) FL and weight of H. huso was increased from 218.8±41.1cm and 137.3±96.6kg in 2009 to 231.3±45.2cm in FL and 146.2±78.5kg body weight in 2012, respectively. Consequently, the results show that stocks of sturgeon in the Caspian Sea has a trend declined because of some species in IUCN categorize list was Endangered in 2006 but at this moment lie in Critically Endangered list of IUCN categorize were down which could be a serious alarm for the valuable sturgeon fish in the Caspian Sea. Therefore, recommendation that trade catch of sturgeon in the Caspian Sea must be forbidden and continue legal catch for spawner fish that needede to artificial propagation only.
    Description: Iranian Fisheries Science Research Institute
    Description: Published
    Keywords: Biology ; Sturgeons ; A. persicus ; A. stellatus ; A. guldenstaedtii ; A. nudiventris ; H. huso ; CPUE
    Repository Name: AquaDocs
    Type: Report , Refereed
    Format: 98pp.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
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