stocks status of kilka in iranian waters of the caspian sea

Authors

hasan fazli

abstract

the present study considered the situation of kilka stocks in last decades by using overfished biomass threshold, fishing effort ratio and fishing mortality proxy during 1991-2010. the cpue index of anchovy and mixed-species of kilka indicated an undepleted from 1991 to 2000. in 2000, the cpue ratio declined to close to the “in danger” region, and subsequently collapsed to “overfished” region from 2001 to 2007 for both of anchovy and mixed-species of kilka. the cpue ratios of common kilka have been in an overfished state during 1991-2003. during 2008-2010 the biomass increased and the cpue ratio of common kilka and mixed-species moved to not overfished region. the control rule of anchovy kilka showed that overfishing was occurring from 1998 to 2010, ovefishing-effort was exceeded the overfihing threshold (mfmt) by 12-66%. the trajectory of the phase-plot of biomass proxy (cpue ratio) and fishing mortality proxy (effort ratio) of anchovy kilka showed that the status of the fishery of anchovy kilka has generally declined since 1998 collapsed to lowest level in 2010. the trajectory for common kilka has generally increased since 1991 which it was closed to the fisheries management target in 2007. in conclusion, in the new condition, common kilka is the main species in the caspian sea. for stock recovery of anchovy kilka, the catch of kilas must be restricted during reproduction periods, and also, a coordinated international effort is needed.

Upgrade to premium to download articles

Sign up to access the full text

Already have an account?login

similar resources

Stocks status of kilka in Iranian waters of the Caspian Sea

The present study considered the situation of kilka stocks in last decades by using overfished biomass threshold, fishing effort ratio and fishing mortality proxy during 1991-2010. The CPUE index of anchovy and mixed-species of kilka indicated an undepleted from 1991 to 2000. In 2000, the CPUE ratio declined to close to the “in danger” region, and subsequently collapsed to “overfished” region f...

full text

Multi-species approach for stock management of kilka fish (genus: Clupeonella) in Iranian waters of the Caspian Sea

There have been recent changes in the Caspian Sea ecosystem, such as those due to changes in sea level or those caused by the invasive ctenophore, Mnemiopsis leidyi. It is believed that these changes had significant impacts on the absolute and relative abundance of the commercially important anchovy kilka (Clupeonella engrauliformis) and common kilka (C. cultriventris caspia) leading to decline...

full text

Multi-species approach for stock management of kilka fish (genus: Clupeonella) in Iranian waters of the Caspian Sea

There have been recent changes in the Caspian Sea ecosystem, such as those due to changes in sea level or those caused by the invasive ctenophore, Mnemiopsis leidyi. It is believed that these changes had significant impacts on the absolute and relative abundance of the commercially important anchovy kilka (Clupeonella engrauliformis) and common kilka (C. cultriventris caspia) leading to decline...

full text

Poulations dynamics and stock assessment of common kilka (Clupeonella cultriventris caspia ) in Iranian waters of the Caspian Sea

This paper examines the changes in the population biology and biomass of common kilka (Clupeonella cultriventris caspia) in the Iranian waters of the Caspian Sea from 1995-2004. For most years during this 10-year period, we estimated the age structure of the catch, length-weight relationship, von Bertalanffy growth parameters, condition factor, sex ratios, maturity stages determined from ovaria...

full text

Age and growth of bigeye kilka (Clupeonella grimmi Kessler, 1877) in Iranian waters of the Caspian Sea

Age and growth of Bigeye Kilka, Clupeonella grimmi, were studied in Iranian waters of the Caspian Sea from early May 2006 to April 2007. The sagitta otoliths were removed for each 5 mm length interval up to a total number of 262 fish. Fork length and weight ranged from 92.5 to 142.5 mm and 4.2 g to 23.4 g, respectively. The largest length-groups was observed from December to February and the lo...

full text

the effect of taftan pozzolan on the compressive strength of concrete in the environmental conditions of oman sea (chabahar port)

cement is an essential ingredient in the concrete buildings. for production of cement considerable amount of fossil fuel and electrical energy is consumed. on the other hand for generating one tone of portland cement, nearly one ton of carbon dioxide is released. it shows that 7 percent of the total released carbon dioxide in the world relates to the cement industry. considering ecological issu...

My Resources

Save resource for easier access later


Journal title:
environmental resources research

Publisher: gorgan university of agricultural sciences and natural resources

ISSN

volume 1

issue 2 2014

Hosted on Doprax cloud platform doprax.com

copyright © 2015-2023