Unsustainable fisheries as present and future disaster of the Caspian Sea
Ghayyem Ashrafi
1*
, M., S.N. Nabavi
2
& S.M.B. Nabavi
3
1
PhD student in Marine Biology, Khorramshahr university of marine science and technology,
Iran
2
PhD student in Marine Biology, Khorramshahr university of marine science and technology,
Iran
3
Associate Professor
in Marine Biology, Khorramshahr university of marine science and
technology, Iran
Keywords: Caspian Sea, fisheries, Sturgeon, Kilka, Caspian Seal
Introduction
Caspian basin is the largest enclosed body of water on the world, containing some 44% of all
inland waters on the Earth (370,000 km
2
, 1,200 km long and 466-204 km width). This sea
hasn’t connection to the oceans and its surface level is 27 m below mean sea level. Some 130
rivers flow into the Caspian Sea, the largest is the Volga River. Physically, the Caspian Sea is
one of extremes (Several climatic zones, salinity varies from 0.1 ppt to 12, 50 and 300,
oxygenated and anoxia waters and Temperature variations). Due to long-term isolation from
other water bodies, the Caspian Sea is characterized by many endemic species (Stolberg
et al.,
2006). The number of endemic aquatic taxa is over 300 and there are over 100 species of fish.
The best known of these are the six species and subspecies of sturgeon and the endemic
Caspian Seal. Caspian basin is surrounded by five riparian countries and several cultures,
religions and rituals with principal economic activities same as fisheries for provide much
needed protein and for the delicacy of the Caspian sturgeon’s roe called Caviar. As well as Kilka
is the important Caspian Sea crop (CEP, 2005). The aim of this study is to find out the effect of
unsustainable fisheries on the main fish resources in the Caspian Sea region.
Materials and Methods
In this present study the available data regarding to fisheries in the Caspian Sea from 1990 up
to now specially Sturgeon and Kilka as well as Caspian Seal and IUCN Red List reports has been
analyzed and the main causes of fish decline in the region discussed.
Results
According to the data
Hoso hoso (Linnaeus, 1758) the main sturgeons fish in Caspian Sea in the
red list of IUCN is in critically endangered level (Gesner
et al., 2010), global
fisheries statistics
show that there has been a 93% decline in catch from 1992 (520 tonnes) to 2007 (33 tonnes)
and in the Caspian Sea catch from 1,380 tonnes in 1950 decline to 60.8 tonnes in average of
1996-2003 (Gesner
et al., 2010). As well as Killka fish catches fell from 95,000 tonnes in 1999
to 16,700 tonnes in 2008, although there are some signs of slow recovery in 2014 (FAO, 2016).
And results for Caspian Seal or
Pusa caspica (Gmelin, 1788) show this mammal in the red list
category of IUCN is in endangered level from 2008 until now (Goodman and Dmitrieva, 2016),
estimated the total population of adult females as 354,210 in 1945 to 34,000 in 2015, and in
another calculator show period 1955 to 2015 declined 91.5% (Goodman and Dmitrieva, 2016).
107
Discussion
The giant Beluga sturgeon (
Hoso hoso) is threatened due to over-fishing
and loss of spawning
grounds mainly resulting from dam construction on the major rivers of the Caspian Basin (CEP,
2005; Gesner,
et al., 2010). And for reasons of decline of Kilka we can point to over-fishing too,
for example in the Iranian part there are 5 main landing sites for Kilka vessels, an also a
jellyfish,
Mnemiopsis leidyi, feeds on the larvae and eggs of kilka and other fishes
so stocks of
kilka have diminished as have the fisheries (FAO, 1016). As well as Caspian Seal, unsustainable
hunting was the main driver of Caspian Seal decline during the 20
th
century (Goodman and
Dmitrieva, 2016) and the another reason for Caspian Seal mortalities due to Canine Distemper
Virus (CDV) and possibly due to high concentrations of certain organochlorinated pollutants
found in the tissues of many dead specimens (CEP, 2005). Some of the natural
resources like
fisheries depend on a healthy environment. Environmental pollutions of the Caspian Sea not
only have
negative impact on the sea, but also influence the population of all neighboring
countries (Nasrollahzadeh, 2010). Classifying all the major sturgeon species as critically
endangered by the IUCN in its red list of threatened species as well as reduction of
Pusa
caspica population and Kilka stocks in the Caspian Sea are the results of unsustainable
fisheries
in the past and at the present time. If this trend continues a disaster will happen. To solve this
problem an urgent for the five member states of the Caspian Sea to develop a strategy to
rebuilt fish stocks and
Pusa population is essential.
Acknowledgements
We are indebted
to Professor Mustafa Ergun, Head of INOC to invited us to Understanding the
Problems of Inland Waters, case study for the Caspian Basin 12-14 may 2018,
Baku-Azerbaijan
Conference and asked us to write a paper about Hazar Sea problems.
References
Cep, Prepared by the Caspian Environment Programme, (2005),
An Introduction to the Caspian Sea and
the Caspian Environment Programme, Art. Cri. Des. Co., 44p.
FAO, (2016), Fishery and Aquaculture Country Profiles. Iran, Islamic Rep. of, Country Profile Fact Sheets.
In: FAO Fisheries and Aquaculture Department. Rome.
Gesner, J., Chebanov, M. and Freyhof, J., (2010)
Hoso hoso. The IUCN Red List of Threatened Species
Goodman, S. and Dmitrieva, L., (2016),
Pusa caspiaca. The IUCN Red List of Threatened Species
Nasrollahzadeh, A. (2010), Caspian Sea and its Ecological Challenges, Caspian J. Env. Sci., Vol. 8, No. 1 pp.
97-104
Stolberg, F., Borysova, O., Mitrofanov, I., Barannik, V. and P. Eghtesadi, (2006),
Global international
Waters Assessment Regional assessment 23 Caspian Sea, Uni. Of Kalmar behalf of UN Env. Pro.,
71p.
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