Publication Date:
2021-05-19
Description:
After the arrival of the invasive spexies (Mnemiopsis leidyi) in the ecosystem of Caspian Sea in 1999, It had
notable impacts. In this study, we,re assessing impacts of quantitative M. leidyi as a biopllutant on zooplankton
community in the southern part of the Caspian Sea during 2001-2010 period. It becomes clear that Abundance
and Distribution Range ( ADR) of M.leidyi during 2001-2009 was in class E( occurrence in high numbers in all
localities) and in year 2010 was in class D( occurrence in moderate numbers in all localities). from 2001- 2009,
ADR in Summer season was in class E, but in summer 2010 , relatinve biomass of M.leidyi has decreased and
ADR was evaluated as D. During the fall seasons of 2001 -2010, only in fall of 2003 and 2010, the ADR was C(
occurrence in low numbers in all localities) and D respectively and in other years, the ADR was in class E. In
winter season relative biomass of M.leidyi decreased and only in winter of 2001 relative biomass was high and
the highest ADR ( class E). In winter 2003 and 2004, ADR was in class D . The biomass of M.leidyi was found
to be zero in winter 2008. From winter of 2009-2010,ADR, were assessed B and A respectively. In the spring,
ADR was evaluated A and D. Considering the obtained results, the yesr 2001, which the relative niomass was
more than 90 percent,could be considered as the expantion phase and the following years( 2002-2010) with
regard to decrease of relative biomass as the adjustment phase. With regards to the loss of the keystone species
(Eurytemora sP.) and some other native species ,our evalution showed that the impact of M.leidyi on structure of
zooplankton community was assessed as massive (C4).During summer and fall seasons that biomass of M.leidyi
was higher than 50%, only A.tonsa exist, but during spring and winter seasons that biomass of M.leidyi was
decreased and more species have a chance to exist.
Description:
Iranian Fisheries Science Research Institute
Description:
Published
Keywords:
Mnemiopsid leidyi
;
Zooplankton Community
;
Native species
;
Bioinvasions
Repository Name:
AquaDocs
Type:
Report
,
Refereed
Format:
52pp.
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