Details of this species in Caspian Sea, Turkmenistan Status: Alien
Invasiveness: Invasive
Occurrence: Established
Source: Dumont and Shiganova, 2002 Arrival Date:
Introduction: Unintentional (accidentally) Species Notes for this Location:
In 1999, M. leidyi was recorded in Iranian waters in the Caspian Sea in winter (Esmaeili et al. 2000) at almost the same time as it was recorded in the Middle Caspian in November by scientists from the Caspian Institute for Fisheries (Ivanov et.al., 2000, Shiganova et al. 2001b). Most probably it was transported with ballast water aboard oil tankers or other ships in the Black Sea or the Sea of Azov (where Mnemiopsis occurs in warm months), and released into the salty Middle or South Caspian (Ivanov et al. 2000) after ships had passed through the Volga-Don Canal and the shallow freshwater North Caspian Sea. The fact that the first individuals of Mnemiopsis were found with large individuals of Aurelia aurita supports the hypothesis that Mnemiopsis arrived from the Black Sea (Shiganova et al. 2001b). In 2000 it spread across all areas of the Caspian with a minimum salinity of 4.3 ‰. In 2001 – 2002 it greatly increased in population size, to reach a critical wet mean biomass of about one 1 kg. m-2 (55 g m-3) in 2001 (allowing a coefficient 2 to compensate for imperfect catchability). This abundance is in excess of the highest values ever recorded in the Black Sea. In 2002 this biomass doubled again. The main area of Mnemiopsis leidyi distribution is the southern Caspian, where it occurs year round. In spring it begins to penetrate into the Middle Caspian and in late July-August it appears in the Northern Caspian where salinity is no higher than 4‰. (Dumont and Shiganova). Management Notes for this Location:
Location Notes:
The Caspian Sea is a completely closed saline basin, which is subdivided on the Northern, Middle and Southern areas. The Northern Caspian is a shallow area with average depth 5-6 m, maximal 15 -20 m, salinity from 0.1 ‰ near the Volga and Ural delta and 10-11 ‰ near the boundary with the Middle Caspian, temperature in winter 0-0.5 0 C , very often freeze since November in most of areas, particularly in shallow parts and in summer 24-250 C. The Middle Caspian has mean depth 190 m, maximal depth 788 m in Derbent depression, salinity 12-13‰ increasing from the north to the south, mean temperature in winter 0-8 0 C, the eastern shallow areas freeze in December-January. Temperature in the western part is at 1-20 C higher than in the eastern part. The mean depth of the Southern Caspian is 180 m, maximal depth is 1025 m in Southern Caspian depression, salinity is 12.6-13‰, temperature reaches 10-110C in winter, 25-280 C - in summer, higher in the south-eastern part. Last Modified: 30/05/2005 10:38:56 a.m.
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