Ctenophores-invaders and their role in the trophic dynamics of the planktonic community in the coastal regions off the Crimean coasts of the Black Sea (Sevastopol Bay)

Autor: Z. A. Romanova, Levent Bat, G. A. Finenko, T. V. Pavlovskaya, B. E. Anninsky, Ahmet E. Kideys, G. I. Abolmasova
Rok vydání: 2006
Předmět:
Zdroj: Oceanology. 46:472-482
ISSN: 1531-8508
0001-4370
DOI: 10.1134/s0001437006040047
Popis: The abundances, biomasses, and population structures of two introduced ctenophore species—Mnemiopsis leidyi and Beroe ovata—were monitored along with mesoplankton in the near-shore waters of the northern Black Sea (Sevastopol Bay and adjacent regions) over a period of four years (2000–2003), after the B. ovata invasion. The annual dynamics of the M. leidyi population were similar in these years: very low abundances and biomass values were observed during the major part of the year (unlike previous years) with a shortterm peak in the summer-early autumn. B. ovata development during the growth in the M. leidyi biomass resulted in a sharp fall in the M. leidyi biomass down to extremely low values. The interannual differences in the populations of both ctenophore species were reflected by their quantitative parameters: the maximum biomass of M. leidyi varied from 790 g/m2 in 2001 to 211–266 g/m2 in other years. The maximum biomass values of B. ovata (38.9 and 32.5 g/m2) were observed in 2001 and 2003, respectively. In 2000–2003, from July to September, during the peak in mnemiopsis development, the population consumed from 1.9 ± 0.4 to 13.4 ± 5.7% of the mesoplankton biomass per day, while in the years of B. ovata absence, these values were as high as 30–40%. For the first time, the grazing rate of microzooplankton by M. leidi larvae was estimated. In August 2003, the maximum daily consumption rate was as great as 23–25% of the microzooplankton biomass. The daily rations of the mnemiopsis larvae on microzooplankton were close or even higher than those on mesoplankton.
Databáze: OpenAIRE
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