Open AccessMetabolism and biomass vertical distribution of zooplankton in the Bransfield Strait during the austral summer of 2000
Author(s) -
Yebra Lidia,
HernándezLeón Santiago,
Almeida Carlos,
Bécognée Pierrick
Publication year - 2009
Publication title -
polar research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.508
H-Index - 49
eISSN - 1751-8369
pISSN - 0800-0395
DOI - 10.1111/j.1751-8369.2009.00116.x
Subject(s) - zooplankton , copepod , mesopelagic zone , euphausia , biomass (ecology) , oceanography , calanus finmarchicus , water column , phytoplankton , environmental science , krill , bloom , biology , ecology , crustacean , pelagic zone , nutrient , geology
Abstract The vertical distribution (0–550 m) of zooplankton biomass, and indices of respiration (electron transfer system [ETS]) and structural growth (aminoacyl‐tRNA synthetases activity [AARS]), were studied in waters off the Antarctic Peninsula during the austral summer of 2000. The dominant species were the copepod Metridia gerlachei and the euphausiid Euphausia superba . We observed a vertical krill/copepod substitution in the water column. The zooplankton biomass in the layer at a depth of 200–500 m was of the same magnitude as the biomass in the layer at a depth of 0–200 m, indicating that biomass in the mesopelagic zone is an important fraction of the total zooplankton in Antarctic waters. The metabolic rates of the zooplankton community were sustained by less than 0.5% of the primary production in the area, suggesting that microplankton or small copepods are the main food source. Neither food availability nor predation seemed to control mesozooplankton biomass. The wide time lag between the abundance peak of the dominant copepod ( M. gerlachei ) and the phytoplankton bloom is suggested to be the main explanation for the low summer zooplankton biomass observed in these waters.