TY - JOUR
T1 - The functional biology and trophic role of krill (Thysanoessa raschii) in a Greenlandic fjord
AU - Agersted, Mette Dalgaard
AU - Nielsen, Torkel Gissel
AU - Munk, Peter
AU - Vismann, B.
AU - Arendt, K.E.
PY - 2011/6
Y1 - 2011/6
N2 - Despite being a key zooplankton group, knowledge on krill biology from the Arctic is inadequate. The present study examine the functional biology and evaluate the trophic role of krill in the Godthåbsfjord (64°N, 51°W) SW Greenland, through a combination of fieldwork and laboratory experiments. Krill biomass was highest in the middle fjord and inner fjord, whereas no krill was found offshore. The dominating species Thysanoessa raschii revealed a type III functional response when fed with the diatom Thalassiosira weissflogii. At food saturation, T. raschii exhibited a daily ration of 1% body C d -1 . Furthermore, T. raschii was capable of exploiting plankton cells from 5 to 400 μm, covering several trophic levels of the pelagic food web. The calculated grazing impact by T. raschii on the fjord plankton community was negligible. However, the schooling and migratory behaviour of krill will concentrate and elevate the grazing in specific areas of the euphotic zone.
AB - Despite being a key zooplankton group, knowledge on krill biology from the Arctic is inadequate. The present study examine the functional biology and evaluate the trophic role of krill in the Godthåbsfjord (64°N, 51°W) SW Greenland, through a combination of fieldwork and laboratory experiments. Krill biomass was highest in the middle fjord and inner fjord, whereas no krill was found offshore. The dominating species Thysanoessa raschii revealed a type III functional response when fed with the diatom Thalassiosira weissflogii. At food saturation, T. raschii exhibited a daily ration of 1% body C d -1 . Furthermore, T. raschii was capable of exploiting plankton cells from 5 to 400 μm, covering several trophic levels of the pelagic food web. The calculated grazing impact by T. raschii on the fjord plankton community was negligible. However, the schooling and migratory behaviour of krill will concentrate and elevate the grazing in specific areas of the euphotic zone.
KW - EUPHAUSIA-SUPERBA DANA
KW - MARGINAL ICE-ZONE
KW - COPEPOD ACARTIA-TONSA
KW - ANTARCTIC KRILL
KW - FEEDING-BEHAVIOR
KW - BODY-SIZE
KW - MEGANYCTIPHANES-NORVEGICA
KW - VERTICAL-DISTRIBUTION
KW - COASTAL WATERS
KW - FECAL MATERIAL
U2 - 10.1007/s00227-011-1657-z
DO - 10.1007/s00227-011-1657-z
M3 - Journal article
SN - 0025-3162
VL - 158
SP - 1387
EP - 1402
JO - Marine Biology
JF - Marine Biology
IS - 6
ER -