Bioluminescence as an ecological factor during high Arctic polar night.
Bioluminescence commonly influences pelagic trophic interactions at mesopelagic depths. Here we characterize a vertical gradient in structure of a generally low species diversity bioluminescent community at shallower epipelagic depths during the polar night period in a high Arctic fjord with in situ bathyphotometric sampling. Bioluminescence potential of the community increased with depth to a peak at 80 m. Community composition changed over this range, with an ecotone at 20-40 m where a dinoflagellate-dominated community transitioned to dominance by the copepod Metridia longa. Coincident at this depth was bioluminescence exceeding atmospheric light in the ambient pelagic photon budget, which we term the bioluminescence compensation depth. Collectively, we show a winter bioluminescent community in the high Arctic with vertical structure linked to attenuation of atmospheric light, which has the potential to influence pelagic ecology during the light-limited polar night.
University of Delaware, School of Marine Science and Policy, Lewes, DE 19958 USA.
Heather A
HA
Cronin
University of Delaware, School of Marine Science and Policy, Lewes, DE 19958 USA.
Jonathan H
JH
Cohen
UiT The Arctic University of Norway, Faculty of Biosciences, Fisheries and Economics, Dept. of Arctic and Marine Biology, N-9037 Tromsø, Norway.|University Centre in Svalbard, Pb 156, N-9171 Longyearbyen, Norway.
Jørgen
J
Berge
University Centre in Svalbard, Pb 156, N-9171 Longyearbyen, Norway.|NTNU AMOS-Centre for Autonomous Marine Operations and Systems, Department of Biology, Norwegian University of Science and Technology, N-7491, Trondheim, Norway.
Geir
G
Johnsen
University of Delaware, School of Marine Science and Policy, Lewes, DE 19958 USA.
Mark A
MA
Moline