Seasonal vertical strategies in a high-Arctic coastal zooplankton community
Permanent lenke
https://hdl.handle.net/10037/10108Dato
2016-08-18Type
Journal articleTidsskriftartikkel
Peer reviewed
Forfatter
Bandara, Kanchana; Varpe, Øystein; Søreide, Janne; Wallenschus, Jago; Berge, Jørgen; Eiane, KetilSammendrag
We studied the larger (>1000 µm) size fraction of zooplankton in an Arctic coastal
water community in Billefjorden, Svalbard (78°40’ N), Norway, in order to describe seasonal vertical
distributions of the dominant taxa in relation to environmental variability. Calanus spp.
numerically dominated the herbivores; Aglantha digitale, Mertensia ovum, Beroë cucumis, and
Parasagitta elegans were the dominant carnivores. Omnivores and detritivores were numerically
less important. Descent to deeper regions of the water column (>100 m) between August and
October, and ascent to the shallower region (<100 m) between November and May was the overall
seasonal pattern in this zooplankton community. In contrast to other groups, P. elegans did not
exhibit pronounced vertical migrations. Seasonal vertical distributions of most species showed
statistical associations with the availability of their main food source. The vertical distribution of
later developmental stages of Calanus spp. was inversely associated with fluorescence, indicating
that they descended from the shallower region while it was still relatively productive, and
ascended before the primary production had started to increase. Strong associations between the
vertical distributions of secondary consumer M. ovum and Calanus spp., and tertiary consumer
B. cucumis and M. ovum indicated that these carnivores seasonally followed their prey through
the water column. We conclude that seasonal vertical migrations are a widespread trait in the high
Arctic community studied, and predator−prey interactions seem particularly central in shaping
the associations between the seasonal vertical strategies of adjacent trophic levels.