Impact of tidal dynamics on diel vertical migration of zooplankton in Hudson Bay

Hudson Bay is a large seasonally ice-covered Canadian inland sea connected to the Arctic Ocean and North Atlantic through Foxe Basin and Hudson Strait. This study investigates zooplankton distribution, dynamics, and factors controlling them during open-water and ice cover periods (from September 201...

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Bibliographic Details
Published in:Ocean Science
Main Authors: Petrusevich, Vladislav, Dmitrenko, Igor, Niemi, Andrea, Kirillov, Sergey, Kamula, Christina Michelle, Kuzyk, Zou Zou A., Barber, David G., Ehn, Jens
Format: Report
Language:English
Published: Copernicus Publications, European Geosciences Union 2020
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Online Access:http://hdl.handle.net/1993/34780
https://doi.org/10.5194/os-16-337-2020
Description
Summary:Hudson Bay is a large seasonally ice-covered Canadian inland sea connected to the Arctic Ocean and North Atlantic through Foxe Basin and Hudson Strait. This study investigates zooplankton distribution, dynamics, and factors controlling them during open-water and ice cover periods (from September 2016 to October 2017) in Hudson Bay. A mooring equipped with two acoustic Doppler current profilers (ADCPs) and a sediment trap was deployed in September 2016 in Hudson Bay ~190 km northeast from the port of Churchill. The backscatter intensity and vertical velocity time series showed a pattern typical for zooplankton diel vertical migration (DVM). The sediment trap collected five zooplankton taxa including two calanoid copepods (Calanus glacialis and Pseudocalanus spp.), a pelagic sea snail (Limacina helicina), a gelatinous arrow worm (Parasagitta elegans), and an amphipod (Themisto libellula). From the acquired acoustic data we observed the interaction of DVM with multiple factors including lunar light, tides, and water and sea ice dynamics. Solar illuminance was the major factor determining migration pattern, but unlike at some other polar and subpolar regions, moonlight had little effect on DVM, while tidal dynamics are important. The presented data constitute the first-ever observed DVM in Hudson Bay during winter and its interaction with the tidal dynamics. Natural Sciences and Engineering Council of Canada (NSERC) Collaborative Research and Development project: BaySys (grant no. CRDPJ 470028-14), Manitoba Hydro, the Canada Excellence Research Chair (CERC) program, and the Canada Research Chairs (CRC) program