Abstract
High-latitude environments show extreme seasonal variation in physical and biological variables. The classic paradigm of Arctic marine ecosystems holds that most biological processes slow down or cease during the polar night. One key process that is generally assumed to cease during winter is diel vertical migration (DVM) of zooplankton. DVM constitutes the largest synchronized movement of biomass on the planet, and is of paramount importance for marine ecosystem function and carbon cycling. Here we present acoustic data that demonstrate a synchronized DVM behaviour of zooplankton that continues throughout the Arctic winter, in both open and ice-covered waters. We argue that even during the polar night, DVM is regulated by diel variations in solar and lunar illumination, which are at intensities far below the threshold of human perception. We also demonstrate that winter DVM is stronger in open waters compared with ice-covered waters. This suggests that the biologically mediated vertical flux of carbon will increase if there is a continued retreat of the Arctic winter sea ice cover.
Highlights
Many marine predators search for their prey visually, and their search efficiency is directly linked to ambient irradiance intensity ( Yoshida et al 2004)
We argue that even during the polar night, diel vertical migration (DVM) is regulated by diel variations in solar and lunar illumination, which are at intensities far below the threshold of human perception
It is clear that zooplankton at both sites do perform DVM through most of the Arctic winter, even in those periods of the Received 24 August 2008 Accepted 30 September 2008
Summary
Many marine predators search for their prey visually, and their search efficiency is directly linked to ambient irradiance intensity ( Yoshida et al 2004). Zooplankton ascend into food-rich surface waters during darkness and retreat to deeper waters during day (Fortier et al 2001) These vertical migrations are integral to structuring pelagic communities and food webs because pelagic predators. This, combined with the strong attenuation of light by sea ice, leads to the conventional paradigm that DVM should cease completely during winter in the Arctic marine environment. This understanding is entirely commensurate with the low food availability in winter (Smetacek & Nicol 2005) and the dormant overwintering strategies of some zooplankton species ( Fortier et al 2001; Falk-Petersen et al 2008)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
