Timing of reproductive events in the marine copepod Calanus glacialis: a pan-Arctic perspective

Abstract

The timing of reproductive events of Calanus glacialis is closely coupled to the two major marine primary production events in the Arctic: the ice algal and phytoplankton blooms. Reproductive strategies vary between different physical and biological environments of the European and Canadian Arctic. In the Canadian Beaufort Sea and the high Arctic Rijpfjorden on Svalbard, C. glacialis utilized the ice algae bloom to fuel spawning in spring, while growth and development of the new generation was primarily supported by the phytoplankton bloom. In the predominantly ice-free Arctic Kongsfjorden (Svalbard), C. glacialis was mainly a capital breeder spawning early in the season in the absence of food. This enabled the offspring to synchronize their growth and development with the phytoplankton bloom and, thus, reproduce successfully despite the lack of an early ice algal bloom. The variability in life history traits observed in the Canadian and European Arctic is compared with data from other Arctic regions to present a pan-Arctic perspective on life cycle strategies of C. glacialis.

Large versus small zooplankton in relation to temperature in the Arctic shelf region

“…CIV, CV and adults. We are aware that this size fraction includes the older life stages of both co-occurring and morphologically similar Calanus species, the Atlantic C. finmarchicus and the Arctic C. glacialis Daase et al 2013). However, based on our experience gained from long-term Hornsund plankton monitoring and from multiyear observations ) that showed the substantial domination of C. glacialis older copepodite stages over C. finmarchicus in the Arctic shelf community at this time of the year, we assumed that the preferred zooplankton prey of the little auk, C. glacialis (CV), constituted a substantial part of the large size fraction in this particular zone.…”

Advection in polar and sub-polar environments: Impacts on high latitude marine ecosystems

“…Conversely, expanded areas of open water may delay the phytoplankton bloom due to wind-induced mixing delaying the formation of the seasonal pycnocline, as is apparently the case in the eastern Bering Sea (Baier and Napp, 2003;Bluhm and Gradinger, 2008;Hunt et al, 2011). Changes in timing of bloom events may have repercussions for herbivorous zooplankton and ice fauna species as the probability for a ''mismatch" increases if the sequential timing is altered for primary production blooms relative to life history events of herbivores that rely on energetic input from the blooms (e.g., for reproduction and recruitment; Baier and Napp, 2003;Søreide et al, 2010;Varpe, 2012;Daase et al, 2013). In the southeastern Bering Sea, a mis-match between the timing of blooms related to sea-ice retreat and the needs of hebivores appears to have severe negative impacts on the recruitment and subsequent abundance of large copepods and euphausiids (Baier and Napp, 2003;Hunt et al, 2011;in press;Renner et al, 2016).…”

Physical control of the distributions of a key Arctic copepod in the Northeast Chukchi Sea

“…They often only reach full maturity just before spawning. This life history also can be accomplished in less than 3 years (Daase et al, 2013). Gonads are typically developed to an advanced stage using lipid reserves during the second winter.…”

“…It commonly exhibits pulsed reproduction with overlapping cohorts present together as a result of ontogenetic redistribution (Ashjian et al, 2003). South of Spitsbergen, C. glacialis acted as a capital breeder, spawning early before the spring bloom supplied parents with food (Daase et al, 2013).…”

“…In the Canadian Arctic, C. glacialis were seen to use the initial under ice algae bloom to fuel spawning. This allowed the growth and development of their offspring to be supported by the secondary phytoplankton bloom in the water column (Daase et al, 2013).…”