Biogeographic responses of the copepod Calanus glacialis to a changing Arctic marine environment

Abstract

Dramatic changes have occurred in the Arctic Ocean over the past few decades, especially in terms of sea ice loss and ocean warming. Those environmental changes may modify the planktonic ecosystem with changes from lower to upper trophic levels. This study aimed to understand how the biogeographic distribution of a crucial endemic copepod species, Calanus glacialis, may respond to both abiotic (ocean temperature) and biotic (phytoplankton prey) drivers. A copepod individual-based model coupled to an ice-ocean-biogeochemical model was utilized to simulate temperature-and food-dependent life cycle development of C. glacialis annually from 1980 to 2014. Over the 35-year study period, the northern boundaries of modeled diapausing C. glacialis expanded poleward and the annual success rates of C. glacialis individuals attaining diapause in a circumpolar transition zone increased substantially. Those patterns could be explained by a lengthening growth season (during which time food is ample) and shortening critical development time (the period from the first feeding stage N3 to the diapausing stage C4). The biogeographic changes were further linked to large-scale oceanic processes, particularly diminishing sea ice cover, upper ocean warming, and increasing and prolonging food availability, which could have potential consequences to the entire Arctic shelf/slope marine ecosystems. K E Y W O R D SArctic Ocean, biogeography, climate change, copepod, individual-based model, marine ecosystem, ocean warming, poleward range shift

Pushing the limit: Resilience of an Arctic copepod to environmental fluctuations

“…Highest abundances were predicted in the Greenland Sea, Baffin Bay, and Canadian Archipelago, which have been described as C. hyperboreus distribution centers (Hirche, , ). As suggested by the IBM results, the probability of reaching the first diapausing stage is higher in shelf‐ and lower‐latitude basin areas compared to the northernmost basins (Figure ), due to higher concentration and longer duration of food supply (longer growth season) and higher temperature (faster development rate and thereby shorter development time) (Feng et al., ; Xu, Zhang, & Sun, ; Table ). For the Baffin Bay and Canadian Archipelago, highest abundances were observed in the Cape Bathurst polynya, North Water polynya, and nearby Lancaster Sound (Figure ; dataset 13, Supporting Information Table S1).…”

“…We used an IBM (github.com/fengzhixuan/ArcIBM/tree/trunk‐1) (Feng, Ji, Ashjian, Campbell, & Zhang, ; Feng, Ji, Campbell, Ashjian, & Zhang, ; Ji et al., ) to identify successful diapausers, that is C. hyperboreus individuals reaching halfway through stage C3. To simulate physical advection and temperature‐ and food‐dependent life cycle development, the IBM was coupled offline to BIOMAS, which provided upper 60 m depth‐averaged flow fields, temperature and food concentration, which includes phytoplankton (diatoms and flagellates), sea ice algae and microzooplankton.…”

“…We used an IBM (github.com/fengzhixuan/ArcIBM/tree/trunk-1) (Feng, Ji, Ashjian, Campbell, & Zhang, 2018;Feng, Ji, Campbell, Ashjian, & Zhang, 2016;Ji et al, 2012) to identify successful diapausers, that is C. hyperboreus individuals reaching halfway through stage C3.…”

Bowhead whales use two foraging strategies in response to fine-scale differences in zooplankton vertical distribution

“…Like other large, zooplanktivorous predators, they must consistently locate energy-rich prey patches (e.g., North Atlantic right whales 4 – 6 ), which are in turn controlled by temperature, salinity, ice-formation and recession, phytoplankton availability, and mixing 7 , 8 . However, the predictability with which important prey such as calanoid copepods occur is likely to change in the North Atlantic and Arctic Ocean 9 – 14 due to rapid changes in sea surface temperature and ice conditions 15 – 17 .…”

A glimpse into the biogeography, seasonality, and ecological functions of arctic marine Oomycota

“…Elevated atmospheric temperatures and the inflow of warmer waters from the Pacific and Atlantic oceans are reducing sea ice extent and thickness (Vihma 2014). The associated physical changes in the Arctic marine environment are altering the phenology of primary producers (Castellani et al 2017), their associated consumers, and subsequent higher trophic levels (Feng et al 2018). As sea surface temperatures continue to increase, southerly Atlantic and Pacific species are migrating north, ushering in novel biological interactions that have unknown consequences on existing Arctic marine food webs (Kortsch et al 2015).…”