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

• Published in: Global change biology 2018-01, Vol.24 (1), p.e159-e170
• Main Authors: Feng, Zhixuan, Ji, Rubao, Ashjian, Carin, Campbell, Robert, Zhang, Jinlun
• Format: Article
• Language: English
• Subjects: Ablation; Animals; Aquatic crustaceans; Arctic environments; Arctic Ocean; Arctic Regions; Biogeochemistry; Biogeography; Calanus glacialis; Climate Change; Computer simulation; copepod; Copepoda - physiology; Diapause; Ecosystem; Ecosystems; Endemic species; Environmental changes; Food availability; Food supply; Ice; Ice Cover; Ice environments; individual‐based model; Life cycle; Life cycle engineering; Life cycles; marine ecosystem; Marine ecosystems; Marine environment; Ocean temperature; Ocean warming; Oceans and Seas; Phytoplankton; Plankton; poleward range shift; Prey; Sea ice; Seasons; Temperature; Transition zone; Trophic levels; Upper ocean
• ISSN: 1354-1013; 1365-2486
• DOI: 10.1111/gcb.13890

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. This study investigated the biogeographic responses of a critical endemic copepod species, Calanus glacialis, to multiple changing environmental drivers and the driving mechanisms for potential range shifts of this species using a copepod individual‐based model. Over the period of 1980–2014, the northern boundaries of modeled diapausing C. glacialis expanded poleward, and the annual success rates of C. glacialis individuals increased substantially. These changes can be explained by a lengthening growth season and shortening development time in response to warming upper ocean temperatures and increasing algal food availability.