Arctic marine ecosystems face increasing climate stress

Arctic warming is occurring at a much faster rate than in other parts of the globe, with potentially devastating consequences for the diverse array of species within ecologically and biologically sensitive areas in the Arctic marine region. However, climate change research in this region is sparse compared to other biomes, hindering conservation efforts. In this article, we review and synthesize the available literature to understand the observed and potential impacts of climate change on different species and ecosystems in the Arctic marine region. We reviewed 253 articles reporting changes in species and ecosystems in the Arctic marine region in response to climate change (225 studies documenting observed impacts and 28 reporting predicted impacts). The review revealed that most research effort has been concentrated in only a subset of Arctic Large Marine Ecosystems (LMEs) (5/18 LMEs), with the majority of Arctic LMEs being poorly studied. The majority of the reviewed papers focused on marine mammals (19%) followed by microalgae (17%). A number of studies documented variability in planktonic communities (microalgae, macroalgae, zooplankton), resulting in alteration in ecosystem structure and function. Reproductive failure, decline in populations, and changes in diet composition, behavior and breeding biology were reported for sea birds and mammals. Further, shifts in spatial distribution of fishes were observed by several studies. This review provides persuasive evidence that multiple climate change indices in the Arctic region are changing, with impacts on almost all components of marine biotic ecosystems (from plankton to top predators). We identify a number of gaps (such as limited inventory of biota, robustness of data supporting climate change indices on an Arctic Ocean scale, and climate suitability assessment for all species) in climate change research in Arctic marine ecosystems where future studies can help to quantify the impacts of climate change on species and ecosystems and advance understanding for their adaptive management.