Trophic, biochemical, and behavioural impacts on beluga whales (Delphinapterus leucas) caused by depleting arctic sea-ice

A. Lewis \ Oceans First, Issue 5, 2018, pgs. 8-16. Download PDF


Over the last 25 years, the arctic has sustained an 8% decrease in sea-ice cover, and this trend is undoubtedly expected to continue into the next several decades. Belugas, an ice- associated near-threatened arctic cetacean species, share an important relationship with sea-ice. The goal of this review is to examine existing literature to gain a comprehensive understanding of how sea-ice depletion is affecting the ecology of belugas. Impacts of ice cover loss are trophic, biochemical, and behavioural. Trophic effects include increased orca whale predation, redistribution of beluga prey, and increased competition. Biochemical effects involve contaminant biomagnification in beluga whales, vulnerability to pollutant exposure, and stress-induced metabolic toxin overdose. Behavioural effects consist of an inability of belugas to adapt to rapidly changing environments, influences on migration, and the consequences anthropogenic noise impose on beluga communication and stress. Two beluga populations are currently identified as endangered, and impacts caused by sea-ice reduction could put other beluga populations at further risk as well. Due to the fragility of the arctic ecosystem, it is crucial that more effective conservation efforts be put in place to protect all vulnerable species, belugas included.