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Friendly, gre­gar­i­ous, pure white — the Arc­tic’s bel­uga whales are crea­tures like no other on Earth. It’s not easy to dive with them — Nether­lands-based Water­proof Ex­pe­di­tions (water­proof-ex­pe­di­ runs trips in May and June, when lucky vis­i­tors might get a glimpse — soon it might be im­pos­si­ble. De­pen­dent on a food chain that starts with al­gae found un­der the sea ice, the rapid dis­ap­pear­ance of that ice might end with the dis­ap­pear­ance of belugas them­selves.

De­scribed as “near threat­ened” on the IUCN list of en­dan­gered species be­cause of wa­ter con­tam­i­na­tion and whal­ing, Del­phi­napterus leu­cas is near the top of a food chain that starts with al­gae formed on the bot­tom of sea ice. In sum­mer, that al­gae sinks to the bot­tom, where it’s con­sumed by worms that are in turn eaten by fish such as Green­land hal­ibut, which are then eaten by belugas.

Com­pared with 30 years ago, Arc­tic sea-ice cov­er­age has de­clined greatly. “It is very sim­ple,” re­searcher Thomas Brown of the Scot­tish As­so­ci­a­tion for Ma­rine Sci­ence told Bri­tain’s Guardian news­pa­per. “If you take the sea ice away, you can­not have sea-ice al­gae.” If present rates of warm­ing con­tinue, sci­en­tists es­ti­mate there could be zero sum­mer sea ice by mid­cen­tury.

With­out that ice — which also gives Arc­tic an­i­mals hunt­ing and calv­ing grounds — sci­en­tists pre­dict huge im­pacts on wildlife, and on the 4 mil­lion hu­mans who live in the Arc­tic and de­pend on this com­plex ecosys­tem.

Belugas are “on the front line of change in the Arc­tic, and it is clear they are hav­ing to make changes in be­hav­ior to sur­vive, fish­ing far­ther and far­ther into open wa­ter,” Brown told The Guardian. “We need to find out ur­gently how sig­nif­i­cant are these changes.”


Pro­jected amount of sum­mer seaice cov­er­age in Arc­tic by 2050


Num­ber of hu­mans in Arc­tic who de­pend on sea-ice ecosys­tem for sur­vival

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