The last time the Arctic was completely free of ice, during the Pliocene Era about 3.5 million years ago, an ice-free passage across the Arctic facilitated the movement of mollusks into the North Atlantic. The open water route was rich with floating phytoplankton, which fed the mollusks during their traverse. When Arctic temperatures cooled, the path was blocked and the phytoplankton declined.
Well, here we go again.
Scientists believe this invasion may soon be repeated if global warming persists at its current rate, most likely causing the Arctic to become ice-free by or before 2050. This would once again allow the invasion of shellfish and other mollusks, along with algae, fish, barnacles, and other marine organisms into the North Atlantic from the Pacific via the Bering Sea causing a shift in the area's biodiversity.
Interestingly, the overall consequences of a mollusk invasion on the North Atlantic ecosystem remain uncertain, but shifts in the abundance of some species are anticipated.
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