The grey whale population along the North Pacific has suffered from two major unusual mortality events during the last two decades. Far more whales than natural died between 1999 and 2000 and again since 2019. During the migration back from Mexico to Arctic feeding grounds, an unexpectantly large proportion of whales was reported skinny or emaciated and stranding numbers were much higher than usual. The exact cause is still unexplained.
However, a small group of whales has been very successful in surviving the die-off. Based around a small core group of 12 known individuals, the so-called “Sounders” take an annual detour into Pudget Sound. In this shallow inlet of the Pacific Ocean, just north of Seattle, the grey whales feed on ghost fish buried beneath the sand. Hunting for those fish is a distinct but risky behaviour pattern unique to the ‘Sounders’. During high tide,” they roll on their side and they come into water that is sometimes no deeper than they are thick," says Howard Garrett, a co-founder of the Orca Network and the Langley Whale Center on Whidbey Island. In their wake, they leave distinct markings in the mud.
Usually, the grey whales do not feed until their get to their feeding grounds in Alaska. In contrast, the ‘Sounders’ “grab a good snack, hang out for a month or so, fill up and then continue up to the Bering Sea” – and have been doing so for thirty years. The core individuals have all been identified by the scar patterns. During this time, the group seems to have been exceptionally successful in evading the causes of the die-off that is likely associated with food shortage. “It's a testament to how adaptive the Sounders are: they knew they were hungry and have figured out how to find a new source of food.”
To see the full article, click here: Group Of Gray Whales Survives Die Off With Annual Detour to Puget Sound : NPR
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