November 10, 2021 — In September of 2019, Tracy Pugh started getting phone calls about dead lobsters.
Pugh is a biologist with the Massachusetts Division of Marine Fisheries, and a handful of fishermen in Cape Cod Bay were reporting traps full of dead lobsters — “anywhere from several dozen to hundreds,” she recalled. “So way, way more than normal.”
Some reported dead fish and crabs in their traps, as well. One trawler came up with a bunch of dead scallops.
Pugh, working with scientists at the Center for Coastal Studies, found the reason soon enough: a roughly six-mile stretch of water in Cape Cod Bay almost completely depleted of oxygen. “It was pretty bad,” said Pugh.
The hypoxic zone — or “blob,” as it became known — ambled around the sea floor for at least a week. Any animals that could swim or crawl away from the blob did, said Pugh. But those stuck in traps or unable to move, died.
The hypoxic zone dissipated in October of that year, but a new one appeared in 2020, around the same time and place. The blobs left behind a mystery: what caused them? And were they going to come back every year?