Weather or not

Temperature records fell like sweat in a sauna this week, dozens of them across the country. From Birmingham, Ala. (103 degrees) to Washington, D.C. (96), October highs weren’t merely broken, they were shattered.

Many cities in the Southeast eclipsed 100 degrees; many in the Midwest and Northeast — though not here — sweltered in the mid-90s. The heat was accompanied by July-like humidity, compounding the misery. Wednesday, 16 cities set all-time temperature highs and the National Weather Service estimated that 131 million Americans endured temperatures in the 90s.

New England mostly missed out, the intense heat petering out at our doorstep. Central Park in New York City reached 93 degrees Wednesday, while we frolicked in the 70s. Still, early autumn in New Hampshire has been considerably warmer than average, though chances are no one’s complaining about a steady diet of 70s, and occasional forays into 80s.

Yet it was a story in the Cape Cod Times Friday that had me riveted, for it revealed the potential consequences of what the unusual can unleash — especially if it becomes the norm. Last month a number of lobstermen and fishermen on Cape Cod Bay contacted the Massachusetts Division of Marine Fisheries to report dead lobsters and dead bottom-feeding fish in their traps. Even shellfish and sea worms, which live on the bottom, were coming up dead. The alarmed fishermen thought something in the water was killing them.

They were right. But it wasn’t what they thought.

According to the Cape Cod Times, researchers from the Center for Coastal Studies in Provincetown boarded several fishing vessels and took samples for a couple of weeks. They didn’t find any toxins in the dead lobsters and fish, but instead found low oxygen levels in water near the sea floor — so low that they couldn’t sustain life.

Researchers calculated that warm, sunny weather had extended too long into the fall. In tandem, there was a lack of storms to stir the water, which helps keep temperatures moderately similar at different depths. A layer of ice-cold water built up on the bottom and creatures living there used up the oxygen.

That’s the simplified version, and it’s not an unusual phenomenon in the fall, but the severity of it is. “It’s typical to see that, but not below critical levels,” Robert Glenn, a senior biologist with the Division of Marine Fisheries, told the Times. Beth Casoni, executive director of the Massachusetts Lobstermen’s Association added:

“This is the first time I’ve heard of anything like this, and the fishermen who have been fishing in these waters for 50-plus years hadn’t seen this.”

Also, for much of the summer, fishing columnists in New England coastal communities have been writing that some species — striped bass, in particular — are showing way-below-average numbers in the reports they’re getting from anglers.

No doubt this will be monitored closely in upcoming years; already scientists are seeing lobsters driven farther north as ocean temperatures warm, and the effects of climate change possibly take hold.

After all, who 20 years ago could have imagined Cape Cod would become one of the great white shark hotspots in the world. And residents of Cape Town, South Africa, where cage diving is a huge business, are pondering why all their great whites are missing this year.

Anyway, Monadnock Region residents who crave stability in their weather may be pleased to know this should be a quintessential October-like week. Cool, crisp and bright skies should define today, while clouds increase Sunday with rain possible late in the day. Monday looks dreary, but the rest of the week could bring sunshine and highs consistently in the low 60s.