When their current waters warm sea creatures often migrate to cooler waters. So just noticing the fewer creatures in the warmer waters will overestimate the harm done by the warming. In the article quoted below, when Mediterranean waters warm, Octopuses migrate to English waters. Mediterranean fishermen lose, English fishermen gain, but there is no clear net loss or gain to the Octopuses or to humanity in general.
This example supports my claim that we too often ignore the benefits of global warming.
(p. A4) Expecting his normal catch of plaice, turbot and Dover sole, Arthur Dewhirst was surprised when his nets spilled their contents onto his ship’s deck earlier this year. Instead of shiny, flapping fish, hundreds of octopuses wriggled and writhed.
His first thought? “Dollar signs! Dollar signs! Dollar signs!” he recalled with a laugh, sitting in his trawler last month in the harbor at Brixham in Devon, England.
Across England’s southern coast, fishing crews reported an extraordinary boom in octopus catches this summer. Sold for around 7 pounds a kilo, it was sometimes worth an extra £10,000 ($13,475) a week to Mr. Dewhirst, he said.
. . .
There are several theories about the causes of this puzzling phenomenon, but scientists say that warming water temperatures make the region more hospitable to this species of octopus, which is normally found off the Mediterranean coast.
According to Steve Simpson, a professor of marine biology at the University of Bristol, “climate change is a likely driver” of the population boom. “We are right on the northern limit of the octopus species range, but our waters are getting warmer, so our little island of Great Britain is becoming increasingly favorable for octopus populations,” he said.
For the full story see:
(Note: ellipsis added.)
(Note: the online version of the story has the date Sept. 29, 2025, and has the title “Octopuses Invade the English Coast, ‘Eating Anything in Their Path’.”)