Climate Change: the Fish Notice

One of the most pernicious arguments from climate deniers is that “a few degrees” doesn’t have much of an effect. After all, if you raise the temperature of the room you’re sitting in by a “mere” 1°C (1.8°F), you might not even notice.

Nature notices. The fish notice.

The Gulf of Maine includes Atlantic ocean waters along the coast of much of New England and part of Canada, stretching from Cape Cod in Massachusetts to the southernmost tip of Nova Scotia. From ocean heat content data we know that the water in that region has been warming rapidly of late:

For a long time, cod was a mainstay of the fishing industry. But cod numbers have been declining, so it became necessary to limit catches in order to allow the population to rebound. Unfortunately, the plan didn’t work so well — because just as it was implemented, ocean warming undermined those efforts. An NPR report tells the story well:

Cod was once so plentiful in New England that legend had it you could walk across the local waters by stepping on the backs of the fish.

Now, though, this tasty species is in such trouble there that cod fishing is practically shut down.

And scientists say it looks like rapid warming in the Gulf of Maine explains why regulators’ recent efforts to help the cod while allowing fishing were a failure.

“Year after year, as they looked at the population, they realized that there were fewer cod than they expected there to be,” says Andrew Pershing, an oceanographer at the Gulf of Maine Research Institute. “They thought that they should be rebuilding, but they were actually declining.”

At the same time the cod were mysteriously failing to rebound, he says, strange things were happening on the shores of Maine. People were finding seahorses, which almost never go that far north.

“We had squid we don’t normally find here,” recalls Pershing, “we had species like black sea bass that are normally found around Long Island that were hanging out in the lobster traps here in Maine.”

These oddities were happening because the Gulf of Maine was warming. In the journal Science, Pershing and his colleagues say the warming was also hurting the cod — and managers didn’t take it into account when setting their fishing quotas. That means even if people didn’t exceed their quotas, too much cod got taken.

“In really warm years, every female cod produces fewer babies than we would expect, and we also see that the young fish are less likely to survive and become adults,” says Pershing.

Ecosystems all around the world are warming up due to global climate change, says Pershing, but the Gulf of Maine is ahead of the curve. Over the past decade, it’s warmed faster than 99.9 percent of the global ocean.

“That happened so fast that the people that were managing this very important fishery were not able to keep up with the changes,” he says.

Now that we know of the impact of ocean warming, further steps can be taken. But even if they work as planned, things won’t be like they were before; the ocean waters will remain warmer.

But Pershing says rebuilding will look different in 2020 than it would in 1990.

“Even with the lowest warming that we could find out of any of the climate model runs, we still end up with a population that’s only about a half of what the population should have had in the 1990s,” says Pershing. “We’re headed for a Gulf of Maine where there still should be cod, but where there will be fewer cod than there used to be. They will be a much smaller part of this ecosystem than they were 20 years ago.”

New England isn’t the only part of the U.S.A. already impacted by climate change. The Pacific Northwest has also felt the pain:

The line I like most from that video is: “So anyone who claims that this massive coal project is about jobs, had better learn how to subtract.”

Climate change is destructive — already. It costs money, it costs property, it costs jobs, even livelihoods — already. Who pays for those costs? It isn’t the fossil-fuel industry. It’s you and me.

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