Intuitively, I would agree that some tropical species have been moving northwards from latitude 20 towards the Arctic Circle. The tuna, swordfish, and cod have always been way up north so that is not unusual.  However, when sub-tropical and tropical species start moving up the coastlines, that is really something.

Several years ago during a warm water event on the West Coast, giant jumbo squid showed up in Homer, Alaska - these squid should in theory get no farther north than Los Angeles. On the East Coast, Portuguese Man-O-War have been sighed as far as Cape Cod, and Lionfish as far north as North Carolina. Both are extremely toxic by the way.

I wish I could read the real study even a more profound problem is the kind of bacteria in the waters. Vibrio Vulnificus, a devastating flesh eating bacteria that also attacks the nerve system, is definitely moving northward. Sea lice, those critters that ruin wild salmon farms, is on an alarming rise. The only good news is that the Eastern Seaboard has been very cool this year.

Once August rolls around again, I bet we'll hear more about the northern migration of some really strange species.  -sammie

Depletion of fisheries is only a problem for humans, and a rather minor one at that compared to what it is for the fish themselves.  The real problem is that human caused climate change is wreaking havoc on marine ecosystems, among other things.  Sheesh people, get some perspective.

Wolverine a good comment but the central thesis is that as global warming occurs - fish depletion or not - migration patterns will change in many significant ways. It is a matter of an educated guess, such as by using models and such, to predict these changes but I can say without a a doubt they are happening right now - a seemingly irreversible thing.

Certain duck, goose, owl, and other bird species are going to areas never seen before. Arctic birds are showing up in Tennessee. Certain birds found way down deep in South America are now found in Texas. And the fish are no different.

An aquatic biologist would also agree that global warming has also caused certain invasive or opportunistic plant species to multiply like heck. I could go on and on about this. In many cases we're not talking about depletion as much as a invasive species taking over the habitat and multiplying geometrically. Forget what you learned in college and the common-speak, what is happening is truly momentous. -sam

I totally agree with your post.  If I remember correctly, the first species to become extinct due to global climate change did so because of having to move to ever higher elevations.

However, my problem is with the framing of the original post.  As has been shown, framing is all-important.  If people are ever going to get the idea that they're not the center of the universe, it's important for environmental writers to focus on human-caused harms to non-humans.  Focusing on fisheries just continues the self-centered paradigm, which is one of the ultimate roots of all environmental problems.