The Atlanta Journal-Constitution reports:
As climate change heats our oceans, you’d expect temperature-sensitive marine species to flee poleward to cooler waters. So why have some headed to warmer regions toward the equator?
Scientists have solved the puzzle. For the most part, these animals are relocating to cooler waters. But since the effects of climate change can vary widely across regions, sometimes those cooler regions are closer to the poles and sometimes they’re closer to the equator.
In other words, marine animals are still reacting to climate change, but at a local scale. And they’re doing it so reliably that you can actually measure the speed and direction of those changes by watching where animals go, according to a study published Thursday in the journal Science.
This is junk! Many types of fish undertake migrations on a regular basis, on time scales ranging from daily to annual, and with distances ranging from a few meters to thousands of kilometers.
The purpose usually relates to either feeding or breeding; in some cases the reason for migration is still unknown.
Salmon are capable of going hundreds of kilometers upriver, and human dams must install fish ladders to enable the salmon to get past.
For more information about the topic Fish migration, read the full article at Wikipedia.org, or see the following related articles:
http://www.sciencedaily.com/articles/f/fish_migration.htm
Anyway I think food source isn’t as dependent on temp as they think either. The food source responds to upwelling – where colder water from the ocean surface comes up – but it isn’t the temperature that causes the food growth. The upwelled water is richer in nutrients from the ocean floor. If it is upwelled water but 2 degrees warmer – it should fit the food sources needs just as well.
Well your point kinda affirms the study then. It may not be the fish but the food source – the krill and what no that need the lower temperatures.
I guess we now have to add “climate velocity” to the lexicon. They have a model that explains 70% of fish movement all based on temperature? I thought fish moved according to the food distribution. I’ve been told that Great Lakes salmon like the 55°F thermocline because that’s where the food supply (alewives) are. This article didn’t seem to mention food supply.