This is Scientific American 60-Second Science. I'm Christopher Entagliata.

As it happens, tiger sharks have something in common with certain east coasters.

During the winter when it's cold, they kind of snobr down near the Bahamas and off of

Florida, and then during the summer they migrate north.

Neil Hammerschlag is director of the Shark Research and Conservation Program at the University

of Miami. He and his colleagues analyze 40 years of fishing catch data, and they

found that as ocean waters have warmed, the sharks range has shifted, some 250 miles to

the north. The sharks, it seems, are chasing their preferred water temperatures toward the

pole. They also track dozens of tiger sharks with satellite tags for nine years, and they

found similar results.

So taken together, we have several lines of evidence that tiger shark distributions and

their migrations are changing from ocean warming, causing their distributions and migrations

to extend and expand further north, and in these northern areas, they actually occur

earlier in the year for ocean warming.

Their findings appear in the journal Global Change Biology.

This shift matters, Hammerschlag says, because tiger sharks are apex predators, and where

they go, influences the food web beneath them. The sharks are also moving outside marine

protected areas, and into places where they could be more vulnerable to commercial fishing.

What this points to is that these marine protected areas need to consider current, but also

future changes in species distributions from ocean warming, and they certainly have to

be adaptive, and maybe work with not only having marine protected areas, but also other

types of protections like catch limits, and other types of more traditional species conservation

...