Rapid ID

Sharks and rays are in trouble. A study a few years ago found that the global population had dropped by more than 70 percent since 1970. And three-quarters of all shark and ray species could face extinction in the next few decades.

The main threat is overfishing. Sharks and rays are valued for their meat, fins, and liver oil. Some countries provide strong protections. Others—especially those where the fish are big business—have weak protections or none at all. And even where sharks and rays are protected, it can be hard to keep track of them.

A recent study found that some fairly new techniques could help: rapid DNA testing and environmental DNA—finding out which species are present in a region just by analyzing the water. That could help scientists monitor populations and movements. And it could help management and enforcement agencies know if protected species are being caught and sold illegally.

The study looked at 25 years of research into rapid DNA and environmental DNA testing. These techniques are much faster than traditional DNA testing. They’re also much less expensive. So it might be possible to deploy them in the field—identifying shark and ray species on the spot.

The study said there’s a lot of work to be done to make that happen. The technology has to get easier to use. And scientists have to compile a more thorough database of shark and ray DNA. Still, the technique offers a possible way to ease the stress on these troubled fish.