Florida Fish Spinning in Circles

On a night dive last November, Florida diver Gregg Furstenwerth shone his flashlight on a pinfish in a seagrass meadow in the Florida Keys. The fish was spinning and whirling in upside-down circles. He'd never seen such behavior, so he video'd the fish.

Then he began to hear similar reports of spinning fish from friends and other divers, so Furstenwerth documented more sightings, and knowledge of the issue spread.

National Geographic reports that at first, the sightings of spinning fish mainly occurred along a 35-mile stretch of water in the lower Keys. Then, according to the conservation group Bonefish and Tarpon Trust, three reports surfaced in Miami and most recently, one case occurred in the upper Keys.

By March, scientists had identified the bizarre actions in at least 44 species, including the critically endangered small-tooth sawfish. Many fish have been washing up dead, though there's not a formal count, according to the Florida Fish and Wildlife Conservation Commission.

The cause of the spinning, which continues until the fish dies, is unknown, which has prompted a collaborative investigation among several universities, institutes, and state agencies in a race to identify the culprit. Possible causes include harmful algal blooms, which can produce neurotoxins that affect fish behavior, pollutants, parasites, or changes in the water, such as low oxygen or high temperature. Whatever the cause, it's of great concern to those studying the strange behavior.

Furstenwerth has created a group on Facebook called The Spinning Fish Florida Keys, which you can visit here: www.facebook.com/groups/1438019537141745