Endangered smalltooth sawfish, marine creatures virtually unchanged for millions of years, are exhibiting erratic spinning behavior and dying in unusual numbers in Florida waters.

Sawfish, related to rays, skates and sharks, are named for their elongated, flat snout that contains a row of teeth on each side. They can live for decades and grow quite large, some as long as 16 feet (about 5 meters). They were once found all along the Gulf of Mexico and southern Atlantic coasts in the U.S., but now are mainly in southwestern Florida and the Keys island chain as their habitats shrink. A related species is found off Australia.

Since late January, state wildlife officials have been documenting what they call an “unusual mortality event” that has affected about 109 sawfish and killed at least 28 of them. There have been reports of abnormal behavior, such as the fish seen spinning or whirling in the water. Other species of fish also appear to have been affected.

We suspect that total mortalities are greater, since sawfish are negatively buoyant and thus unlikely to float after death