White sturgeon, the sometimes 8- to 10-foot fish covered in bony plates and virtually unchanged since appearing in the fossil record 175 million years ago, have been turning up dead by the dozens in Washington's Columbia River in the state's southwest area, according to the Seattle P-I.

The Washington Department of Fish and Wildlife (DFW)'s Paul Hoffarth says the department is considering closing catch-and-release fishing of the species, and that more than 80 dead sturgeon have been reported on the river from Hanford Reach to Boardman, Oregon, the Seattle P-I said. 

All of the deceased fish have been large, ranging from 5 feet to 8.5 feet long, the Spokane Spokesman-Review reported.

The DFW's theories include that the sturgeons have eaten sockeye salmon that are diseased from migrating upstream in the Columbia River's unusually warm water; or that the sturgeon are stressed by dramatically lower water flows combined with higher-than-normal July water temperatures, the Seattle P-I said.

Along with being distinctly large and prehistoric in appearance, sturgeon are unique for living very long lives: sometimes 100 years or more. The fish grow slowly and do not spawn until females are over 18 years old and males are at least 14. They're capable of spawning many times in their lives, unlike salmon.

Here's an article about a sturgeon found in Seattle's Lake Washington

For coverage about other types of that fish, read our article here.