The sturgeon count on the Columbia River has plummeted from 202,200 in 1995 to 77,000 this year. The Oregon Department of Fish and Wildlife is expected to cut sturgeon catch limits for the fourth year in a row. The fish aren’t at risk of extinction, but something is wrong. As The Oregonian reports today, fishery managers don’t know as much about sturgeon as they do salmon and steelhead. But they note five threats that could be contributing to their decline:
- Lack of food: Two of the fish sturgeon like to eat – Pacific smelt and lamprey eels – are down in the dumps. Smelt were listed under the Endangered Species Act last year, and lamprey populations have fallen from as high as 400,000 in the 70s to around 20,000 last year. Shad, another good eat, is also on the decline. Shad numbers have dropped 25 percent over the past five years.
- Sea lions: Biologists estimate sea lions killed 6,680 sturgeon last year and will kill 10,400 a year by 2014. Older, breeding sturgeon below Bonneville Dam may be especially vulnerable to sea lions because they can’t move over the dam to safety like salmon and steelhead can.
- Poachers: And a lack of enforcement to catch them in the act.
- Fishermen catching them – and throwing them back: Sport and commercial fishermen on the Columbia catch sturgeon. Sometimes they can keep them, and sometimes they can’t. When they’re caught and thrown back, the way they’re handled could affect their long-term survival.