WASHINGTON DEPARTMENT OF FISH AND WILDLIFE
NEWS RELEASE
600 Capitol Way North, Olympia, WA 98501-1091

July 24, 2000
Contact: John DeVore, (360) 906-6710 or
Virginia Painter, (360) 902-2256

  Digg it!  StumbleUpon  Reddit

Stressed-out sturgeon? Biologists study effects of catch-and-release fishing on oversized sturgeon

Click here to watch video
Click here to watch video

Real Video Format

WDFW is currently researching the health of sturgeon resources in the Columbia River. While there is a fishery for sturgeon, the very large ones may only be caught and released.

Here is this largest of all the fresh water fish, the white sturgeon, being caught by sport anglers and then taken aboard by a WDFW research team. This sturgeon is about 9 feet in length. The agency biologist will take a blood sample, implant an ID tag under the skin and a visable tag. The fish will be released within 10 mintues unharmed.

Sturgeon of this size may not be removed from the water by the sport angler. Besides, what would you do with 9 feet and 300 pounds of fish on your boat. If hit by the tail, you could be injured or thrown overboard.

With the help of sport fishing guides, biologists from the Washington and Oregon departments of fish and wildlife are collaborating this summer on a project to determine whether catch-and-release fishing of oversized sturgeon in the lower Columbia River puts undue stress on the fish and disrupts spawning.

This is the first year of a multi-year study to learn more about the dynamics of large, adult sturgeon as well as the effects of the sport fishery.

"We haven't seen any overt signs that the fishery is affecting the sturgeon in a negative way," said John DeVore, a fish and wildlife biologist with the Washington Department of Fish and Wildlife. "But because it has become such a popular fishery, we want to get ahead of the curve and find out just what the effects are.

The sampling activity on the river is expected to continue until early August, when the sturgeon season begins to taper off. By then, the biologists hope to know a little more about the effects of the catch-and-release fishery on the sturgeon.

Though the sturgeon season is year-round, it is closed from May 1 to July 15 to angling from a boat in the 4-mile reach between Beacon Rock and Bonneville Dam. The closure is to protect spawning sturgeon from the stress of catch-and-release fishing."

DeVore said this is how the study works: When an adult sturgeon is hooked and close to release on a guide boat, the river guides radio personnel on board Fish and Wildlife boats. Biologists then take the fish, mark and tag any previously unmarked fish, draw blood to determine sex and maturity, measure stress levels, and release the fish back into the river.

In the spring before the height of the season, the two departments contracted with a gill-net fisherman to catch some 75 sturgeon so the scientists could establish similar baseline data for comparison.

DeVore said if biologists find there is undue stress on the fish, further restrictions may be imposed on the popular sport fishery. Currently, the fishery allows catch-and-release fishing of sturgeon of spawning size (60 inches and larger) called broodstock, all year round from Beacon Rock downstream to the mouth of the Columbia River.

Besides stress indicators, the sampling under way this summer will help fish biologists measure such things as the abundance of the broodstock population, the repeat recapture rate of broodstock-sized sturgeon, the sex and maturity of broodstock-sized sturgeon being handled and the percentage of mature, ripe females being caught.

The data also will show time and area distribution of marked broodstock within and downstream of the seasonal spawning sanctuary.

White sturgeon are a long-lived species, with the typical longevity pegged at 30 to 80 years, though a few fish over 100 years old have been verified in the Columbia River, and some scientists believe the fish can live to approximately 170 years. The fish is popular among sport fishers because of the challenge to anglers; the broodstock fish weigh anywhere from 100 to 500 pounds and are known for putting up a good fight when hooked.

The white sturgeon stock in the lower Columbia downstream from Bonneville Dam is the most productive of its species. During the past 20 years, the sport and commercial sturgeon fishery has grown in popularity, partly because of diminished salmon fishing opportunities and partly because of an increased abundance of sturgeon.

Fish and Wildlife staff from both states have worked to track the positive trend in sturgeon and set sustainable harvest guidelines that allow enough fish to spawn and replenish the broodstock population in balance with the natural mortality of broodstock-sized surgeon.