In catch-and-release angling competitions, freed bass still face risk
August 3, 2009
Joseph Love says his job as tidal bass manager for the Maryland Department of Natural Resources is great. The only part the fisheries biologist says he hates is dead fish counts.
In June, Mr. Love was called to Smallwood State Park in Charles County, Md., to investigate reports of a fish kill following a weekend in which four bass tournaments were held simultaneously on the same stretch of the Potomac River. What he found surprised him.
DNR personnel counted 601 dead largemouth bass and some 200 other fish of assorted species belly up in a six-mile stretch of the Mattawoman Creek, where tournament organizers had released fish after weigh-ins. The Washington Times reported "the stench of dead, decaying fish permeated the air."
"We haven't seen these numbers on record," said Mr. Love. "We've never seen such a high level of delayed tournament mortality."
That's the name given to a well-researched syndrome in which fish caught and released by tournament competitors die within days of release. While the death rate for fish caught and immediately released by sport anglers is between 1 and 2 percent, biologists say the acceptable death rate in tournaments -- in which fish are caught, held for hours in live wells and handled before release -- is 26 to 28 percent.
Texas Tech University biologist Gene Wilde, who has spent about 10 years studying fish deaths after tournaments, said they are believed to die from a combination of conditions.
"Stress comes from a variety of factors," he said, "beginning with the angling event itself. Fish exert a lot of energy during the fight. Their muscles produce lactic acid, much like our muscles do when we're running and our legs cramp up. Fish deal with that by respiring more oxygen from the water."
But the stress of catch-and-release common to sport angling isn't usually enough to kill them.
"In an experiment a couple of years ago, we hand-hooked fish in various parts of the mouth and played them," said Mr. Wilde. "Survival was around 98 or 99 percent."