Popular bait might harm salmon
A recent study from the Oregon Department of Fish and Wildlife confirmed a popular salmon and steelhead bait containing sodium sulfite can harm juvenile fish.
Scientists from ODFW and Oregon State University tested a random sample of commercially cured fish eggs and found that some juvenile fish died after ingesting some brands, and later determined that sodium sulfite was the ingredient causing death.
Fishermen cure salmon eggs to preserve them and to add fish-attracting elements, said Joe Cook, manager of The Bait’s On Bait and Tackle shop in Coos Bay.
“Color, scent and texture all play into it,” Cook said.
Some anglers use their own egg cure recipes, while others use commercially available products, and both can contain sodium sulfite. There are three main cures: borax-based, sodium nitrate-based and sodium sulfite-based cures, Cook said. Borax-based cures are popular, and the easiest to use, he said.
Charlie Owen, an avid local fisherman, makes his own egg cure, and said that curing eggs is important to salmon and steelhead anglers, who guard their recipes carefully once they find a combination that works.
“I won’t catch a fish on fresh eggs,” he said.
Cook said salmon eggs are a successful bait, hence their popularity.
“It’s a very effective bait,” he said. “Nearly everything in the rivers will eat salmon eggs.”
Questions about the bait arose in April 2008, when a group of anglers approached ODFW with concerns that the egg cure was toxic to juvenile salmon, according to a summary of the study. Testing began the following month.
The cured eggs were fed to groups of 55 salmon and steelhead held in tanks over a 23-day period, and mortality was assessed after each feeding. Specific mortality rates varied among products, and ranged from 0 to 30 percent. Some fish died after the first feeding, but most were able to survive through 23 days of presumably eating the cured eggs, the study said.
Removal of sodium sulfite eliminated the mortality.
“We’ve already talked with several manufacturers and we’re encouraged by their commitment to solving this problem,” said Bruce McIntosh, ODFW deputy administrator of inland fisheries, in a press release. “Our emphasis will be on informing anglers, guides and other manufacturers about the risks sulfites pose to juvenile fish.”
ODFW cannot predict whether this has a significant effect on the overall health of salmon and steelhead populations.
Local ODFW fish biologist Tom Rumreich pointed out that there are too many variables in determining salmon population.
“But it can certainly impact individuals,” he said.
Rumreich said sodium sulfite has been widely used in various areas, including the treatment of salmon eggs.
“I know this information has really raised some eyebrows,” Rumreich said. “And I know I will never use it again.”
Rumreich said he will spread the word to other fishermen, and that his co-workers also won’t be utilizing sodium sulfites.
Though he’s not sure sodium sulfite could have long-term effects on salmon populations, he won’t rule out the possibility the ingredient could hurt future numbers.
“I certainly will be going around telling people that we shouldn’t be using it,” he said.
Rumreich pointed out that there are many alternatives for egg cures, and he has long used a store-bought meat tenderizer ??” anything derived from salt works just fine, he said.
“And the sky’s the limit,” he said.
Cook agreed, adding that a book he sells on egg cures lists at least 20 different recipes.
“There would be few people who would be harmed by switching because there are so many alternatives,” Cook said.
For more information on the ODFW study, visit www.dfw.state.or.us, and search “harmful salmon bait.” The press release contains a link to more specific information on the study
