MEDFORD, Ore. — The Columbia River Basin and other Oregon coastal rivers are experiencing low summer steelhead returns. But the Rogue River’s early season is already trending above its 10-year average.
The low returns have been attributed to drought and poor ocean conditions the past few years. The Rogue’s summer success, however, has dodged the rough conditions thanks to the halfpounder steelheads’ life cycle, the Mail Tribune reported (http://bit.ly/2w6NUJR ) on Friday.
Steelhead spend two years in freshwater before heading to the ocean as smolts. But the Rogue’s summer steelhead return in late summer and fall as halfpounders — a term based on their 8-ounce (227-gram) bodies — instead of staying in the ocean for one to three years before returning to freshwater.
Pete Samarin, an Oregon Department of Fish and Wildlife biologist, said this early freshwater return has become the Rogue steelheads’ advantage. It has allowed the fish to avoid the drought and poor ocean conditions of the past few years that’s affecting its species elsewhere.
“It’s one of these evolutionary advantages of halfpounders,” Samarin said. “In those years, they’re probably getting more to eat than in the ocean. … In the river, they’re the top predator.”
Samarin said because halfpounders leave the ocean quicker, they have a better chance of survival than a spring chinook smolt or a steelhead smolt in poor ocean conditions.
Information from: Mail Tribune, http://www.mailtribune.com/