Rogue 'stream-enrichment' less problematic for dogs
This is in regard to your story about fishing groups throwing salmon carcasses into Rogue Valley creeks as part of a “stream-enrichment” program. Isn’t this really a dog-killing program? They’re putting hundreds of carcasses out there for dogs to eat and get poisons, right?
— Debbie, email submission
Well, yes, the Oregon Department of Fish and Wildlife does put salmon and steelhead carcasses in some Rogue River Basin salmon-spawning areas to add natural nutrients from these fish, but the truth is your dog is far more at risk from eating naturally spawned-out fish than stream-enrichment fish.
The risk is salmon-poisoning disease, or SPD, a usually fatal disease that occurs when dogs eat fish that contain a trematode that also contains rickettsia, the cause of SPD, says Ryan Battleson, the ODFW fish biologist who oversees the local stream-enrichment program.
Rickettsia, which is a hybrid bacteria-virus, occurs naturally in wild salmon and steelhead returning to streams from Northern California to British Columbia, so your dogs could be exposed any time they enter the Rogue or tributaries during and after spawning, Battleson says.
Dogs exposed to SPD can survive if the disease is caught early enough and the dogs are treated with antibiotics.
Several safeguards are used to protect your dog from contracting SPD from any of the salmon and steelhead carcasses placed in streams to add nutrients, Battleson says.
The main safeguard is that the fish used in the program are surplus spring chinook or summer steelhead killed at the hatchery and placed in a deep freeze at minus-10 degrees for at least three weeks, Battleson says.
Studies show that freezing them at minus-4 degrees over that period of time kills the rickettsia.
The stream-enrichment fish usually are placed during or right after natural spawning, Battleson says.
Excess spring chinook carcasses are placed in the main-stem Rogue where natives spawn in late fall, he says.
In fact, Battleson had a crew of volunteer driftboaters who tossed 18,000 pounds of spring chinook carcasses just last weekend in the main-stem Rogue from Cole Rivers Hatchery to Shady Cove. More tosses are planned later this month and early December, he says.
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