A little home cooking is helping tribal hatcheries keep chinook and coho disease-free and eliminating the need for antibiotics that could lead to drug resistance in people.

For the past three decades, staff from the Northwest Indian Fisheries Commission’s tribal fish health program have been producing vaccines to treat vibriosis and enteric redmouth disease that can be lethal to young salmon in hatcheries. Treaty tribes in western Washington produce about 40 million salmon annually.

Both of the vaccines produced in NWIFC’s lab eliminate or sharply reduce the need for antibiotics to treat infected fish in hatcheries. It is thought that the overuse of antibiotics in animals used for food reduces the effectiveness of antibiotics in humans.

“The vaccines we produce are highly effective and can be made at a fraction of the cost that companies charge,” said Bruce Stewart, the lab’s director. “We made 750 gallons of vaccine for use this year that we can use to inoculate about five million fish, saving the tribes tens of thousands of dollars a year, and protecting salmon that are harvested by Indian and non-Indian fishermen.”

Enteric redmouth disease is a bacterial infection of freshwater and marine fish that mainly affects steelhead and chinook early in their life cycle, sometimes before their immune system is developed.

The vibrio virus occurs naturally and is widespread in western Washington marine waters. Outbreaks are influenced largely by water temperatures that exceed 55 degrees. If unchecked, the disease can lead to huge losses of young salmon in hatcheries.

Coho and chinook are especially susceptible to vibriosis, but their treatment varies because of the difference in size and how much the young fish are handled before release.

To further gauge the effectiveness of inoculating young chinook in fresh water, tribal and fish health lab staff will use a coded-wire program to track survival rates of the treated fish over the next three years.

Much of the credit for the success of this program is due to the work of microbiologists Betsy Hall and Matt Stinson, Stewart said.

“Betsy and Matt are the heart of our vaccine production program,” he said. “They have clearly demonstrated the effectiveness of our vaccines and have doubled our production capacity at no additional cost in recent years.”

Betsy Hall, NWIFC microbiologist, checks the status of vaccines being produced in the NWIFC fish health lab in Olympia. Photo: Tony Meyer