CHETCO CHINOOK: THE NEXT GENERATION

December 10, 2008 12:00 am
Chinook eggs are prepared in the hatchery. ( By Chad Robert SnyderPilot staff writer).
Chinook eggs are prepared in the hatchery. ( By Chad Robert SnyderPilot staff writer).

By Chad Robert Snyder

Pilot staff writer

One year ago, 104 Chetco Chinook were still roaming the ocean, looking for something to eat.

Two months back, the same fish were caught in seine nets at Social Security bar and later transported to Elk River Hatchery near Port Orford.

Over the last 3 weeks, the salmon have taken the last step in their journey to become 150,000 smolt. They've been spawned.

The process is not exactly rocket science, but it does require a dedicated and knowledgeable staff to make sure it happens.

Enter Robin Crisler, Hatchery manager of the Elk River facility.

As he said, his job is to ensure a successful "full factorial matrix spawn."

It may sound complicated, but the goal is simple.

"It's intended to maximize the genetic diversity of each spawn group," Crisler said.

Translation: mix as many different eggs with the sperm of various males so you end up with as much interbreeding as possible.

The physical act of spawning may seem simple, but it too requires a great deal of knowledge about the Chinook's breeding habits.

Spawning only begins when Crisler and staff members select fish they know are ready to give eggs and sperm. The selection process means literally jumping in with both feet and "physically handling" each fish.

Once selected – females are ready when they feel like a "loose water ballon" according to Crisler, and males, when sperm emerges when they're squeezed – the salmon are taken to the "spawning deck." Females are cut open and stripped of their eggs. The eggs are then fertilized directly by male sperm in individual bags that represent a mixture of all the females.

It terms of fertilization, that's really it. Within seconds the eggs are fertilized and ready for the 100-day period in which they'll transform into fully functional fish.

Only one critical element remains. Before the eggs can be stored in flood-irrigated trays, they must be soaked for one hour in 100-parts-per-million iodine solution to ensure no viruses or bacteria infect the batch.

The cycle will be complete when the smolt are released into the Chetco during mid-September, 2009.

Crisler said, there are many facets to the program, including the stated goal of "supplementing natural production."

There's also a more immediate and local impact.

"We grow fish for people to catch," Crisler said.