MATTAWA — A smattering of small, bright-orange orbs lay on the dark asphalt of the Priest Rapids Hatchery spawning area like pearls suddenly set free from a broken necklace. They attracted fifth graders like a magnet.
“What is that?” Asked one of boys in a louder-than-speaking voice. He bent over for a closer look.
“Eeeew! Don’t touch it,” said another, rushing over. A huddle quickly formed – and clamor grew – around and over the curious spheres. What could they be?
This inquisitive bunch of students from Mattawa’s Morris Schott STEAM Elementary School were getting their first look at real salmon eggs, and they were about to see tens of thousands more.
The 64 students – two classrooms worth – and their teachers Erin Tostenson and Laura Catlin got an up-close look Nov. 6 at both the human-assisted and natural ways fall Chinook salmon spawn. See a video of their visit here.
Led by Grant PUD biologists Eric Lauver and Rolland O’Connor, the group watched state Department of Fish and Wildlife hatchery workers corralling the previously trapped Chinook, euthanizing them with a blow to the head and tossing them onto a special tray for the next step in the process.
The students and other guests watched, as fish processors expertly sliced open the females, catching their thousands of eggs in white buckets, and squirting the white “milt” – seminal fluid – from the males into the buckets to fertilize the eggs.
“That was my favorite part,” student Litzy Ramirez said with a smile. “It was very satisfying.”
“What you’ve just seen is the spawning process,” PUD biologist Lauver told the group. “In the wild, the female would dig what in the gravel?”
“A redd!” the kids responded of the depression in the riverbed the female excavates with swishes of her tail to hold her deposit of eggs – somewhere between 3,600 and 4,000 of them per redd.
They’d been studying the salmon lifecycle as part of an ecosystem lesson at school, Teacher Tostenson said. Like the STEAM in its name indicates, the school is focused on a curriculum heavy on science, technology, engineering, art and math.
Each classroom built a terrarium on top of an aquarium filled with guppies and snails to observe how whatever is deposited into the terrarium soil can leach into the water below, affecting the aquatic flora and fauna.
“We’re learning what the PUD does to maintain the health of the river, and what they (the students) can do,” Tostenson said.
The PUD annually spends about $15 million to support operations and maintenance of approximately 20 hatcheries, hatchery programs and fish-rearing facilities throughout the Columbia Basin. The cost includes habitat improvements, control of birds and fish that feast on young salmon, and monitoring and evaluation of hatchery and wild fish populations in the region.
In the wild, a male salmon releases his milt over the eggs as they are being deposited in the redd. The female covers them with a layer of gravel to protect them until they hatch into tiny frye.
At the hatchery, the crew places the fertilized eggs onto trays infused with circulating cold-water until they hatch – about 12 weeks.
As the Chinook grow, they’re transferred first to outdoor raceways inside chain-link cages to protect them from predators, then to larger rearing tanks until they’re ready for release into the Columbia River for their 400-mile journey to the ocean.
Many Chinook spawn naturally right in the hatchery’s water-filled channel to the Columbia. The tour ended with the students getting a close-up look at the females and bright-red males doing what nature intended.
“Their tails are very strong,” Lauver said of the females. They’ll stay with the redd until they get so weak they fall over and die.”
Student Francisco Capi, listened intently, after peppering Lauver with questions.
“Oh, pobrecitos! (poor things!),” he said softly in Spanish and headed off with his classmates to board the bus.
Story and photos by Christine Pratt, email@example.com, Grant PUD Public Affairs.