Minter Creek Hatchery: Serving Fishermen and Ensuring Survival of Threatened Salmon


Sara Thompson, KP News

Fall chum return to Minter Creek every November. Photo: Ed Johnson, KP News

The Minter Creek Hatchery sends millions of salmon into Puget Sound each year. It’s been in business since 1936, when it was built as a collaborative effort between the University of Washington and the Washington State Department of Fisheries and Wildlife (WDFW). When it expanded in the mid-1990s, it became a model for other hatcheries in the state.

The first hatchery in Washington opened on the Kalama River in 1895 and was built primarily to compensate for damage to large areas of habitat caused by logging. Now, the 83 state hatcheries are an important part of the state economy, releasing more than 100 million fish each year and accounting for about three-quarters of the commercial and recreational fish caught in Puget Sound. They have also taken on the critical role of recovering and conserving the state's naturally spawning salmon populations when their survival is threatened.

The hatchery system is complex.

“We are continually learning more about how quickly salmon can adapt to their environments and, even with the same genetic stock, hatchery fish over time are not genetically identical to the wild fish,” said Jim Jenkins, WDFW operations and reform manager for region six (South Puget Sound). “So, how we approach our salmon recovery efforts is constantly being re-evaluated. We are also careful to be sure that the salmon we raise to augment recreational and commercial fishing doesn’t impact the wild populations.”

Funding for the hatcheries comes from the federal government, state and local general funds, and the state wildlife account. Some of this money is collected through recreational and commercial fees.

Deidre Bissonnette manages the Minter Creek Hatchery and lives there with her husband and two elementary school-aged children, along with one other employee and his family. She also manages the small Hupp operation nearby and the Coulter Creek Hatchery near Allyn, where another employee lives fulltime. Together, the three hatcheries ensure there are plenty of fall chum, coho and chinook salmon for recreational, commercial and tribal fishing. They also make sure that the endangered spring chinook stock is preserved.

The spring chinook from the White River and Puyallup River are threatened. A recovery program designed to protect and preserve the species was started in the late 1970s and Minter Creek has participated since 1996. The chinook arrive at Minter in June and July. Because the hatchery is not far from the mouth of the creek, and in the natural world they would have a longer swim upstream to spawn, the fish are collected and held in the tanks until they are “ripe.”

The eggs and sperm are harvested; the eggs are fertilized and then incubated until they hatch. The fry are sent to the Hupp site to grow and are brought back to Minter for release. Before they are released, the adipose fin is clipped so they can be identified as hatchery-raised. The program will continue until the wild salmon return to their native watershed at a sustainable rate.

The fall chinook come originally from Green River. This program is aimed at augmenting the supply of fish for Puget Sound recreational and tribal fishing. The fall chinook return to Minter Creek about a month after the spring chinook and the process for harvesting, fertilizing, raising, marking and releasing the salmon is the same. The hatchery expects to harvest over 2-1/2 million eggs. About a third of the fertilized eggs will be transferred to Suquamish tribal facilities and the remainder will be raised and released from Minter Creek.

Minter Creek also receives fertilized eggs from the Tumwater Falls Hatchery, hatches them and ships juveniles to the Coulter Creek Hatchery where they are sent to grow because the Tumwater facility is not big enough. About 4 million smolt will be shipped back to Tumwater Falls to acclimatize before they are released.

The coho program, like the fall chinook, is designed to increase the number of salmon for tribal and recreational fishing. The coho return is in early fall. Minter Creek has historically been home to wild coho and about 10 percent of the returning fish are wild, so the wild and hatchery fish are interbred. This year, the hatchery estimates that more than 1 million eggs will be harvested. About half will be raised and released at Minter Creek; the rest will be shipped to hatcheries and salmon clubs.

The chum return is the most intense, taking place over just two to three weeks in late fall. The harvest and raising is similar to that for coho, with interbreeding of wild and hatchery stock. Chum smolt are so small when they migrate to the Sound that the adipose fin is not clipped.

The chum program is intended to augment fish for the commercial fall chum salmon harvest and for recreational and tribal needs. The program also supplies eggs to schools for their educational programs. It is estimated that more than 4 million eggs will be harvested this year. Twenty-six schools will receive about 250 eggs for school projects and tens of thousands of eggs will be shipped to fishermen organizations and state projects.

The Minter Creek Hatchery is a 24/7 operation. Bissonnette or one of her colleagues is always on call in case of emergencies. In the winter, when the incubators are in full operation, a power outage with loss of continuous water flow and oxygen supply could decimate the eggs. The response time is just 15 minutes. The holding tanks are less sensitive, but the response time during the spring and fall is still less than an hour.


What Exactly Happens at the Minter Creek Hatchery?


Fish that have been released at a hatchery site are imprinted to return to spawn several years later, after maturing and growing—first along the shoreline and finally in the Pacific Ocean. The four species of salmon at Minter Creek all return at different times and are kept separate from one another.

When the adults return to Minter Creek, they swim up the fish ladder and are routed into holding ponds via chutes. In the wild, they would have a longer swim before reaching spawning sites, so they are kept in the ponds and fed until the eggs are ready. The number of eggs from each adult female depends on the species: chinook have about 3600; coho 2600; and chum 2300.

When it is time, the fish are separated by gender. They are killed with a blow to the head, the females are stripped of their eggs and the males are milked for their sperm.

Washington state contracts with a private company to manage all the adult fish once they have been killed. The fish that are spawned (harvested for eggs and sperm) are used for fertilizer and animal food. Some fish are not spawned. If the quality is good, they can be used for human consumption and are sent to the NW Harvest Food Bank.

The eggs and sperm are mixed and the fertilized eggs are taken to the incubators where they are doused with an iodine-containing solution to kill bacteria.

The incubators are elaborate mesh trays with continually circulating fresh water. At Minter Creek, both ground (well) water and surface (creek) water are available, and what is used varies depending on the type of salmon. For the salmon that are not native to Minter, well water is used. It has a constant temperature, no contaminants and no debris. For the coho and chum, there may be advantages to the surface water—the fish are acclimated to their native stream and the water has nutrients or minerals missing from the well water that allow the eggs to harden. Once the fish are “eyed”—when an eye is actually visible—the shell has hardened and they are at their sturdiest.

Eggs are shipped at the eyed stage. If they are to be hatched at Minter, the eggs stay in the incubators. When they hatch, they still have a yolk sac visible on the belly that is absorbed in a process called “buttoning up.” Once they are buttoned up, they are ready to feed and are sent to ponds to grow, some at Minter Creek and some at other sites, depending on the program. Before release, the salmon have their adipose fin clipped to mark them as hatchery fish (except for chum because they are so small when they are released). The marking program has been in place since the late 1990s. The WDFW encourages the harvest of hatchery fish while leaving the wild fish in the oceans and rivers to allow them to survive and spawn. [/box]