By Rick Smeriglio for SCN – On Friday the 23, two hefty trucks from the Alaska Department of Fish & Game, Wm. Jack Hernandez fish hatchery lumbered up to the Seward Lagoon and released their shimmering cargo of 95,000 quite lively coho salmon smolts into the brackish water. Those that survive north Pacific rigors will return as adults in August and September of 2015. Seward Chamber of Commerce purchases coho salmon, also known as silver salmon, to support the recreational fishery on Resurrection Bay. ADF&G annually collects eggs and milt from adult salmon at the Bear Creek weir and cultures the resulting juvenile fish until they reach viable size. The smolts released into the lagoon took 18 months to reach a size of about 21 grams and 5 inches.
Katie Whitmore, ADF&G Fish Culturist, clearly has great concern for the thousands of small lives in her care. Her truck has a paint job that simulates a school bus with a sign that tongue-in-cheek says “Fish School Bus”. Whitmore proudly shows off two powerful aerators that circulate oxygen-rich water through five separate tanks, each holding 400 gallons. The tanks have an oxygen sensor that measures the amount of dissolved oxygen in the water. If not enough, the truck carries oxygen cylinders to add more to the water, kept at a sparkling, 40 degrees F.
Whitmore checks the tanks one last time before the smolts make their splashing entry to the reality of life in the wild. She regards it as a good sign if the smolts dive when she lifts the lid.
“These are happy campers,” says Whitmore as the entire wad of silver fingerlings dives for the bottom.
ADF&G Regional Stocking Coordinator, Andrew Garry, describes Seward Lagoon as a “terminal fishery” meaning that returning adults can’t spawn there. All the returnees will die if not caught or killed beforehand. Garry estimates that about 3 percent of the smolts return as adults. They return because waters of the lagoon have imprinted upon the smolts, a process that takes about 48 to 72 hours. More adults returning to the lagoon means a better shore fishery in Seward.
Tom Prochazka, manager of the Cook Inlet Aquaculture Association hatchery in Moose Pass, recommends releasing the fish into a net pen suspended in the lagoon to hold the fish long enough to become imprinted. Otherwise, many of them may just slip out to sea a little too early he says. The pen would need an anti-predator top and the fish would need a food supply. Seward Chamber of Commerce may try this approach next year.
Garry does not shy away from discussing the issue of so-called “Frankenstein fish“. He explained that the hatchery does not genetically manipulate the fish that it cultures. Hatchery personnel make random grabs of adults at the weir when collecting eggs and milt, and do not select fish for any favored traits. Although the young fish thrive in optimum conditions at the hatchery, they face the same rigorous conditions as do wild fish once released into the wild.
“These are not genetically modified fish,” says Garry flatly. “They’ve still got the instinct to avoid predators. They’ve been tested to see that they can survive the same salinity conditions as Seward Lagoon.”
Garry characterized the day’s efforts as a “successful release”. No gulls, mergansers, river otters or other predators harassed the newly freed fish. Twenty minutes after splashdown, the glistening smolts had spread out over a sizeable area and moved to deeper, cooler water. Many of them jumped. They seemed ready to meet the salt-water challenge.
Seward Chamber of Commerce expects delivery of about 192,000 king salmon smolts in June.