Wild or hatchery fish: opinions vary on large pink return

Sep 21, 2017

A pink salmon swims through Beluga Slough.
Credit Aaron Bolton, KBBI News

Pink salmon seem to be showing up everywhere in creeks and along beaches all around Kachemak Bay and the outer coast of the Peninsula. Pinks are returning to systems that have historically never supported salmon. That has caused some head scratching in the fishing community, and there are differing theories as to why pinks are colonizing new systems.

This summer was a significant year for commercial fishermen in Lower Cook Inlet. Glen Hollowell, area management biologist for the Alaska Department of Fish and, says two million pink salmon were commercially harvested, double the historic average.

This year’s run is a reflection of 2015’s record breaking returns, which led to fish straying from overcrowded streams into odd water systems. Pinks return two years after hatching, and this year pinks were again seen in odd places.

Hollowell thinks that’s because 2015 was followed by an unusually warm winter, allowing eggs laid in atypical streams and creeks to hatch the following spring. He says that gave birth to the odd returns in Beluga Slough and other systems in 2017. The fishing community and others have taken notice.

“There were pink salmon everywhere coming out of the water like popcorn all of late July,” Dave Lyon, owner of Ashore Water Taxi, recalled.

He thinks there’s something more happening than just a big wild run.

“My anecdotal impression is that these must be hatchery fish,” Lyon says. “The vast majority of them seem to be in Tutka and outside Port Graham. Those are the two hatcheries we have operating in this area.”

Lyon is not the only person who thinks hatcheries are causing problems.

Nancy Hillstrand is a seafood processor who spent 21 years working with Department of Fish and Game as a fish culturist and habitat rehabilitator. She believes that pinks coming out of hatcheries produce negative consequences for the natural ecosystem.

“The food web I think is what is most concerning to me because the pink salmon are heavy duty predators,” Hillstrand explains. “To have this many predators out in the area and to keep adding predators every year from the local hatchery, it can’t do anything but eat our local zooplankton.”

While there are some who believe that the hatcheries are releasing too many fish, others don’t believe that is the case.

Malcolm Milne has fished around Lower Cook Inlet since 1995. He sees this year’s large return as a product of previous years, not significantly affected by hatcheries.

“2015 there was a really good run of pinks, and that winter of 2015-16 was very mild. So that makes for a great breeding population,” Milne says.

So, are hatchery fish straying and colonizing new systems? Hollowell is currently figuring that out.

“That’s something I can tell after the ear bones have been read” Hollowell notes. “We’ve collected ear bones from not only the streams from Kachemak Bay, but we’ve also been sampling commercial harvest. We are going to mail them to Cordova in the next couple of weeks, and they’re going to read them throughout the winter. We should get those results in February”

The ear bones from hatchery fish show different thermal marks than wild salmon.

Gary Fandrei, executive director of the Cook Inlet Aqua Culture Association, is also gathering data to find out how many fish from his hatcheries made their way to new areas. 

“You know there are samples that are collected throughout the drainage, and once those samples are looked at and read, we will have a better idea how many of our fish returned to some of these other systems,” Fandrei explained.  

As far as previous runs, Hollowell stated that hatchery fish have not strayed in large numbers historically.

“2015, which is the parent year, the department did a fairly comprehensive look at straying hatchery fish in Kachemak Bay,” Hollowell says. “We found zero to about one percent hatchery fish outside the special harvest area.”

Hollowell adds that the 2015 run was also overwhelmingly comprised of wild fish.