By Lindsay Phillips and Pete Rand
The Prince William Sound Science Center has recently started field sampling for the 2018 season of the Alaska Hatchery Research Project for the Alaska Department of Fish and Game. Two weeks ago, ecologist Pete Rand and UAF graduate student Julia McMahon held a training at the Cordova Center where seven crew members learned sampling protocols, which they later practiced in Hartney Creek. They also had CPR, first aid, and firearms training as well as lessons in bear and small boat safety. This year’s team is full of new energy, with one of the nine crew members returning from last season. In the upcoming weeks, two vessel-based crews and one camping crew will work every day collecting pink salmon samples in five different streams in Prince William Sound. If past years are any indication, the number of pink salmon sampled by hand could exceed 50,000 fish.
Tasks for these crews include: counting live and dead salmon by species, collecting spawned out fish, measuring fish lengths, collecting heart tissue for DNA samples, and collecting the fish otoliths (ear bones). The DNA and otolith samples are preserved in deep-well trays, and data is transmitted over the internet every day to the Prince William Sound Science Center.
The otoliths are used to determine whether the fish are natural or hatchery-origin salmon. When viewed under a microscope, salmon otoliths have rings that record changes in water temperature. Hatcheries manipulate the water temperature they hold the fish in, marking the fish otoliths with a unique sequence, like a barcode. Each hatchery in Prince William Sound marks fish ear bones with a distinct pattern, allowing a technician reviewing samples to determine the hatchery of origin. Wild salmon otoliths have variable patterns and will not display the same sequence as a hatchery fish.
The Hatchery-Wild Salmon Research Project will provide valuable information and new insights into an industry that is considered vital to Alaska’s economy. For more program details, click here and here and follow Auklet Charter Services and Prince William Sound Science Center on Facebook for in-the-field updates.
*Photo credit to David Janka / Auklet Charter Services