Seward, Alaska - Biologists from both Lake Clark and Kenai Fjords National Parks have nearly completed their field season investigating silver (coho) salmon in the upper Resurrection River system.Resurrection Bay drainages produce one of the state's largest coho salmon sport fisheries, which is supported by a combination of hatchery-reared and wild stocks.Because wild Resurrection River coho salmon must migrate through this sport fishery, it is imperative to better understand the behavior of this coho salmon population.
In order to do this, biologists employed radio telemetry technology to track migration patterns and identify spawning locations of wild Resurrection River coho.Results from this multi-agency (National Park Service, Alaska Department of Fish and Game, United States Forest Service) cooperative study will provide the information necessary to implement an effective monitoring program for coho salmon in the Resurrection River watershed, as well as provide baseline information against any future changes in this stock.
For the past two months, the field crew from Lake Clark National Park could be seen seining through the low-flow eddies adjacent to swift glacial water of the Resurrection River just downstream from Exit Glacier.The crew leader, Andrew Kirby, noted his surprise in catching more fish than expected in what he describes as the "dynamic, glacial part of the system where you can't really see the fish."Despite these limitations, Andrew and the crew captured and tagged 90 adult coho salmon this season.While seining, they quickly removed captured fish, identified fish to species and then, if a coho, determined sex, measured length, and inserted a radio tag into its stomach.After tagging, the coho were released into the stream with the long, radio-tag antenna hanging from the corner of the fish's mouth.The crew monitored the movements of tagged fish using a combination of tracking stations located along the river corridor, hand held telemetry receivers, and the occasional aerial flight.Location data will be used to identify migration corridors and spawning areas throughout the drainage.
In addition, the crew collected fin clips from a subset of all salmon captured in the river.Samples will be analyzed by the Alaska Department of Fish and Game and will provide a baseline of genetic variation for the wild stock of salmon in the Resurrection River drainage.
This season has proven challenging and exciting for the field crew.From dealing with high flows and frigid water to catching fish and discovering where they spawn, every day provided a new adventure.The crew even found one of their telemetry tags onshore, most likely the remnant of a bear's dinner.Kirby smiles as he recollects this season, calling himself, "an opportunist in an unpredictable environment!"