Copper River, Alaska- Summary of the Biology of Coastal Cutthroat Trout at the Northern Extent of Their Geographic Range

In the past15 years, the PNW Research Station and the Cordova Ranger District of the Chugach National Forest conducted four studies involving coastal cutthroat trout on the Copper River Delta (CRD) and in Prince William Sound (PWS), which is the northern distributional limit of these fish.  These studies considered spatial scales from the distributional range of coastal cutthroat trout to individual streams, and biological levels of organization from metapopulations to local populations. Populations from this area are genetically unique relative to populations from other parts of the distributional range. Populations in PWS are generally isolated from each other except for populations that are connected by areas of shallow water.  Hybridization with Oncorhynchus mykiss varied from more than 60% in a few populations to no hybridization in most populations.  A range of movement and life-history patterns were observed in populations on the CRD.  The rich levels of genetic diversity and life-histories are likely a result of the environmental diversity and complexity of the CRD and PWS and the unimpacted status of populations in these areas.