Do We Need to Manage for Iteroparity in Steelhead Trout?
Steelhead trout iteroparity (repeat spawning) can be highly variable across populations, seasonal races, maturational strategies (stream vs. ocean-maturation), and annually. In the Columbia River basin, many populations of wild inland stream-maturing steelhead are listed as threatened or endangered (e.g., Snake River Basin). Increasing the survival of kelts from natural or hatchery populations has been viewed as a potential tool for improving genetic diversity and population viability especially among wild stocks. For example, artificial reconditioning of wild kelts in hatcheries has been successfully used to increase the number of natural spawners in the Yakama River Basin. In the Snake River, assessment of the physiological and energetic constraints of natural emigrating kelts has been used to inform managers of actions to improve post spawning survival and successful downstream migration in the Federal Columbia River Power System, especially through increased spill. However, historical records of iteroparity in the Columbia and Snake Rivers are poor and existing data indicate that repeat-spawning in inland stream-maturing steelhead is low. This begs the question, how much effort should be devoted to enhancing and/or managing for iteroparity in populations where repeat-spawning may have always been low? The focus of this presentation is to review current activities and questions related to kelt management in Columbia River inland stream-maturing steelhead.
Penney, Z. 2016. Do we need to manage for iteroparity in steelhead trout? Pacific Coast Steelhead Management Meeting, Pacific Grove, CA, March 2016.