Experimental Designs for Testing Differences in Survival Among Salmonid Populations.

The Yakima Fisheries Project (YFP) is a supplementation plan for enhancing salmon runs in the Yakima River basin. It is presumed that inadequate spawning and rearing habitat are limiting factors to population abundance of spring chinook salmon (Oncorhynchus tshawyacha). Therefore, the supplementation effort for spring chinook salmon is focused on introducing hatchery-raised smolts into the basin to compensate for the lack of spawning habitat. However, based on empirical evidence in the Yakima basin, hatchery-reared salmon have survived poorly compared to wild salmon. Therefore, the YFP has proposed to alter the optimal conventional treatment (OCT), which is the state-of-the-art hatchery rearing method, to a new innovative treatment (NIT). The NIT is intended to produce hatchery fish that mimic wild fish and thereby to enhance their survival over that of OCT fish. A limited application of the NIT (LNIT) has also been proposed to reduce the cost of applying the new treatment, yet retain the benefits of increased survival. This research was conducted to test whether the uncertainty using the experimental design was within the limits specified by the Planning Status Report (PSR)