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Issue Papers Overview Idaho's Anadromous Fish Stocks Their Status and Recovery Option Idaho Fish & Game Report to the Director 5/1/98

Overview

To better understand the two major hypotheses, Issue Papers were developed to respond to common questions about smolt transportation and normative river assumptions. We used the following logic to develop these questions:

If smolt transportation has compensated for the dams, then why aren't the fish runs recovering? If the lack of adults is due to ocean and estuary conditions, then why are similar downriver stocks surviving two to five times better than upriver stocks? Why did this discrepancy only become evident after the dams were completed?

If upriver stocks are performing worse than similar downriver stocks because they enter the estuary at a different time or go to a worse place in the ocean, then why does existing data indicate similar migration timing and ocean distribution among these upriver and downriver stocks? Why did this phenomena begin at the same time the dams were completed? Why is this phenomena less apparent for years when migration conditions (flow and spill) in the lower Snake and Columbia rivers are relatively good?

If upriver stocks are performing worse than similar downriver stocks because of poor genetics or elevated disease, then why have upriver stocks shown the ability to rebound when migration conditions are favorable? Why does genetic monitoring indicate genetic integrity is still strong? Why doesn't pathogen monitoring indicate significant differences in disease history, prevalence and infection level between these upriver and downriver stocks?

If dams are removed there will be sediment release? Will there be lethal levels of sediment? How long will the effects last?

IDAHO's ANADROMOUS FISH STOCKS:
Their Status and Recovery OptionsAppendix 3
Report to the Director Idaho Fish & Game 5/1/98