Ted salmon and dams

US Fish and Wildlife Wildlife biologist Ted Cook delivers a very unique perspective on dams and salmon.There's been increasing numbers of dam removals nationwide over the last 15 years, but one of the most famous dam removal situations, opportunities, needs is with a lower four Snake River dams in southeastern Washington state, where it flows into the Columbia River. And the reason, of course, is that salmon and steelhead upstream of those dams are slowly becoming extinct despite having some of the best quality headwater habitat. The reason for that slow extinction is manyfold. But perhaps the biggest source of mortality is for salmon going downstream and upstream through those four lower Snake River dams. Speaker1: What's the source of mortality? Speaker2: Well, what's interesting is perhaps the greatest source of mortality is for the young salmon migrating downstream in the springtime. The downstream migration is one of the biggest problems. And the reason is, baby salmon do not actually turn their heads downstream and swim to the ocean. They don't want to actually go downstream. What happens is they lose body condition and they become more buoyant, which means they can't stay on the bottom of a stream. So when the spring flood flows come, they get washed tail first to the ocean. historically. The problem is when you have a series of impoundments behind dams, you don't have the current to wash them to the ocean. And it takes weeks longer for a baby salmon to get through each dam. Speaker1: Which means they're vulnerable to so many mortality factors.

US Fish and wildlife biologist TED KOCH told me that baby salmon due to a loss of body condition become more buoyant as they are in freshwater streams. They are literally being washed, without swimming, downstream. And this is where they run into trouble.