The Silver Lining in the Dark Cloud

Environment

Sep 01, 2010  2

Of course no one wants or likes power outages. However there was one good thing that happened as a result of an outage on August 18th. It allowed us to find a new tool to help the Yukon River Chinook salmon reach their spawning grounds upstream from the Whitehorse Rapids fishladder. 

During the outage, we first had to increase the amount of water we allowed through the spillway of our Whitehorse dam so that our reservoir, Schwatka Lake, would not overflow. Then we slowed the flow so that the lake could re-fill. The extra water seemed to push the salmon closer to the entrance of the ladder. Then when the water flow was cut back the fish seemed to be enticed by the water flowing in the ladder. More than 100 salmon swam up the ladder in the few hours after the power outage. 

We had never seen anything like this before. Working with fishladder and fish hatchery staff, we simulated these conditions four times over the last two weeks (minus the outage of course). Each time there was a similar response from the salmon.

The faster the salmon can move through the fishladder and get to their spawning grounds the better it is for their health, so we hope to be able to use this tool in future years as a way of helping the fish on their migration. However we can't guarantee that we'll be able to do this every year; it will depend on summer water levels.

2 comments

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Comments

by Me

You know what would be even better for the fish?  No ladder at all!

09.02.2010

by Yukon Energy

The fishladder is in place to help the fish get around the Whitehorse dam. Without it, the fish would swim into the turbines and die. Without the hydro dam, we would be burning hundreds of thousands of litres of diesel, which is not desirable for obvious environmental reasons. As with many things, this is all about balance, and trying to find the best solution possible given the circumstances. We invite you to visit our website at http://yukonenergy.ca/services/facilities/fishway/ to learn more about the ladder.

09.03.2010