Workshop 8
Interactive Activity
This activity requires Shockwave.
Introduction
The following
activity presents GIS map data that you can manipulate in order
to better understand the forces acting on the Columbia River basin.
We'll be looking
at the Columbia River basin, an area that includes the Columbia
River and its branches. Dams on rivers in the basin have taken
a toll on the salmon population. As young salmon, born wild or
in fisheries upriver, make their way out to sea, they run the
very real risk of being killed in the spinning blades of the turbines
generating hydroelectricity. As adults returning to spawn, the
dam presents an insurmountable barrier in their journey upriver.
One of the
dams in the Columbia basin is the Bonneville dam. At 77 feet high,
it would be an impossible barrier for migrating salmon if it weren't
for two critical features.
The first
feature is rotating screens in front of the turbines. The screens
deflect the young salmon up and away from the spinning blades.
The second feature is fish ladders located on the sides of dams.
The ladders guide the young salmon down the sides of the dam and
help adults gradually make their way up and around the concrete
barriers.
At the Bonneville
dam, returning adult salmon making their way up the fish ladder
pass a glass window, behind which sits biologists who count each
mature steelhead, Chinook and sockeye in order to monitor the
salmon population.
Click BEGIN
to explore the Columbia basin and the effects of dams on the salmon
population using GIS.
