Shrinking glaciers threaten B.C. salmon

The viability of B.C.'s salmon streams could be threatened by glacial melting caused by global warming, says one expert.

Many glaciers in B.C are losing ground every year because of climate change and that reduces the amount of cold water going into mountain streams and rivers during hot summer months, University of British Columbia geography professor Dan Moore told CBC News on Friday.

"In the coast mountains of B.C., I think many of the smaller glaciers will disappear or may become very, very small over the next few decades," Moore said.

If the retreating glaciers continue to shrink or disappear at the current rate, the river waters won't be cold enough for salmon in the summer, he said.
 
"Glaciers provide a nice buffering effect. When we get the nice hot weather, it increases the glacier melt and keeps the flows high and the streams cool," he said.

If the rivers are not cool enough, salmon are not able to spawn and survive, Moore said.

Moore and his colleagues are now analyzing all B.C. watersheds that are fed by glaciers.

"I did some rough estimates for Place Glacier [near Pemberton] and my estimates were that even if the climate doesn't get any warmer, that if the conditions of the last 20 years prevails into the future, the glacier will shrink to half it present size," he said.

The modeling shows with present trends for the Place Glacier, the flow rate into streams will be reduced substantially and the water temperatures in those streams will rise significantly, Moore said.