Warm water killing fish in Columbia River
Print Edition
MORE than a quarter million sockeye salmon returning from the ocean to spawn are either dead or dying in the Columbia River and its tributaries due to warming water temperatures.
US Federal and state fisheries biologists say the warm water is lethal for the cold-water species and is wiping out at least half of this year’s return of 500,000 fish.
“We had a really big migration of sockeye,” said Ritchie Graves of the National Oceanic and Atmospheric Administration. “The thing that really hurts is we’re going to lose a majority of those fish.”
He said up to 80 percent of the population could ultimately perish.
Elsewhere in the region, state fisheries biologists in Oregon say more than 100 spring chinook died earlier this month in the Middle Fork of the John Day River when water temperatures hit around 23 degrees Celsius.
Oregon and Washington state have both enacted sport fishing closures due to warm water, and sturgeon fishing in the Columbia River upstream of Bonneville Dam has been halted after some of the large, bottom dwelling fish started turning up dead.
Efforts by management teams to cool flows below 21 degrees by releasing cold water from selected reservoirs are continuing in an attempt to prevent similar fish kills among chinook salmon and steelhead, which migrate later in the summer from the Pacific Ocean.
The fish become stressed at temperatures above 20 degrees and stop migrating at 23 degrees. Much of the basin is at or over 71 degrees due to a combination that experts attribute to drought and record heat in June.
Thirteen species of salmon and steelhead are endangered or threatened in the Columbia River basin.
Don Campton of the US Fish and Wildlife Service said fish are more susceptible to pathogens in warmer water.
- About Us
- |
- Terms of Use
- |
-
RSS - |
- Privacy Policy
- |
- Contact Us
- |
- Shanghai Call Center: 962288
- |
- Tip-off hotline: 52920043
- 沪ICP证：沪ICP备05050403号-1
- |
- 互联网新闻信息服务许可证：31120180004
- |
- 网络视听许可证：0909346
- |
- 广播电视节目制作许可证：沪字第354号
- |
- 增值电信业务经营许可证：沪B2-20120012
Copyright © 1999- Shanghai Daily. All rights reserved.Preferably viewed with Internet Explorer 8 or newer browsers.
