The Columbia Riverkeeper conservation group recorded a video on a day when water temperatures reached 21 degrees Celsius, a level that can be lethal to fish if they are exposed for extended periods, according to Guardian on July 27.
The group believes that the salmon in the video may be injured due to stress and high temperatures.
In the video, the salmon are seen covered in cloudy white patches, which could indicate a fungal disease that occurs when salmon are stressed due to warm water. (Photo: Columbia Riverkeeper).
According to Brett VandenHeuvel, the executive director of Columbia Riverkeeper, the salmon are migrating to the Little White Salmon River, a tributary of the Columbia River where the video was recorded, primarily to escape the heat.
He compared the situation of the migrating salmon to a person trying to run a marathon in temperatures exceeding 38 degrees Celsius.
The salmon in the video will likely be unable to spawn in the tributary and are expected to die from disease and thermal stress.
A dead salmon due to high water temperatures. (Photo: Columbia Riverkeeper).
This is one of the devastating scenes resulting from the recent heatwave in the Pacific Northwest and Canada. The heatwave has caused hundreds of deaths, potentially wiped out over 1 billion marine animals, and contributed to wildfires throughout the region.
VandenHeuvel stated that it is still too early to determine exactly how many salmon have died due to the warm water. However, there are still tens of thousands in the Columbia and Lower Snake Rivers, and as these rivers are expected to become increasingly warmer over the next two months, many salmon are likely to perish.
