Salmon Shortage Threatens Grizzly Bear Populations

By: ​Lauren Clegg

Summary: ​There has been a drastic salmon shortage this season leading to extreme weight loss for many grizzly bears. This is an issue in the British Columbia area of Canada and in Alaska. This year is said to be the worst salmon season in over fifty years. One reason for the lack of salmon is climate change, which increased water temperatures to levels that made the water uninhabitable for salmon. Alaska had a heat wave this past summer where water temperatures reached eighty-one degrees, causing the salmon to die due to heat stress. Another reason the salmon population is so low is due to open-net fish farms. This type of fish farming can spread diseases and pollute the water, which can potentially kill salmon. This lack of salmon is forcing grizzly bears to travel great distances for their food. Bears now have to spend a lot of their energy swimming or walking to these new areas in hopes of finding something to eat. This constant travel makes the bears lose more weight which does not help their situation. Although the situation may seem dire for the bears, people are trying to help. A guardian watchman for the Mamalilkulla First Nation arranged a salmon drop along shorelines where grizzlies frequent. The drop was successful, but the group has only done one drop of five hundred fish, which is not nearly enough to help all bears gain enough weight for their winter hibernation. Its predicted that many grizzlies will not live through the winter due to how thin they are. There is also a fear that if female grizzlies hibernate leaner than usual their lack of body fat will affect how many cubs they can have. Also, if the female grizzly has cubs while she is underweight, the cubs could have serious health issues or die shortly after birth. The death of a great deal of grizzlies this winter might bump grizzlies from the threatened species list to the endangered species list. This is concerning to think about because if we eventually lose enough grizzly bears it could disrupt ecosystems and cause chain reactions which could greatly alter many plant and animal lives. 

Why we should care? The misfortune of the bears and the lack of salmon were caused by global warming, which is something we should all care about. The impact on ecosystems due to a lack of salmon is also concerning.

Credit: Rolf Hicker

Example News Article:
https://www.cnn.com/2019/10/03/americas/emaciated-grizzly-bears-knights-inlet-canada-trnd-scn/index.html

​I found this article interesting because it’s a topic that is not talked about much on the news, so it’s sad to see that this is happening. I’m glad people are trying to help by doing the salmon drop, but it’s heartbreaking to know that a lot of grizzlies will not live through the winter. I also was unaware that salmon die of high heats, which I found interesting. This article shows real time destruction caused by climate change which I found interesting sense most articles I’ve seen about climate change talk about potential effects of climate change or ways to prevent it. ​

Science in Action.
Dr. David Huff is NOAA Fisheries, Estuaries and Ocean Ecology Program Manager in the Fish Ecology Division.

Dr. Huff and his team work toward understanding the migratory behavior of fish as well as ecosystem processes that affect the fish growth and survival rates. In this particular study Dr. Huff and his team studied fish up the cost from Oregon to Washington. Instead of the expected fish breeds like salmon and plankton the team found mackerel and pacific pompano which are both warm water fish. The mackerel fish is also a predator of young salmon. I think Dr. Huff and his team’s research is important to understanding the lack of salmon this season. Their findings of warm water fish help us understand why there may not be as many salmon as usual. Their research shows that salmon could be dying not only from high water temperature, but new predators as well.