Coho salmon is the first species featured in the endangered species spotlight. This spotlight series will focus on the factors responsible for the decline of key species that have become endangered and simple ways that we can help the recovery of these species. Coho salmon (Oncorhynchus kisutch) existed historically in the entire west coast of the United States, Alaska, Japan, regions of eastern Russia and possibly as far inland in the U.S. as Idaho. Current levels of the Coho salmon are only 6-15% percent of what they were in the 1940s, according to the U.S. Fish and Wildlife Service.
Why are they endangered?
Some of the biggest obstacles for this species include dams, erosion and siltation in breeding areas of freshwater streams/rivers, lack of water due to the diversion of freshwater for irrigation and electricity generation purposes and a rapid decline in the quality and quantity of wetlands in areas where Coho salmon exist and breed. This salmon species is particularly sensitive to stream quality issues in their fry stage. Dissolved oxygen is very important for their survival and may be affected by human activities such as recreation, mining, logging, channelization of steams and other changes in the banks of streams. Human activities have had a pronounced effect on Coho salmon habitat in the state of California, where only about 9% of the original wetlands in the state still exist!
WE NEED OXYGEN!
Dams and erosion into streams/rivers cause increases in water temperatures, which lessen the amount of dissolved oxygen for salmon necessary for breathing. Dams also pose a physical obstacle for Coho salmon that are trying to reach spawning destinations upstream in coastal rivers. Irrigation systems take water from rivers such as the Russian River in Sonoma County, California, and divert it to agricultural use such as growing grapes for wine. Many agricultural areas that are close to such rivers containing Coho salmon and other species contribute to pollution in the water from fertilizers (particularly nitrates and phosphates) and pesticides. Storm water drains in urban areas that drain in to rivers where Coho salmon live and breed may also create pollution from runoff and products thrown into storm drains near residential areas. These fish must have good gravel beds to lay their eggs in or their offspring will not survive!
What YOU can do to help
There are many small things that we can all do to help the recovery of endangered Coho salmon and other endangered species.
-Do not throw trash or any liquids (other than water) onto the street or in storm drains. These drains go directly into streams and rivers that effect fish and other river dwellers.
-Buy dry farmed wine and sustainably farmed produce. One of the biggest users of water in our country is agriculture. Wine grapes and other crops that are dry farmed use no water and thus do not take water away from local streams or rivers.
-Follow fishing regulations. If you are fishing, do not take more fish than is allowed by the law.
-Do not buy farmed salmon. In some areas, farmed salmon populations threaten wild populations of salmon. The best way to find out is know your salmon source.
-Volunteer in environmental restoration activities. There are many local and national organizations that restore habitat to help endangered species recover. The Nature Conservancy does great work in restoration. Google your local watershed and find out what group is actively restoring the watershed.
If we all take these small steps in caring for our natural world, species such as Coho salmon may soon be as plentiful as they were 70 years ago!!! Check out this great video on Coho salmon in West Marin!