Salmon began to evolve into the species around today about six million years ago. Salmon have been used as a food source for humans for thousands of years. Humans used large numbers of salmon as far back as 9,000 years ago. The early salmon runs were perhaps the most productive in the history of salmon. The Colombia River made netting, spearing, and trapping the fish pretty easy for the native people.

During the Ice Age, salmon took refuge in areas such as the southern Oregon coastline, the California coastline and the Queen Charlotte Islands of British Colombia. These areas were not covered in ice, or affected by unstable rivers. Salmon were most likely more abundant when the climate was cool and wet; and less abundant during warm, dry periods.

Salmon face many problems from humans. Logging around streams causes erosion, which can trigger topsoil to flow into the rivers and streams. This abundance of soil smothers salmon eggs, which are very fragile the first two days. Golf courses located close to salmon spawning grounds can pollute the water because of fertilizer and river water mixing and running back into the stream. Juvenile fish need to have quick-moving, cool water to help get them to the ocean. Hydroelectric dams can raise water temperature, slow down the water speed and the turbines kill many fish before they can even get downstream. Fish ladders were put in for the adult salmon to aid their return upstream, but only a few fish make it over the dam. Many streams are poisoned by nitrogen runoff, which is cattle waste. Herbicides, pesticides, and wastewater from washing cars all produce toxic runoff. Overfishing by both commercial and sport fisherman diminish the fish supply. Sewage that isn’t treated and runoff from paved roads that collects motor oil and other toxins also poison streams. Toxic and warm water, due to industrial activities, makes the water bad for salmon.

Robertson, Shaun. Lecture on Salmon. Conservation, Period 2: September 8, 1999.

Moulton, Coby and Jeff Neal. John Day Screen Shop Field Trip. October 5, 1999.

Some topics in this essay:
Colombia River, Native American, Native Americans, Opinion Based, Sockeye Coho, British Colombia, History Salmon, Status Seven, Robert Bell-Irving, Ice Age, field trip, endangered species list, ago salmon, colombia river, british colombia, john day, cattle waste, history salmon, fish salmon, golf courses, spawning grounds, salmon endangered species,