As Clark County’s human population has boomed, its fish population has plummeted. The relatively high numbers of returning salmon in recent years, while encouraging, should not be misinterpreted as a sign that everything is fine. Fish populations in our region have always fluctuated, but the overall trend continues downward. While natural phenomena such as flooding, predators, and ocean currents affect salmon populations, human activity poses by far the greatest threat to salmon survival. The effects of human activity on fish populations have been many decades in the making and will take many decades to remedy. The four main areas of human activity that threaten salmon are known as the four H's:
- Harvest: Commercial and sports fishing directly reduce fish populations.
- Hatcheries: Artificial production facilities produce domesticated fish that threaten the ability of wild fish to survive when they interbreed with the wild fish.
- Hydropower: Dams block salmon migration up and down rivers and inundate fish habitat.
- Habitat: Streams, rivers, estuaries, marine waters, and surrounding flood plains are being steadily degraded by human activities that increase soil erosion, reduce the amount of woody debris in streams, raise the water temperature, add contaminants to the water, decrease water flow, and create barriers to fish passage. Diminishing habitat and loss of habitat complexity increases vulnerability to predators.
The first three are the focus of state and federal activities. The last H-habitat-falls under the jurisdiction of Clark County and is a local problem we can work on together.
For more information about salmon recovery in Clark County or for information on getting involved, contact the Clark County Endangered Species Program at (360) 397-2121.