Studies suggest that most of the problems salmon face are downstream, far away from creeks in the forested mountains. In fact, the ebb and flow of salmon populations are nearly identical in both logged and- unlogged forests (see graph). Downstream is also where most of the solutions lie. Fish biologists make several recommendations for salmon recovery in both coastal and inland areas:
Spring chinook salmon trends are nearly identical for streams in wilderness forests and those in logged, managed forests.
From Idaho Department of Fish and Game salmon stream redd count.
Hydropower facilities must improve technologies to reduce the impacts of their operations
Most on/off electrical switches in homes and businesses indirectly impact salmon. Inland hydroelectric facilities that provide this necessary electricity present a hazard of monumental proportions for salmonids, a term that generally refers to salmon, trout, chars, and whitefish. On the Columbia and Snake Rivers, for example, many major dams impede the route to and from the spawning areas. When migrating downstream, juvenile fish that pass through the dams may be injured or killed by the turbines. They may be temporarily stunned or disoriented and fall victim to predators. Studies show that 10 to 30 percent of the juvenile salmonids passing through the turbines of every Columbia River Basin dam are killed.
Reservoirs that store water for hydroelectricity, provide flood control, and collect irrigation water for fertile fields also impact fish migration. The results can be disastrous for fish that are undergoing smoltification and must reach the ocean at the same time their bodies need salt water to survive. The warm water in the reservoirs can also increase susceptibility to disease. The upstream return is hazardous as well, even though some safety measures are being employed. Fish ladders have been only partially successful in providing stairways around the dams. It is estimated that about 10-percent of the salmon die at each dam while migrating upstream past the 13 dams on the Columbia and Snake Rivers.
Fishing activities must be restricted to prevent the accidental catching of wild salmon
About 85 percent of salmon caught by commercial, tribal, and sport enterprises are hatchery reared. However, hooks and nets do not discriminate between scarce wild stocks and more plentiful hatchery fish. Generally, wild stocks should not be reduced at rates that exceed their ability to reproduce. But actual ocean and river harvests for both wild chinook and coho salmon have exceeded those rates, primarily due to commercial fishing. And indirect mortality of fish injured by commercial gill nets ranges from 12 to 30 percent. By law, sport fishermen must release inadvertently caught wild salmon, yet estimates show that about 10 percent of those die later of stress or hook-related injuries. The very fish we want to protect may be taken by fishing.
The agriculture industry must implement additional practices that protect streams, provide fish-screening devices at water diversions, conserve water usage,, and protect riparian areas.
Agriculture, like forestry, is a land-intensive industry. The agriculture industry has implemented many protective practices, but more can be done. Land that is improperly cultivated, overgrazed, or misused can erode into sediment that smothers fish eggs or otherwise affects salmon. Unscreened irrigation diversions can cause significant salmon losses by directing fish into fields. Diverting water to crop-producing fields can also cause streams to dry up before salmon hatch, grow into fingerlings, and move to larger waterways. Return flows from irrigated fields may be too warm or contain elevated levels of chemicals that can degrade water quality.
Predation by freshwater fish must be controlled, and the numbers of seals and sea lions must be managed.
The warmer water within the dam-created reservoirs provides excellent habitat for fish that eat salmon. Squawfish, walleye, channel catfish, and smallmouth bass all thrive in reservoir conditions and prey on salmon smolts. Squawfish, in particular, linger in reservoirs and aggressively feed on juvenile salmon. Predation by fish accounts for as much as 10 to 20 percent of all salmon mortality.
Coastal seals and sea lions, both species protected by the Marine Mammal Protection Act, have dramatically increased in numbers. Between Netarts Bay in Oregon and Grays Harbor in Washington, the number of seals has increased from 6,500 to 10,000 since 1980. The sea lion population along the Oregon coast has also grown in that time, from about 400 to 3 ‘000.8
This population of seals and sea lions consumes a total of 2.7 million pounds of salmon per year. (By comparison, the Oregon troll fishing industry landed about 2.8 million pounds of salmon in 1990.) Salmon injuries by seals and sea lions increased from 0.4 percent to 19 percent in the 1980’s, nearly a 50-fold increase. 10 Most of these salmon later die or become easy prey for other fish.
Estuary habitat must be restored and enhanced.
Estuaries are areas where rivers meet the sea. They are important sources of food supply, resting places, and nursery habitat for salmon. They also provide gradual transition areas from fresh to salt water. Studies show an estuary loss of about 40 percent and a flood plain loss of about 50 percent in the lower Columbia River area.”
Loss of estuary habitat to development near the mouths of Oregon and Washington rivers has created additional complications for the salmon.
The resulting reduction of habitat and food may cause juvenile salmon to spend less than one week in estuaries such as the Columbia’s, instead of the former three- to four-week residency. Consequently, outmigrating salmon may move into the ocean before they are physically able to escape predators or before the smoltification process is complete, increasing the likelihood of premature mortality. Seals and sea lions, both protected species, have dramatically increased in population and take many salmon along the Pacific Northwest coast. Idaho’s public forests provide vast areas of suitable upstream spawning habitat ready for salmon to return. Idaho has more than 4,000 miles of spawning and rearing habitat for salmon and steelhead. About 44 percent of that habitat is rated as good to excellent. Ratings below those standards are primarily due to natural features rather than habitat degradation. Much of the habitat less suitable for salmon serves well for steelhead production. From Strategies of Recovery of Snake River Salmon, State of Idaho, November 1980
Municipalities must reduce water usage, control sewage, and minimize water pollution, and the public must show more care when using the waterways and forests.
Municipalities and recreational users of forests and waterways have direct and indirect effects on salmon and their habitat. Municipalities may discharge partially treated sewage, chlorinated drinking water, or overflow from city storm drains into rivers. Such pollution can weaken fish, making them more susceptible to disease or predation. Also, county and state roads with inadequate stream crossings may block salmon passage. Activities such as power-boating, sailing, and water-skiing potentially damage sensitive fish passages and spawning grounds. Off-road vehicles may damage vegetation, causing increased soil runoff into streams. This may result in decreased salmon numbers.
The mining industry must take steps to avoid disturbing water habitat and altering water characteristics.
Mining and gravel extraction activities may affect salmon or their habitat. Direct effects include physically disturbing both eggs within the redds and adult salmon. Indirect effects may include adverse changes in temperature, turbidity, sedimentation, and chemical pollution of the water.