While the nutrients in salmon carcasses can be the engine that drives the productivity of our river systems we need the physical and biological processes that cycle those nutrients into that system. Historically the carcasses fed the food cycle by decomposing after becoming trapped by log jams, root wads, and other complex channel factors and by animals dragging and "recycling" the carcasses in the ripparian areas.

Unfortunately we as a society have destroyed much of the complexity of our stream channels. The use of rip-rap etc have resulted in stable channels will little or no migration across the valley floor. The end result is essential a single channel. This has been compounded by increased flooding caused by excessive imprevious surfaces in the basin and denuding of the hill sides. The result is that in most systems I know the only place that carcasses are retained long enough in the stream channel to decompose are the small coho streams - this past winter is the first time in more than 20 years that I saw significant numbers of chum carcasses actually shedding flesh into the water and the fish actually eating it - that should be an annual event.

In addition we have so reduced the ripparian areas on most main stem streams that it is hard to imagine bears etc being much of a factor in draggng carcasses from the river.

Bottom line other than the small coho streams additional carcasses are likely to washed out to sea rather than becoming part of the freshwater food chain - they might be good for the crabs though. While placing carcasses in the stream is a feel good project unless we are at the same time working to restore the river processes that creates complex habitats the benefits will be limited.

POS -
While insects are very important here in the North Puget Sound region where there still are substantial numbers of chum and pink salmon they may be less critical than the annual bonanza of loose eggs in the fall and fry in the spring in driving the productivity of the system.

Tight lines
Smalma