Question for Smalma

[duchunter]

Curt,

I grew up at Warm Beach and as a kid I spent many a day playing on the tide flats at the mouth of the Stilly.
With the huge slide on the North Fork I was wondering your thoughts on several thing:
All of this silt coming down into Port Susan Bay, do you think this will have an impact of any kind on the crabbing there?
The last slide in '06 made the tide flats very soft and you could hardly walk out there to wade for Crabs.
The other thing I was wondering about is what % of salmon go up the 2 forks as well as Steelhead?
I was thinking it might be a 50/50 split between the North and South forks for both Salmon and Steelies.
Thanks for all of your in put as I enjoy reading all of your information.

Duc

[Smalma]

Duc -
A couple good questions.

Yes the recent slide it add a lot of sediment to Port Susan over the next decade or so. Much like the Deer Creek slides in early 1980s eventually much of the material that enter the river ends up in the Bay. As I'm sure you have noticed both Port Susan and South Skagit bay are filling with sediment. This is a natural process that has been greatly accelerated by man's actives upstream in the basin. Much of the material that came down in this recent event is relatively small material and will mover quickly downstream and settle in the Bay. While you may not see too much over the next 6 months or so (other than turbid water conditions) the higher flows this fall and coming winter will move a lot of material. As you noticed much of the material will be fine soupy muds and people wading in the bay or the river need to be mindful on that condition as it can be both slippery and dangerous (quicksand like).

For fish like steelhead and Chinook it is probable that something like 85% of the basin's population use the north fork. For coho it would be closer to 50/50 while for pinks and Chums more use the North Fork than the South fork. The North Fork downstream of Deer Creek just the last few years was recovering from the Deer Creek slides in the early 1980s. Even down into the lower North Fork above and into the "Canyon" was being used by increasing numbers of Chinook and steelhead and this past fall there were tremendous numbers of pinks spawning in the lower North Fork (there may have been more pinks this past fall that the previous 30 years combined. For steelhead and Chinook the core production zone for those species will be limited to the area from C-post bridge to and including Squire Creek with the 4 miles around Hazel being the most important.

This latest slide drives home point how "iffy" the habitat conditions of our rivers have become for the anadromous species that use them. Not only have the over all capacity of them to produce fish has been greatly reduced the associated lower productivity means that its a population much longer to recover from a disaster. In more intact system population may have recovered in a fish generation or two but in these degraded system that recover time has been extended to 3 to 10 or more generations. That makes a depleted population becomes more likely to experience another damaging events before recovering from previous one. This not keeps the populations depressed by dramatically increases the risk of extinction.

Curt

[duchunter]

Curt,

Thanks for the reply and lets hope the Stilly recover's sooner that later!!

[onwhiskeycreek]

I was talking to Niel from the US Fish And Wildlife at the watershed meeting in Juneau about some of the long term effects on our watershed from from logging. The Harris has been the focus of numerous studies as it was one of the first watersheds in SE that was heavily logged in the 1950s. One of the long term effects on fish populations was from a change in gravel sizes. Different gravel sizes favor different species. The smaller gravel sizes here favored pinks over coho.

Gary

[Smalma]

onwhiskeycreek -
Great point that is rarely discussed. We see the same thing here in the Puget Sound rivers. Historically the Chinook and pinks partitioned the spawning habitat in our rivers. The Chinook tended to use areas of larger gravel (often 4 to 8 inches in diameter) and heavier currents (often in the main current thread) while the pinks were found more on the edges in smaller gravel (fist size and smaller) and lighter flows.

Between the combination of habitat changes caused by land use practices and the shrink size of our Chinook (driven in at least part by ocean fisheries on immature fish) the pinks and Chinook are forced to spawn in much of the same areas. Here in Puget Sound for most Chinook stocks there is a significant overlap in spawn timing. It is come to see a female Chinook start constructing her redd and almost immediately she will swamped to a horde of pinks who seem to be attracted to the freshly disturbed gravel.

That competition between Chinook and pinks continue at several levels which typically results in lower fewer Chinook.

The real bottom line is that river systems are complex ecosystems and anything that alters that system results in complex changes and impacts to the fish communities using those systems.

Curt