Wild Summer Run Steelhead, and Hatcheries
I think I have spoken before about why there are Summer Steelhead, if I haven't I will now. People know that there are Summer Steelhead, and that they are a very prolific game fish, aggressive, active, and spectacular fish, especially for us fly fishers on the west coast, but not many people know what created them and why they are there.
Summer Steelhead are usually (Ie about 90 plus percent of cases) found on rivers with barriers to migration that most other species of Salmonids can not surmount, or are reluctant to surmount in a time frame that will get them to Up River spawning grounds. This Barrier may be a Strong chute, a Falls, or a distance/cold barrier. Summer Steelhead are proflic migraters, not in their abilities neccessarily to migrate long distances (although they do migrate long distances, the Sustut, Thompson, and Chilcotin stocks are examples), but also more so in their ability to surmount rapids, cascades, fast water, and the like with their powerful, long, robust genetically tuned to their watershed bodies.
Steelhead are cold blooded animals. Thus their metabolism is dictated by the temperature of the water. In the Summer when the water temperatures are at their peak in warmth, Steelhead are at their peak in activity, both juveniles, and Adults. Adults, as we all know are very active at this time, and much more "fly chasing friendly." The Summer monthes also aid the Steelhead in their increased metabolism, and this their ability to challenge chutes of fast water, jump falls up to 4 metres high if neccessary, and migrate long distances in the case of Interior Summer run stocks such as the ones I mentioned earlier. This is why you don't see Winter run Steelhead that migrate far in the Skeena (Spring run fish migrate to about Terrace as far as they go from my knowledge), and it's the reason that the Thompson and Chilcotin stocks are Late Summer run stocks as if it was the winter their metabolism would be so low that they would be reluctant to migrate to their spawning grounds over 350 KM plus Up river through the Fraser Canyon and Thompson Terrors.
So now we understand the difference between Summer run and Winter run Steelhead habitat and what creates a Summer run of Steelhead. Now we have to look at the situation.
We all speak of the need to protect Wild Steelhead. Myself, being a member of the Steelhead Society of BC, am obviously all for it. But there is a case where I don't know if I can say that Wild Steelhead are an option. Rivers with Dams.
Take River A for example. Historically there was a significant falls on this river with a large amount of river habitat above. This Falls marked the barrier between Summer run and Winter run Steelhead historically. Now, there is a Dam put on this River and the Summer run Steelhead are forced to compete with Winter Steelhead which have strongly colonized this habitat below the barrier already. Now we have competition between two races of Steelhead in the same river, and from my understanding, most times the Winter Steelhead will dominate more often than not. So how do we keep this race of Summer run Steelhead alive?
IN the case of this River, the Summer Steelhead are still alive somewhat, but they are fairly hatchery dependant now. The Winter run Steelhead has taken up more residence in the Lower section of the River below the Dam, where as the Summer run has taken up residence in the River directly below the Dam for a few KM downward. However, me thinks that eventually, if hatchery enhancement is discontinued, that this Summer run race will eventually will probably end up spawning with Winter runs creating a Fall and Winter run, and then eventually a Winter run, or it will survive for a short time before the Winter run's outright outcompete the Summer runs.
So what are the options to keep the Summer run alive?