Salmon or Steelhead?

I walked this afternoon on Alameda Creek. A strong cold wind was blowing from the Northwest, so generally up the creek. Alameda Creek, like many waterways in California, is heavily managed. There are a number of inflatable dams where the creek flows through Niles to divert water into nearby quarry ponds and to thereby recharge the water table. This time of year there is usually a lot of water backed up behind a dam where the creek flows under the BART tracks and only a trickle below the dam. Later the stream below the dam will dry up completely.

Because of, I imagine, the cold upstream wind, the creek was unusually clear this afternoon. As I was admiring this clarity, I began to notice forms moving in the stream. Large forms. Fish, in fact. Quite a number of them , in fact. I counted one congregation to be more than thirty, but most were swimming along in columns of four or five, so all in all there were probably more than a hundred. I was quite astonished. I have seen one or two large fish, floundering in the margins of the creek before, but never this many.

As far as I could tell this was the end of the line for these fish. Since they were mature fish I am assuming they were attempting to swim upstream. There was no way they could cross the dam in its inflated state. I don't know whether they were salmon or steelhead. From my experience, they resembled salmon quite a lot, but I have no point of reference for steelhead. Whatever they were, would that there were more of them.

- J