Yesterday was the 31st annual Deschutes fisheries workshop. I can’t recall exactly when I started attending these but I think I’ve been to about half of them. I’ll post again when the presentations are made available online, but here’s a summary. The headline is that, once again, real science shows that the Lower Deschutes is in fine shape. Anadromous fish reintroduction has not been a success but it is not negatively impacting the lower river.

If you have been reading this blog for a while you know that for decades ODFW has been annually sampling trout in the Lower Deschutes to monitor abundance and condition factors (visual markers of health like length and weight). Once again, trout in the Lower D are in great shape with no change in status from prior years, including prior to the operation of the Selective Water Withdrawal tower in Lake Billy Chinook. There is no evidence that the SWW is negatively impacting resident fish. Don’t be fooled, pH is not a problem for Deschutes redbands.

Yes, some fish have black spot disease, but it’s not really a disease and it does not impact on fish health. Yes, some bass seasonally move into the lowermost sections of the Deschutes from the Columbia River where they are abundant, but there is no evidence they spawning in the Lower D and they move out in the fall.

There is also little change in the status of anadromous fish from recent years. Fall chinook continue to do very well. Steelhead continue to be in a general downward trend, consistent with the entire Columbia River Basin. Spring chinook returns remain critically low. See here for more on steelhead returns.

One of the benefits of attending the workshop is the ability to speak to presenters and scientists during breaks and at the social hour at the end of the day. I asked why fall chinook are doing so well while spring chinook and steelhead are not. The consensus is that it has to do with when and where they spawn (spatial and temporal differences to use biologist speak). Steelhead and spring chinook in the Deschutes are tributary spawners while fall chinook are mainstem spawners. The mainstem is easy to access, provides ample spawning habitat, and has consistent high quality flows. The same cannot be said of tributaries. Dams, urbanization, agriculture, and global warming are to blame.

There were a variety of other presentations I found interesting on topics like water quality (which remains fine), habitat restoration efforts, smolt outmigration, strays, a genetic study, etc., but I was particularly interested in the presentation of an ongoing study of the parasite c. shasta in the Lower Deschutes being conducted by scientists from Oregon State University and ODFW. As I wrote about here, the tin foil hat crowd, also known as the Deschutes River Alliance, recently sounded the alarm that this study showed that c. shasta is a significant lethal threat to salmonids in the Lower D. This is overly alarmist and not supported by the research.

The presentation and a subsequent lengthy discussion with one of the scientists was illuminating. C. shasta is a natural presence in many Oregon rivers. Concentrations in the Lower D vary by location and over time. There is a natural cycle of higher and lower concentrations based on their complex life cycle. They are also impacted by natural events like high water flows which can flush the parasite down river.

While there have been samples in some places at some times that contained c. shasta in concentrations high enough to potentially infect some outmigrating smolts, it has not been shown to be a significant factor. Further, as one the presenters told me, there is no evidence that the operation of the SWW plays a significant role in the presence of c. shasta.

For many years, essentially for as long as the DRA has been releasing reports, I have heard the same comment from numerous scientists in response to claims from the DRA. In short, they “twist” the science to erroneously make it appear to support their preconceived and prefered conclusions. I heard the same thing yesterday and all the scientists could say is that it is extremely “frustrating”. They are much more polite than I need to be. Bottom-line: the Deschutes River Alliance are spreaders of disinformation.