​For the last decade, Pacific Rivers has spear-headed juvenile steelhead surveys in Steamboat basin (Steamboat and Canton Creeks) of the North Umpqua River, which give us a snapshot of the abundance and distribution of the juvenile steelhead and help us understand how the fish are adapted to the basin. Recently, two new developments have made the surveys more valuable. 

One was the creation of Frank and Jeanne Moore Wild Steelhead Sanctuary, which includes all the Steamboat Basin except Canton Creek. Our surveys are providing a snapshot of how steelhead are using the sanctuary today. 

The other development is recent genetic work on the steelhead in the North Umpqua basin, concluding that all the steelhead in both Canton and Steamboat are summer steelhead. No other tributary of the North Umpqua has predominantly summer fish. 

Steelhead have two basic life-histories, winter steelhead and summer steelhead. Winter fish are the more prevalent. The rarer summer fish spend all summer in the river and tributaries. The North Umpqua has gained an international reputation for flyfishing for these summer run fish. Canton and Steamboat Creeks are the two most important tributaries in the North Umpqua supporting the summer steelhead. ​

​We have been doing the surveys in the sanctuary in Steamboat Creek for four years now (2019-2022). Unfortunately, in 2020 and 2021, we could not dive the whole basin because of wildfires. It is also very difficult to evaluate these surveys after only a couple of years of work.

​However, we have been surveying Canton Creek for 11 years with a number of partners: Phoenix school, Bureau of Land Management (BLM), and Cow Creek Tribe. For ten of the years the Phoenix School students participated in the dive counts. Each student crew was supervised by one of our experienced divers and their counts verified. The surveys are conducted by a team of at least two divers. One crew member is tallying the stream into​ habitat types: riffles, pools, and glides. We dive every fifth pool, eighth glide, and tenth riffle. When a habitat is snorkeled, we divide the steelhead into their three age groups: age-0, age-1, and age-2. Steelhead spend at least two years in the streams before they go to the ocean.

Student from the Phoenix School conduct in-stream counts of juvenile salmonids. Courtesy of Audrey Squires.

​Rather than provide figures presenting all of the survey results for the period, I will present a summary and highlight the major points of interest from the last four years. Let us start with a summary of age-0 steelhead from the Canton Creek over the last eleven years. Age-0 steelhead have ranged between 7,000 and 40,000 individuals annually (Table 1).  The eleven-year average is around 26,000 fish. In years when there are fewer fish, the center of their distribution is in Pass and Upper Canton Creeks. In years when they are abundant, their center of distribution is lower in the  basin in the main-stem of Canton Creek.

Now let us look at the results of the surveys for the last four years in Canton Creek (Table 2). Only one year in the last four were the age-0 steelhead over the average of 26,000 fish. In 2021, Upper Canton Creek could not be surveyed because it was closed due to wildfires. However, it is unlikely that the unsurveyed section would have raised the total to the average. In 2019, there were only 7,302 age-0 fish estimated to be in the basin. 

This is the lowest estimate for the entire 11 years of survey. In 2019, both the mainstem of Canton and Upper Canton had only 24% of the long-term average estimated number of fish, while Pass Creek had 40% of the long-term average estimated number of fish. This suggests that the age-0 fish in Pass Creek did better than other reaches of stream in the basin during 2019.

Figure 1. 

Why were the age-0 steelhead estimates so low in 2019? In April 2019, there was a storm which caused a peak flow of 18,000 cubic feet per second (cfs) (Figure 1). By contrast, most annual peak flows in the last decade have been less than half that, around 8,000 cfs. The 2019 storm flows scoured out steelhead redds (nests) and the eggs were destroyed. Remember, there were more age-0 steelhead in Pass Creek than in the other reaches.
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The second lowest year was 2022, which was also the second lowest year of the eleven years of the surveys. All reaches of Canton Creek were well below average. In fact, Pass Creek had only 30% of the long-term average -- lower than the other sections. Pass Creek did not buffer the fish during this event, but it did buffer them from the 2019 event.

​What caused these low numbers? Starting in early March, there was a series of nine storms which did not end until mid-June that raised flows to 1,000 to 4,000 cfs (Figure 2). These series of high flows scoured eggs out of redds and destroyed the juvenile salmon which were just emerging from the gravel.
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High flow events are not the only cause of low counts of age-0 steelhead. In two of the eleven years of surveys, summer droughts with high stream temperatures caused a great deal of mortality of juvenile steelhead in the mainstem of Canton Creek.

Now let us return to the four years of Steamboat surveys (Table 3). We would expect similar trends to those of Canton Creek. 

Figure 2. 

Many of the reaches, mainstem and tributary, where we were able to survey all four years, showed the same trends. Curiously, Cedar Creek, which we have surveyed three years, has had a similar number of age-0 steelhead in each of the three years. It will be very interesting to see how many age-0 fish are in it during the coming year.

​We will now move to age-1 steelhead, beginning with Canton Creek. The number of age-1 has ranged from 1,460 to 5,000, with an average of 2,700 fish (Table 2). Over the last four years, the estimated number of age-1 steelhead has been under the average in three of the four years. In 2022, it was twice the long-term average and the second highest estimate in the long-term survey. The lowest number of age-1 steelhead also did not occur in 2019. The peak flow event that devastated the age-0 steelhead did not appear to dramatically affect the age-1 steelhead. The series of nine storms in 2022 that devastated the age-0 fish appears to have benefited the age-1 fish. It ensured that the summer flows were high and there would be less likelihood of high summer stream temperatures. So, age-1 steelhead are affected quite differently than age-0 steelhead during the same year.

There is one more trend that is important to understand about steelhead. In the Western Cascade Mountains, the number of age-0 fish has almost no correlation to the number of age-1 steelhead we see in the next year. In other words, the number of age-0 steelhead in a year has virtually no effect on the number of age-1 steelhead observed the following year. The correlation that we see in Canton Creek from age-0 to age-1 is about 0.07. Zero means no relationship. One means a perfect relationship. This correlation is close to the no relationship, and typical for steelhead. Also, notice that the long term average number of age-0 steelhead is estimated to be 26,000 fish and the long-term estimated number of age-1 steelhead is 2,700 fish. That is a survival rate from age-0 to age 1 of slightly more than 10%. Turning now to Steamboat Creek, the trend in higher than average estimates for age-1 fish in 2022 appears to hold (Table 4). No other trends stand out. 
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Now we will turn to age-2 steelhead. Their range has been from 52 to 2,425 fish, and the long- term average number of fish is estimated to be 786 (Table 2).

​This is a survival rate from the long-term average age-1 steelhead of about 30%, much higher than that of the age-0 to age-1 steelhead. It was also the case that the number of age-1 steelhead observed the previous year does not correlate well with the number of age-2 fish that we see the following year. The correlation is 0.18, which is low. 

In the last four years, the age-2 steelhead in Canton Creek have had a greater than the long-term average estimated population in two years. One of those years was 2022, which had the highest estimate of all eleven years. The age-2 steelhead appeared to benefit greatly from the series of spring storms, like the age-1 fish. The lowest estimated number of age-2 steelhead occurred in 2021, the year when we could not dive Upper Canton because of wildfires, but it is unlikely there were a high number of age-2 steelhead in that reach. Turning to Steamboat Creek, the main stem counts were also very high in 2022, as we would expect (Table 5). No other trends stood out.

The surveys are limited to the steelhead that stay in the Steamboat basin, but we know that steelhead of all ages migrate out of Steamboat Creek down into the North Umpqua River. We have no idea what happens to those fish. So, the surveys are giving us information about the fish that stay in the basin, but that is not the whole story.

Even though these surveys do not provide the whole story about the summer steelhead in Steamboat Creek, they provide us with a snapshot of the abundance and distribution of juvenile steelhead of the juveniles rearing in Steamboat basin. Without this information we do not have any idea of the trends in juvenile summer steelhead estimates, how the fish are distributed in the basin, and how they are responding to natural and man-made events. These surveys are essential to understanding the trajectory of summer steelhead in the Steamboat basin.

In two of the last four years, high water in the spring has decimated age-0 steelhead, but that does not mean that these year classes will necessarily send a low number of steelhead juveniles to the ocean. The year class strength is usually determined by the survival of age-1 or age-2 steelhead. Also, the spring storms that decimated the age-0 steelhead were beneficial to the age-1 and age-2 steelhead, because it created higher than average streamflow in the summer which both provides more and better habitat and keeps stream temperatures lower during the summer months.

Student from the Phoenix School conduct in-stream counts of juvenile salmonids. Courtesy of Audrey Squires.