Fraser River. FISH SURVEY AND MANAGEMENT INFORMATION Jon Ewert - Aquatic Biologist (Hot Sulphur Springs)

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1 Fraser River FISH SURVEY AND MANAGEMENT INFORMATION Jon Ewert - Aquatic Biologist (Hot Sulphur Springs) General Information: The Fraser River is a highly diverse river offering many transitions in habitat type through the course of its length. Public access is somewhat limited in some sections and care should be taken to avoid trespass problems. Please consult with local agencies regarding access locations. Guided fishing is available on some privately held reaches. Location: Eastern Grand County towns of Winter Park, Fraser, and Granby. Recreational Management: US Forest Service, towns of Winter Park, Fraser and Granby, and BLM. Amenities and General Info. The Fraser River flows through multiple towns which offer general amenities in close proximity to the river. Guide services available through several area outfitters. Regulations Fraser River - Grand County a. From the headwaters downstream to the confluence with St. Louis Creek: 1. Fishing is by artificial flies and lures only. 2. All rainbow trout must be returned to the water immediately upon catch. b. From the confluence with St. Louis Creek downstream to the Colorado River: 1. The bag and possession limit for trout is two fish. Previous Stocking Whirling Disease-resistant Rainbow trout have been stocked at various sizes in most recent years with the goal of establishing a wild, self-sustaining rainbow fishery. Due to the success of this stocking, beginning in 2014 rainbow trout stocking ceased in order to give the rainbows a chance to sustain themselves. See discussion on following pages. Sportfishing Notes The Fraser offers an enjoyable mix of fishing for brook, rainbow and brown trout. The composition of these three species depends on the location in the river one fishes. It is home to the highest densities of mottled sculpin in the area, so streamer fishing for large browns beneath undercut banks is always an option. The most prolific insect hatch is caddis, which takes place after runoff. Golden stoneflies and various mayflies are also adundant. Terrestrial fishing can be productive in late summer as well. This 5 sculpin had recently consumed a 3 dace. This is the only time we have documented sculpin piscivory in this area. This brown trout, captured in the same reach, had recently eaten a sculpin.

2 Fraser River fish population information Jon Ewert Aquatic biologist Hot Sulphur Springs We conducted electrofishing surveys of the fish populations at four locations on the Fraser River during the first week of September, 2014 (see map at right). We used wade electrofishing equipment to generate multipass depletion estimates of the fish populations. At the Kaibab, Safeway, and Confluence Park stations, we used Kaibab Park five electrodes to survey the reach. Due to the smaller size of the stream at Idlewild Campground, we used four. The lengths of the four stations are all similar, averaging 647 linear feet. The Kaibab, Safeway, and Confluence Park locations are standard sites that have been surveyed multiple years. The long-term history of those sites is discussed on the following pages. The Idlewild Campground site was a new location that was surveyed for the first time in Our intention is for that site to become a standardized site as well and continue to survey there in future years. Population estimates for all four stations are shown in the table at right. The stations are arranged in the table from upstream to downstream. The Fraser is a very diverse river in terms of habitat type and quality, and these rapid changes are reflected in the different species compositions at different locations. Mottled sculpin (pictured below) are of great interest in the Fraser. They are the most numerous Station fish species throughout much of the river, they are one of the few native species remaining in this part of the state, they are an important component Brown trout of the food web, and they are an excellent indicator species when assessing water quality or habitat issues. In the table, the total number of sculpin collected at these sites is presented, because due to the fish s small size, we typically do not collect enough fish to accomplish a statistically valid Rainbow trout depletion estimate. Therefore, the number of fish that we collected should be viewed as an index, not an estimate. The trend of higher sculpin densities farther downstream is common in the Fraser and we have observed that trend in other years as well. Brook trout** Confluence Park Safeway Idlewild CG Fraser River 2014 Fish Population Estimates Idlewild Campground Confluence Park Safeway Kaibab Park Date of survey 9/3 9/4 9/3 9/4 Biomass (pounds per acre) 15 * Fish > 14 per surface acre Fish > 6 per mile Biomass (pounds per acre) Fish > 14 per acre Fish > 6 per mile 297 1, Biomass (pounds per acre) BRK > 6 per mile TOTAL TROUT BIOMASS Total sculpin captured *We did not capture enough brown trout at Confluence Park to generate a biomass estimate. ** No brook trout greater than 14 were caught in any of the surveys. Mottled sculpin. Photo by Corey Lewellen

3 This site is located adjacent to the Forest Service campground just upstream of the town of Winter Park. At right is the size structure of brook trout and rainbow trout captured at the Idlewild Campground station in The highest point in the drainage that we have been stocking rainbow trout is the Highway 40 bridge upstream of this station, so that is the origin of the rainbows that we captured in the 5-10 range. However, due to the excellent success of establishing rainbows through stocking, we actually did not stock fish in 2014 in order to assess the potential for a self-sustaining rainbow fishery. Therefore, the two small rainbows we captured, 1-2 in length, are evidence of successful natural reproduction. It should also be noted that the population estimates presented on the previous page are for fish 6 and larger per mile, because that is our standard size cutoff when calculating those estimates. But the figure at right shows that this site did contain a high density of brook trout in the 2-5 range, and fits the description of a stunted, high-density brook trout population. Idlewild Campground Confluence Park Confluence Park Station Population Estimates Year Brown trout: pounds per acre > 14 per acre > 6 per mile Rainbows: pounds per acre >14 per acre >6 per mile , ,201 Brook trout: pounds per acre >6 per mile TOTAL TROUT BIOMASS Total sculpin captured The Confluence Park station is located in the town of Winter Park. The upstream end of the station is the pool where Vasquez Creek joins the Fraser. The entire recent survey history at this site is contained in the table above. The size distribution of the trout captured in the last three surveys is displayed in the graphs at right. The rainbow trout stocking of recent years has been very successful at this site. In fact, the rainbows currently appear to have a competitive advantage over the brook trout, which is a rare situation. By 2013 it was evident that our rainbow stocking was possibly verging on overpopulating the reach, and this was one of the factors that led to the decision to cease rainbow stocking beginning in This is not necessarily a permanent decision; the coming two years will be very important in assessing whether or not the rainbows in the Fraser will be able to sustain themselves without supplemental stocking. The variations in sculpin densities on this reach appear to reflect hydrologic cycles. At this point in the watershed the Fraser is still a higher-gradient, montane stream. Runoff in this section can reach great intensities. There is probably a wash-down effect that takes place with the sculpin, in which many fish are displaced downstream during the runoff period. Conversely, during drier periods such as 2012 and 13, sculpin numbers build.

4 Safeway Safeway Staion Population Estimates Year Brown trout: pounds per acre > 14 per acre > 6 per mile Rainbows: pounds per acre >14 per acre >6 per mile Brook trout: pounds per acre >6 per mile TOTAL TROUT BIOMASS Total sculpin captured The table above contains population estimates for the Safeway station, located immediately behind the Safeway store in the town of Fraser. This station has the longest and most consistent history of surveys. The Town of Fraser, in partnership with other entities including Trout Unlimited and the Colorado Division of Wildlife (now CPW), completed a habitat improvement project in this area in These surveys show that the habitat project has proven to be overwhelmingly successful was the only year that this station was surveyed prior to the habitat project was undertaken. The survey that year yielded population estimates that were quite poor in all parameters of the trout population. All subsequent sampling occasions have produced estimates that are many times greater than the 2003 values. On the following page, the size distributions of rainbow and brown trout for the past five years are shown. This station is a very interesting location to observe the interaction of rainbow, brown, and brook trout populations. Populations of all three species have been highly dynamic through the years the survey has been conducted. Many of the changes in the rainbow population can be directly attributed to stocking patterns. Soon after the habitat project was completed, we stocked rainbows in this reach at relatively high densities in order to quickly occupy habitat and possibly gain a competitive advantage over the brown trout. In both 2007 and 2008, we stocked several hundred large brood fish, averaging This is what produced the elevated rainbow biomass and quality fish density estimates in those years. The intention of stocking those fish was to kick start the rainbow population in the newly-improved habitat. These fish occupied the stream for a couple of seasons but do not appear to have accomplished natural reproduction (see 2010 graph on following page). In 2010, we began a four-year period of stocking approximately 50,000 whirling-disease resistant rainbow fingerlings. The 2010 fish were stocked after our survey, and averaged 3.5 in length. We were pleased to find these fish one year later in good numbers averaging 7 in length. This resulted in greatly improved population estimates for rainbow biomass and fish greater than 6, but rainbows greater than 14 were still scarce. The large number of 2 rainbows found in 2011 were the fingerling plant that had occurred a month earlier we stocked the fish in August at 1, to observe whether or not fry stocking would be successful here in the same way that it has been on the Colorado River. During this same period (2010 and 2011), brown trout were found to be relatively sparse on this reach. It appears that high water years disadvantage brown trout on this section, probably by displacing them to points downstream, and because those years produce colder temperature regimes. The lower-water years of 2012 and 2013 saw much higher recruitment of brown trout, resulting in increased population estimates beginning in Densities of brown trout larger than 14 have remained similar since 2008, indicating that these larger fish are not as susceptible to the displacement that seems to occur during high water years and 2014 saw the highest brown trout biomass estimates on this reach to date. Rainbow stocking continued through 2012 and In 2012, fish were again stocked at 1 earlier in the year, resulting in the large number of 2-3 appearing in the catch. The previous two years stocking efforts could be seen in the presence of two size groups of rainbows that year, one averaging 8 and the other averaging 11. This was the first time we were able to verify multiple year-classes of recruitment through fingerling stocking. In 2013, rainbows were stocked on August 1, but were larger, at This can be seen in the large group of fish in the 4-5 range we captured that year. We actually caught several hundred of those fish. Interestingly enough, in 2013 we also caught a large number of 2 rainbows, which were not explained by stocked fish and were likely the result of wild reproduction. Because of this, and the success of these plants that we have also observed at Confluence Park, beginning in 2014 we ceased all stocking of rainbows in order to observe whether or not they will sustain themselves through natural reproduction. There are no plans to stock any rainbows in this reach in The 2014 survey revealed an adult population with a high enough density that we should be able to observe a naturally-produced 2015 year class. The 2014 survey also revealed a robust age-1 brown trout year class averaging 5, but no 2-3 brown trout, suggesting that the higher runoff of 2014 probably prevented survival of that year s progeny.

5 Safeway station size structure Rainbow trout Brown trout

6 Kaibab Park Population Estimates Date of survey 9/1 9/2 9/1 9/6 9/3 9/4 Brown trout: pounds per acre >14 per acre >6 per mile , Total number mottled sculpin , The Kaibab Park station is located within the town of Granby, where the river flows between the park and the fire station, immediately downstream of the Highway 40 crossing. This is the farthest downstream location on the Fraser that we survey regularly. Population estimates are shown in the table above and the size distribution of brown trout and rainbow trout is shown in the graphs. Only brown trout population estimates appear in the table because rainbow trout have not yet constituted a significant portion of the fish population, despite the fact that rainbows have been stocked here on the same occasions that have been so successful farther upstream. We have observed the same pattern at Kaibab Park that we have observed at Safeway, of high brown trout recruitment in low water years such as However this station seems to hold less fish as they get larger. This is probably a reflection of the quality of habitat in this reach. While it is not what would be considered poor, it is not of the same excellent quality found in the other locations upstream that have been discussed in this report. Especially striking is the significant decrease in fish larger than 14 in This was a drought year with very low flows and high water temperatures. It is likely that large fish vacated this reach in search of more suitable low-flow habitat. By 2014 the density of large fish appeared to have recovered. Because of the lack of success of rainbow stocking to date, we do plan to stock rainbow fingerlings in this location in 2015 to continue to try to establish an adult population on this reach.