Arizona Game and Fish Department Region I Fisheries Program. Chevelon Canyon Lake Fish Survey Report Trip Report April 2015

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1 Arizona Game and Fish Department Region I Fisheries Program Chevelon Canyon Lake Fish Survey Report Trip Report April 2015 Authors: Sally Petre and Mike Lopez Report Date: June 25, 2015 The Arizona Game and Fish Department (AGFD) prohibits discrimination on the basis of race, color, sex, national origin, age, or disability in its programs and activities. If anyone believes that they have been discriminated against in any of the AGFD's programs or activities, including its employment practices, the individual may file a complaint alleging discrimination directly to the AGFD deputy director, 5000 W. Carefree Hwy, Phoenix, AZ 85086, (602) or U.S. Fish and Wildlife Service, 4040 N. Fairfax Dr., Suite. 130, Arlington, VA Persons with a disability may request a reasonable accommodation, such as a sign language interpreter, or this document in an alternative format, by contacting the AGFD Deputy Director, 5000 W. Carefree Hwy, Phoenix, AZ 85086, (602) Requests should be made as early as possible to allow sufficient time to arrange for accommodation.

2 Arizona Game and Fish Department Page 1 Executive Summary On April 6-7, 2015, a trend fish survey was conducted at Chevelon Canyon Lake, Coconino County. Six standardized monofilament gill nets were set (one at each of four random sites and one at each of two fixed sites) in the lake to monitor the success of fingerling and subcatchable rainbow trout stockings in The survey found a fair number of Rainbow Trout Oncorhynchus mykiss in stock size, but none larger, indicating a failure of one or more stockings. It is unknown which stocking is more successful, which should be determined in a more in-depth investigation. Stock size Rainbow Trout had fair condition, while larger wild Brown Trout Salmo trutta (which were all larger size) had poor condition, indicating that Chevelon Canyon Lake is limited in the size of trout it can grow. Introduction Chevelon Canyon Lake, located in southeastern Coconino County on the Apache- Sitgreaves National Forest, was constructed in 1965 by damming Chevelon Canyon. The lake is 208 surface acres in size, with a maximum depth of 80 feet. Approximately 70,000 fingerling Rainbow Trout Oncorhynchus mykiss are normally stocked each spring, and approximately 10,000 subcatchable Rainbow Trout each year in the fall. Chevelon Canyon Lake is managed as a put-grow-and-take Rainbow Trout and wild Brown Trout Salmo trutta fishery with special regulations to grow larger fish and limit harvest because of its remote location. Current angling regulations include artificial fly and lure only, with a limited daily bag limit of two trout. Chevelon Canyon Lake is categorized as a Tier II priority and the fish community is monitored each spring (Meyer et. al 2008). Methods One monofilament gillnet (150 x 6, 6-panel experimental 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 ) was set at each of two fixed and four random sites for a trend survey of the fish community, according to standardized protocols (AGFD 2004; Meyer et. al 2008), in Chevelon Canyon Lake for a total of six nets. Nets were set April 6, 2015 for an overnight set and pulled the next morning. All fish caught were identified to species, measured to the nearest millimeter, and weighed to the nearest gram, except for suckers, in which only a subsample were measured and weighed due to their large numbers. Live fish were released back into the lake, while dead fish were returned to the lake. Species composition (% of total), relative abundance (catch per unit effort [CPUE]; fish/h), length-frequency distribution, and relative weight (W r ) were calculated for principal species according to standard protocols for all fish species (AGFD 2004). Species composition (%), CPUE (fish/h), and length-frequency distributions were determined for non-principal species (AGFD 2004). All proportional size distribution (PSD) length categories and relative weight (W r ) calculations are from Neumann et. al (2012).

3 Arizona Game and Fish Department Page 2 Results Little Colorado Suckers comprised 67.4% (n=95), Rainbow Trout 26.2 % (n=37), and Brown Trout 6.4% (n = 9) of the catch at Chevelon Canyon Lake (Table 1). Overall CPUE was 1.94 fish/h (Table 1). Rainbow Trout ranged from mm in length and averaged 289 mm (Table 2). Most Rainbow Trout (81%) ranged from mm (10 13 in; Figure 1). Catch per unit effort for Rainbow Trout was 0.39 fish/h (n=37; SE=0.17; Table 1). Their weight ranged from g, averaging 254 g. All Rainbow Trout fell into stock size according to Neumann et. al (2012) with a W r of Brown Trout were larger than Rainbow Trout, ranging from mm in length and averaging 550 mm (Table 2). Their weight ranged from g, averaging 1554 g. Catch per unit effort for Brown Trout was 0.09 fish/h (n=9; SE=0.03; Table 1). One Brown Trout was preferred size with a W r of 80.53, seven were memorable size with a W r of and one trophy size with a W r of (Table 3). As Brown Trout length increased, W r decreased (Table 3). Little Colorado Sucker ranged from mm and averaged 400 mm in length (Table 2). The majority (89%) of Little Colorado Suckers caught were in the mm range (Figure 1). Their weight ranged from g and averaged 788 g (Table 2). Catch per unit effort for Little Colorado Sucker was 1.43 fish/h (n=95; SE=0.40; Table 1). Discussion There was a relatively high CPUE for Rainbow Trout (0.39 fish/h) compared to last year s survey (0.18 fish/h) in Chevelon Canyon Lake (Dreyer and Lopez 2014). All Rainbow Trout were within the catchable or stock size class, indicating success of only one size class or stocking of fish, which is consistent with past years (Dreyer and Lopez 2014). It would be advantageous to mark one of the two stockings and identify those fish during the spring surveys to determine if spring fingerlings or fall subcatchables are recruiting well, or if one is more successful than the other. Stocking strategies would follow recommendations for best recruiting size and timing. In 2014, unlike previous years, an additional stocking of small catchables occurred during July. These may be representing the size class of Rainbow Trout we found in this 2015 spring survey, however, marking of Rainbow Trout would enable us to determine which stocking is most successful. Brown Trout continue to maintain a small population of fairly large fish (preferred, memorable, and trophy size) within Chevelon Canyon Lake. They will likely continue to persist as long as wild Brown Trout exist in Chevelon Creek upstream of the lake and have access to the creek. Brown Trout do not spawn successfully within the reservoir and must enter the stream above the lake to have success.

4 Arizona Game and Fish Department Page 3 The condition of both trouts was low. Rainbow Trout, which were smaller than Brown Trout likely get enough nutrition rom zooplankton, but this alone is not enough to maintain good condition (W r 95) in larger trout. Chevelon Canyon Lake is only moderately productive and the nature of the lake limits the availability of larger food items that would better sustain larger trout. The lake is very deep with steep slopes, leaving a very narrow littoral zone, which would supply other food items and macro invertebrates. There are very little to no aquatic weeds, which typically grow prey (i.e., snail, Odonates) and much of the lake bottom falls within the anoxic zone during the summer, limiting the production of benthic invertebrates. Thus, the lake is limited in the size of trout it can grow, but should still provide a moderate fishery as long as the stocked juvenile Rainbow Trout survive. Little Colorado Sucker continue to maintain a large population thin the lake. The mass of fish caught in the mm range are adults mobilizing to spawn. Surveys conducted later in May would most likely occur during their spawn, thus catching even more during the survey, which is why this survey is in early April. The strong population of Little Colorado Sucker is a good indicator that trout management at Chevelon Canyon Lake is not preventing this native fish from recruiting, and thus the two appear to be compatible. Recommendations 1. Conduct study to determine which stocking (spring fingerlings, fall subcatchables, or other) is most successful, then adjust stocking strategy accordingly. 2. Continue to survey each spring in early April to monitor stocking success and for new species that could establish from upstream. 3. Maintain the access road to the dam to allow adequate access for stocking trucks. Literature Cited Arizona Game and Fish Department (AGFD) Standard Fish Sampling Protocol for State of Arizona Waters. Arizona Game and Fish Department, Phoenix, Arizona. 123 pp.6 Dreyer, R. J. and M. A. Lopez Chevelon Canyon Lake Sport Fish Survey Trip Report. Arizona Game and Fish Department, Phoenix, Arizona. Meyer, K. J., R. J. Dreyer, and M. A. Lopez New Protocol on Reservoirs in Region I and Proposed Sampling Schedule. Arizona Game and Fish Department, Pinetop, AZ. 12 pp. Neumann, R. M., C. S. Guy, and D. W Willis Length, weight, and associated indices. Pages in A. V. Zale, D. L. Parrish, and T. M. Sutton, editors. Fisheries techniques, 3 rd edition. American Fisheries Society, Bethesda, Maryland.

5 Arizona Game and Fish Department Page 4 Acknowledgements We thank AZGFD employees who helped with the survey especially Ken Clay.

6 Arizona Game and Fish Department Page 5 Tables, pictures, and figures Table 1. Number of fish caught, species composition (%), catch per unit effort (CPUE; fish/h) and standard error (SE) of CPUE from overnight gillnet survey at Chevelon Canyon Lake on Aril 6-7, Species Species Total Composition (%) CPUE (fish/h) SE Rainbow Trout Brown Trout Little Colorado Sucker Total

7 Arizona Game and Fish Department Page 6 Table 2. Range and mean of length (mm) and weight (g) of fish (Rainbow Trout Oncorhynchus mykiss, Brown Trout Salmo trutta, and Little Colorado Sucker Catostomus spp.) captured during overnight gillnet survey in Chevelon Canyon Lake, Arizona April 6-7, Length (mm) Weight (g) Species Min. Max. Mean Min. Max. Mean Rainbow Trout Brown Trout Little Colorado Sucker

8 Arizona Game and Fish Department Page 7 Table 3. Proportional size distribution (PSD) length categories (mm) for stock, quality, preferred, memorable, trophy sized Rainbow Trout Oncorhynchus mykiss and Brown Trout Salmo trutta; number (n) of fish; and relative weight (W r ) of fish caught in overnight gillnet sets in Chevelon Canyon Lake, Arizona. PSD categories and W r calculations are according to Neumann et. al (2012). Stock Quality Preferred Memorable Trophy Total Rainbow Trout Length (mm) n W r Brown Trout Length (mm) n W r

9 Arizona Game and Fish Department Page Number of fish (n) ONMY SATR CASP Size class (mm) Figure 1. Length-frequency distribution of Rainbow Trout Oncorhynchus mykiss (ONMY; black bar), Brown Trout Salmo trutta (SATR; white bar); Little Colorado Sucker Catostomus spp. (CASP; gray bar) captured during overnight gillnet survey in Chevelon Canyon Lake, Arizona April 6-7, 2015.