DRAFT Compatibility Determination for Fish Stocking at Deer Flat National Wildlife Refuge

Refuge Name: Deer Flat National Wildlife Refuge

Location: Canyon, Owyhee, Payette, and Washington Counties, Idaho, and Malheur County, Oregon

Date Established: 1909

Establishing and Acquisition Authorities

Deer Flat National Wildlife Refuge (NWR) was originally established in 1909 by President Theodore Roosevelt as Deer Flat Bird Reservation as a “preserve and breeding grounds for native birds” (E.O. 1032). In 1937, President Franklin D. Roosevelt revoked Executive Order 1032 and reestablished the Refuge as the Deer Flat Bird Reservation to “further the purposes of the Migratory Bird Conservation Act” and “as a refuge and breeding ground for migratory birds and other wildlife” (E.O. 7655). Also in 1937, 36 islands in the Snake River were designated as the Snake River Migratory Bird Refuge (E.O. 7691).

In 1940, the Refuges’ names were changed by Presidential Proclamation No. 2416, to Deer Flat National Wildlife Refuge and Snake River National Wildlife Refuge respectively. In 1963, Public Land Order 3110 transferred all lands of the Snake River National Wildlife Refuge (consisting of 74 islands) to the direct jurisdiction of Deer Flat National Wildlife Refuge. Any lands (including those in the Snake River Islands National Wildlife Refuge) that were added to Deer Flat National Wildlife Refuge assume the purposes for which Deer Flat National Wildlife Refuge was established as well as keeping any individual purposes that were provided at the time of their establishment or acquisition.

Refuge Purposes

 “to further the purposes of the Migratory Bird Conservation Act” and “as a refuge and breeding grounds for migratory birds and other wildlife” (E.O. 7655).  “for use as an inviolate sanctuary, or for any other management purpose, for migratory birds” (Migratory Bird Conservation Act [16 U.S.C. 715d]).  “suitable for (1) incidental fish and wildlife-oriented recreational development, (2) the protection of natural resources, (3) the conservation of endangered species or threatened species” (16 U.S.C. 460k-1) and “the Secretary … may accept and use … real … property. Such acceptance may be accomplished under the terms and conditions of restrictive covenants imposed by donors” (16 U.S.C. 460k-2) (Refuge Recreation Act [16 U.S.C. 460k- 460k-4], as amended).

National Wildlife Refuge System Mission

The mission of the Refuge System is to administer a national network of lands and waters for the conservation, management, and where appropriate, restoration of the fish, wildlife, and plant resources and their habitats within the United States for the benefit of present and future generations of Americans (National Wildlife Refuge System Administration Act of 1966, as amended [16 U.S.C. 668dd-668ee et seq.]). Description of Use:

The Service coordinates with the Idaho Department of Fish and Game (IDFG) on management of sport fisheries, and fishing seasons and regulations at Deer Flat NWR. The statewide, multi-year Fisheries Management Plan provides guidance and policy direction to fishery biologists for each major river basin in Idaho (IDFG 2019a). IDFG has also prepared the Lake Lowell Fisheries Management Plan (IDFG 2019b). IDFG’s fishery management activities on the Refuge include regulating harvest, fish population monitoring, and fish stocking. Fish stocking of the Refuge’s Lake Lowell Unit by IDFG in support of sport fishing was included in the Refuge’s CCP (USFWS 2015), which states: “The Refuge will continue to coordinate with IDFG on the stocking of the following fish species at the Lake Lowell Unit: largemouth bass, smallmouth bass, bluegill, channel catfish, black crappie, yellow perch, rainbow trout, and Lahontan cutthroat trout. Stocking of any other fish species will require additional planning.”

Because Lake Lowell is an artificially created off-channel reservoir, no fish were originally native to its waters. Fish occurring in the lake were introduced intentionally or unintentionally, or entered the lake via entrainment. The current practice of stocking nonnative fish is inconsistent with USFWS policies (7 RM 10 and 601 FW 3). However, fish native to Idaho and naturalized species that have been historically stocked species come as close to meeting the policy as possible given the human- made quality of the lake (CCP; USFWS 2015). IDFG’s fish stocking program supports recreational fishing on the Refuge’s Lake Lowell Unit, a compatible, priority public use. Due to its proximity to Idaho’s population center, Lake Lowell receives substantial fishing pressure, with largemouth bass being of primary interest to recreational and tournament anglers (IDFG 2009). Currently, spring and summer fishing on Lake Lowell focuses on large and smallmouth bass from boats. The majority of bank fishing is focused on catfish. Panfish (black crappie, bluegill, and yellow perch) are also popular despite widely fluctuating populations that have led to inconsistent use (USFWS 2015).

Fish stocking of Lake Lowell has occurred by two entities, the U.S. Fish Commission in the early 1900s, and the Idaho Department of Fish and Game. Historical stocking records for Lake Lowell prior to the late 1960s are incomplete. Stocking and translocation records from 1967 on are available at https://idfg.idaho.gov/ifwis/fishingPlanner/stocking/ (IDFG n.d.). The lake has been stocked by IDFG with species both nonnative (i.e., channel catfish, black crappie, bluegill, largemouth bass) and native (i.e., Lahontan cutthroat and rainbow trout from hatchery sources) to Idaho. Plants of Lahontan cutthroat trout fingerlings have ranged from 40,000 to 103,000 annually, but this species has not been stocked in the lake since 2009 (IDFG n.d.). Since 2003, approximately 6,000 to 10,000 fingerling channel catfish have been planted annually. This is the only species that has been planted in Lake Lowell since 2010. In the last decade, most stocking in Lake Lowell has occurred between May 1 and August 1 (IDFG n.d.).

Changes to Described Use

IDFG would provide additional sport fishing opportunities in Lake Lowell by adding one species, tiger muskellunge (Esox masquinongy x E. lucius), to species that may be stocked in Lake Lowell (IDFG 2019b). Tiger Muskellunge are preferred over their parental species due to their superior performance under hatchery conditions (Graff 1978; Pecor 1978) and because of sterility (Crossman and Buss 1965). Sterility allows agencies to stock tiger muskellunge with no threat of creating self- sustaining populations. Tiger muskellunge would also exert additional predation pressure on carp and sucker in Lake Lowell (IDFG 2019b). Generally, tiger muskellunge are stocked at rates of 1-2 fish per hectare (ha). However, due to the large size of Lake Lowell (10,000 ac/4,000 ha) and limited availability of hatchery stock, IDFG plans to stock 1,000-2,000 hatchery-raised juvenile tiger muskellunge per stocking event, which would equal a stocking density of 0.25 to 0.50 fish per ha. Stocking would occur annually if fish are available; however, stocking may occur only every other year due to intermittent availability. Tiger muskellunge will be acquired from other states, most likely Nebraska or Wyoming. Prior to importation, the rearing source would be certified as disease free under the guidelines outlined in the American Fisheries FHS Blue Book (AFS-FHS 2016) by the rearing or exporting agency. Transportation would occur in well water to eliminate the potential for any water-borne contamination. After importation, the next step(s) would depend on fish size. If tiger muskellunge were approximately 250 mm or longer, stocking would proceed immediately during spring-summer, as fish would be long enough (250-300 mm) to avoid significant largemouth bass predation (Stein et al. 1981). If average fish length were less than 250 mm, tiger muskellunge would need to be reared for additional time at an IDFG facility. Each tiger muskellunge will be measured and tagged with a passive integrated transponder (PIT tag) prior to stocking to allow estimation of survival and growth rates if encountered during periodic fisheries assessment efforts (IDFG 2019b).

Availability of Resources

Fish stocking and associated monitoring is conducted by IDFG; therefore, no Refuge resources are required for this use. Refuge staff time is required to coordinate with IDFG. There are sufficient resources to conduct the use.

Anticipated Impacts of the Use

Impacts to Habitat and the Fish Community

The most recent comprehensive survey (2006) documented presence of 12 fish species in Lake Lowell. Nine of these species are considered introduced game fish, including brown bullhead (Ameirus nebulosus), black crappie (Pomoxis nigromaculatus) , bluegill (Lepomis macrochirus), channel catfish (Ictalurus punctatus), largemouth bass (Micropterus salmoides), pumpkinseed (L. gibbosus), smallmouth bass (M. dolomieu), white crappie (P. annularis), and yellow perch (Perca flavescens) (Kozfkay et al. 2007). For the most part, these species are self-sustaining. IDFG monitors harvest and fish populations in the lake (IDFG 2019a). Refuge fishing regulations and harvest are coordinated with the IDFG to avoid excess pressure on populations. Idaho’s Fisheries Management Plan (IDFG 2019a) also lists rainbow trout (Oncorhychus mykiss) and Lahontan cutthroat trout (O. clarkii) as occurring in Lake Lowell.

Two other species are considered native to the Boise River drainage, largescale sucker (Catostomus macrocheilus) and redside shiner (Richardsonius balteatus). Though not sampled in the comprehensive survey, fathead minnow (Pimephales promelas) and oriental weatherfish (Misgurnus anguillicaudatus), which were unintentionally or illegally introduced, have been sampled within the last decade and are thought to have established self-sustaining populations in Lake Lowell (IDFG 2019b).

One species, common carp (Cyprinus carpio), may have been introduced to the area prior to 1887 by the U.S. Fish Commission (newspaper article from Shoshone Journal re-published in Boise Democrat; 4/16/1887). It is considered an invasive, nonnative nongame fish (IDFG 2019b). Fish population surveys conducted in 2008 (IDFG 2009) indicate that the Lake Lowell fish community has become dominated by carp and sucker. Carp represented 58 percent of the catch by number, followed by channel catfish at 27 percent and black crappie at 6 percent. Yellow perch, bluegill, largemouth bass, smallmouth bass, largescale sucker, and northern pikeminnow, represented cumulatively 8 percent of the catch. Carp degrade water quality, alter food webs, and negatively impact native or recreationally important fish populations (Jackson et al. 2010; Zambrano et al. 2001). Carp control has intermittently occurred for many years to enhance submergent vegetation and moist-soil plants in Lake Lowell. IDFG’s Fisheries Management Plan (IDFG 2019a) states that the State will “reduce common carp and largescale sucker abundance.” During the development of the CCP, the Service and IDFG discussed strategies to reduce carp abundance in Lake Lowell to enhance habitat and sport fisheries. IDFG recommended three options for significant carp reduction: physical control such as seining, a yet-to-be-studied biological control using a koi-herpes virus, or chemical control using a fish toxicant (rotenone or antimycin-a) applied to the lake in an extreme low-water year (Kozfkay et al. 2011; IDFG 2019b). IDFG is no longer considering physical control as a control option due to logistical concerns and lack of nearby processing facilities, and koi-herpes virus is not being considered at this time. If a severe, multi-year drought led to historically-low reservoir levels, fish toxicants might become a viable control option (IDFG 2019b).

IDFG assessed the potential utility of biological control methods for reducing carp and sucker abundance, including assessment of introducing additional piscivorous fishes as predators. Tiger muskellunge were considered the only possible and best option for exerting some additional predation pressure on rough fish in Lake Lowell. The total number of tiger muskellunge in Lake Lowell would be low, approximately 3,200 or 0.8 fish/ha, based on anticipated stocking rates and plausible survival rates from literature (IDFG 2019b). Given their small numbers, it is very unlikely that tiger muskellunge could collapse carp or sucker populations in Lake Lowell, but they are predicted to provide some predation pressure, reduce rough fish biomass to a small degree, provide a unique fishery, and increase economic value of this fishery (IDFG 2019b).

Based on previous experiments, peer-reviewed literature, and case histories, including Idaho and Washington lakes and reservoirs, the addition of tiger muskellunge to the IDFG’s fish stocking program would have a negligible effect to existing game fish populations at Lake Lowell. As noted above, numbers and density of tiger muskellunge would be low. Tiger Muskellunge and their parental species, referred to as esocids, feed on a wide variety of food items including fish, invertebrates, mammals, amphibians, and birds (Kerr and Lasenby 2001). Although a wide variety of food items may be sampled in tiger muskellunge stomachs, fish compose the vast majority of their diet. In the 35 diet studies reviewed by Kerr and Lasenby (2001), esocids preferentially selected soft- rayed fish species with long, cylindrical body types, when available. The majority of these studies were conducted on northern pike (Esox lucius). Fewer evaluations have been conducted on tiger muskellunge specifically. However, an intensive tiger muskellunge diet study was conducted by Washington Department of Fish and Wildlife. In this study, Tiger Muskellunge preferentially selected long, cylindrical prey items such as largescale sucker, rainbow trout, and northern pikeminnow (Ptychocheilus oregonensis), when available (Baker et al. 2015). For their two study waters, fish composed 89 or 90% of stomach contents with the entire remaining 10 or 11% being invertebrates, primarily Decapoda (crayfish) as well as Amphipoda (amphipods) and Odonata (damselfly or dragonfly). Furthermore, largemouth bass were infrequently sampled in diets, most likely due to their laterally compressed body form and well-developed spiny rays. Deep-bodied, spiny-rayed fish (e.g. bluegill and other sunfish) are not ideal food for the tiger muskellunge, and lakes dominated by sunfish typically produce slow-growing tiger muskellunge (O’Keefe 2016). Both tiger muskellunge and their parent species generally take advantage of the most abundant prey species available that are of sufficient size for them to eat. At Lake Lowell, tiger muskellunge would be primarily expected to feed on largescale suckers, smaller age classes of carp, and yellow perch.

Additional concerns associated with fish stocking include introduction of fish diseases from hatchery stock, and introduction of invasive plants or animals in water used for transport. Rearing sources of any fish used for stocking would be certified as disease free under the guidelines outlined in The American Fisheries Society FHS Blue Book (AFS-FHS 2016) by the rearing or exporting agency. Transportation would occur in well water to eliminate the potential for any water-borne contamination or invasive species.

Impacts to Wildlife

Many of the wildlife species that frequent Deer Flat NWR rely on aquatic vegetation. Herons and egrets forage in smartweed beds, grebes make their nests from and in emergent vegetation, and ducks raise their broods in the protection that its cover provides. Lake Lowell and other reservoirs in Idaho support both recreational fisheries that include stocked species, and breeding colonies of grebes and other piscivorous birds. Fish stocked by IDFG, as well as rough fish, provide a prey base for grebes and other waterbirds. Therefore, artificial reservoir habitat, combined with fish stocking, provides benefits to many bird species.

Lake Lowell is an important nesting and brood-rearing site for western and Clark’s grebes (Aechmophorus occidentalis, A. clarkii), both Tier 2 Species of Greatest Conservation Need in Idaho. There have been steep declines in breeding colonies of these species at all sites in Idaho that are monitored (IDFG 2017). However, grebes have occupied habitat with stocked fish at Lake Lowell for decades, and the smaller age classes of stocked fish provide prey for foraging grebes. Western and Clark’s grebes are primarily piscivorous and opportunistic; size class of prey items is more important than the species. In general, western and Clark’s grebes require small fish (<9cm) to feed their broods (Storer and Nuechterlein 1992). Lawrence (1950) examined stomach contents of western grebes on their breeding grounds, and found that contained 81% fish 27-88 mm long (88mm = approx. 3.5 inches), 17% insects, and 2% plants (Lawrence 1950). Another study in British Columbia found that class one yellow perch were the preferred food of western grebes during brood rearing (Forbes and Sealy 1990). Therefore, it is unlikely that the addition of tiger muskellunge to fish currently stocked by IDFG would have measurable effects on breeding western and Clark’s grebes on the Refuge. The lake has an ample forage base for both piscivorous stocked fish species, and piscivorous birds; there is only partial overlap between prey sizes preferred by grebes during brood rearing and that of adult muskellunge; and populations and densities of muskellunge would be low.

Finally, predation of juvenile waterbirds, including grebe chicks, by tiger muskellunge is expected to be a rare occurrence. As noted above, both the density and total number of tiger muskellunge in Lake Lowell would be low. Tipping (2000) reviewed available literature describing esocid (pike and muskellunge) stomach contents including from 49,908 northern pike, 2,860 muskellunge, and 1,436 tiger muskellunge. Fish and aquatic invertebrates were primarily found. 45 waterfowl (mostly American coot (Fulica americana) were found. The detection of 45 waterfowl or water birds in 54,204 esocid stomachs equates to less than one-tenth of one percent (0.083%) occurrence. There have been no specific studies of grebe predation by esocids; however, some observations have been made regarding common loon (Gavia immer), a species similar in size and behavior to Clark’s and western grebe. In Minnesota, where muskellunge and common loon overlap and where approximately 11,000 common loon reside, no common loon chicks were found in examination of more than 2,000 muskellunge stomachs (Rod Ramsell; Minnesota DNR; personal communication; cited in Montana Fish, Wildlife, and Parks 2005). Based on foraging habitats, low densities of adult tiger muskellunge, high density of buffer forage organisms, and the tiger muskellunge’s preference for fusiform fish, predation of waterfowl or other water birds by tiger muskellunge will be nearly nonexistent and undetectable. Therefore, the presence of tiger muskellunge would not be expected to measurably affect populations of grebes or any other bird species.

In the Lake Lowell Fishery Management Plan, IDFG agreed to conserve grebes and take no action that weakens population status of migratory birds. IDFG committed to sharing monitoring information for both grebes and tiger muskellunge. Additionally, should the status of grebes at Lake Lowell change appreciably, IDFG committed to cooperating with refuge staff to implement measures to improve population status (IDFG 2019b).

Impacts to Listed Species

There are no listed species known to occur on the Refuge. The counties that surround both units of the Refuge have a variety of listed species historically or currently occurring within each county. Of these species, only the yellow-billed cuckoo has ever been documented on Deer Flat NWR, and it is currently considered a vagrant because sightings are highly unusual. The Columbia spotted frog could conceivably exist on the Refuge but has not been documented. The condition of habitat for both of these species is either unknown or marginal. The likelihood of any other of the listed species that occur in the surrounding counties existing on the Refuge is slim. Most of these other species have known populations that occur off-Refuge (e.g., Bruneau hot springs snail, Packard’s milkvetch) or roam great distances and/or will not find suitable habitat on the Refuge (e.g., North American wolverine, greater sage-grouse) (USFWS 2015). It is anticipated that impacts from fish stocking will be negligible. If any use results in unacceptable adverse effects to candidate species or habitats, the Refuge will impose restrictions to mitigate impacts.

Impacts to Other Priority Public Uses

IDFG’s fish stocking program supports the Refuge’s sport fishing program. Fishing is considered a priority public use under the 1997 Refuge Improvement Act (Public Law 105-57). Lake Lowell is recognized by the angling public and IDFG staff as a primary fishery in Idaho’s Southwest Region. Presently, the majority of fishing effort is directed towards largemouth and smallmouth bass. However, many anglers target other species within this diverse fishery. During 2011, IDFG staff estimated that anglers completed nearly 18,000 trips to Lake Lowell and expended more than $1.1 million on those trips. This represented about 25-30% of the fishing trips and expenditures for Canyon County. With average trip duration approximating 4 hours, more than 70,000 hours of fishing effort were expended during 2011. These totals occurred despite a relatively confined fishing and boating use season (April 15-September 30), occasional closing of boat ramps due to low reservoir levels, and area closures during the majority of the year (IDFG 2019b).

As noted above, the addition of tiger muskellunge to the IDFG’s fish stocking program would have a negligible effect to existing game fish populations at Lake Lowell, and therefore, to existing fishing opportunities (Kerr and Lasenby 2001), (Baker et al. 2015), (O’Keefe 2016). Rather, tiger muskellunge would provide a unique fishing opportunity that adds to existing opportunities. Public Review and Comment

IDFG’s fish stocking program was described as an action common to all alternatives in the Comprehensive Conservation Plan for Deer Flat National Wildlife Refuge (USFWS 2015). The CCP was prepared along with an Environmental Impact Assessment. The proposed stocking of tiger muskellunge in addition to species currently stocked represents a minor amendment to the existing CCP. Therefore, this Draft Compatibility Determination has been prepared along with a Categorical Exclusion from further NEPA compliance, and will be available for public comment at the Refuge and on the Refuge website for 15 days.

Determination

Use is Not Compatible X Use is Compatible with the Following Stipulations

Stipulations Necessary to Ensure Compatibility

 IDFG will consult with the Refuge regarding time and place of fish releases to minimize impacts to nesting birds and protect sensitive wildlife habitat.  Rearing sources of any fish used for stocking will be certified as disease free under the guidelines outlined in the American Fisheries Society’s FHS Blue Book (AFS-FHS 2016) by the rearing or exporting agency. Transportation will occur in well water to eliminate the potential for any water-borne contamination or invasive species.  IDFG will monitor diet of adult tiger muskellunge when encountered during surveys, and will discontinue stocking this species if substantial grebe or other conservation-priority species are encountered in stomachs in substantial numbers.  Refuge staff will monitor impacts of these activities annually to assess compliance with these stipulations, impacts to wildlife and wildlife habitat, conflicts between user groups, and user satisfaction. Monitoring data will be used to modify these stipulations if necessary to ensure continued compatibility of this activity.

Justification

Fish stocking supports fishing, a priority wildlife-dependent use for the NWRS through which the public can develop an appreciation for fish and wildlife (E.O. 12996, March 25, 1996; National Wildlife Refuge System Improvement Act of 1997 [Public Law 105-57]). Without stocking, the Lake Lowell Unit of Deer Flat NWR, an artificially created off-channel reservoir, would not support a sport fishery. Although this activity can result in disturbance to wildlife and habitat, disturbances on the Refuge related to fish stocking are expected to be intermittent and minor and are not expected to diminish the value of the Refuge for its stated purposes. The stipulations stated above will ensure proper control of the use and provide management flexibility should detrimental impacts develop. Facilitating this use on the Refuge will provide opportunities for sport fishing, which in turn will increase visitor knowledge and appreciation of fish and wildlife resources. This enhanced understanding will foster increased public stewardship of natural resources and support for the Service’s management actions in achieving the Refuge purposes and the mission of the NWRS.

It is anticipated that wildlife populations will find sufficient food resources, nesting and breeding areas, and resting places such that their abundance and use of the Refuge will not be measurably lessened from allowing fish stocking on the Refuge’s Lake Lowell Unit. The relatively limited number of individuals expected to be adversely affected due to fishing will not cause wildlife populations to materially decline, the physiological condition and production of wildlife species will not be impaired, their behavior and normal activity patterns will not be altered dramatically, and their overall welfare will not be negatively impacted. Thus, allowing fish stocking will not materially interfere with or detract from the mission of the NWRS or the purposes for which the Refuge was established.

Mandatory Reevaluation Date

2029 Mandatory 10-year reevaluation (for uses other than priority public uses)

NEPA Compliance for Refuge Use Decision

______Categorical Exclusion without Environmental Action Statement.

References

AFS-FHS (American Fisheries Society-Fish Health Section). 2016. FHS blue book: suggested procedures for the detection and identification of certain finfish and shellfish pathogens, 2016 edition. Accessible at: http://afs-fhs.org/bluebook/bluebook-index.php Accessed August 15, 2019. Baker, W. P., M. J. Divens, and B. D. Bolding. 2015. Tiger muskellunge growth, condition, diet, and effect on target prey species in two eastern Washington Lakes: Progress report 2001-2006. Washington Department of Fish and Wildlife, Fish Program, Fish Management Division. Report No. FPT 15-02. Crossman, E. J., and K. Buss. 1965. Hybridization in the family Esocidae. Journal of the Fisheries Research Board of Canada 22:1261-1292. Forbes, L. S. and S. G. Sealy. 1990. Foraging roles of male and female Western Grebes during brood rearing. Condor 92 (2):421-426. Available at: https://sora.unm.edu/sites/default/files/journals/condor/v092n02/p0421-p0426.pdf Accessed August 15, 2019. Graff, D. R. 1978. Intensive culture of esocids-the current state of the art. Transactions of the American Fisheries Society Special Publication 11:195-201. IDFG (Idaho Department of Fish and Game). n.d. Historical stocking records. Available at: https://idfg.idaho.gov/ifwis/fishingPlanner/stocking/ Accessed August 15. 2019. IDFG. 2009. Fishery management annual report, southwest region. IDFG 09-130. Idaho Department of Fish and Game. Boise, ID. 142 pp. IDFG (Idaho Department of Fish and Game). 2017. Idaho State Wildlife Action Plan, 2015. Boise (ID): Idaho Department of Fish and Game. Grant No.: F14AF01068 Amendment #1. Available from: http://fishandgame.idaho.gov/. Sponsored by the US Fish and Wildlife Service, Wildlife and Sport Fish Restoration Program. IDFG (Idaho Department of Fish and Game). 2019a. Fisheries Management Plan 2019-2024. Boise, ID. 402 pp. Available at: https://idfg.idaho.gov/sites/default/files/2019-2024-idaho-fisheries- management-plan-original.pdf Accessed August 15, 2019. IDFG (Idaho Department of Fish and Game). 2019b. Lake Lowell Fisheries Management Plan. Unpublished report. Jackson, Z., J.M.C. Quist, J.A. Downing, and J.G.G. Larscheid. 2010. Common carp (Cyprinus carpio), sport fishes, and water quality: ecological thresholds in agriculturally eutropic lakes. Lake and Reservoir Management 26:14-22. Kerr, S. J., and T. A. Lasenby. 2001. Esocid stocking: an annotated bibliography and literature review. Ontario Ministry of Natural Resources, Fish and Wildlife Branch, Peterborough. Kozfkay, J. R., L. Hebdon, A. Knight, and J. Dillon. 2007. Regional fisheries management investigations, 2006 Job Performance Report Project F-71-R-31. Idaho Department of Fish and Game, Boise. Kozfkay, J. 2011. Idaho Department of Fish and Game news release: dealing with Lake Lowell’s carp. August 8, 2011. Available at: https://idfg.idaho.gov/press/dealing-lake-lowells-carp Accessed August 15, 2019. Lawrence, G. E. 1950. The diving and feeding activity of the Western Grebe on the breeding grounds. Condor 52:3-16. Montana Fish, Wildlife, and Parks. 2005. Draft Environmental Assessment. Introduction of sterile tiger muskellunge in Lake Elmo and Lake Josephine, Billings, MT. O’Keefe, D. 2016. Tiger muskies: to stock or not to stock. Michigan State University Extension News. Available at: https://www.canr.msu.edu/news/tiger_muskies_to_stock_or_not_to_stock_okeefe16 Accessed August 15, 2019. Pecor, C. H. 1978. Intensive culture of tiger muskellunge in Michigan during 1976 and 1977. Transactions of the American Fisheries Society Special Publication 11:202-209. Stein, R. A., Carline, R. F., and R. S. Hayward. 1981 Largemouth bass predation on stocked tiger muskellunge. Transactions of the American Fisheries Society 110:604-612. Storer, R. W. and G. L. Nuechterlein. 1992. Western and Clark’s Grebe. In The Birds of North America, No. 26 (A. Poole, P. Stettenheim and F. Gill, editors). Academy of Natural Sciences, Philadelphia, and American Ornithologists Union, Washington D.C. Available at: https://birdsna.org/Species-Account/bna/species/wesgre/foodhabits Accessed August 15, 2019. Tipping, J. 2000. Mayfield Lake Tiger Muskie Report for 1999. Annual Report #FPA00-03. Washington Department of Fish and Wildlife, Fish Program, Fish Management Division. USFWS (U.S. Fish and Wildlife Service). 2015. Comprehensive Conservation Plan, Deer Flat NWR. Available at: https://www.fws.gov/refuge/Deer_Flat/what_we_do/planning.html Accessed August 15, 2019. Zambrano, L., M. Scheffer, and M. Martinez-Ramos. 2001. Catastrophic response of lakes to benthivorous fish introductions. Oikos 94:344-350.

Refuge Compatibility Determination for Fish Stocking at Deer Flat National Wildlife Refuge

Use is compatible with stipulations.

Project Leader Approval: ______(Signature) (Date)

Concurrence:

Regional Chief, National Wildlife Refuge System: ______(Signature) (Date)