DRAFT Compatibility Determination for Fish Stocking at Deer Flat National Wildlife Refuge
Total Page:16
File Type:pdf, Size:1020Kb
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