CONSERVATION ACTIONS TO BE IMPLEMENTED

Conservation measures needed for the continued existence of Virgin spinedace focus on two objectives: 1) to eliminate significant threats or reduce those that cannot be completely eliminated to the maximum extent possible, and 2) to stabilize, restore and enhance specific reaches of occupied and unoccupied historic habitat. The goal of these measures is to expand the range so that the species occupies at least 80% (approximately 181 km/112 mi) of its historically occupied habitat. Attainment of the goal and objectives of this strategy would be achieved by imp1ernenting the following management actions: 1) establish existing conditions as a baseline 2) re-establish population maintenance flows 3) enhance and maintain habitat 4) selectively control non-indigenous fish S) maintain genetic viability; 6) monitor populations and habitat and 7) develop a mitigation plan and protocol for future activities

Establish Existing Conditions As A Baseline

All management actions associated with the conservation of virgin spinedace will be evaluated as to their effectiveness. In addition, any modification to the existing conditions upon which Virgin spinedace depend, will be evaluated as to their potential effect on the species. For these purposes, the existing conditions of historic habitat are considered to be this baseline. Three primary attributes will be used to describe existing conditions. 1) basin hydrology averaged over the last 20 years, 2) water rights and depletions, and 3) Virgin spinedace populations .

Re-establish Population Maintenance Flows

Existing flow patterns provide the habitat requirements of the Virgin spinedace in approximately 159 km (99 ni) of the species historic habitat (Table 1. These conditions are described by hydrographs in terms of flow quantity, timing, duration, and frequency. In approximate1y 91 km (57 mi) of historic habitat, stream channels are dry or flows are significantly depleted during the late-summer and early-fall period (Table 1).

Population maintenance flows will be re-established and maintained in approximately 39 km (24 mi) of de-watered historic habitat of the Virgin spinedace in order to reduce habitat fragmentation and to restore populations. These flows will be re-established based on determining the flow requirements of the species using an empirical approach by incorporating components of the conceptual framework outlined by Hill et al. (1991). This empirical approach incorporates current data on flow patterns that are currently maintaining self-sustaining populations in reaches of the Virgin River basin. The process of re-

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~~establishing flows adheres to the following step-wise outline: 1) Estimate population maintenance flows, 2) provide population maintenance flows, 3) Evaluate population maintenance flows, 4) Finalize flows required, and S) protect flows.

Estimate Population Maintenance Flaws

Population maintenance flows currently occur in approximately 15 occupied stream reaches (Table 2). These flows were estimated by comparing Virgin spinedace population numbers, stream flows, and habitat characteristics throughbut the drainage for empirical relationships (Addley and Hardy, 1993; Valdez et al, 1991). A total of 10 reaches have been identified as potential sites for population maintenance flow re-establisbment to reach the goal of 80% of historic habitat (Tables 3 and 4). These reaches were selected because they were identified as areas that are dewatered or experience significant depletions (Table 1). Two reaches have been designated as priority areas toward attaining the goal. The first encompasses approximately 31 km (19 mi) of the Santa Clara River between Gunlock Reservoir and the confluence with the Virgin River. The second encompasses approximately 5 km (3 mi) of the Virgin River between Quail creek Diversion and pah Tempe Springs. Historically, these areas supported common to abundant populations of Virgin spinedace. Additional reaches of Virgin spinedace habitat to have flows restored will include one or a combination of the other reaches listed in Tables 1 and 4.

Evaluate Population Maintenance Flaws

The response of Virgin spinedace populations and habitat to population maintenance flows will be evaluated over a five year period. A detailed study plan will be developed for each stream reach. The study plan will include, but not be limited to, estimations of population abundance, recruitnent, habitat utilization and availability. A progress report will be provided annually. A completion report will be provided at the end of the five year period.

Finalize Population Maintenance Flows Required

A final recommendation for re-establishing population maintenance flows in specific reaches will be developed after completion of the population maintenance flow evaluations. Information obtained from other instream flow studies will be considered in making those recommendations. In the Santa Clara River, the maximum amount of flow provided will not exceed 3 cfs at the point of release.

Protect Population Maintenance Flows

Flow protection measures will be implemented that are consistent with state laws. These measures may include: river operating

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agreements, minimum instream flow rights, irrigation rights, and federal reserved water rights. Instream flows for water-related resource attributes, including native fish, are currently being discussed by the National Park service, the State of Utah, and the washington County water Conservancy District. These discussions are part of ongoing negotiations to determine Federal reserved water rights for Zion National park in the Virgin River adjudication.

Enhance and Maintain Habi tat

Habitat enhancement procedures will be implemented in approximately 26 km (16 mi) of occupied habitat. Enhancement projects will focus on specific factors that contribute to virgin spinedace habitat degradation including: agricultural activities, mining activities, recreational use of riparian zones, and activities that affect water quality (Table 4). Enhancement projects will include maintenance and construction of boundary line fences between federal and private parcels to control unauthorized grazing and recreational (ie: ORV, hiking, etc.) use along the riparian zones, establishment of intensive grazing management programs for federal lands along streams, and development of barriers and conservation easements within the Virgin River floodplain to reduce additional agricultural, recreational, and developmental impacts. Any future projects which alter habitat will be evaluated as described in the mitigation section of this strategy.

Selectively Control Non-indigenous Fish

Non-indigenous fish populations identified in Table 2 will be evaluated in order to identify detrimental effects on Virgin spinedace populations. Management and control of non-indigenous fish will focus on implementation of stocking and introduction procedures as well as control and/or eradication of selected populations of these fish in the Virgin River basin. specific management actions will be developed on a reach-by-reach basis to remove the threats to Virgin spinedace associated with non- indigenous species. Table 4 summarizes reaches where non- indigenous fish management actions will be implemented.

control Fish stocking and rntroductions

The following basin-wide procedures for controlling stocking, introduction, and spread of non-indigenous aquatic species of vertebrates and invertebrates will be implemented by the appropriate agencies. These procedures have been developed using adapted versions of The American Fisheries Society procedures for nonnative fish introductions.




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Stocking of Non-indigenous Species Already Occurring:
SALMONIDS:
several species of salmonids are routinely stocked in the Virgin River Basin. Stocking of salmonids is to be restricted to areas in association with existing salmonid populations OR made in new areas only where they will not conflict with native species of special concern. Areas where salmonids are routinely stocked are presented in Table 5-



OTHER NON-INDIGENOUS SPECIES:



Introduction of a New Species:
Guidelines for introducing a new species to the drainage will follow the "Introduction of Aquatic Species, Environmental Policy Statement of the American Fisheries Society" and the "Non- indigenous Aquatic Nuisance/Prevention and Control Act of 1990"

Prohibited Species:
Non-indigenous minnows (Family: cyprinidae), smallmouth bass (Micropterus dolomieni), green sunfish (Lepomis cyanellus), black crappie (Pomoxis nigromaculatus). all crayfish species (i.e., Astacidae) and all other non-indigenous aquatic species prohibited by respective state regulations or recommended for prohibition by the Colorado River wildlife Council.

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selective Removal of Non-indigenous Fish

Eradication of detrimental non-indigenous fish will be implemented where feasible and controlled to the maximum extent possible where eradication is not possible (Table 4). several species have already been targeted for control and/or eradication including rainbow trout in the upper reaches of Beaver Dam Wash, green sunfish from the Santa Clara River and red shiner in the mainstem Virgin River below the washington Fields Diversion (see below for details) . Engineering feasibility for fish barrier structures to control non-indigenous fish is currently being developed. possible impacts to native species will be evaluated prior to implementation of control and eradication actions.

Upper Beaver Darn Wash:
NDOW will have lead responsibility for an interagency effort to re-introduce Virgin spinedace into historic habitat in Nevada below Schroeder Reservoir. Efforts will be focused on re- creating the historic species matrix which occurred in this reach prior to dam construction, through selective removal of rainbow trout from the reach below Schroeder Reservoir. Virgin spinedace will be obtained from other populations within the Beaver Dam Wash drainage. The anticipated date of re-introduction will be early summer 1995 following the normal peak spring runoff period for upper Beaver Darn Wash. NDOW will provide pre-project assessments, documentation and monitoring of re-introduction efforts .

Santa Clara River:
UDWR will initiate efforts to control and manage green sunfish in the Virgin River basin in ways to benefit native fishes, including Virgin spinedace. The feasibility of chemical renovation projects in the Santa Clara River drainage will be evaluated in respect to controlling or eliminating green sunfish and other exotic fishes that are determined to be a problem.

The overall project will be divided into workable segments that can be treated separately. For example, if upstream sources of green sunfish can be eliminated above Baker Reservoir then, in turn, the stream segment between Baker Reservoir and Moody Wash could be renovated to remove exotic fishes. Providing that upstream treatments are feasible, this area could also be isolated from contamination by exotic fishes from downstream sources. Other project segments could include Moody Wash downstream to Gunlock Reservoir, and from Gunlock Reservoir downstream to the confluence of the Virgin River.

Control of green sunfish in the Santa Clara River below Gunlock Reservoir might be necessary after population maintenance flows are established. In this case, chemical treatments to temporarily reduce exotic fish while Virgin spinedace are re introduced and become established night be needed. Such work

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could be conducted regardless of upstream occurrence of non- indigenous fishes .

Virgin River:
Attempts to eradicate the red shiner from the Virgin River basin, particularly from the washington Fields diversion downstream to the Mesquite diversion, have been conducted in the past. Though these attempts were not 100% effective, they were successful at eliminating red shiners between washington Fields and Johnson diversions. These attempts included construction of fish barriers and chemical treatments with the pesticide rotenone.

chemical procedures to eradicate red shiners will be implemented in 1995 and followed up by subsequent treatments as needed. General chemical treatment methodology will involve 1) approximately 20 drip stations where rotenone will be introduced into the river, 2) spraying Noxfish in standing water areas along stream channels, 3) detoxifying the rotenone in the Virgin River with potassium permanganate. Temporary fish barriers will be constructed in Utah at strategic sites in 1995 to prevent upstream migration of red shiners. These barriers will also assist in dividing the chemical treatments into manageable treatment areas.

Maintain Genetic viability

Protocols for introduction, re-introduction, and sub-basin transfer of Virgin spinedace will be established and utilized.

population and Habitat Monitoring

Virgin spinedace population and habitat monitoring will be implemented. Information obtained from the monitoring process will be used to determine if current management actions are attaining the objectives set forth in the conservation Agreement. In addition, a general assessment of the overall response of other species occurring in the Virgin River basin will be conducted .

Population and habitat monitoring will be implemented cooperatively by participating Virgin spinedace Conservation Team (VSCT) personnel. VsCT responsibilities regarding monitoring actions are described in Table 3 of the accompanying Conservation Agreement. protocols for monitoring will be similar to those established by the Virgin River Recovery Team. A general overview of the methodology is presented below.

Monitoring Plan Methodology
A minimum of 10 stations will be chosen as monitoring points throughout the basin. Once re-establishment procedures have been completed, the number of stations established may increase to include the new areas. sampling will be conducted annually in

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the fall.

Seining will consist of repeated hauls of a 4.6 meters wide x 1.8 meters deep x 3.2 mm mesh seine until depletion (the number of fish captured in a haul is 10% or less of the highest seine catch for that sample site) . samples will be taken from preferred virgin spinedace microhabitats approximately 10 meters in length. In areas where seining is not feasible, electrofisbing methods will be incorporated. These repetitive techniques will primarily provide that the population in a given habitat has been thoroughly sampled. It secondarily provides depletion information for population estimates.

All native fish will be identified to species, counted, measured, and returned to site of capture. All non-indigenous fish will be identified to species, counted, measured and returned to site of capture .

In addition to the sampling described above, virgin spinedace population information will be obtained from data acquired in the bi-annual sampling by the virgin River Recovery Team.

Data obtained on responses of populations and habitat to management actions from the monitoring process will be assessed and evaluated annually by the virgin spinedace conservation team. The effectiveness of the management actions will be measured using empirical criteria to be established for this strategy.

Develop Mitigation Plan and Protocols for Future Activi ties

A mitigation plan and protocols for mitigating future activities will be developed. during 1995. Any new water depletion or habitat alteration of baseline conditions of historic habitat will require prior evaluation, assessment, and approval. Mitigation will be determined based on an evaluation of how baseline conditions would be altered. During 1995, methodologies for conducting this evaluation will be developed. The evaluation will incorporate procedures for determining flow requirements by integrating components of the conceptual framework outlined by Hill et al. (1991).

Descriptions of existing flow patterns will probably include details on the timing, duration, magnitude, slope, and frequency of high-flow events in selected streams along with analyses to determine an average annual hydrograph for timing and slopes of rising and falling limbs. The HEC-2 analysis (U.S. Army Corps of Engineers 1982) may be used to estimate bankfull flows. A frequency-of-occurrence curve may be required to describe the return period for peak flows. A flow duration curve may also be required to describe the flow duration associated with specific exceedence values .


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DESIRED OUTCOME


Implementation of the Conservation Agreement and Strategy will initiate management actions that should provide for the continued existence and recovery of Virgin spinedace. We anticipate that the range of the species WIll be increased to occupy 80% of its historic habitat (Figure 2). The most significant threat to the species has been identified as dewatered-historic habitat (60 km or 37 mi) . This threat will be significantly reduced by providing flows in approximately 39 km (24 mi) of stream channel. We anticipate that this single action will greatly enhance current populations of Virgin spinedace by reducing habitat and population fragmentation, enhancing stream productivity, enhancing water quality, and enhancing the riparian communities. Actions such as non-indigenous fish management and habitat improvement should provide additional benefits by removing negative fish interactions and enhancing impacted habitats.




































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LITERATURE CITED












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