Draft Compatibility Determination for Mosquito Management Umatilla NWR
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
Draft Compatibility Determination for Mosquito Management
Umatilla NWR
Title
Draft Compatibility Determination for Mosquito Management, Umatilla National Wildlife
Refuge
Refuge Use Category
Pest and Predator Management
Refuge Use Type(s)
Mosquito Management
Refuge
Umatilla National Wildlife Refuge
Refuge Purposes and Establishing and Acquisition Authorities
● “... shall be administered by him [Secretary of the Interior] directly or in accordance with
cooperative agreements ... and in accordance with such rules and regulations for the
conservation, maintenance, and management of wildlife, resources thereof, and its
habitat thereon, ...” 16 U.S.C. § 664 (Fish and Wildlife Coordination Act )
● “... for the development, advancement, management, conservation, and protection of
fish and wildlife resources ...” 16 U.S.C. § 742f(a)(4)
● “... for the benefit of the United States Fish and Wildlife Service, in performing its
activities and services. Such acceptance may be subject to the terms of any restrictive or
affirmative covenant, or condition of servitude ...” 16 U.S.C. § 742f(b)(1) (Fish and
Wildlife Act of 1956)
National Wildlife Refuge System Mission
The mission of the National Wildlife Refuge System (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 (Pub. L. 105-57; 111 Stat. 1252).
Description of Use
Is this an existing use?
Yes. Currently, mosquito monitoring and control on the Refuge is conducted in accordance with
the Service’s Integrated Pest Management (IPM) Policy (569 FW 1). This use is being
Umatilla NWR Draft Compatibility Determination for Mosquito Management 1reevaluated in conjunction with the development of the Mid-Columbia National Wildlife Refuge Complex Mosquito Management Plan (USFWS 2021a). What is the use? The use is mosquito management, defined as “activities undertaken to monitor and control mosquitoes, including pesticide use and vegetation and water management”. The Service would issue annual Special Use Permits (SUPs) to the North Morrow Vector Control District (NMVCD) that would allow the NMVCD to conduct mosquito monitoring on the Refuge, and conduct mosquito control (apply pesticides) on Refuge lands where monitoring data indicate a risk to public health from mosquito-borne disease. While rare, the most often detected virus and cause of mosquito-vectored disease in humans in this area is the West Nile virus (WNV). WNV is an arthropod-borne virus (arbovirus) which is transmitted to humans by the bite of infected mosquitoes. The following mosquito species have been documented to breed on the Refuge: Culex tarsalis, Culex pipiens, Culiseta inornata, Aedes dorsalis, Aedes vexans, Aedes sticticus, Aedes cinereus, Anopheles freeborni, Anopheles punctipennis, and Coquillettidia perturbans. Several of these species are strong fliers and biters of humans or livestock. However, the Refuge only allows mosquito control for human health reasons, and treatment is not intended to eradicate mosquito populations or remove annoyance mosquitoes. The Centers for Disease Control and Prevention (CDC) indicates Cx. pipiens and Cx. tarsalis as the competent vectors of WNV in the northern and western United States, and these species are targeted by the NMVCD for monitoring, disease surveillance, and control on the Refuge. More information on WNV and mosquito-borne disease can be found on the CDC website https://www.cdc.gov/mosquitoes/ (CDC 2019a). Is the use a priority public use? No Where would the use be conducted? The NMVCD conducts mosquito monitoring and control on the Oregon units of Umatilla NWR. Monitoring and control currently focuses on approximately 1,000 acres of palustrine wetlands and riparian habitat along McCormack Slough, within the McCormack Unit (approximately four percent of the total Refuge area). However, specific areas and number of acres monitored and treated would vary from year to year depending on mosquito populations and environmental conditions. Most of McCormack Slough is a lacustrine wetland. Palustrine wetlands (approx. 450 acres) lie along shorelines of McCormack Slough, and are managed as moist-soil habitat. Approximately 550 acres of the McCormack Unit is riparian habitat. When would the use be conducted? During an average mosquito monitoring period, NMVCD field technicians assess larval mosquito populations between the months of April through October. Monitoring activities may occur at Umatilla NWR Draft Compatibility Determination for Mosquito Management 2
any time during the day. Mosquito monitoring crews may require one-half to one full day to conduct monitoring activities and the frequency would depend on mosquito activity which is in turn dependent on environmental conditions such as temperature. The more active the mosquitoes become, the greater the monitoring frequency. Monitoring frequency may range from once every two weeks to once every three days. Whenever water levels are changing on the Refuge, dipping occurs more often. Sampling (pooling) of adult mosquitoes for disease surveillance would begin weekly in June. Treatment thresholds may be reached or exceeded at any point during the monitoring season from April through October. Larval treatments may occur anytime during the daylight hours. The frequency of larval treatments depends on the larvicide’s persistence, rate of post treatment mosquito recovery, and species-specific seasonal development, which in turn depends on environmental conditions. Larval treatment frequency may range from once per seven days to once per month. Actual treatment of breeding sites depends on larval populations, but the majority of larvicide treatments would occur May through July. Adult thresholds may be reached or exceeded at any point during the monitoring season from April through October. Treatments with adulticides by NMVCD off-Refuge have typically peaked in June and July, extending into August in some years. Adult mosquito treatments on the Refuge would occur during early morning or evening hours. Under this MMP, only one adulticide treatment would be authorized annually. Additional adulticiding may occur if a public health emergency is declared, but that action would fall under the Service’s emergency regulations and is outside the scope of the MMP. How would the use be conducted? The use would be conducted in accordance with the Mid-Columbia National Wildlife Refuge Complex Mosquito Management Plan (MMP; USFWS 2021a) and the Service’s Handbook for Mosquito Management on National Wildlife Refuges (USFWS 2018), which describe the management actions necessary to protect sensitive species and biological integrity and ecological health on the Refuges, while authorizing local mosquito control organizations to manage mosquitoes on refuge lands when necessary to ensure the health and welfare of surrounding human populations. The MMP follows the Service’s IPM policy, which directs managers to use the most effective control method or combinations of methods that pose the lowest risk to fish, wildlife, and their habitats. Following long-standing IPM principles that include surveillance/monitoring and thresholds that document the need for mosquito control treatments, the Refuge would work with the NMVCD to implement the MMP to reduce the risk of public health threats due to mosquitoes on the Refuge, as necessary. Under the Plan, the Service would issue annual SUPs that allow the NMVCD to conduct mosquito monitoring and control activities on the Refuge. The SUP would describe access, restrictions, vehicle access, and information regarding sensitive habitats/species. Mosquito Monitoring: The NMVCD employs the dip count method to monitor larval stage and identify species, which informs the need for larvicide application (USFWS 2018). For adult mosquito monitoring, the NMVCD uses a combination of CDC-approved carbon dioxide baited Umatilla NWR Draft Compatibility Determination for Mosquito Management 3
traps (USFWS 2018) to estimate the mosquito abundance and identify species. Gravid traps and/or light traps may also be used. The NMVCD conducts pathogen surveillance through trapping and testing of adult mosquitoes. Presence of pathogens in mosquitoes is detected directly by the NMVCD and may be sent to Oregon State University Veterinary Diagnostic Lab for confirmation. They also consider positive pathogen reports for bird and equine samples. Mosquito Control: Application of Service-approved larvicides or adulticides would be authorized if specific action thresholds were reached. For larvicides, the Action Threshold would be an average of 3 larvae per dip when WNV-comptent mosquito species are documented on the Refuge. Adulticiding would be authorized when a Minimum Infection Rate (MIR) of 4 is found in pools of adult mosquitoes collected on the Refuge, or when a public health authority has determined and communicated with the refuge staff in writing that there is a risk to public health from mosquitoes on-refuge. For detailed information on action thresholds, see the MMP (USFWS 2021a). Pesticide Use Proposals (PUPs) must be approved for each mosquito larvicide or adulticide proposed for use, and must include specific information on formulations, application rate, and the location, timing and method of application. PUPs consider effects to nontarget species of not only the active ingredients in pesticide formulations, but other ingredients such as adjuvants and synergists. An adjuvant is a substance that is added to a pesticide product or pesticide spray mixture to enhance the pesticide's performance and/ or the physical properties of the spray mixture. Synergists are chemicals that can boost the pesticidal activity of an active ingredient. Synergists typically have little, if any, activity against the pest when used alone. However, EPA policy is to include synergists in the active ingredient statement on the product label (Martin et al. 2011). Synergists such piperonyl butoxide (PBO) are commonly mixed with pyrethrin or pyrethroid-based insecticides. For detailed information on the mosquito larvicides and adulticides described below, see the Service’s Mosquito Management Handbook (USFWS 2018). The preferred larvicides contain the active ingredient Bacillus thuringiensis serovar israelensis (B.t.i.) or Lysinibacillus sphaericus (L.s.), which are derived from naturally-occurring soil bacteria. Bti and Ls act as a larval mosquito stomach poison and must be ingested by the larval form of the insect in order to be effective. Bti is highly targeted to flies belonging to the suborder Nematocera: mosquitoes (Culicidae), black flies (Simuliidae), and midges (Chironomidae), while Ls is highly specific to mosquito larvae. Bti and Ls have low risk to non- target organisms (other insects, aquatic invertebrates. fish, amphibians, reptiles, birds, and mammals). Due to this highly targeted specificity, Bti and Ls are preferred for routine use on a refuge and PUPs may be approved by the Refuge Manager. Larvicides can be applied through a variety of methods including hand application, backpack sprayers, low-pressure amphibious tracked vehicles, truck-mounted equipment, and aerial sprayers. Umatilla NWR Draft Compatibility Determination for Mosquito Management 4
Less-preferred larvicides containing the active ingredients S-methoprene (a synthetic mimic of the naturally produced insect juvenile hormone, which interferes with maturation of insect pupae) and spinosad (a contact neurotoxin that disrupts the nicotinic acetylcholine receptors in insects). These larvicides are nontoxic to mammals, birds, fish, reptiles, and amphibians, but they target a wide array of invertebrates and therefore would rarely be approved for use, and only when preferred larvicides failed to achieve the desired reduction in larval populations of WNV-competent mosquito species. PUPs for larvicides containing S-methoprene and spinosad must be approved at the regional level. Under the MMP, the Refuge would allow up to one application annually of preferred adulticides containing pyrethrins or pyrethroids as active ingredients, if the action threshold for adulticiding is met. Pyrethrins are naturally occurring compounds extracted from chrysanthemum plants. Pyrethroids have similar molecular structure to pyrethrins, but are synthetically derived. Pyrethrins and pyrethroids are sodium channel blockers and are less toxic to birds and mammals than organophosphate insecticides. However, they are toxic to fish, bees, and other pollinators. Non-target toxicity may occur in either terrestrial or aquatic species as a result of deposition, runoff, inhalation, or ingestion. Therefore, application methods and timing that minimize effects to non-target organisms would be used (see Effects below). Adulticides are applied as aerial (helicopter or fixed-wing) sprays or truck-mounted ground- based fogs as ultra-low volume (ULV) sprays (very fine droplets). Aerial drift is a part of application because these sprays are most effective on, and are intended to target, flying insects. Naled is an organophosphate mosquito adulticide that affects the nervous system by disrupting the enzyme that regulates the neurotransmitter acetylcholine. Generally, organophosphates would not be authorized for use on the Refuge because of their known impact to a broad spectrum of insects and aquatic life. Approval for use may occur only when preferred adulticides failed to achieve the desired reduction in populations of WNV-competent mosquito species. PUPs for all adulticides must be approved at the regional level. Why is this use being proposed? The need for mosquito management (monitoring and control) on Umatilla NWR is to keep populations of mosquito species that are known vectors of West Nile virus (WNV) and other arboviruses, e.g. the western equine encephalitis (WEE) and St. Louis encephalitis (SLE) viruses, below thresholds that would pose a threat to human health, while meeting the Service’s priorities and mandates as outlined by the NWRSAA to “ensure that the biological integrity, diversity, and environmental health of the NWRS are maintained” and that “the purposes of each refuge are carried out” 16 U.S.C. 668dd(a)(4)). The Service considers mosquitoes to be a natural component of ecosystems, but also recognizes that mosquitoes may pose a threat to human health. The presence of West Nile Virus (WNV) has been documented in Refuge mosquito populations, and there is potential for other mosquito-borne diseases to occur. Therefore, there is a need to authorize the NMVCD to Umatilla NWR Draft Compatibility Determination for Mosquito Management 5
monitor and sometimes to manage mosquito populations that occur on Refuge lands, especially
lands that are in proximity to human populations, to protect human health and welfare.
Availability of Resources
The analysis of cost for administering and managing each use will only include the incremental
increase above general operational costs that we can show as being directly caused by the
proposed use.
Cost of mosquito monitoring and control would be borne by the NMVCD. One-time costs to the
Service to prepare the Mosquito Management Plan, EA, and CD are estimated at $40,000.
Recurring (annual) costs to the Service to administer the use include Refuge staff time needed
to prepare the annual SUP and coordinate with the North Morrow VCD. Service coordination
with the VCD would include communication with the District on timing of habitat treatments
and VCD activities, and review of the VCD’s monitoring data and post-season report. Refuge
and/or Regional Office staff time would be needed to prepare, review, and approve PUPs.
Expenses for staff time are estimated at $2,500 annually and would be covered under existing
salaries. Existing refuge resources are adequate to administer the use.
Anticipated Impacts of the Use
The effects and impacts of the proposed use to Refuge resources, whether adverse or
beneficial, are those that are reasonably foreseeable and have a reasonably close causal
relationship to the proposed use. This CD includes the written analyses of the environmental
consequences on a resource only when the impacts on that resource could be more than
negligible (or in the case of ESA-listed species, have the potential to be more than negligible)
and therefore considered an “affected resource.” Air quality, water quality, geology and soils,
and cultural resources will not be more than negligibly impacted by the action, and have been
dismissed from further analyses. Since CDs must be consistent with approved plans and
associated NEPA documents, we adopt the effects analysis in the Environmental Assessment for
the Mid-Columbia National Wildlife Refuge Complex Mosquito Management Plan (MMP EA;
USFWS 2021b) here. For more detail on effects, refer to the MMP EA.
Factors that influence the effects of the use include:
• Estimated number of VCD staff that access the Refuge at one time to conducting
mosquito monitoring/control
• Number and type of vehicles used to conduct monitoring and control
• Total acres and acres of specific habitats where monitoring and control occurs
• Percent of refuge or specific habitats affected
• Timing and frequency of monitoring or control activities
• Which mosquito monitoring and control techniques would be permitted, including
specific larvicides and adulticides
• Sensitivity of specific refuge resources to disruption, disturbance, or specific mosquito
management techniques
Umatilla NWR Draft Compatibility Determination for Mosquito Management 6Potential impacts of a proposed use on the refuge's purpose(s) and the Refuge System mission The proposed use has the potential to impact the Refuge’s ability to meet its purposes of the “development, advancement, management, conservation, and protection of fish and wildlife resources.” The use also has the potential to impact the biological diversity, integrity, and health of the Refuge as mandated under the NWRSAA (16 U.S.C. 668dd(a)(4)). However, as described in the Environmental Assessment for the MMP (USFWS 2021b) and summarized below, effects to wildlife resources and to the biological diversity, integrity, and health of the Refuge would be negligible to minor. The use would allow the Refuge to “ensure effective coordination, interaction, and cooperation with owners of land adjoining refuges” as mandated by the NWRSAA by providing a consistent framework whereby the Refuge would work with local public health authorities to monitor, and were necessary control, mosquito species that may pose a threat to human health while adhering to our mission to conserve wildlife and habitats and maintain biological integrity, diversity, and health of the NWRS. Short-term impacts Impacts to Mosquitoes: We would expect short-term, localized reduction in mosquito abundance, and possibly changes in the relative abundance of mosquito species, in areas targeted for treatment (approximately 1,000 acres, including approximately 450 of the Refuge’s 851 acres of of the palustrine wetlands (53%) and 553 of the Refuge’s 1,500 acres of riparian habitat (37%). However mosquitoes would not be eradicated from either the treatment areas, or the Refuge. On the Refuge as a whole, impacts to mosquito populations would be minor to moderate over the short term. Impacts to Non-Target Invertebrates (Terrestrial Invertebrates, Aquatic Invertebrates): Monitoring activities would not significantly impact invertebrates. Chemical mosquito treatments may adversely impact non-target invertebrate populations. Bti is highly targeted to mosquitoes, black flies, and midges, and has not been found to be toxic to terrestrial or aquatic invertebrates. Ls is a very targeted larvicide for mosquitoes and has no demonstrated toxicity for midges or other invertebrate larvae. Overall, the preferred larvicides Bti and Ls are very targeted and have minimal impact on non-mosquito invertebrates especially when used at mosquito treatment rates (USFWS 2018). Less preferred larvicides spinosad and S-methoprene are less targeted broad-spectrum pesticides and can negatively impact all larval insects that it comes in contact with. Spinosad and S-methoprene are not preferred by the Service and their use would rarely be authorized; therefore larviciding would have a minimal impact on non- target invertebrates. Adulticides, specifically pyrethrin and pyrethroid-based insecticides applied as ultra low-volume (ULV) sprays, are less targeted than larvicides and are toxic to both terrestrial and aquatic invertebrates. The aerial application of adulticides could also lead to drift resulting in greater interaction with non-target invertebrates on and off the Refuges. Non-target toxicity may occur Umatilla NWR Draft Compatibility Determination for Mosquito Management 7
in terrestrial or aquatic species as a result of deposition, runoff, inhalation, or ingestion. Adulticides are particularly toxic to aquatic invertebrates at low concentrations so pesticide drift, deposition, and runoff could have a large impact on aquatic invertebrates. Adulticides are also toxic to pollinators such as bees and butterflies. Oberhauser et al. 2006 experimentally showed that permethrin mosquito treatments (pyrethroid based adulticide) are specifically toxic to monarch larvae and adults and this toxicity can persist in the environment and on monarch food sources (milkweed plants) for up to 21 days. The use of adulticides would have a particularly negative impact on pollinators on Umatilla NWR due to the close proximity of pollinator buffers to mosquito breeding habitat in the McCormack Slough. Application of adulticides near the pollinator buffers could potentially kill beneficial pollinators. Impacts to these non-target organisms would be minimized by: (1) applying adulticides in the evening or early morning hours to target times of the day when the majority of mosquito species are active and other insects (e.g., butterflies, bees) are less likely to be flying; (2) using truck-mounted sprayers where feasible since they provide more targeted adulticide treatments and minimize spray drift adjacent to sensitive refuge resources; (3) Applying adulticide when winds are 3-7 mph and directionally away from sensitive resources as identified by the refuge staff; and (4) Implementing buffers and no-spray zones implemented when sensitive resources are present. Mosquito, black fly, and midge larvae provide a food source for aquatic invertebrates such as dragonfly and damselfly larvae. Larvae treated with Bti and Ls are still available to aquatic insects. Trophic level effects could potentially occur from the reduction in larval populations, but we expect the effect to be minor. Impacts to Birds, Mammals, Reptiles, and Amphibians: Larvicides (Bti and Ls) only affect mosquitoes, black flies, and midges, and have no direct toxicity to amphibians, reptiles, birds, or mammals. Less preferred larvicides S-methoprene and spinosad would rarely be authorized for use on the Refuge, but also have no direct toxicity to these taxa. Pyrethrin and pyrethroid-based adulticides applied at mosquito treatment rates have been shown to be nontoxic to mammals and birds, and there is no known direct toxicity to amphibians and reptiles. The primary impact to birds and other wildlife would be disturbance caused by monitoring and control to bird species that use riparian and wetland habitat in spring and summer. The footprint of disturbance would be approximately 1,000 acres of the McCormack Unit, or four percent of the Refuge’s total area. This area includes approximately 450 of the Refuge’s 851 acres of palustrine wetlands (53%) and 553 of the Refuge’s 1,500 acres of riparian habitat (37%). (See MMP, Map 5). Disturbance to birds and other wildlife (reptiles, amphibians, and mammals) is a concern associated with mosquito monitoring and control. Mosquito monitoring and treatment activity, especially during the spring and summer breeding season, may disturb wildlife and may result in some bird species altering their behavior. The majority of mosquito monitoring and treatment would occur during the summer months of May through August. Waterfowl Umatilla NWR Draft Compatibility Determination for Mosquito Management 8
populations are very low at this time of year, so effects on waterfowl would be negligible. Disturbance to migrating and breeding shorebirds, passerine birds, and landbirds could occur. The Refuge’s riparian areas contain continuously occupied great blue heron and great egret rookeries. Mosquito monitoring occurring in early spring may overlap with heron nesting in February-April, potentially disturbing sensitive nesting behavior. The presence of people near rookeries may cause nestlings to fall out of trees, increasing their vulnerability to predation, or cause adults to abandon the rookery (Buckley and Buckley 1978). Disturbance would generally expected to be minor because site visits are infrequent (see When would the use be conducted, above) and generally only one or two VCD or Refuge personnel would be present at any given time. To minimize the potential for disturbance to rookeries and sensitive species, Refuge staff would work with the VCD to identify rookery locations, create appropriate buffers for application activities, and monitor the presence of sensitive and breeding birds. Low-flying aircraft used to apply larvicides and/or adulticides will cause disturbances to wildlife, but overall the disturbance impact would be minor given the small number of such treatments. Birds, reptiles, amphibians, and mammals on the Refuge may be affected by pesticide use through reduction in food resources. Targeted larvicides, Bti and Ls, only kill mosquitoes, black flies, and midges, which represent only a small portion of insect food sources utilitzed by birds (such as swallows) or bats in terms of biomass. Pyrethrin and pyrethroid-based adulticides would have a greater impact on food resources because they are toxic to most invertebrates and fish. Impacts to aquatic invertebrates and fish would be of particular concern since these are an important food sources for breeding waterfowl and waterbirds in spring and summer. However, we expect these impacts to be minor, for several reasons, including the infrequent use of adulticides (not every year, and once per year when used), the limited area and duration of adulticide use, the rapid degradation of pyrethin-based adulticides, the timing of application (at dusk when day-flying insects are not active), and measures taken to minimize drift and runoff into aquatic habitat. Insect taxa most likely to be affected by adulticiding would be small- bodied species that are active at dusk or during the night. Therefore, although reductions in invertebrate food sources would be expected, trophic effects to birds would be minor overall. Impacts to Fish (including ESA listed species): Larvicides (Bti and Ls) only affect mosquitoes, black flies, and midges, and have no direct toxicity to fish. Less preferred larvicides S- methoprene and spinosad would rarely be authorized for use on the Refuge, but also have no direct toxicity to fish. Pyrethrin and pyrethroid-based adulticides are toxic to fish. However, there would be negligible impacts to fish, including listed salmonid species, based on their general absence from treatment areas and/or during treatment periods. And the policy of the NMVCD to not apply pesticides to surface water in or directly flowing into or out of the major rivers of the area. Impacts to Habitat: Pesticides (larvicides and adulticides) are non-toxic to plants and would not directly impact vegetation. However, many mosquito monitoring and control actions would require off-trail and off-road access to certain areas of the Refuge. This access would result in Umatilla NWR Draft Compatibility Determination for Mosquito Management 9
vegetation being disturbed by trampling and potentially damaged by equipment. Vehicles with tires would remain on established roads and monitoring activities are conducted on foot. The impacts of monitoring would be confined to pathways along shorelines where dip net samples will be taken or traps will be placed and checked. Therefore, small areas of vegetation may be crushed in transit to monitoring sites. Sensitive habitats such as wetland and wet meadow habitats would be particularly vulnerable to this damage because of the presence of fragile rhizome mats and other vegetative structures. Vehicles and equipment could create ruts in wetland habitats damaging fragile root structures and potentially creating additional areas for pooling that is attractive for mosquito breeding (CDC 2019). Equipment and human access to these habitats could also introduce and spread invasive species in these sensitive habitats. Since adulticides are toxic to all insects, adulticiding could impact the number of pollinator species present to pollinate native vegetation on the Refuge. The Refuge staff would work with the VCD to identify particularly sensitive areas and implement best management practices to mitigate the impact. The Refuge staff would provide maps, when feasible, that indicate sensitive habitats and locations harboring sensitive species where treatment or other related activities should be avoided or minimized. The VCD would use best management practices to limit the spread of invasive species and disturbance including pressure-washing vehicles before entering sensitive habitats, using tracked vehicles, and conducting activities on foot where feasible. Impacts to Visitor Use and Experience: Public uses that occur on the McCormack Unit during times where mosquito monitoring and control would occur include wildlife observation, photography, environmental education, and interpretation, which mostly occur on the Heritage Trail and Auto Tour Route, and fishing in the Columbia River and McCormack Slough. Hunting occurs in fall and winter, at times when mosquito management does not occur. The presence of VCD staff for mosquito monitoring and treatment during the spring and summer might slightly impact visitors’ experiences. However, most mosquito treatment and surveillance activities would occur away from public use areas. Exposure of visitors to larvicides is unlikely due to targeted application. Even in the event of exposure, larvicides authorized for use on the Refuge are not toxic to humans. Exposure to adulticides is even less likely treatment would be authorized only once per year, and would occur at night when the refuge is closed to the public. Although the Services does not control nuisance mosquitoes, preventing of adult flyoffs as a result of larval mosquito control to reduce public health threats would also reduce mosquito nuisance to Refuge visitors. Impacts to Human Health and Surrounding Communities: The McCormack Unit of Umatilla NWR is 2.5 miles from the town of Irrigon, OR and six miles Boardman, OR. Neighboring communities, farms, and residences are affected by mosquito flyoffs from the Refuge (MMP, Map 8). As noted above, WNV is present in local mosquito populations but human cases in the area are rare. Effects to local communities are due to nuisance mosquitoes. Although the Service does not control nuisance mosquitoes, preventing of adult flyoffs as a result of larval Umatilla NWR Draft Compatibility Determination for Mosquito Management 10
mosquito control to reduce public health threats would also reduce mosquito nuisance to
nearby residents and farm workers.
Long-term impacts
As noted above, reductions in mosquito populations or changes in relative abundance of
mosquito species would be short-term and localized. Overall, mosquito populations in the
Refuge area would be determined by environmental conditions over time.
Over the long-term, mosquito monitoring and management would assist local public health
authorities in reducing risks to public health from mosquito-borne disease by controlling
populations of mosquito species that are competent vectors of West Nile virus. In addition,
allowing the North Morrow Vector Control District to monitor mosquitoes on the Refuge would
assist public health authorities in detecting changes in mosquito populations and mosquito-
borne disease over time.
Public Review and Comment
This draft compatibility determination will be available for public review and comment for 14
days in conjunction with the public comment period for the Draft Mid-Columbia National
Wildlife Refuges Mosquito Management Plan and Environmental Assessment. The public will be
made aware of this comment opportunity through letters to affected Mosquito Control
Districts. It will be made available electronically on the refuge website
(https://www.fws.gov/refuge/Umatilla/). To request a hard copy, contact the Refuge Manager
at mcriver@fws.gov or call 509-546-8300. Concerns expressed during the public comment
period will be addressed in the final Compatibility Determination.
Determination
Choose an item.
Stipulations Necessary to Ensure Compatibility
1. Mosquito monitoring and control will be conducted in accordance with the Mid-
Columbia NWR Complex Mosquito Management Plan (MMP). Mosquito monitoring and
control would be authorized on an annual basis by a Special Use Permit (SUP), which will
specify access conditions and restrictions, larvicide treatment locations and products for
VCD operations on Refuge lands, and reporting requirements. Use of mosquito
adulticides is not included in the Special Use Permit.
2. In advance of each season, the Refuge will share information on major habitat
management actions, such as shoreline modification, that could impact mosquito
control operations and help mosquito control organizations with the planning of
monitoring and treatment activities.
3. SUP conditions will stipulate that all mosquito control work will be carried out under the
guidance of a preapproved Pesticide Use Proposal (PUP).
Umatilla NWR Draft Compatibility Determination for Mosquito Management 114. Only Service-approved pesticides may be applied on Refuge lands and waters, and only
after PUPs have been approved.
5. Action threshold levels described in the MMP will determine whether treatments will be
authorized by the Refuge Manager. Larval control is to be conducted only when and
documented mosquito species vectoring pathogens occur on refuge and action
thresholds are exceeded.
6. Adult control is to be conducted only when documented mosquito species vectoring
pathogens occur on refuge and either (1) the action threshold is exceeded and
monitoring data shows an increasing trend for WNV positive on-refuge pools over time
or (2) the public health authority submits a request based on a risk to human health
from WNV transmission due to on-refuge mosquitoes.
7. When the threshold for adulticide treatment is reached, the mosquito control
organization must contact the Refuge Manager (1) in writing (email) and include (2) the
data necessary to document that the threshold has been met and (3) the proposed
application date, to receive authorization to proceed with an application of adulticide.
Application cannot proceed until the Refuge Manager provides authorization in writing.
8. The Refuge and the VCD will meet annually after each season to discuss management
results and future needs. Critical time periods and sensitive areas with breeding and
nesting birds will be discussed at the annual meeting so that the VCD can avoid
disturbing wildlife and use the least intrusive methods of control and access into these
sensitive areas.
9. Reporting requirements are contained within the annual Special Use Permit (SUP). The
VCD shall submit an annual post-season report to the Refuge Manager. Reports should
include annual monitoring results for both larvae and adult mosquitoes and pathogen
surveillance data, such as positive pools and number of pools tested and/or submitted
for confirmation. Reports should also provide information on treatment activities,
including pesticide product(s) applied, amount of pesticides applied, locations of
application, dates, and method of application.
10. The VCD shall limit the spread of noxious weed seeds from vehicles used in wetland
areas by cleaning of vehicles after each day of use when in areas with noxious weed
problems (e.g., knotgrass, purple loosestrife, false indigo, reed canary grass, phragmites,
yellow flag iris).
11. The VCD shall reduce risk of wildfire ignition by operating trucks and other vehicles on
Refuge roads, and refraining from driving or parking on dry vegetation.
12. At this time, natural resource and compliance monitoring are not required for the
mosquito management actions implemented on the Refuge. If information on sensitive
resources and impacts from the mosquito management activities change, natural
resource monitoring and compliance monitoring/reporting may be re-considered in
coordination with the mosquito control organizations.
13. The Refuge may modify or rescind this CD at any time based on future Service policy
determinations or scientific studies of the effects of pesticides on the environment or
nontarget organisms.
Umatilla NWR Draft Compatibility Determination for Mosquito Management 12Justification The stipulations outlined above would help ensure that the use is compatible with the establishing purposes of Umatilla NWR and the mission of the National Wildlife Refuge System. Mosquito management, as outlined in this compatibility determination, would be conducted in accordance with the Service’s Integrated Pest Management policy (569 FW 1) which directs managers to use the most effective control method or combinations of methods that pose the lowest risk to fish, wildlife, and their habitats. Therefore, the use would not conflict with the national policy to maintain the biological diversity, integrity, and environmental health of the refuge. Based on available science and best professional judgement, the Service has determined that allowing the North Morrow Vector Control District to conduct mosquito monitoring and, where necessary to protect public health, control mosquitoes on Umatilla NWR in accordance with the stipulations provided here, would not materially interfere with or detract from the fulfillment of the National Wildlife Refuge System mission or the purposes of the Refuge. Rather, appropriate and compatible mosquito monitoring and management would assist local public health authorities in reducing risks to public health from mosquito-borne disease while minimizing risk to Refuge resources. In addition, allowing the North Morrow Vector Control District to monitor mosquitoes on the Refuge would assist public health authorities in detecting changes in mosquito populations and mosquito-borne disease over time. Signature of Determination Refuge Manager Signature and Date Signature of Concurrence Regional Refuge Chief Signature and Date Mandatory 10- or 15-Year Reevaluation Date Delete this text and insert year for reevaluation Umatilla NWR Draft Compatibility Determination for Mosquito Management 13
Literature Cited/References Buckley, P.A. and F.G. Buckley. 1978. Guidelines for the protection and management of colonially nesting waterbirds. North Atlantic Regional Office, National Park Service, Boston, MA 02109. 54p. CDC 2019a. Mosquitoes. [online] Available at: https://www.cdc.gov/mosquitoes/ [Accessed 6 June 2019]. CDC.gov. 2019b. CDC - NIOSH - Mosquito-Borne Diseases. [online] Available at: https://www.cdc.gov/niosh/topics/outdoor/mosquito-borne/default.html [Accessed 7 June 2019]. Martin, A., Whitford, F., and Jordan, T. 2011. Pesticides and Formulation Technology. Purdue University Extension. 16 pp. URL: https://www.extension.purdue.edu/extmedia/ppp/ppp- 31.pdf#page=13 Oberhauser, K. S., S. J. Brinda, S. Weaver, R. D. Moon, S. A. Manweiler, N. Read. 2006. Growth and survival of monarch butterflies (Lepidoptera: Danaidae) after exposure to permethrin barrier treatments. Environ. Entomol. 35 (6): 1626-1634. USFWS. 2007. McNary and Umatilla NWRs Comprehensive Conservation Plan and Environmental Assessment. Available at: https://ecos.fws.gov/ServCat/DownloadFile/161367 USFWS. 2018. Handbook for mosquito management on National Wildlife Refuges. Available at: https://www.fws.gov/policy/MosquitoHandbook_6_2018.pdf USFWS. 2021a. Draft Mid-Columbia River National Wildlife Refuges Mosquito Management Plan. Available at: https://www.fws.gov/refuge/Umatilla/ USFWS. 2021b. Environmental Assessment for the Mid-Columbia River National Wildlife Refuges Mosquito Management Plan. Available at: https://www.fws.gov/refuge/Umatilla/ Umatilla NWR Draft Compatibility Determination for Mosquito Management 14
You can also read
