Chapters 1 - U.S. Fish and Wildlife Service

Environmental Consequences
to mammals (Thompson et al. no date), while no effects to mammals would be expected as a result
of the use of Agnique MMF. Phenothrin (Anvil) is not known to be acutely toxic at high exposure
levels to humans or mammals, but exhibits low acute toxicity by oral, dermal, and inhalation routes
of exposure (USEPA 2008b). The data also indicates that piperonyl butoxide does not effectively
act as a pyrethroid synergist in mammals.
Public Use
As no new public use opportunities are proposed under Alternative B, the effects to mammals
would be the same as those described for Alternative A.
5.4.3 Alternative C (Proposed Action) – Optimize Upland/Wetland Restoration, Improve
Opportunities for Wildlife Observation
5.4.3.1 Effects to Waterfowl, Seabirds, Shorebirds, and Other Waterbirds
Wildlife and Habitat Management
Management actions under Alternative C would be similar to those provided under Alternative B.
The primary difference between the two alternatives involves the types of habitats that would be
restored. Under Alternative C, there would be a greater mix of upland and wetland/upland
transitional habitat restored than is proposed in Alternative B. Despite this difference, the effects
to waterbirds of implementing the restoration proposals included under Alternative C would be
generally the same as those described for Alternative B.
The proposal to improve the habitat quality within a portion of the Refuge’s cordgrass-dominated
salt marsh habitat would have a temporary adverse effect on waterbirds as a result of the
disturbance and temporary loss of habitat from placing a thin layer of soil on top of the existing
cordgrass vegetation. This activity would occur outside of the nesting season and outside of peak
migration periods to minimize impacts to avian species present in the marsh. Only a small portion
of the marsh would be impacted at any one time and cordgrass would be expected to grow up
through the soil within several months, therefore, impacts would be short in duration and limited in
area resulting in less than significant impacts to avian species. This activity is expected to improve
habitat quality within cordgrass habitat resulting in benefits to a variety of marsh-dependent avian
species.
The removal of the drop tower would eliminate a current great blue heron nesting site. In 2009,
approximately three pair of herons nested on the drop tower and similar numbers of nesting pairs
have used the tower over the last several years (pers. comm. John Fitch, April 7, 2010). Herons
have also been observed nesting in the eucalyptus trees on NWSSB near the recreational vehicle
park, located to the northwest of the Refuge, and on buoys in the outer portion of Anaheim Bay.
The drop tower supports relatively few nesting herons compared to other known nesting sites in
Orange County, including nesting sites at Anaheim Lake, where up to 50 nesting pairs have been
observed and Irvine Lake where up to 40 nests have been observed (Hamilton and Willick 1996).
Although the removal of the drop tower would displace nesting herons, the elimination of this
nesting site would not represent a significant adverse impact to the regional population of nesting
great blue herons. Other nesting opportunities are available in the area, including elsewhere on
NWSSB, at Bolsa Chica, and in various locations in adjacent Huntington Beach and Long Beach.
Pest Management
The analysis of potential effects to waterfowl, seabirds, shorebirds, and other waterbirds from the
implementation of the IPM and Mosquito Management Plans would be the same under this
Draft Comprehensive Conservation Plan 5-51