Chapters 1 - U.S. Fish and Wildlife Service

Environmental Consequences
to the OCVCD, as well as compliance with the BMPs included in the Mosquito Management Plan.
The potential for impacts related to specific control products used or proposed for use on the
Refuge would be the same as those described in Sections 5.4.2.1 and 5.4.2.2.
Public Use
The effects of continuing the existing public use program, as proposed under Alternative B, would
result in the same effects as described under Section 5.5.1.5.
5.5.3 Alternative C (Proposed Action) – Optimize Upland/Wetland Restoration, Improve
Opportunities for Wildlife Observation
5.5.3.1 Effects to California Least Tern
Wildlife and Habitat Management
The effects to the California least tern of implementing the actions described in Alternatives A and
B would also be realized under Alternative C. Of the additional actions proposed under Alternative
C, only the proposal to remove the drop tower would have an effect on the California least tern.
Removal of the drop tower located at the end of 7 th Street would eliminate a significant avian
predator perching spot. The drop tower is currently used by raptors, corvids, and great blue
herons, all of which are known to prey on least tern adults, chicks, and/or eggs. Therefore, the
removal of this tower would represent a benefit to the tern colony. Removal of the drop tower
would occur outside of the breeding season to avoid any direct or indirect impacts to nesting least
terns as a result of demolition. The differences in proposed habitat restoration between
Alternatives B and C would have no effect on the least tern colony.
Pest Management
The analysis of potential effects to the California least tern from the implementation of the IPM
and Mosquito Management Plans would be the same under this alternative as described previously
for Alternative B.
Public Use
The limited increase in public use activities on the Refuge, as proposed under Alternative C, would
have no effect on California least terns, as no public access is permitted in proximity to NASA
Island during the tern nesting season. The elevated observation platform would be located a
sufficient distance from the nesting colony to prevent its use as an avian predator perch and would
therefore have no effect on least terns.
5.5.3.2 Effects to Light-footed Clapper Rail
Wildlife and Habitat Management
The effects to the light-footed clapper rail of implementing the actions described in Alternatives A
and B would also be realized under Alternative C. Of the additional actions proposed under
Alternative C, the proposals to remove the drop tower and to study and implement actions to
improve the quality of the cordgrass-dominated salt marsh habitat on the Refuge would have an
effect on the light-footed clapper rail. Removal of the drop tower, which sits at the edge of the
marsh, would eliminate a substantial perching structure, where avian predators known to prey on
adult rails and chicks have been observed. The removal of this structure is therefore likely to
benefit rails. Removal of the drop tower would occur outside of the breeding season to avoid any
direct or indirect impacts to nesting rails as a result of demolition.
Draft Comprehensive Conservation Plan 5-63