Chapters 1 - U.S. Fish and Wildlife Service

Chapter 5
restoration/creation using accepted replacement ratios for the affected native habitat would be
provided.
Predator management is generally conducted from the edges of the marsh and in the vicinity of the
least tern nesting area, therefore, the potential for trampling of sensitive habitat and vegetation is
minimal.
Based on the information provided above, the wildlife and habitat management actions associated
with Alternative A would not result in significant adverse impacts to Refuge habitats or sensitive
vegetation. Rather, the effects to these habitats of implementing this alternative would tend to be
neutral or in some cases beneficial.
Pest Management
Under Alternative A, invasive plant removal involves both mechanical and chemical control
methods, with control focused on invasive, weedy plant species present in the Refuge’s upland and
upland transition areas. The primarily locations on the Refuge where this control occurs include:
the upland area north of the Case Street Pond; the area southeast of the 7 th Street Pond; NASA
Island; and Hog Island. Other focus areas include the shoulders of Bolsa Avenue, Forrestal Lane,
and the east side of Kitts Highway. The use of herbicides to control invasive, nonnative plants,
could adversely impact non-target plants due to pesticide drift, if appropriate application
techniques are not employed. However, the potential for adverse effects is considered minimal
because of the small quantities of herbicide used and the precautionary measures taken during
application, including applying all herbicides in accordance with label requirements. Hand
weeding, rather than spraying, would be conducted in sensitive habitat areas, such as areas
dominated by native salt marsh habitat. If spraying is proposed in proximity to sensitive habitat
areas, the area to be sprayed would first be surveyed for sensitive species and areas to be avoided
during spraying would be flagged or otherwise delineated to ensure avoidance of these areas.
Hand weeding and limited herbicide spraying would also provide minor benefits to habitat areas by
providing opportunities for increased native plant cover.
Activities associated with mosquito management on the Refuge could result in impacts to
vegetation related to trampling. This is of particular concern in areas that support salt marsh
habitat. To minimize such impacts, access into the marsh by mechanized vehicles is prohibited and
mosquito monitoring and control is limited to six specific areas on the Refuge. These areas are
located around the perimeter of the salt marsh complex, and can only be accessed via foot traffic.
If a significant mosquito problem is identified elsewhere on the Refuge, access into the affected
area requires prior approval by the Refuge Manager and OCVCD staff must be accompanied into
the area by authorized Service personnel.
The application of VectoBac 12AS, VectoBac G, VectoLex WDG and Altosid to control mosquito
production on the Refuge is not likely to adversely affect vegetation directly because these
pesticides are not known to harm plants. Although reductions in certain invertebrate populations
as a result of repeated pesticide applications may have the potential to impact specific
invertebrate-plant interactions (e.g., pollination) on the Refuge, because only a limited portion of
the Refuge is subject to mosquito control, the adverse effects to vegetation and habitat quality of
such an impact would be minimal.
Public Use
Activities associated with the existing public use program on the Refuge are limited to existing
roadways, trails, and unvegetated areas to avoid impacts to sensitive habitat and vegetation.
Therefore, the continuation of these programs would not adversely affect any Refuge habitats.
5-32 Seal Beach National Wildlife Refuge