Chapters 1 - U.S. Fish and Wildlife Service

Environmental Consequences
Contaminants – Adverse effects related to contaminants are considered significant when
constituents of concern are present in the soil, groundwater, or surface water at levels that
exceed standard screening levels for assessing ecological risk.
5.2.1 Alternative A – No Action
5.2.1.1 Effects to Topography/Visual Quality
Wildlife and Habitat Management
Conducting the wildlife and habitat management activities currently occurring on the Refuge,
including monitoring of listed endangered and threatened avian species; management of NASA
Island to support least tern nesting; trash and debris removal, culvert management, scientific
research, and predator management would not result in adverse effects to topography.
Annual pre-nesting site preparation for the California least tern involves removing weedy
vegetation from the NASA Island nesting site and improving substrate quality when necessary by
spreading additional clean, light sand and shell fragments over some or all of the site; and
addressing any erosion problems around the outer edges of the nesting site. The continuation of
these types of actions would result in negligible changes to the topography within the nesting site;
therefore, no adverse effects related to topography would occur.
Current Refuge wildlife and habitat management activities that could affect visual quality include
the removal of weeds, repair to subsurface culverts, removal of trash and debris, installation of
clapper rail nesting platforms, and yearly maintenance at the NASA Island California least tern
nesting site. While some of these activities, including vegetation removal associated with culvert
maintenance and control of invasive species, may change the visual character of the affected areas;
these impacts are temporary in nature and result in only minor changes to the Refuge’s visual
quality. Following construction, affected areas are replaced with appropriate native vegetation
and areas where invasive species are controlled are replanted with native upland species. These
actions serve to mitigate temporary changes in the visual character of the site. Therefore,
continuation of these management activities would not result in significant adverse effects to visual
quality. Some minor beneficial effects would be expected as a result of trash and debris removal
and the replacement of weedy species with native plants.
Public Use
No changes to the existing topography within the Refuge occur as a result of conducting the
existing limited public use program on the Refuge; therefore, no impacts to topography related to
public use would occur under this alternative.
The facilities provided on the Refuge to accommodate public use include a pedestrian pathway
along the south side of Bolsa Avenue east of Kitts Highway, an observation deck at the end of the
pathway, low interpretive signage along the pathway and at the deck, and a kiosk to the north of
the Refuge office/visitor contact station. None of these facilities block views of the Refuge, nor do
they create any significant adverse effect to the visual quality of the Refuge.
5.2.1.2 Effects to Geology/Soils
Wildlife and Habitat Management
None of the wildlife and habitat management activities currently occurring on the Refuge would
trigger or accelerate substantial slope instability, subsidence, ground failure, or erosion, nor would
they make the Refuge and its facilities any more susceptible to geological hazards, such as
Draft Comprehensive Conservation Plan 5-3