Chapters 1 - U.S. Fish and Wildlife Service

Environmental Consequences
habitat by 2050 and all of the salt marsh habitat and undeveloped upland areas would be converted
to subtidal habitat by 2100.
Wildlife and Habitat Management
Under Alternative A, the Refuge would continue to be managed as it is today, with no specific
actions being taken to address sea level rise. However, management actions such as the
monitoring of the Refuge’s light-footed clapper rail population and conducting monthly avian
surveys could provide some insight into how sea level rise may be affecting wildlife resources on
the Refuge.
Over the next 15 years, it is likely that the effects of sea level rise (e.g., higher high tide elevations,
increases in the frequency of surface flooding due to higher high tides that occur during storm
events) will become more evident. However, the effects of sea level rise over the next 15 years are
not anticipated to adversely affect Refuge resources.
As time goes on, these effects are expected to become progressively more profound. Based on the
results of the SLAMM, sea level rise over the next 25 to 100 years could inundate the cordgrass
habitat on the Refuge; adversely impacting the light-footed clapper rail and the habitat that
supports this species. In addition, the condition of existing culverts serving the restoration areas
of the Refuge could be degraded as a result of increased tidal elevations. Wind and wave erosion
would also be expected to increase along the slopes located adjacent to the restored area at the
north end of the Refuge, as well as around the perimeter of NASA Island. Actions to address
these impacts will be required at some point in the future, possibly requiring major revisions to the
Refuge goals and objectives to address the changes associated with sea level rise.
Public Use
The SLAMM assumes that the developed dry land within the Refuge (e.g., areas supporting
streets, buildings, and other facilities) would be maintained and protected; however, there are no
assurances that this will in fact be the case. Bolsa Avenue, which includes a public use trail along
its western edge, is already subject to tidal flooding during extreme high tides. The cost of
protecting this road from more frequent inundation may be excessive and would likely be the
responsibility of the Navy. Therefore, the trail, an existing observation deck, and interpretive
signs that have been installed along the length of the trail would be subject to damage as a result of
sea level rise. These effects are not anticipated to occur over the next 15 years, but are anticipated
to occur at some point in the future. At such time as inundation becomes too frequent, these
facilities would have to be abandoned or relocated. Monitoring of tidal elevations over time will
provide insight into when plans should be initiated to address the removal and/or relocation of
these existing facilities. Opportunities for wildlife observation, interpretation, and environmental
education would however continue to be available despite the effects of sea level rise. No new
facilities are proposed under Alternative A; therefore, the anticipated impacts to the Refuge’s
public use facilities would be limited to those facilities that are already present on the Refuge.
5.2.1.8 Effects to Air Quality
Wildlife and Habitat Management
Current wildlife and habitat management activities on the Refuge require the use of motorized
vehicles for access to various project sites, to accommodate habitat and species monitoring, to
deliver tools, supplies, and other equipment to habitat management sites, and for removing trash
and debris from the marsh. The staff on the Refuge consists of one full-time Refuge Manager and
a part-time maintenance worker, generating approximately 32 vehicle trips to and from the Refuge
per week. Refuge volunteers who assist at the Refuge generate an estimated 20 additional trips
Draft Comprehensive Conservation Plan 5-9