Chapters 1 - U.S. Fish and Wildlife Service

Environmental Consequences
Coastal salt marsh, covering approximately 565 acres within the Refuge, would continue to be the
dominant habitat type on the Refuge and intertidal channels and tidal mudflats would not be
altered. No actions would be implemented to address the effects of limited sources of freshwater
input and higher tidal elevations and/or subsidence on the overall quality of the cordgrassdominated
habitat on the Refuge.
The Refuge’s upland habitat, most of which was historically wetland habitat that was filled during
the last century to accommodate development, would be retained under Alternative A. Hog Island,
which is the only area within the Refuge that historically supported native upland vegetation,
would also remain unchanged under Alternative A.
Management activities proposed under Alternative A that could have an effect on the existing
habitat and vegetation on the Refuge include:
Light-footed clapper rail monitoring to record nesting activity and estimate overall
population size;
Conducting monthly bird surveys;
Inspecting, maintaining, replacing and/or installing clapper rail nesting platforms in
salt marsh habitat;
Conducting invasive plant control in upland and upland transition areas;
Removing trash and debris from upland and upland transition areas, as well as along
the edges of the marsh;
Inspecting, cleaning, and/or replacing culverts on the Refuge that convey tidal waters
into various portions of the Refuge; and
Implementing predator management, including conducting periodic night surveys to
identify potential predators.
Monitoring of light-footed clapper rails is generally conducted from the edges of the marsh and
from non-motorized boats traveling through the marsh. Actions related to the nesting platforms
are also conducted using boats. Monitoring teams and volunteers are trained to understand the
importance of protecting the sensitive marsh habitat and every effort is taken to avoid the
trampling of vegetation during these activities. As a result, adverse effects to native habitat
related to clapper rail management are minimal and do not represent a significant adverse impact
on the environment.
The effects to habitat and vegetation as a result of conducting monthly bird surveys are similar to
those described for clapper rail monitoring. Therefore, this activity would not result in any
significant adverse impacts to the environment.
Removal of trash and other debris from the Refuge could result in temporary impacts related to
trampling of vegetation; however, the majority of trash removal occurs in areas dominated by
nonnative vegetation or at the edges of the marsh. Any trampling of marsh vegetation that may
occur would be minor and would be offset by the benefits of removing trash and debris from the
marsh.
Monitoring, cleaning, and/or replacing of the various culverts on the Refuge could result in some
temporary impacts to marsh habitat, but these effects would be minimal and the benefits of
maintaining adequate tidal circulation within the various wetland areas on the Refuge would offset
any temporary impacts to existing habitat. If permanent impacts to native habitat would occur as
a result of the activities associated with culvert replacement, mitigation in the form of habitat
Draft Comprehensive Conservation Plan 5-31