Chapters 1 - U.S. Fish and Wildlife Service

Chapter 5
Public Use
No adverse or beneficial effects to Pacific green sea turtle would result from the public use
program carried out under Alternative B.
5.5.2.6 Effects to Belding’s Savannah Sparrow
Wildlife and Habitat Management
Under Alternative B, management actions such as limiting human disturbance in and around the
marsh, particularly during the nesting season, and accommodating the State-wide Belding’s
savannah sparrow survey, would continue. These actions provide direct and indirect benefits to
the State endangered Belding’s savannah sparrow, and would not result in any significant adverse
effects to this species (refer to Section 5.5.1.5 above).
Other actions included in Alternative B, such as construction of the water control structure in the
Bolsa Cell levee, the removal of concrete and debris from the marsh, species monitoring, and the
restoration of various areas throughout the Refuge could result in temporary adverse impacts to
this species. To minimize the potential direct and indirect effects of construction on Belding’s
savannah sparrows, various measures would be incorporated into the scope of work including
prohibiting any construction during the nesting season and protecting sensitive salt marsh habitat
adjacent to construction sites from temporary direct or indirect effects of construction by clearly
delineating construction boundaries and monitoring construction activities throughout the duration
of the project. In addition, time spent conducting monitoring and other activities in sensitive
habitat areas would be limited to reduce the disturbance levels that could be associated with
monitoring. The implementation of these measures would reduce the potential for adverse effects
to Belding’s savannah sparrows as a result of construction activities to below a level of significance.
Replacement of the existing culverts at the west end of the Bolsa Cell with a water control
structure is expected to eliminate the fluctuations in tidal flow into the Cell that over the years
have resulted in excessively high or low water levels and degraded water quality. This will in turn
provide more consistent conditions in the Cell for supporting habitat preferred by the Belding’s
savannah sparrow. Based on previous modeling results (Sea Dyn, Inc. 1993), the higher high
water and lower low water levels in the Bolsa Cell are directly influenced by the tidal regime in the
mitigation channel. Therefore, the higher high water levels in the Bolsa Cell could achieve levels
similar to those experienced in the Cell prior to the Port of Long Beach restoration project, while
the lower low water levels would be approximately 0.3 feet higher than pre-restoration levels. The
water control structure would therefore be used primarily to control the higher high tide levels in
the cell, and these water levels would be regulated to optimize habitat for a range of wetland
dependent species, including the Belding’s savannah sparrow. The water control structure would
also allow for adjustments in response to sea level rise.
Alternative B proposes to regulate water levels in the Bolsa Cell, as well as restore approximately
15 acres of coastal salt marsh. These proposals would benefit the Belding’s savannah sparrow.
Pest Management
Herbicide treatments are generally limited to areas of disturbed weedy upland vegetation;
therefore, impacts to Belding’s savannah sparrow and its habitat are not anticipated. The
implementation of the BMPs included in the IPM Plan for the Refuge would ensure that pesticides
used during invasive plant control does not enter or drift over into occupied salt marsh habitat.
Potential effects to Belding’s savannah sparrow as a result of mosquito management would be
minimized through adherence to the conditions related to access included in the annual SUP issued
5-62 Seal Beach National Wildlife Refuge