2008 Annual Monitoring Report (pdf 10.9MB) - Bolsa Chica ...

Bolsa Chica Lowlands Restoration Monitoring
2008 Annual Report
Table 1-2 also summarizes the total number of native and non-native species found within one meter
on either side of the transect line. The salt marsh in the MPM was by far the most diverse of all the
areas surveyed, followed by Rabbit Island. One species was found in the 2-m belt that was not
detected on any transect: western sea purslane (Sesuvium verrucosum) along transect MPM2. As noted
above the marshes in the MTBs are low in diversity, supporting primarily S. pacifica and D. spicata.
The FTB transects were primarily unvegetated in 2008, with the exception of a small amount of S.
pacifica becoming established at the north end of the basin at FTB North and considerable growth of
R. maritima on the intertidal mudflats on the east shore of the FTB.
Although not captured in the transect monitoring, there was a narrow band of S. pacifica seedlings that
had established on the large mudflats of the eastern shore of the FTB (cordgrass bench) near the base
of the riprap. In some cases the pickleweed extended out as far as 30 m onto the mudflat from the
riprap. Also of note, though not captured in the transect monitoring, was the persistence of the rare
coastal dune plant coast woolly heads (Nemacaulis denudata var. denudata) on Rabbit Island. The
restoration project aimed to protect this species at the highest elevations of Rabbit Island through
removal of hottentot fig during the project and by preserving the dune areas about the highest tides in
the project design. A comprehensive survey for this species was not conducted, however four patches
covering approximately 50m 2 in total were mapped incidentally during the survey work on the island.
Hottentot fig was encroaching on the remaining patches of woolly heads and immediate intervention
through removal of the non-native will be critical to the survival of woolly heads at Bolsa Chica.
The scars from the construction grading of the cordgrass bench were still evident in 2008 and created
pools of standing water at low tide, which had heavy growth of R. maritima in them. An interesting
observation was made by Peter Knapp of a snowy plover foraging for small fish in these pools, an
unusual behavior for this bird. The bench showed signs of growing maturity with the natural
development of tidal channels at the edges of the bench.
Pickleweed seedlings, Ruppia maritima, and channel development on the mudflats of the eastern shore of the FTB.
The photos taken at each of the nineteen transects will be presented following the next monitoring
event in series to illustrate change over time.
Discussion
The 2008 vegetation monitoring at Bolsa Chica was the first full monitoring event to document habitat
distribution and species composition following the restoration. Coastal salt marsh was the most
abundant vegetated habitat and changes in its distribution will be tracked in the coming years, since its
availability is critical for nesting by Belding’s Savannah sparrow. In 2008, only the west MTB was
open to tidal influence and the marsh had had limited time to respond prior to the monitoring. It is
Merkel & Associates, Inc. 31