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

Bolsa Chica Lowlands Restoration Monitoring
2008 Annual Report
It was interesting to note during the avian surveys throughout the year that large shorebirds showed a
clear preference for foraging and loafing on portions of the mudflat where cordgrass was growing.
There are other locations within the restoration area that are suitable for cordgrass establishment and
should be the focus of future transplants, particularly around the west and south side of Rabbit Island
and in the MTBs. Cordgrass establishment on the shores of NS 1 on the west side of the FTB is not
desirable, because clear access from the nest site to the shoreline should be maintained for snowy
plovers.
Another habitat goal of the restoration was the establishment of eelgrass in the FTB. The 2007
transplant was successful, with a doubling of the area covered after one year. The eelgrass began
flowering shortly after transplant, which was likely the source of its spread to areas nearly a kilometer
from the transplant sites. During 2008, eelgrass may have been able to extend to higher elevations in
the basin due to the tidal muting and resulting higher low tides. The eelgrass may recede from these
upper elevations in 2009 and 2010 following maintenance dredging to restore lower low tide
conditions. These losses will be more than offset by the large increases in distribution that are
anticipated in the coming years, with the most dense and expansive growth occurring in the mid and
lower portions of the FTB.
The next full vegetation monitoring event, including aerial photography, habitat mapping, and transect
surveys, will be conducted in summer 2011 (Year 5) as called for in the Monitoring Plan. Additional
photography and habitat mapping will be done in 2009 to document interim conditions.
Recommendations
• Continue collection of aerial imagery each year (rather than in Years 2, 5, and 10 only) to track
changes in water levels, site conditions, and habitat development.
• Consider adding species diversity to the Bolsa Chica system by transplants from other areas such
as Upper Newport Bay or Outer Bolsa Bay.
• Consider opportunities for introduction of Salt Marsh Bird’s Beak (Cordylanthus maritimus) from
Upper Newport Bay into areas of Freeman Creek, the Seasonal Ponds, and the Muted Tidal Basins,
where seasonally lowered salinities would promote seed germination.
1.2. SOILS/SEDIMENT MONITORING
Introduction
The Monitoring Plan anticipated that soil and sediment conditions throughout the restored portions of
Bolsa Chica might be changed in the course of dredging and/or introduction of tidal flushing.
Monitoring was developed to document the soil conditions in the restored areas as new vegetation
colonized and existing vegetation adjusted to the restoration of tidal influence.
The Monitoring Plan calls for soils monitoring to be initiated in Year 2 of the program, coinciding with
the vegetation monitoring task described in the previous section.
Merkel & Associates, Inc. 33