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

Bolsa Chica Lowlands Restoration Monitoring
2008 Annual Report
central and east MTBs) are species that are tolerant of highly saline soils. This relictual marsh is
almost entirely composed of large expanses of pickleweed (Sarcocornia pacifica and Arthrocnemum
subterminale). The pickleweed quality varies throughout the site from tall and robust, to short in
stature and desiccated. Other species common in the salt marsh in low densities included: salt grass
(Distichlis spicata), saltwort (Batis maritima), and alkali heath (Frankenia salina).
The majority of this salt marsh habitat is of moderate quality based on its fairly expansive nature,
isolation from human disturbance, and limited infestation by exotic and upland species. While there is
low plant diversity within this habitat, such conditions are normal for coastal salt marsh habitats and
especially so for non-tidal marshes that experience hypersaline sediment conditions and the
environmental extremes of wet and dry seasons and years.
More functional coastal salt marsh habitat is now present in the FTB (on Rabbit Island) and Muted
Pocket Marsh, both of which received daily tidal flushing following the restoration completion.
Additionally, in March 2008 the west MTB was opened to muted influence from the FTB, with the salt
marsh receiving daily tidal flushing for the first time in many decades. This resulted in the inundation
of large areas of pickleweed for some or nearly all of each day. In some areas the inundation
frequency may be greater than the tolerance of the pickleweed; those areas are expected to convert to
open mudflat in future years.
As noted above, cordgrass was not included in the coastal salt marsh mapping in order to better track
its spread over time.
Disturbed Southern Coastal Salt Marsh
This habitat category was used to distinguish areas of
southern coastal salt marsh that were degraded due
primarily to disturbance by heavy equipment and
vehicles associated with both the construction elements
of the restoration program and the on-going
contamination remediation activities within the oil field.
This category was also used for the unvegetated sidecast
piles of sediment place on either side of the channels
that were dug out of the marsh as part of the restoration
of the MTBs. These will be re-categorized in future
assessments if salt marsh vegetation becomes reestablished.
Sidecast mounds remaining from channel excavation.
Cordgrass
New cordgrass growth with flowers.
One year post-transplant, 196 m 2 of cordgrass was mapped at 10
of the 14 transplant sites (Figure 1-4). At most locations
cordgrass was present in only portions of the original transplant
site, and in some cases had spread laterally some distance out of
the site. Within plots of cordgrass the shoot density ranged from
2 to 98 shoots/m 2 , with a mean of 23 shoots/m 2 . The canopy
height ranged from 9 to 85 cm, with a mean of 52 cm. Nearly all
cordgrass was flowering, with seeds seen scattered on the mudflat
around the plants.
Merkel & Associates, Inc. 23