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

Bolsa Chica Lowlands Restoration Monitoring
2008 Annual Report
It is clear that the quadrat sampling effort to characterize epibenthic communities did not provide a
good representation of the invertebrates present. Most epibenthic organisms are highly mobile and had
vacated the mudflat shoreline during the low tides targeted for the survey work. Additionally, the
limited frequency of sampling did not capture the pulses of invertebrate usage of the basin that were
observed during other, more frequent, sampling elements of the biological monitoring program. The
tracking of invertebrates in the fishing gear more comprehensively and frequently documented the
epibenthic community, though examination of community parameters, such as density, diversity, and
evenness, cannot be done due to the incidental nature of the sample collection.
Epibenthic invertebrates present after the opening of the basin to tidal influence were all marine
species associated with estuarine or bay environments. It is expected that the species list will continue
to expand over time as additional sampling is conducted. These macroinvertebrates also provide an
important prey base for fish and birds in the basin.
Recommendations
No changes to the benthic monitoring program are recommended at this time. The Monitoring Plan
calls for benthic monitoring to be repeated in Years 5 and 10 following the opening of the FTB to the
ocean.
1.5. WATER QUALITY MONITORING
The Monitoring Plan calls for water quality monitoring to be initiated in Year 2 of the monitoring.
Monitoring began in October 2007 (reported in the 2007 report). Quarterly monitoring continued
through July 2008 and documented water quality conditions through the use of untended, deployed
instruments programmed to collect continuous data.
Methodology
Hydrolab Datasonde 5 ® water quality instruments were deployed at two stations within the FTB:
Station 1 and Station 2 (Figure 1-1). The station coordinates are provided in Appendix 1-B. These
locations were positioned to correspond to the general location of fisheries and benthic invertebrate
monitoring. The depths at water quality Stations 1 and 2 are approximately –1.2 m and –1.3 m NAVD,
respectively.
The units were calibrated in accordance with manufacturer specifications and programmed to log water
depth (m), temperature (°C), dissolved oxygen (DO)(mg/L), turbidity (NTU), and salinity (ppt) at 20-
minute intervals for 30 days. The units were mounted to weighted boards and deployed in the FTB in
January, April, and July 2008 to document the second, third and fourth quarter conditions during Year
2. At the time of deployment and retrieval, water quality readings were taken with an independent,
tended instrument next to the Hydrolab for quality control purposes.
Following data collection, the retrieved units were placed in calibration solutions and re-checked for
accuracy. A technician downloaded the units and transferred the data to the project database for
review and analysis. The data were reviewed to detect and remove spurious data points that may have
resulted from algal fouling of probes, signal decay from sediment loading or biotic activities, or that
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