Core Monitoring
The core-monitoring program includes measurements, sample collection and analyses, and data interpretation to evaluate potential impacts of treated wastewater on the following:
• Coastal water quality;
• Sediment quality;
• Benthic infaunal community health;
• Fish and macroinvertebrate community health;
• Fish tissue contaminant analyses; and
• Fish health (including external and internal examinations and pathologies).
Sampling locations include 17 offshore and 17 surfzone water quality stations, 49 stations to assess benthic (bottom-dwelling) organisms and sediment chemistry, and 9 trawl stations to evaluate fish and macroinvertebrate communities.
Regional Monitoring
Regional studies measure the environmental conditions within the Southern California Bight (the area from Santa Barbara to Ensenada, Mexico).
These results provide valuable information that can be used to improve our understanding of regional-scale processes and provide a regional perspective for comparisons with data collected for the core program and special studies.
Special Studies
As specified in the ocean release permit, the district conducts special studies to study important coastal issues and processes that are not addressed by routine monitoring.
These projects study oceanographic and biological processes that enhance data interpretations and data quality of the core program.
Trawling
Trawling is accomplished by dragging an otter trawl net behind the boat on the bottom at a specific speed and for a specified distance collecting fish and invertebrates as the net is towed along the bottom. OCSD Trawl sampling consists of semiannual sampling at nine stations in summer and winter surveys. All of the fish and invertebrates from each haul are enumerated, weighed and measured, and checked for external parasites or abnormalities. Some fish are also checked for internal pathologies or are saved for laboratory bioaccumulation analyses.
Sediment grabs
Sediment grabs samples are collected using a Van Veen sampler that is designed to be lowed from a boat, impact the bottom and close upon retrieval to collect sediments. Separate samples are collected to assess sediment chemistry and to enumerate and identify organisms that are living in the sediment. Samples are collected at 10 stations quarterly and an additional 39 stations annually.
Mooring sampling
Mooring stations collect long term (up to one year) of continuous data of currents, temperature, and conductivity to get a more comprehensive look at oceanographic conditions at a fixed location. This long-term data is used to complement the temporal water quality data that is collected as part of the core-monitoring program.
Water quality sampling
Offshore water quality sampling includes three days per quarter sample collection of both discrete seawater samples and continuous oceanographic parameters at 17 stations ranging from 0.25 miles from shore to six miles offshore. Continuous data is collected through the entire water column including, data on depth, temperature, conductivity, pH, dissolved oxygen, water clarity, chlorophyll-a, and photosynthetically active radiation. The discrete samples are analyzed for ammonia and bacteria.
Surf Zone sampling
Samples are collected in ankle deep water at seventeen stations along the shoreline in Newport Beach and Huntington Beach to access swimming safety. These samples are analyzed for three indicator bacteria that the Orange County Health department uses to determine the presence of harmful pathogens. Surfzone sampling is conducted five days a week by OCSD staff and results are given to Orange County Health Officials who determine ocean swimming safety.
