February 2023 Oyster Time Series: Los Penasquitos Lagoon

Southern California estuaries are increasingly the focus of management decisions around estuary mouth closures, water quality improvement plans, and sewage impact monitoring. Managers are left to infer biotic responses from observed abiotic water quality measurements, such as the water level, dissolved oxygen, and salinity data provided by the NERR System-Wide Monitoring Program. Regional partners expressed the need to better understand water quality threats the biotic community, specifically by using living organisms such as oysters and mussels that serve as indicators, or “biosentinels”. 

This Habitat Heartbeats project is developing a monitoring system to integrate these living organisms with existing monitoring efforts to determine how the estuary responds to environmental variation and human impacts.

The two screenshots below show timeseries visualizations of oyster openings and closings at both a surface and bottom mooring at one of the project sites, Los Penasquitos Lagoon, over a period of 5 days. During the final few days of this time period, the estuary accumulated freshwater and the surface animals closed (low values) earlier than the bottom animals and stayed closed. The bottom oysters mostly remained open (high values) up until Feb 26 when the estuary mouth opened and freshwater started flushing through the entire water column out to sea. The expectation is that they reopen in the following days as freshwater flows subside and the tide starts flowing back into the estuary regularly. 

Surface Mooring:

time series graph of oysters opening and closing over 5 days, February 22-26. Closing (low values) remains constant after February 24
click to view larger

Bottom Mooring:

time series graph of oysters opening and closing over 5 days, February 22-26. Closing (low values) remains constant after February 26
click to view larger
Citation

Data retrieved from temporary storage on Monitor My Watershed. https://monitormywatershed.org/