Los Penasquitos Lagoon bivalve shell gape data 2024-10 to 2025-05

Groups of Mytilus galloprovincialis mussels and Crassostrea gigas oysters obtained from the Los Penasquitos Lagoon near the railroad bridge were outfitted with Hall effect sensors and a magnet, glued to the exterior of the shell near the shell valve margin, in order to record opening and closing of the shell valves. A floating mooring was deployed in Los Penasquitos Lagoon southwest of the railroad bridge, near the center of the channel. A group of mussels and oysters was suspended from the underside of the mooring float approximately 5cm beneath the water surface. A second group of mussels and oysters was suspended from the line near the channel bottom, approximately 50 cm above the benthos. Shell valve gaping values were recorded as raw sensor counts from the analog-to-digital converter of the data logger, and those raw counts were subsequently converted into an estimate of proportional shell opening, scaled as a percentage between 0 (fully closed) and 100 (fully open), for each individual mussel.