Tijuana River mussel and oyster shell gape data 2024-01 to 2024-09

Groups of Mytilus galloprovincialis mussels and Magallana [Crassostrea] gigas oysters obtained from the Tijuana River Estuary at the Boca Rio site 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 at the Boca Rio site on 2024-01-31 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. The deployment ended on 2024-09-03.