Tijuana River mussel shell gape data 2025-02 to 2025-04

Groups of Mytilus galloprovincialis mussels 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 2025-02-25 near the center of the channel. A group of mussels was suspended from the underside of the mooring float approximately 5cm beneath the water surface. A second group of mussels 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 2025-04-30. Most of the mussels died during the course of the deployment, so data collected after death have been converted to NA values during the quality-checking process.