FLUPSY bivalve gape data 2024-01 to 2025-05

Mytilus galloprovincialis mussels and Magallana [Crassostrea] gigas oysters were obtained from Tuna Harbor in San Diego Bay. A Hall effect sensor and magnet were attached to the exterior of the shell at the posterior end of the shell margin. Raw data were recorded on an 8-channel data logger as voltage read by an analog-to-digital converter and recorded as counts. The raw gape values were quality checked and then converted into a 0-100 percent scale where 0 represents a fully-closed shell and 100 represents the widest opening observed during the observation period. The animals were deployed on hanging lines off the side of the FLUPSY (floating upwelling system) docked at Tuna Harbor, on the bay-side of the platform. A group of mussels and oysters was suspended near the surface at a depth of 30 centimeters, from 2024-01 through 2025-05. A second group of mussels and oysters was suspended near the bottom on a 3 meter line from 2024-05 through 2025-05.