Mussel respiration data from experiments with mussels sourced in WA conducted at University of Washington Friday Harbor Laboratories, Friday Harbor, WA from 2020 to 2023

From 2021 to 2023, we measured aquatic respiration rates of three species of mytilid mussels (Mytilus trossulus Gould, M. galloprovincialis (L.), and M. californianus Conrad) under a range of water temperatures and velocities. M. californianus was obtained from the intertidal zone at Cattle Point, WA, USA (48.449966, -122.964350) and shipped in chilled coolers to the University of Washington Friday Harbor Laboratories (48.545998, -123.013046). M. trossulus and M. galloprovinicialis were obtained from a commercial supplier (Penn Cove Shellfish, Coupeville, WA, USA). Mussels were acclimated in a recirculating seawater.

We conducted lab experiments to investigate the effects of multiple environmental stressors (e.g., water temperature and velocity) on physiological responses in three closely-related mytilid mussel species. In closed respirometry chambers (15 cm × 5 cm × 5 cm, L × W × H), we measured oxygen use by individual mussels under a combination of five temperatures (e.g., 5, 11, 17, 23, and 29°C) and five velocities (2, 4, 6, 10, and 20 cm s-1) in a fully crossed design. Oxygen concentrations were measured with non-intrusive fiber-optic O2 sensors (Pyroscience, Aachen, DEU). Samples were recorded at a rate of 1 Hz and drift of the O2 probe was negligible (e.g., <0.1% over 2 h at 20°C). Trials were run for 2 h, ensuring that a stable rate of decline could be identified. After each trial, all soft tissues were dried for 72 hours at 60°C (Lindeberg/Blue M Vacuum Oven; ThermoScientific Inc., Waltham, MA, USA) and weighed using an analytical balance (0.001 g; PA153 Pioneer Analytical Balance; Ohaus Corp., Pine Brook, NJ, USA). Data were analyzed to estimate respiration rates using the R package respR (Harianto, 2019).