Dataset: 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

M. californianus Conrad, 1837 were obtained from Cattle Point on San Juan Island, WA (48°26'59.6811"N, 122°57'51.9358"W). M. trossulus and M. galloprovincialis were obtained from a commercial supplier (Penn Cove Shellfish, Coupeville, WA, USA; 48°13'06.5579" N, 122°42'25.4331"W). The mussels were maintained in seatables (66 × 135 × 32 cm) with a constant flow of seawater at the Friday Harbor Laboratories (48°32'45.7249" N, 123°00'46.9262"W). Mussels were fed twice daily with a total of approximately 10 mL of Shellfish Diet 1800 TM (Reed Mariculture, Campbell, CA, USA).

Aquatic respiration rates were measured in a closed, recirculating flow chamber of 1-liter capacity.  The transparent acrylic test chamber (15 cm × 5 cm × 5 cm, L × W × H) was connected to a submersible pump (360 GPH, Model 25D, Rule Industries, Gloucester, MA, USA) via PVC pipe (25.4 mm i.d.) and custom machined high-density polyethylene connector fittings. The water-tight test chamber was filled with artificial seawater (32 PSU; Instant Ocean; Spectrum Brands, Blacksburg, VA) and submersed in a temperature-controlled water bath (50 L). The water bath's temperature was maintained using a programmable, recirculating water heater/chiller (±0.005°C; AP07R-20-A11B, Polyscience, Niles, IL, USA).  Trials were run at water velocities were estimated along the centerline of the testing chamber by tracking the displacement of glass microbeads at each flow setting (mean particle diameter 9 μm, density 2.0 g cm⁻³; Potters Industries, Malvern, PA, USA).  

Oxygen concentrations were measured with non-intrusive fiber-optic fluorescence-based optodes and sensor spots on the inner surface of the chamber (FireSting Pro; OXSP5 and TPSP5 spots, 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).

Each trial involved positioning individual mussels along the centerline of the chamber and subsequently measuring the organism's oxygen usage at stable temperatures of 5, 11, 17, 23, and 29°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).