Results from the Baynes Sound Environmental Intelligence Collaboration (BaSEIC)

• Main Authors: Evans, Wiley, Winterburn, Darlene, Pocock, Katie, Weekes, Carrie, Hare, Alex
• Format: Text
• Language: English
• Published: Western CEDAR 2018
• Subjects: Ocean acidification; Fresh Water Studies; Life Sciences; Marine Biology; Natural Resources and Conservation; Terrestrial and Aquatic Ecology; Pacific; Tula; Pacific oyster
• Online Access: https://cedar.wwu.edu/ssec/2018ssec/allsessions/169; https://cedar.wwu.edu/cgi/viewcontent.cgi?article=2604&context=ssec

Baynes Sound, in the northern Salish Sea, hosts more than 50% of the BC shellfish aquaculture industry, with Pacific oyster (Magallana gigas) as the dominant production species. The known vulnerability of this species to ocean acidification (OA)-driven changes in seawater chemistry – specifically through alteration in calcium carbonate (CaCO3) mineral stability, combined with periodic production problems in Baynes Sound – have led to a growing concern regarding possible contemporaneous impacts of OA in spite of lacking environmental intelligence detailing baseline conditions. In order to build our understanding of current biogeochemical patterns in this key Salish Sea setting, the BC Shellfish Growers Association and the Hakai Institute, with support from partnering shellfish growers, the Province of British Columbia and the Tula Foundation, formed a research initiative, known as the Baynes Sound Environmental Intelligence Collaboration (BaSEIC), in early 2016. Seasonally-resolved and spatially-distributed discrete seawater samples were collected by shellfish growers and an independent citizen science group operating in the area. Discrete measurements were used to add spatial context to a high-frequency data stream produced by instrumentation installed at a shore-side facility for continuous observing of in situ (8 m) CO2 chemistry. Taken together, the discretely-collected and continuously-measured seawater CO2 data provide a dynamic picture of the baseline conditions in Baynes Sound, including: (1) a pronounced seasonal cycle with surface-focused favorable conditions for CaCO3 mineral precipitation between spring and early autumn, (2) a sharp decrease in mineral stability of sub-surface water including excursions toward CaCO3 undersaturated conditions during the winter season and summer neap tides, and (3) a seasonal north-south gradient in mineral stability. These results illustrate the current CO2 system patterns in Baynes Sound that are now being considered in shellfish industry management discussions.