The Dungeness crab is a culturally and economically significant marine species in the Pacific Northwest, playing an important role in supporting tribal and non-tribal commercial fishers. Climate change poses a significant threat to Dungeness crab through increasing the frequency and severity of low oxygen zones and through making the ocean more acidic. When dissolved oxygen levels drop low enough, it can be deadly for these crabs and other organisms, especially if they are unable to move away from a low oxygen area or are stuck in a crab pot. More acidic ocean waters are dissolving Dungeness crab shells, damaging their sensory organs and affecting prey behavior. Despite these threats, the timing and extent of low oxygen zones and ocean acidification in Puget Sound is not well understood.

Haley and colleagues at Oregon State University formed a collaborative partnership with the Tulalip Tribe Shellfish Program, located near Marysville, Washington, to assess the impact of these threats to the Dungeness crab fishery that they co-manage with the state of Washington. The team used a novel ocean-observing system to expand the number of areas where low oxygen zones can be monitored. The project pairs low-cost, rugged dissolved oxygen and temperature sensors with the Tulalip Tribe’s Dungeness crab test fishery sampling events. This structure leverages the time on the water for fishers and existing infrastructure in the water (crab pots). It also enables real-time reporting as the data is immediately displayed and transferred online.

For this project, Haley will continue to partner with the Tulalip Tribes’ Shellfish Program to understand the point at which low dissolved oxygen levels start to affect the Dungeness crab fishery. The project team will also map the areas and times in which low oxygen zones and ocean acidification are most severe in Puget Sound. Information about where and when low oxygen zones occur will inform the Tulalip Tribe shellfish management plan. This will help them decide if and when fishing grounds may need to be closed and will prevent gear deployment in areas that are unproductive.