Expanding Hypoxia Monitoring in the Ocean through Community Science

Ocean deoxygenation has been recognized among the most critical pathways through which global climate change is detrimental to marine resources. Anthropogenic climate change has increased the temperature of the ocean, which decreases its capacity to hold oxygen. Additionally, climate-driven changes in upwelling patterns on the Northen California Current System increase the intensity and duration of hypoxia (low oxygen events). This trend overlays persistent eutrophication concerns in estuaries and coastal systems.

Hypoxia can have significant impacts on economically and culturally important fisheries in the region as well. Dungeness Crab is the most valuable fishery in the NCCS and is among the most severely impacted. In addition to morality, hypoxia causes physiological stress to organisms which can alter ecological interactions and predator prey dynamics. Additionally, fisheries management techniques don’t currently account for hypoxia driving species distributions.

Adding to the challenge of the worsening hypoxia under climate change is its high spatial and temporal variability. Researchers have a limited ability to monitor with high resolution in both space and time. My research aims to better quantify the impacts of hypoxia on Dungeness crab catch and investigate spatial and temporal variability off the Oregon Coast and Puget Sound through collaborative research using novel sensor technology.

The project developed a low-cost rugged DO and Temperature sensor designed to be deployed in commercial fishing gear in partnership with commercial fishers, natural resource agencies and tribal partners. This structure leverages the time on the water for fishers and existing infrastructure in the water (crab pots). The sensor measures DO and temperature in bottom water at 15-minute intervals for up to three months. When sensors are brought to the surface of the water, data is downloaded onto a Deck Data hub located on the fishing vessel and is then exported to the cloud for remote access and real-time reporting. This high frequency data collection and real time access is critical for ensuring climate adaptation benefits as it allows fishers and managers to respond to real time conditions. Additionally, hypoxia can be difficult to monitor and predict due to its spotty and intermittent nature. The low cost and community science-based design makes deploying more sensors for higher spatial coverage possible. This enables improved detection of hypoxia events.

For the past 4 years, we have partnered with a network of fishermen on the Oregon Coast, and with agencies and tribes in Puget Sound, a semi enclosed estuary in the NCCS. We have found persistent refuges and hotspots of hypoxia with significant differences (up to 2mg/L) in dissolved oxygen between sites less than 20km apart. We have enabled the detection of hypoxia events in important fishing grounds on the Oregon Coast and the capacity for real time adaptation. Ultimately, real-time monitoring of climate stressors and resulting marine resource impacts, will improve our ability to adapt to the climate crisis.