NASA's Satellite Data Revolutionizes Salmon Fisheries Management
A groundbreaking study, funded by NASA, has harnessed over 40 years of satellite data to create a tool that promises to revolutionize the management of salmon fisheries. The research, conducted by the University of Washington, focuses on the Columbia and Snake rivers in the Pacific Northwest, where nearly 20 dams provide essential services but also disrupt the natural flow of these rivers.
The key to this innovation lies in a tool called THORR (Thermal History of Regulated Rivers), which tracks temperature changes upstream and downstream of dams using data from NASA's Landsat satellites. These satellites, alongside the U.S. Geological Survey's (USGS) Landsat satellites, have been instrumental in supporting the nation's agricultural sector, including farmers and food production.
The study revealed that warmer water downstream of dams, a result of water spilling over the dam and warming in the Sun, can stress salmon, causing them to swim faster. Conversely, water discharged through turbines cools the river downstream, providing a healthier environment for salmon. This discovery has led to a strategic suggestion: releasing water from lower reservoir levels could help salmon thrive, potentially saving dam operators time and costly interventions.
One of the challenges in using satellite data to monitor river temperature has been cloud cover and the narrowness of river channels relative to satellite resolution. To overcome this, the University of Washington team employed a machine-learning algorithm to analyze 42 years of Landsat thermal data. This algorithm was trained using temperature gauge measurements along the Columbia River Basin, climate data, nearby land use and temperature, and elevation.
The resulting tool, THORR, was developed in collaboration with the Columbia River Inter-Tribal Fish Commission, ensuring its user-friendliness and relevance to their fisheries' needs. This partnership highlights the importance of end-user involvement in making research practical and applicable.
The implications of this research extend beyond the Columbia River Basin. The tool's methodology could be adapted for other river systems, and the code and data are publicly available, allowing anyone to monitor Earth's freshwater resources using satellite data. This accessibility is a significant step towards better water management and informed fishing regulations.
The Pacific Fishery Management Council, responsible for developing fishing regulations, could benefit from THORR. By integrating the tool into future models, they can account for the impact of river temperature on salmon abundance. This integration would ensure that fishing regulations are based on the best available science, potentially leading to more sustainable salmon management practices.
