Photos: 1,044 marine animal observations analyzed for tidal turbine collision risks

Researchers in Washington State conducted a 141-day study using a small cross-flow tidal turbine equipped with optical cameras and sensors to assess collision risks between marine animals and tidal energy infrastructure. Over 109 days of optical monitoring, they recorded 1,044 observations of fish, seabirds, and seals. Notably, no collisions were observed involving seabirds or seals; seabirds appeared only during daylight when the turbine was stationary, while seals were present day and night, including when the turbine was rotating. Four fish collisions with turbine blades were documented, with most fish successfully avoiding contact, even at water flow speeds exceeding 2 m/s. This study is the first in North America to use optical imagery to directly observe interactions between marine wildlife and tidal turbines, moving beyond theoretical risk assessments. Data collection employed scheduled recordings and real-time sensor-triggered footage, refined during the study to improve detection. Machine learning models were tested for identifying animals underwater, revealing challenges such as differentiating wildlife from organic matter. The behavioral insights