Dear colleagues, The following paper was recently published as an open access journal article in Endangered Species Research: Baumgartner, M.F. 2025. Efficacy of real-time passive acoustic monitoring near wind energy industrial activities for mitigating risks to right whales. Endangered Species Research 57:413–430. https://www.int-res.com/abstracts/esr/v57/esr01432 Abstract: Offshore wind energy development activities pose risks to the Critically Endangered North Atlantic right whale Eubalaena glacialis, including permanent and temporary hearing damage and behavioral changes owing to noise exposure from pile driving at wind turbine construction sites as well as vessel strikes in transit corridors linking wind farms and ports. Real-time passive acoustic monitoring (PAM) is an important and useful means of detecting the presence of whales, but its efficacy in helping to mitigate these risks depends on its site-specific application. This study employed Monte Carlo simulations to evaluate various configurations of a well-characterized real-time PAM system for their efficacy in mitigating risks given the movement and calling behavior of right whales. Configurations with as few as 3 PAM stations using detections only (no localization) to trigger mitigation provided adequate probabilities of missed mitigation (i.e. the probability a whale appears in a risk zone when a risk is present) for a construction site (<0.15) and a transit corridor (<0.001). At a construction site, probabilities of false mitigation for these configurations were high, but 71-76% of simulated pile-driving sessions could proceed when a right whale was nearby. Near a transit corridor, probabilities of false mitigation for these configurations were relatively low, and mitigation was nearly always implemented when right whales were nearby owing to the severe consequences of missing vessel strike risk mitigation. Similar methods can be used to assess whether multi-modal monitoring (e.g. PAM and visual observers together) will meet regulatory limits on missed mitigation. Mark Baumgartner Senior Scientist Biology Department Woods Hole Oceanographic Institution MS #50, Marine Research Facility 107 266 Woods Hole Road Woods Hole, MA 02543 mbaumgartner@whoi.edu<mailto:mbaumgartner@whoi.edu> www.whoi.edu/sites/mbaumgartner<http://www.whoi.edu/sites/mbaumgartner> (508) 289-2678