Global industrialization and climate change have threatened our oceans through man-made noise and rising temperatures, and these threats are worsening by the day. Identifying shifting ecological baselines is an urgent priority but requires a new instrument deployment system that is rapid, quiet, inexpensive, far-ranging, and can sample far below the ocean surface. Using migratory marine mammals as smart sensors, Beltran’s research group will collect large-scale, long-term, 3-dimensional data on ecosystem health, from phytoplankton to prey to predators, along with man-made threats including noise and ocean warming. Continuing these integrated monitoring efforts for decades into the future will facilitate an unparalleled time-series of holistic ocean health and enable critical climate change impact assessments. Our future depends upon understanding and protecting the interconnectedness of human, animal, and environmental health in the ocean – our planet’s largest ecosystem.