Two adult Hawaiian monk seals interacting underwater. Credit: Krista Jaspers New research led by the UH Hawaiʻi Institute of Marine Biology (HIMB) Marine Mammal Research Program (MMRP) has greatly expanded scientists' understanding of how Hawaiian monk seals ( Neomonachus schauinslandi ) produce underwater sounds. The study, published in Royal Society Open Science , examined thousands of hours of passive acoustic recordings and uncovered 25 distinct underwater vocalizations. This represents a