Exploring marine mammal presence across seven US national marine sanctuaries

The United States of America’s Office National Marine Sanctuaries (ONMS) hosts 15 (NMS) and two Monuments in its waters. Charismatic marine megafauna, such as fin whales ( Balaenoptera physalus ), humpback Megaptera novaeangliae various delphinid species frequent these areas, but little is known about their occupancy. As part a national effort to better understand the soundscapes NMS, 22 near-continuous passive acoustic bottom mounted recorders one bottom-mounted cable hydrophone were analyzed within seven NMS (Stellwagen Bank, Gray’s Reef, Florida Keys, Olympic Coast, Monterey Bay, Channel Islands, Hawaiian Islands Humpback Whale sanctuaries). daily presence across 2 years (November 2018–October 2020) hourly delphinids over 1 year (June 2019–May analyzed. showed variability general mostly present January through May September December, more scarce or fully absent June August. Consecutive days whale vocalizations greatest at sites HI01 HI05 fewest NMS. Fin exhibited similar seasonal pattern West Coast Stellwagen Bank Bay had number median consecutive with Delphinid varied throughout Hawaiʻi showing highest All distinct monthly differences detected hours between day versus night. Sixteen medians three days, while 5 presence, site no clear variation how long they occupied different mammals utilized all wide range occupancy, emphasizing importance understanding use biological areas for migration, breeding foraging.