Crew members aboard Coast Guard Cutter Maple work to retrieve a buoy about 90 miles northwest of Barrow, Alaska, July 23, 2017. Attached to the buoy is a high-frequency acoustic recording package (HARP) used to record underwater sound in a broad range of frequencies continuously, for up to a year at a time. (U.S. Coast Guard photo by Petty Officer 2nd Class Nathan Littlejohn/ Released)