This map shows the locations of all Acoustic Program hydrophone mooring deployments from 1995 to present. The hydrophones are autonomous ocean-sound data-loggers that can record continuously for 2-3 years in frequency ranges from 100 Hz to 2 kHz.  Each hydrophone mooring is anchored to the seafloor, but suspended several 100 to 1000s of meters up in the water column using a positively buoyant float. For each deployment, the hydrophone is positioned on the mooring to ensure the acoustic sensor is within the ocean sound channel. An acoustic release is attached between the base of the mooring and anchor to enable easy retrieval of the mooring by a surface research vessel.