Interfacing a scientific echosounder with a cabled ocean observatory.

Abstract

To demonstrate the utility of adding active acoustics to ocean observatories, an upward‐looking, 38 kHz Simrad EK‐60 echosounder package was connected to the Monterey Accelerated Research System (MARS) Observatory. The Deepwater Echo Integrating Marine Observatory System (DEIMOS) integrated the echosounder with commercial electrical and communications hardware in a glass pressure sphere, all mounted in an ROV‐deployable frame. A cabled connection to the MARS node provided instrument power and real‐time TCP/IP network communications to surface control and display systems. DEIMOS sampled the entire water column (875 m) at 0.2 Hz from February 27, 2009 to August 18, 2010. The instrument collected 50 Mbytes of raw data every 3 h resulting in a total of 167 Gbytes of raw data. Metrics developed to quantify distributions and abundances of pelagic organisms show temporal variability over seasons, diel cycles, and minute‐to‐minute predator‐prey interactions. We will present design goals, deployment challenges, an...