Hardware

The NEFSC Passive Acoustic Branch uses a variety of passive acoustic recording platforms to monitor sounds in the ocean. PAM systems often consist of co-located hardware to collect multiple data types, ancillary data about the ocean, or provide mechanisms to recover the instruments.

Bottom-Mounted Mooring components

Bottom-mounted moorings are our most commonly used PAM methods for continuous monitoring at a single location, providing long-term time series for marine mammals, fish, soundscapes, and anthropogenic noise. Our bottom-mounted moorings use acoustic releases to prevent the need for benthic-to-surface vertical line. We use different mooring designs depending on our field sites (refer to field methods for more detail on mooring designs). Below is a list of our mooring hardware components, including our mooring’s primary instruments (SoundTraps, F-PODs, VR2ARs) and auxiliary hardware.

Primary components

SoundTrap: Ocean Instruments

PAB’s primary recorder due to relatively long battery life and large memory, and broad sampling rate. We typically record at 48kHz providing data for most cetaceans, fish and soundscapes. This sampling rate allows for deployments of about 5 months. SoundTraps also record the internal temperature every time a new sound file is saved.

F-POD: Chelonia Wildlife Acoustic Monitoring

F-PODs are a high-frequency click detector used to detect echolocating odontocetes (dolphins and porpoises). The instrument is calibrated, has a long battery life (5 months with alkaline batteries, 8 months with Lithium batteries) and is an integrated product that records audio and automatically detects clicks. FPODs record temperature at a one minute interval.

  • F-Pod protocol link (in progress)

VR2AR (order site - InnovaSea, Acoustic Release Receiver)

Acoustic telemetry release allows researchers to retrieve bottom-mounted recording devices using acoustic signalling. Using VR2ARs eliminates the need for surface buoys or vertical line, reducing whale entanglement risk. VR2ARs simultaneously collect acoustic telemetry data, which PAB submits to the Atlantic Cooperative Telemetry Network (ACT / MATOS). These instruments record temperature and depth at one hour intervals.

  • VEMCO protocol link (in progress)

Auxiliary components

Apollo X1 Satellite Beacon (order site)

  • The Apollo Satellite Beacon is used to monitor unplanned or accidental release of subsurface instrument moorings.

Hermes Beacon Locator (order site)

  • The Hermes Beacon Locator is used to communicate with the Apollo Satellite Beacon to locate mooring units at sea

HOBO Temperature Loggers (order site)

  • Small mechanism that logs temperature over long periods of time. Requires HOBOware software and either an Optic USB Base Station or HOBO Waterproof Shuttle (U-DTW-1).

VEMCO VR100 Deck Box (order site)

  • The VEMCO Deck Box is used to remotely connect and communicate with the submerged VEMCO, primarily to release the VEMCO from the bottom-mounted weights.

VHTx: Transponding Hydrophone (order site)

  • Transponding hydrophone used for communication between VEMCO VR100 Deck Box and VEMCO Acoustic Release Receiver.

Surface-Moored Platforms

Moored Surface Buoy: Woods Hole Oceanographic Institution (Robots4whales, Mark Baumgartner)

A quiet surface buoy engineered by WHOI for acoustic applications. These systems are designed for real-time data collection and transmission, and are fitted with the DMON (WHOI) acoustic recorders. Each DMON has the LFDCS software (Baumgartner and Mussoline 2011) running and detecting for specific species and calls. LFDCS detections are delivered to a shore-side computer via Iridium satellite modem, and can be reviewed on the Robots4whales website. NEFSC collaborates with WHOI over several deployments, and monitors for near real-time detections of humpback, sei, fin, and North Atlantic right whales.

Mobile Platforms

Gliders

  • Slocum Gliders: Woods Hole Oceanographic Institution (Robots4whales)

A glider, or autonomous underwater vehicle (AUV), can be programmed to travel along a given trajectory. Gliders can be outfitted with many different instruments, including passive acoustic recording packages and DMON, which is a WHOI-built acoustic recorder that automatically runs LFDCS. They are able to transmit data back in near real time using an iridium satellite or cellular link as well as storing the data on-board until it is retrieved. Slocum gliders are battery powered, which tend to travel up and down the water column in a vertical zig-zag, utilizing buoyancy and an on-board motor to maintain course.

Towed Array

A towed array usually consists of a long electronic cable with a series of hydrophones and other sensors encompassed within it. Typically, they are towed horizontally behind a vessel and collect passive acoustic data in real time, but they can also be suspended vertically from a stationary mooring or vessel. The most simple array is a linear one in which all hydrophones are arranged in one plane (usually x) and therefore localization occurs in 2D, but there are also volumetric arrays, which have the hydrophones arranged in the x,y, and z planes for 3D localization. Using towed arrays on ship-board surveys are particularly useful for pairing vocalizations with under-studied species.

DASBRs

DASBRs (Drifting Acoustic Spar Buoy Recorders) are floating, mobile platforms that drift, typically incorporating a Soundtrap or other hydrophone components. DASBRs are typically deployed if Gervais’ beaked whales are sighted during offshore fieldwork. GPS will indicate location once the platform is ready to be retrieved.

Additional Hardware

Dipping Hydrophone

Dipping hydrophones are hydrophones that are attached to a cable and can be suspended in the water. NEFSC’s PAM group uses dipping hydrophones to opportunistically collect acoustic data when in the field near study species (i.e. when doing field work with the seal team near gray seal haul-out sites, or recording humpback whale song while sailing near calving grounds in the Caribbean).

Technical Advice

Technical advice list

When should I replace my VR2AR / ASCENT-AR acoustic release battery?

  • Replace the release motor AA batteries once they indicate they are approaching 25%. It is very strange that they did not last longer (5 years estimated life expectancy), but once you replace them, you will be prompted to reset the battery indicator within the VUE software. Vue should then indicate that they are at 100% again with the new batteries. You can then monitor the percentages in future deployments; if they continue to drop towards 25% quickly (within a year or two), then the receiver may be faulty or would at least warrant a call to Innovasea/Vemco to see what might be going on.
  • Web resources:

Flooded ST600s

ST600 Battery bay malfunction

ST600 clock drift

  • Outcome - John Atkins was going to push a universal fix for this
  • Email chains:
    • Clock Drift
    • Fix clock drift manually
    • This email conversation can also be found on the server here: \\stellwagen.nefsc.noaa.gov\stellwagen\MANUALS_SOFTWARE_CODE LIBRARY\HARDWARE\SoundTraps

ST600 Broken Hydrophone

Apollo Beacon Voltage

FPOD Batteries

Piston phone ST calibration

Hydrophone bonding issue for ST600s serial # <7000

  • The bond between the hydrophone and ST600 for serial #s prior to the 7000’s can degrade over time. Need to keep an eye out on hydrophone bond to ST for older ST600s
    • Timothy Rowell - This did happen to the first one we had deployed in Rookery Bay Florida. Scrub gently and inspect often.
  • Email chain:

Data upload errors

  • Google Bucket error
    • Examples - screenshots did not transfer in pdf

ST Recording Start Time Programming

VR2AR temp/depth/tilt Data

Cross-center SoundTrap Issue Documentation

  • It was brought up in a call today about a spreadsheet that has been shared amongst the science centers that annotates the various SoundTrap issues folks have been experiencing. I don’t see any of ours logged on there, if someone wants to and has a moment to log down our issues we’ve had? This is not a high priority by any means. Also I became aware of a StackExchange page that documents the known ST600 issues that I wanted to share with you.
  • Additional resources:

ST Host Connection Error from 512GB SD Card

ST Host Software v4.0.19 and manual

  • Guidance on how to resolve a ST Host connection issue. Ocean Instruments is strongly recommending SoundTrap users from here on out use ST Host version 4.0.19, which is their most recent non-beta software release. I came across this on their most recent ST600 manual. No specific reason was given other than that it will ensure correct operation of the SoundTrap recorders.
  • Additional resources:

ST Card Reader Download Location