JASCO Applied Sciences

The firm deploys calibrated sound recorders to measure underwater sound levels. Projects may be long-term, wide-area acoustic monitoring programs[1][2] or short-term measurements of industrial sources or marine vessels. The data collected are then analysed to determine the acoustic signature of the sound sources, characterize the ambient noise conditions at the measurement site,[3] or detect and identify marine mammal vocalizations.[4][5] JASCO measures underwater anthropogenic noise from many sources, including:

• Pile driving
• Seismic survey operations
• Marine vessels[6][7]
• Construction (offshore) and nearshore)
• High-frequency sonar such as side-scan sonar, multibeam sonar, and echosounders[8]

The firm also conducts numerical modelling studies to predict the underwater sound field of noise sources, which are often required for environmental impact assessments of industrial projects. The large sound levels produced by activities such as pile driving and seismic surveys can disturb and even injure marine mammals[9] and fish. The results of underwater acoustic modelling are commonly expressed as safety radii (or exclusion zone radii) that are used by marine mammal observers during operations to ensure animals are not exposed to harmful levels of noise.[10] Results are also provided as contour maps of the sound levels around the noise source. These maps can be used to assess or mitigate the impacts of the noise on marine mammals,[11] fish, and other aquatic wildlife.

JASCO also performs modelling of aquatic species’ movement and behaviour, exposing simulated marine animals (called animats) to 3-D modelled sound fields. Unique movement and behaviour parameters are determined for each species from animal behaviour studies to simulate how the animals behave and move within the environment. The acoustic exposure of each animat is determined and compared to the regulated exposure criteria to predict potential environmental impacts of an acoustic source.

The OceanObserver is an underwater acoustic data recorder that also does onboard processing, meaning that it can process the sound data to, for example, detect marine mammal vocalizations so that the information can be telemetered to shore via undersea cable, Wi-Fi, VHF radio, satellite, etc. That way the raw acoustic data, which can be very large, need not be transmitted (and often cannot be transmitted due to bandwidth restrictions).

The OceanObserver is used in numerous applications including robotic vehicles (e.g. underwater gliders), spar buoys, real-time monitoring buoys, research buoys, and cabled underwater observatories to transmit acoustic detections and measurements to shore in near real-time. Applications include:

• Real-time pile driving monitoring: sending peak sound pressure levels to shore to ensure regulated threshold levels are not exceeded.
• Marine mammal detection and avoidance: Detecting and localizing marine mammals over vast areas to allow alerting nearby vessels or operations to prevent collision or disturbance. For example, locating North Atlantic right whales in the Gulf of St Lawrence to enable temporary closures of affected areas.[12]
• Quantifying and mitigating vessel noise: Semi-permanent seabed monitoring stations, connected to shore by undersea cable, sending vessel sound source measurements to determine how to reduce impacts from vessel underwater noise pollution.[13]

Two AMAR G4s being deployed near Kitimat, BC, each with a hydrophone surrounded by a yellow shroud to reduce flow-induced noise over the hydrophone

The successor of the AMAR G3, the AMAR G4 (Autonomous Multichannel Acoustic Recorder Generation 4) is an underwater acoustic and oceanographic data recorder with 10 TB of removable SD memory cards and Wi-Fi communications. It consists of recording electronics housed inside a watertight pressure housing. The AMAR can be connected to up to 4 hydrophones sampled at 24-bit resolution at rates up to 512 kHz[14] Up to 7 oceanographic sensors (e.g., dissolved oxygen, salinity, acidity, temperature) can be connected, allowing the system to be used as a mini ocean observatory. It can include a chip-scale atomic clock to allow precise timing and synchronization of multiple AMARs.

Four models are available, spanning water depth ratings of 250 to 6700 m. External battery pack housings are available for deployment lifetimes of up to a year.[15]

The AMAR G3 (Autonomous Multichannel Acoustic Recorder Generation 3) is an underwater acoustic and oceanographic data recorder. It consists of recording electronics housed inside a watertight pressure housing. The AMAR can be connected to up to 8 hydrophones sampled at 24-bit resolution at rates up to 128 kHz, and another high-frequency hydrophone sampled at 16-bit resolution at rates up to 687.5 kHz.[16] Oceanographic sensors (e.g., dissolved oxygen, salinity, acidity, temperature) can also be connected, allowing the system to be used as a mini ocean observatory.

Several AMARs were used on the Strait of Georgia branch[17] of the VENUS ocean observatory, providing publicly available underwater sound recordings.[18][19] [20]