The EU Marine Strategy Framework Directive (MSFD) aims to protect the marine ecosystem and biodiversity. Descriptor D11, in particular, noise should be at levels that do not adversely affect the marine environment. Passive acoustic monitoring (PAM) devices such as smart hydrophones are integrated with marine autonomous systems (MAS) to facilitate compliance with the European Directives aimed at achieving Good Environmental Status regarding underwater noises. Cyprus Subsea has developed and deployed PAM solutions on various oceanographic platforms from environmental data buoys to autonomous underwater vehicles (AUVs).
Marine Strategy Framework Directive Descriptor 11
Anthropogenic underwater noise harms marine biodiversity. From hearing impairment and behavioral disturbances, anthropogenic activity adversely affects aquatic life. In addition, noise travels through the water as pressure affecting the soft bodies of marine biota, in ways that we have yet to explore fully. These potentially harmful activities at sea include shipping, mining, oil and gas exploration and extraction and marine infrastructure projects.
Marine Strategy Framework Directive (MSFD) Descriptor 11 refers to the introduction of energy, including underwater noise, which should be at levels that do not adversely affect the marine environment. Descriptor D11 includes two primary criteria referring to impulsive sound and continuous low-frequency sound.
Introduction of energy, including underwater noise, is at levels that do not adversely affect the marine environment
MSFD Descriptor 11 Energy and Noise
The establishment of thresholds for D11 is led by the Technical Group on underwater noise (TG Noise). These European experts have adopted recommendations on maximum acceptable levels for impulsive and continuous underwater noise. Tolerable statuses advocate these criteria over the course of a year:
- No more than 20% of a given marine area can be exposed to continuous underwater noise.
- No more than 20% of a marine habitat can be exposed to impulsive noise over a given day and no more than 10% over a year.
Marine autonomous systems (MAS) integrated with the Ocean Sonics icListen Smart Hydrophone can facilitate passive acoustic monitoring (PAM) to ensure MSFD compliance. Depending on the marine area, the MAS may require an oceanographic platform such as a buoy or ocean glider to monitor marine areas.
Smart Whale Sounds Project in Ireland
An example of an autonomous passive acoustic monitoring system is Cyprus Subsea’s support of the Smart Whale Sounds Project led by the Ocean Research and Conservation Association (ORCAIreland) in partnership with Huawei Ireland and Rainforest Connection (RFCx).
Since Ireland is home to one-third of all cetaceans worldwide. The project’s overall goal was to utilize the generated data to create a marine wildlife detection and classification model. Cyprus Subsea developed the PAM system integrated into the project.
PAM Recorder: Real-Time MSFD Compliant Noise Monitoring
The PAM Recorder system has a built-in algorithm to convert the acoustic stream into sound pressure levels (SPL) compliant with MSFD requirements. The system subsequently transmits the report in real-time.
This Ocean Sonics sensitive broadband digital hydrophone has a wide dynamic range for high quality data & long term stability. It captures sounds from the surrounding subsea environment and is deployable to a maximum ocean depth of 900 meters. This compact, all-in-one instrument processes data while streaming HD acoustic data in real time. An additional recorder allows for acoustic data to be stored during long deployments.
gListen Board with Bristlemouth
Cyprus Subsea has also developed the gListen Board – an Ethernet to RS-232 converter with voltage regulation and onboard memory for reading and extracting audio data. It was initially developed to conduct PAM with ocean gliders. It is an innovative MAS accessory that is compatible with Ocean Sonics icListen digital hydrophones. For other oceanographic platforms, the gListen Board can be paired with a Bristlemouth Development Kit.
Please reach out if you are interested in these passive acoustic monitoring solutions for your organization.