Humans primarily use light to perceive and understand their surroundings. But what happens in environments where light is scarce, such as underwater? In marine ecosystems, sound travels far more efficiently than light, making it the primary means by which many aquatic species interact with their environment. Most underwater species rely on sound rather than vision to navigate, communicate, and survive.

Marine soundscapes offer a cost-effective, non-invasive way to monitor these environments over long periods. By passively recording sound, researchers can track geophysical events, weather patterns, human activities, and animal behaviour without disturbing the ecosystem. Comparing soundscapes over time allows for the assessment of habitat quality and environmental changes.

The broadband acoustic network continuously records sounds between 10 Hz and 50 kHz, capturing geophonic sounds, most anthropogenic noise (excluding sonar and seabed mapping technologies), and biophonic events. For higher-frequency sounds, the Cetacean Passive Acoustic Network monitors harbour porpoise clicks (120–145 kHz, typically 132 kHz). Additionally, a dedicated sensor network tracks bats, passively recording their echolocation calls, which they use for navigation and foraging.

By listening to the soundscape, we gain a deeper understanding of marine and coastal ecosystems, paving the way for better conservation and management efforts.

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The hydrophones and cetacean loggers are autonomous sensors capable of continuous recording in the field for several months. These devices are carefully maintained and deployed on tripods or multi-sensor bottom moorings, fixed upright on the seafloor. The moorings are attached to a buoy equipped with an acoustic release system, enabling the entire setup to be recovered efficiently. Data from these fixed acoustic recorders is retrieved every 3–4 months, facilitating comparisons of spatial and temporal patterns across recording sites. 

To support various monitoring needs, a multi-purpose mooring was developed as part of the LifeWatch framework. Designed for use in dynamic, high-current, shallow coastal environments, this mooring accommodates multiple autonomous sensors through dedicated slots and clamps. The sensors remain securely attached for the duration of the measurement period, ensuring high-quality data while minimising the impact of environmental currents. This approach provides a non-intrusive method for studying marine ecosystems and their inhabitants. The multi-purpose mooring builds on the tripod system initially developed within the LifeWatch framework for the Fish Telemetry Network and is also equipped with an acoustic release system, ensuring complete recovery without leaving debris on the seafloor. 

On land and along the coast, BatCorders continuously monitor bat activity. Powered by batteries and solar panels, these omnidirectional devices (ecoObs) record sound at a sampling rate of 500 kHz with 16-bit depth, covering a frequency range of 16–150 kHz. The full-spectrum recordings are analysed using advanced software (BatIdent), which classifies calls by species, genus, or higher taxonomic group. All classifications undergo manual validation, ensuring the accuracy of the data, which is stored in a dedicated database for further analysis. 

This integrated infrastructure supports non-invasive, high-resolution monitoring of marine and coastal environments, enabling valuable insights into biodiversity and ecosystem health.