Case Study

Underwater Noise and Whales

Sound is a critical sensory cue for many marine animals, including whales and increasing levels of anthropogenic noise in the world’s oceans is a known stressor to marine life. Marine animals such as whales use sound to communicate, navigate and detect predators and prey.

Woodside continues to focus on managing our underwater noise emissions to minimise any impacts to marine mammals in areas in which we operate. We have continued to harness emerging and innovative technology to improve our knowledge and understanding of whales (their timing, movement and behaviour), explore novel whale detection methods, and engage large project-based offshore workforces in awareness and marine fauna observer programs, with visual whale sightings used to support the implementation of whale management mitigation strategies.

Technology to detect and track whales

With rapid technological and data processing advances, technology and innovation is an important component of Woodside’s science programs and research partnerships to understand and manage underwater noise and potential impacts to marine mammals. Activities in 2025 included support for industry collaborative projects and knowledge sharing via IOGP Joint Industry Programme on Sound and Marine Life and specific Woodside project study programs.

Distributed acoustic sensing (DAS) applied to whale detection - a proof-of-concept case study for the North West Shelf, Western Australia

Distributed acoustic sensing (DAS), a type of distributed fibre-optic sensing, is a technique for taking spatially resolved strain-rate measurements from discrete points along a fibre-optic cable in real time. Several recently published case studies have demonstrated the effectiveness of deploying DAS along un-lit fibre-optic telecommunications infrastructure (referred to as “dark fibres”) for environmental monitoring of baleen whale vocalisations.

Following on from the successful 2024 proof-of-concept DAS trial, Curtin University via the Woodside FutureLab program have confirmed detection, localisation and tracking of two baleen whale species, the pygmy blue whale and Omura’s whale over the trial period which ran from late November 2023 to early January 2024. Publication outcomes at the end of 2025 include six extended abstracts, thirteen conference or workshop presentations, and one journal publication. Based on the proof-of-concept DAS trial outcomes, Woodside is planning further trials to support the development of long-term, DAS-based whale detection systems.

Combining passive acoustic monitoring and biological echosounders at Scott Reef

The proposed Browse to North West Shelf (NWS) Project overlaps a Biologically Important Area (BIA) for pygmy blue whale potential foraging that overlaps the Scott Reef area. To better understand whale presence and seasonality in this area, Woodside is working with JASCO Applied Sciences Australia on a monitoring program that combines two approaches:

Passive acoustic monitoring – listening for whale calls using recorders on the ocean floor.
Biological echosounders – using specialised equipment to measure zooplankton biomass (an important whale food source) in the water column.

JASCO Autonomous Long Term Observers (ALTOs) – moorings for acoustic recorders placed on the seabed - were first deployed in the deep waters around Scott Reef in April 2023, with a focus on detecting whale vocalisations as well as other sources of underwater sound in the region. In September 2024, specialised echosounders were added to each ALTO to measure zooplankton biomass and assess productivity differences across locations and seasons. Field trips in 2024 and 2025 also included zooplankton sampling to identify prey species.

What’s Next ?

The monitoring program will continue in 2026 with routine servicing of the ALTOs and zooplankton sampling trips to Scott Reef. The data is being used to inform timing of construction planning activities for the proposed Browse development to reduce potential impacts to pygmy blue whales.

High-resolution biologging tags to unlock knowledge on whale vocalisations, environmental context and behaviours

Linking the knowledge and environmental context of pygmy blue whale movement, behaviours and vocalisations is an area of research that is being pursued by a PhD candidate at the Centre for Marine Science and Technology, Curtin University. Woodside recognised the value of this research for understanding the context of vocalisations recorded using passive acoustic monitoring (PAM) and have provided funding support for high resolution biologging tags which were deployed on pygmy blue whales feeding within the marine environment of the Perth Canyon in 2025 and further work is planned for 2026.

Satellite tags for whale tracking

The research partnership program with the Australian Institute of Marine Science (AIMS) and the Centre for Whale Research (CWR) to improve the understanding of the movement and behaviour of pygmy blue whales through the offshore waters of northwest Australia utilising satellite tags released a new paper in 2025. The researchers tracked the movement and behaviour of pygmy blue whales migrating through the offshore waters of Western Australia using two types of satellite tags. The fastloc GPS tag tracked the long distance migratory journeys and pathways of northbound whales. The pop-up satellite archival tags (PSATs), equipped with accelerometers, provided 3D dive profiles from which migratory swimming, exploratory dives, foraging and lunge feeding behaviours were identified. Combining both data streams allowed for the tracking of the horizontal and vertical movement behaviour in space and time ,and most importantly they identified where and when foraging and feeding occurred.

Go here for further information and direct access to the publication: Feeding on the go – research provides new insights into pygmy blue whale foraging behaviours | AIMS

All tagging was conducted with the relevant animal ethics permitting and no whale was injured as a result of the tags

Pygmy blue whale. Tiffany Klein