Blue and Fin Whale Acoustic Trends (AT)

 Acoustic trends in abundance, distribution and seasonal presence of Antarctic Blue and Fin Whales in the Southern Ocean

In the Southern Ocean, Antarctic blue whales and fin whales were severely depleted during commercial whaling. To monitor the post-exploitation status of both species in this remote area, the Acoustic Trends Working Group has proposed the use of a circum-Antarctic network of passive acoustic recorders.

The Blue and Fin Whale Acoustic Trends Project (ATP) has continued to develop and mature a long-term acoustic research program to understand trends in Southern Ocean blue and fin whale distribution, seasonal presence, and population growth through the use of passive acoustic monitoring techniques. This international collaboration has continued to deliver:

  • analysis and interpretation of existing ad-hoc acoustic datasets in from the Southern Ocean,
  • the development and implementation of an ongoing network of long-term circumpolar underwater listening stations, and
  • development of novel and efficient methods for standardized analysis of acoustic data collected in the Antarctic and sub-Antarctic

This working group contributes to the SOOS Science Priority Theme 6, impacts of global change on Southern Ocean ecosystems and was approved in 2017 with a proposed finish in 2019.



  1. Provide support to regional working groups in the implementation of observing system components or advances related to the outputs of this proposed capability working group.
  2. Establish linkages with existing and emerging programs of relevance to this proposed capability working group.
  3. Convene focused sessions at national and international meetings, and facilitate synthesis products, to increase the awareness of the scientific community to the importance of the activities and outcomes of this working group.
  4. Provide support to International Program Office (IPO) by providing annual reports to be available at the SOOS SSC annual meeting, as well as providing content for the IPO website/newsletters on the activities and outcomes of the proposed working group.
  5. Develop a funding plan to sustain the Working Group activities.
  6. Have products coming out of the WG acknowledge SOOS.
  7. Provide practical recommendations to guide and support passive acoustic data collection in Antarctic waters.
  8. Provide guidance on standardization of passive acoustic data from different areas for accurate and efficient analysis and interpretation.


Planned Products and Outcomes

  1. Guidelines and practical recommendations, and standards for passive acoustic data collection in Antarctic waters (completed in Van Opzeeland et al 2013)
  2. Guidelines for standardization of analysis of passive acoustic data from different areas for accurate and efficient analysis and interpretation
  3. Peer reviewed publications on Antarctic blue and fin whale distribution, seasonal presence, and population growth
  4. Data on Antarctic blue and fin whale distribution, behavior, and abundance for use in ecosystem models
  5. Increased understanding of Antarctic blue and fin whale distribution, seasonal presence, and population growth
  6. Improved models of Antarctic ecosystem function that incorporate the above knowledge
  7. Increased capacity for passive acoustics in the Southern Ocean including:
    1. Increased data collection efforts to achieve circumpolar acoustic coverage of the Southern Ocean Hydrophone Network
    2. Engagement with SOOS Regional Working Groups to better utilize platforms of opportunity for passive acoustic research
    3. Development of analytical best-practices and guidelines for standardization of Southern Ocean acoustic data
    4. Training of PhD and Masters students in bioacoustics analysis


As per the strategic plan 2017-2020: The project will not only continue to expand spatial and temporal coverage of data collection, but also focus on improving data collection with a view towards testing links among acoustical, biological, and ecological trends. Testing these links will likely require dedicated ship time to deploy acoustic recording tags on animals, and/or a combined visual and acoustic survey. However, such studies could add tremendous value to the long-term data collected by the moored acoustic recorders of the SOHN.

A new analysis framework has been designed and agreed upon, its implementation is expected to occur over the next three years. This new analysis framework will be more general and less proscriptive than the group’s previous vision for a ‘Blueprint of Analysis Methods.” However, the new analysis framework affords more flexibility, which is required to address the wide variety of instruments, duty cycles, sites, and detection algorithms that contribute data to this project. Implementation of this framework will require additional resources, ideally in the form of a 2-year postdoctoral researcher. Funding for such a position has been sought from SORP and Universidad de Concepcion, with supervision and in-kind contributions provided by the project steering group.

The new analysis framework requires and will build upon the Annotated Library of Recordings. Work on the Annotated Library will be ongoing throughout 2017/18 with the aim of creating a fit-for-purpose tool to assess the performance of automated detection algorithms for blue and fin whale calls across a wide variety of recordings made in different years, locations, and using different instruments.


AT is open membership. If you would like to be involved, please contact Brian Miller (Brian.Miller at


Leadership Team:

Flore Samaran (Coordinator, ENSTA Bretagne, France)

Kate Stafford (Coordinator, University of Washington, USA)

Working Group Members:

Susannah Buchan (Universidad de Concepcion, Chile)

Ken Findlay (University of Technology, South Africa)

Danielle Harris (University of St Andrews, UK)

Brian Miller (Australian Antarctic Division, Australia)

Ilse Van Opzeeland (Alfred Wegener Institute, Germany)

Ana Širović (Scripps Institution of Oceanography, USA)


Contributing Field and Modeling Activities

Dates Project Principal Investigator
2016-ongoing Annotated library of acoustic detections SORP Acoustic Trends Steering Committee
2017-2018 Antarctic data collection (>60°S)/Southern Ocean Hydrophone Network: 2017/18 AT Working Group Members
2017-ongoing PhD - Analysis of bioacoustic data recorded in the southern Indian Ocean Maelle Torterotot, Institut Universitaire Européen de la Mer (IUEM)
2018 ENRICH Voyage Ana Širović and Kathleen Stafford
2018 Masters - Analysis of passive acoustic recordings from Elephant Island Lisa Ganz, University of Bremen - Alfred-Wegener Institute (AWI)
2018-2019 Low-latitude data collection AT Working Group Members
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