In a post-industrial whaling world, flagship and charismatic baleen whale species are indicators of the health of our oceans. However, traditional monitoring methods provide spatially and temporally undersampled data to evaluate and mitigate the impacts of increasing climatic and anthropogenic pressures for conservation. Here we present the first case of wildlife monitoring using distributed acoustic sensing (DAS). By repurposing the globally-available infrastructure of sub-sea telecommunication fiber optic (FO) cables, DAS can (1) record vocalizing baleen whales along a 120 km FO cable with a sensing point every 4 m, from a protected fjord area out to the open ocean; (2) estimate the 3D position of a vocalizing whale for animal density estimation; and (3) exploit whale non-stereotyped vocalizations to provide fully-passive conventional seismic records for subsurface exploration. This first example’s success in the Arctic suggests DAS’s potential for real-time and low-cost monitoring of whales worldwide with unprecedented coverage and spatial resolution.
  • @HaggunenonsOPM
    1•1 year ago

    Summary made by Quivr/GPT-4

    This document is a research study that explores the use of distributed acoustic sensing (DAS) for monitoring baleen whales. DAS is a technology that uses fiber optic cables to detect and measure sound waves. The researchers used this technology to monitor whale vocalizations in the waters around Svalbard, Norway.

    The study found that DAS has several advantages over traditional single-point sensing methods. For one, it provides continuous measurements over time and space, allowing for a more comprehensive understanding of whale behavior. The researchers were able to identify different whale species based on the frequency and bandwidth of their calls. They also found that DAS could record vocalizations over tens of kilometers, from protected fjord areas to the open ocean, despite varying noise conditions.

    One of the most significant revelations of the study is the potential for DAS to replace traditional seismic exploration methods. The researchers found that each whale call recorded by DAS could be used to provide seismic records for subsurface exploration. This means that in areas where vocalizing baleen whales and DAS overlap, seismic exploration could be replaced by a completely passive method, reducing human activities and noise in the oceans.

    However, the study also notes some challenges to using DAS on a global scale. For instance, telecommunication fiber optic cables belong to various entities and require specific agreements to be accessed. Additionally, these cables are often equipped with signal-boosting repeaters that block the interrogator’s laser pulses and reduce the usable length to the first 50-70 km.

    In conclusion, this research suggests that DAS has significant potential for whale monitoring and could revolutionize the way we study and protect these creatures. However, more work is needed to overcome the challenges associated with accessing and using telecommunication fiber optic cables.