Tracking Whale Movements and Ship Encounters in the Northwest Atlantic

Jim Crocker
17th January, 2025

Tracking Whale Movements and Ship Encounters in the Northwest Atlantic

Projections show that areas of high relative incident risk for the blue whale (Balaenoptera musculus), concentrated in coastal and shelf areas as well as the Flemish Cap (a), are expected to remain largely stable through the near-future (b) and mid-future (c), indicating persistent vulnerability to vessel activity despite climate change.

Image adapted from: Solway et al. / CC BY (Source)

Key Findings

  • The study analyzed whale sightings, incident reports, and vessel activity in Atlantic Canadian waters to assess risks to baleen whales
  • High-risk areas for whale incidents are near densely populated regions, major shipping routes, and fishing grounds
  • The study's predictions align with independent data, highlighting the need for effective conservation strategies for multiple whale species
Baleen whales, some of the largest marine animals, face increasing threats from human activities such as vessel traffic and fishing gear entanglement. These interactions can lead to distress, injury, or even death for these whales. In Atlantic Canadian waters, reports of such incidents are consistently submitted to marine animal response organizations. However, until now, no comprehensive analysis has examined the relationship between whale distribution, vessel traffic, and the occurrence of these incidents. A new study conducted by researchers at Dalhousie University aims to address this gap by analyzing whale sightings, incident reports, and maritime vessel activity to assess the spatial risk of vessel-induced incidents for six baleen whale species[1]. The study utilized a vast dataset comprising 483,003 whale sightings, 1,110 incident reports, and 82 million hours of vessel activity. Researchers developed habitat-suitability models to conduct a spatiotemporal vulnerability analysis for baleen whales in the Northwest Atlantic Ocean. The analysis covered both present-day (1985-2015) and projected near-future (2035-2055) distributions of these whales. The findings revealed that areas with high habitat suitability for multiple baleen whale species are closely linked to sea surface temperature and salinity. Key hotspots identified include the Bay of Fundy, Scotian Shelf, Laurentian Channel, Flemish Cap, and Gulf of St. Lawrence. The study's projections were validated against an independent database of acoustic detections, which showed a strong alignment with the model's predictions, enhancing the credibility of the findings. The regions of high relative incident risk were found to be near densely populated areas, principal maritime routes, and major fishing grounds. These regions often coincide with reported incident hotspots, indicating a pressing need for effective mitigation strategies. Previous research also supports the findings of this study. An earlier study on the distribution and movement patterns of baleen whales in the western North Atlantic Ocean revealed significant distributional shifts linked to climate-driven changes in ocean temperature and circulation[2]. This study showed that baleen whales, including humpback, sei, fin, and blue whales, have exhibited notable changes in their acoustic occurrence patterns, with a general northward shift observed after 2010. The shifts in whale distribution are likely influenced by changes in prey availability and other climatic factors. Another relevant study analyzed global marine mammal species richness and predicted changes in biodiversity under future environmental conditions[3]. This study projected increases in cetacean richness above 40° latitude in both hemispheres and decreases at lower latitudes, suggesting that climate change will continue to drive distributional shifts in marine mammal populations. These findings align with the current study's projections of future baleen whale distributions under continued environmental change. The Dalhousie University study highlights the importance of considering risks to multiple whale species, not just the North Atlantic Right Whales, which already benefit from targeted mitigation strategies. As vessel traffic and fishing activities continue to pose significant threats to baleen whales, comprehensive and multi-species-focused conservation measures are essential to protect these marine giants. This study provides valuable insights that can inform management decisions and help mitigate the risks associated with human activities in the marine environment.

EnvironmentAnimal ScienceMarine Biology

References

Main Study

1) Assessing changing baleen whale distributions and reported incidents relative to vessel activity in the Northwest Atlantic.

Published 15th January, 2025

https://doi.org/10.1371/journal.pone.0315909

Related Studies

2) Exploring movement patterns and changing distributions of baleen whales in the western North Atlantic using a decade of passive acoustic data.

https://doi.org/10.1111/gcb.15191

3) Current and future patterns of global marine mammal biodiversity.

https://doi.org/10.1371/journal.pone.0019653


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