Monitoring fin and blue whales in the lower St. Lawrence Seaway with onshore seismometers

• Published in: Remote Sensing in Ecology and Conservation
• Main Authors: Alexandre P. Plourde, Mladen R. Nedimović
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2022
• Subjects: Acoustic monitoring; baleen whale; conservation; marine‐mammal tracking; mitigation; seismology; Technology; T; Ecology; QH540-549.5; Canada; baleen whales; Blue whale; Fin whale
• Online Access: https://doi.org/10.1002/rse2.261; https://doaj.org/article/74caba35eb964827a03d47b3becde8f1

Abstract The Lower St. Lawrence Seaway (LSLS), in eastern Canada, is an important habitat for several species of endangered baleen whale. As we seek to reduce the hazards that these endangered species face from human activity, there is increasing demand for detailed knowledge of their habitat use. Only a sparse network of hydrophones exists in the LSLS to remotely observe whales. However, there is also a network of onshore seismometers, designed to monitor earthquakes, that have sufficiently high sample rates to record fin and blue whale calls. We present a simple method for detecting band‐limited, regularly repeating calls, such as the 20 Hz calls of fin and blue whales, and apply the method to build a catalog of fin and blue whale detections at 14 onshore seismometers across the LSLS, over approximately a 4‐year period. The resulting catalog contains over 600 000 fin whale calls and almost 60 000 blue whale calls. Individual calls are rarely detected at more than one seismometer. Fin whale calls recorded onshore often consist of multiple seismic phases arriving as a ∼2 sequence. Onshore seismometers provide a valuable, previously unused source of data for monitoring baleen whales. However, in the LSLS, the current seismometer network cannot provide high‐precision whale tracking alone, so a denser deployment of onshore and/or offshore seismometers is required.