Center of Expertise in Marine Mammalogy

Scientific Research Report
2015-2017

Table of Contents

• Complete Text
• Introduction
• Using aerial infrared images to count ringed seals on ice
• The use of unmanned aerial vehicles (UAV)
• 2017: A Marine Mammal Odyssey, Eh!
• Mark-recapture analysis from long-term study on Sable Island identifies changes in demographic rates in northwest Atlantic Grey Seals
• OTN – Using grey seals (Halichoerus grypus) as bioprobes to estimate phytoplankton biomass
• Northwest Atlantic International Sightings Survey (NAISS) of Marine Megafauna on the Continental Shelf From Northern Labrador to the Bay of Fundy
• Monitoring Movements of Whelping Seals on Drifting Pack Ice
• Marine Mammal Genomics Research in the Central and Arctic Region
• OTN and predator-prey interactions
• Listening in on the Deep: Passive Acoustic Monitoring of Whales off Nova Scotia
• Sharing Meals Keeps Killer Whale Families Together: Provisioning relatives maintains long-term social bonds and helps pass on shared genes
• New developments in the use of fatty acids to determine marine mammal diets
• More than a mouthful – unlocking bowhead whale foraging and reproductive histories from baleen
• Observing walrus behaviour at haulout sites in quasi real-time
• Moving towards automated counting
• References

Listening in on the Deep: Passive Acoustic Monitoring of Whales off Nova Scotia

H. Moors-Murphy

More than twenty different species of marine mammals occur off Nova Scotia including resident and migratory species and several species at risk. Despite this diverse marine mammal community, relatively little is known about the year-round distribution, movement patterns and habitat use of many of these species throughout most of our waters. Of the species and areas that are well studied, the majority of available information on their occurrence comes from studies conducted on boat-based platforms during summer months, when weather conditions are favorable and it is the most logistically feasible to be out in the Northwest Atlantic studying marine mammals.

Most marine mammals in our waters produce underwater calls, unique to each species. Passive acoustic monitoring, or ‘listening in’ on the ocean environment, can provide a means to gain information on how marine mammals are using an area that is less restricted by weather conditions and at-sea platforms. Based out of the Bedford Institute of Oceanography in the Maritimes Region, Team Whale uses underwater listening devices called Autonomous Multichannel Acoustic Recorders (or AMARs for short) to monitor for whale presence in various areas of interest off Nova Scotia. These systems are anchored to the seafloor and collect and store data autonomously. With their terabytes of memory space and large number of batteries, AMARs can be deployed to collect acoustic data for a year or more at a time.

AMARs were used to collect acoustic data from the Gully Marine Protected Area and two nearby shelf-edge areas during 2012-2014 (Figure 11). These systems sat on the ocean bottom at approximately 1500 m depth for about six months at a time, with a few weeks gap between each deployment period to download data, change batteries and refurbish the systems. This resulted in a near-continuous two-year acoustic dataset that could be examined for the presence of whale calls. Analysis has provided information on the regular year-round occurrence of northern bottlenose whales in both canyon and non-canyon areas along the eastern Scotian Slope, and will contribute to identifying additional important areas outside of identified Critical Habitat for this Endangered species. New information on the seasonal occurrence of other species in these areas has also been gained including peaks in Endangered blue whale and species of Special Concern fin whale calls and humpback whale singing^{Footnote 1} during winter months, peaks in sei whale calls during summer months, the relatively consistent year-round occurrence of sperm whale and species of Special Concern Sowerby’s beaked whale clicks, and most excitingly the discovery of a new regular user of the Gully MPA – Cuvier’s beaked whales! While Cuvier’s beaked whales were acoustically detected in the Gully on about 25% of the recording days and showed low but consistent presence throughout the year^{Footnote 2}, only one visual sighting has ever been documented in the canyon despite the numerous beaked whale vessel-based surveys that have been conducted in the area dating back to the 1980’s.

During 2015-2017 (Figure 12), Team Whale’s passive acoustic monitoring program was expanded to five AMAR deployment stations and complimented a larger acoustic study conducted by JASCO Applied Sciences. In total, 25 AMAR recorders were deployed throughout Nova Scotia, Newfoundland and Labrador during this period. Analysis of the large amount of acoustic data collected is currently underway in collaboration with JASCO and the Taggart Lab of Dalhousie University.

Similar passive acoustic monitoring programs using bottom-mounted recorders known as AURALs (Autonomous Underwater Recorder for Acoustic Listening) are being led by DFO researchers in other eastern Canadian regions. Yvan Simard from the Institut Maurice-Lamontagne in Quebec has been conducting AURAL deployments in the St. Lawrence Estuary and Gulf of St. Lawrence and Jack Lawson of the North Atlantic Fisheries Centre in Newfoundland has been deploying AURALs off southern Newfoundland and eastern Labrador since 2009.

Over the next few years, DFO’s passive acoustic monitoring program off eastern Canada will continue to expand under the new Ocean Protection Program (OPP). Funding through OPP supports the acquisition of additional acoustic recording equipment and personnel with acoustics expertise to help increase our understanding of the impacts of human-made noise, particularly shipping noise, on at-risk whale species including Endangered North Atlantic right whales, St. Lawrence belugas and southern resident killer whales in the Pacific. Enhanced passive acoustic monitoring efforts into the future will allow us to continue to expand our knowledge of when and where whales occur off eastern Canada, will help us to monitor ocean noise in our waters, and will contribute to our understanding the impacts of human-made noise on whales to better assess how to mitigate these impacts and protect whales in our waters.