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

Northwest Atlantic International Sightings Survey (NAISS) of Marine Megafauna on the Continental Shelf From Northern Labrador to the Bay of Fundy

Jack Lawson, Jean-François Gosselin

Concurrent with partners in the United States, and using staff from several DFO Regions, in 2016 DFO conducted a large-scale aerial survey of the Atlantic Canadian seaboard as part of a multinational effort to gather data on the distribution and abundance of a variety of marine megafauna in the western North Atlantic. This survey was designated the NAISS (North Atlantic International Sightings Survey).

This was the second large-scale, systematic survey effort, and the first in nine years, to survey the continental shelves along Labrador and Newfoundland, the Gulf of St. Lawrence, and the Scotian Shelf for marine mammals, sea turtles, and other large species that that can be detected near the sea surface. DFO and its international partners were extremely pleased with the coverage achieved during the comparable 2007 TNASS survey; during both 2007 and 2016 DFO was able to realize an unparalleled level of aerial survey coverage.

DFO’s NAISS survey data will be integrated with the 2016 National Marine Fisheries Service and European SCANS III marine surveys, and by doing so will provide a cross-Atlantic context to interpret results. For example, summer 2016 offered an excellent opportunity for DFO to enhance the scientific value of our survey efforts by coordinating with planned American efforts in adjacent waters. During July-Sept 2016 NOAA conducted a l2-ship 2-aircraft marine megafauna (whales, sea turtles, sharks, seals) survey covering all northern U.S. Atlantic waters, as far north as the Canadian border.

By conducting a survey of Atlantic Canadian waters at the same time as NOAA, scientists covered most of the known range of many transboundary species of conservation and regulatory concern for DFO, and ensure that distributional anomalies will not jeopardise the results.

Further, European countries such as the UK, Spain, France and others also conducted large-scale megafauna surveys in the summer of 2016 – further enhancing the value of the NAISS by facilitating ocean-wide comparisons. An international workshop at the recent biennial marine mammal conference finalized plans to move forward with efforts to compare and merge these north Atlantic survey data.

The only way to achieve the designed coverage within a short time window constrained by weather conditions and whale migration was to use three aircraft simultaneously, each with a team of experienced observers. To make this possible, we combined the resources of three regions of DFO: Québec, Newfoundland & Labrador, and Maritimes.

The NAISS survey was flown at an altitude of 183 metres ASL using a deHavilland Twin Otter 300 and two Cessna 337 Skymasters. Expanding slightly on the 2007 TNASS, the 2016 transect lines extended from the shoreline to at least 20 miles beyond the shelf breaks, and crossed bathymetric profiles. Observers in the survey aircraft collected data on the identity, group size, position, and behaviour of large and small cetaceans, plus environmental covariates. Each aircraft was equipped with bubble windows, and the Twin Otter had a trackline video camera system as well. Sighting data were collected by observers using line transect survey methods. The data from fore and aft observers on the same side of the Otter aircraft will be used to estimate the proportion of sightings missed by observers (perception bias) and therefore improve the precision of the results. Surface interval information from whale tagging data collected by DFO and others will be used to estimate the proportion of animals available to be sighted during an overflight (availability bias).

Between August 1 and September 27 2016, DFO achieved almost the same coverage, 49,591 km of line transect effort, as in our previous large-scale marine megafauna survey in 2007 (TNASS); much poorer weather (i.e., unusually high winds and widespread fog) and an extended NATO naval exercise meant that DFO completed 89% of their planned transect effort in 2016, versus 96% in 2007 (Fig. 6).

In Labrador and Newfoundland DFO sighted almost twice as many cetaceans as they did in 2007 (1,073 sightings = 10,956 animals), although there were relatively fewer large whales (fin, humpback, minke); white-beaked dolphins were the most encountered and numerous cetacean. Most of the additional sightings were collected on the Labrador and Newfoundland NE coasts, perhaps a function of intentionally initiating the survey two weeks later than 2007, the later and prolonged presence of spawning capelin, or some other type of environmental change. A greater number of sightings would have been collected if DFO been able to complete four long transect lines off the Newfoundland south coast that were precluded by poor weather. The two Skymaster teams amassed slightly fewer cetacean sightings in the Gulf of St. Lawrence and on the Scotian Shelf than they did in 2007 (1,182 sightings = 4,819 animals; fewer common and unknown dolphins, principally). This smaller sighting total may have been a function of the poorer weather conditions and the weather-related loss of multiple transects on the centre of the Scotian Shelf (Figure 6).

Processing of the survey data, which began in the fall of 2016, involves transcribing, aggregating, and verifying the recordings made by the observers, mapping sightings, assessing duplicate sightings amongst observers, estimating sighting biases using mark-recapture data, and obtaining estimates of marine megafauna abundance using a distance sampling approach. The analysis of the visual survey data will be presented at the annual meeting of the national marine mammal peer-review committee in the winter of 2018.

From data gathered during the survey, the team will produce abundance estimates and distribution maps for species including cetaceans, sea turtles, and large fish species such as basking sharks and sunfish sighted in Canada’s Atlantic waters. Target species include multiple Species at Risk such as the blue whale, north Atlantic right whale, fin whale, St. Lawrence Estuary beluga whale, Scotian Shelf northern bottlenose whale, Sowerby’s beaked whale, leatherback and loggerhead sea turtles, and basking sharks.

Further, these data will be gathered in a way that facilitates their integration with similar types of data being collected concurrently in adjacent regions (e.g., the NOAA surveys). Sighting density data will be compared with physical and biological features such as bathymetry, sea surface temperature, and productivity to determine if there are relationships that could be used later in habitat assessments (such as to support critical habitat designation), or to refine future survey designs. In particular, the effort-weighted sightings data will be used to analytically challenge DFO’s MaxEnt habitat suitability models, and create new GLMMs. As well, DFO will compare the 2016 results with the distribution patterns and estimates from the 2007 survey using density surface mapping and MaxEnt habitat models.