Contact: Shelley Dawicki
NOAA Fisheries Teams Up with Canada for Second Summer of Right Whale Surveys
One Third of Population Documented in the Gulf of St. Lawrence
The Northeast Fisheries Science Center’s right whale aerial survey team is busy documenting whales off Cape Cod and in the Gulf of Maine during the spring. Once the season started to change and sightings got sparse in U.S. waters, the team packed up and headed to Canada, where they helped with whale survey efforts for a second year from June 1 through August 12.
“Once we started seeing just a few right whales in Cape Cod and Massachusetts Bay in the late spring and few in the Gulf of Maine, we knew many had likely moved further north into Canadian waters and into the Gulf of St. Lawrence,” said Tim Cole from the NEFSC’s aerial survey team. “Canada’s Department of Fisheries and Oceans invited us to come help them conduct surveys over the summer. We focused in the area where most of the right whales were aggregated, while they surveyed throughout the Gulf and Maritimes regions to chart the distribution of right whales and the abundance of other marine mammal species.”
The NOAA Fisheries team and the NOAA Twin Otter were based for the summer in Moncton, New Brunswick. They worked in the western part of the Gulf of St. Lawrence, making six-hour flights several times a week and as often as possible, weather permitting, at an altitude of 1,000 feet. They looked primarily for right whales but also recorded sightings of other large whales. Over the nearly three months of survey effort, the NOAA team was joined by staff from the Provincetown Center for Coastal Studies, Florida Fish and Wildlife Research Center, and the Department of Fisheries and Oceans Canada.
In recent years, North Atlantic right whales have been spending less time in their usual summer feeding grounds in the Bay of Fundy. The reasons for the change in distribution are unclear, but it's thought to be related to changing oceanographic conditions and the availability of prey. In 2015, NOAA surveys first discovered large numbers of right whales in the Gulf of St. Lawrence. It is not known if the Gulf has always been an important area for right whales. Last summer (2017), 12 right whales were found dead in the Gulf of St. Lawrence. Entanglement in fishing gear and collisions with ships were identified as the causes of death for animals that could be examined closely.
Listening for Whales in Real Time
Specially-rigged buoys were deployed on many of the surveys to record acoustic data near aggregations of right whales and transmit those sounds to researchers by radio. Called “sonobuoys”, these instruments have also been used occasionally in Cape Cod Bay and in the Gulf of Maine.
Sonobuoys are cylinders containing underwater microphones – called hydrophones – and outfitted with a radio transmitter. The cylinders are about five inches in diameter and three feet long and are deployed from a special tube in the belly of the aircraft. When they drop into the ocean, a float inflates to keep the transmitter above the water’s surface, while the hydrophones drop deeper into the ocean to listen for underwater sounds, in this case from marine mammals.
The mammals can be miles away and are often out of sight of the researchers on the plane. Receivers on the aircraft can record whale vocalizations as long as the aircraft is within 30 to 40 miles of the buoy. The data help researchers compare and relate visual sightings and behaviors with the whales’ underwater sounds.
Unique Acoustic Experiment Combined Technologies
The NEFSC aerial team worked with Dalhousie University and the Royal Canadian Air Force on a sonobuoy experiment for two days in late July. For the first time, information from North Atlantic right whale surveys conducted by underwater robots, vessels, and aircraft was combined with a state-of-the-art military system traditionally used to track submarines.
In the experiment, a Royal Canadian Air Force long-range patrol aircraft dropped 32 sonobuoys in the southern Gulf of St. Lawrence in an area of approximately 1,000 square kilometers (roughly 400 square miles). At the same time, the NEFSC Twin Otter flew overhead and a fishing vessel with Canadian Whale Institute/New England Aquarium researchers aboard surveyed the area to visually document and photograph right whales from the plane and boat. Underneath the water's surface, two autonomous underwater vehicles (Slocum acoustic gliders) from Dalhousie University and the Marine Environmental Observation, Prediction and Response Network recorded right whale calls and measured ocean conditions. A satellite overhead captured images of the area to map the ocean surface and test the ability of such remote sensing to chart whale distribution in the region.
It will take time to combine all the layers of information. Researchers hope the experiment will provide new insights into right whale monitoring and behavior that will help improve conservation outcomes.
The Power of Images
“We worked with scientists from all of the Canadian Provinces that share responsibility for marine mammal research in the Gulf of St Lawrence. Our contribution was to provide an estimate of the number of right whales that are in the Gulf,” Cole said. “We took photographs from the plane when the whales were at the surface, and after the flight our team used the natural markings and scars on the whales to identify who each whale is.”
The images were compared to those of all the previously photographed whales in the North Atlantic Right Whale Catalog, which is curated by the New England Aquarium. The catalog provides life history information about each whale including their age, sex, and where and when they were last seen. According to one of Cole's teammates, many of the whales seen in the Gulf this summer were seen earlier this spring in Cape Cod Bay by the Center for Coastal Studies aerial survey team.
Entanglements, But No Dead Whales
No dead whales were found during this year's survey, while 12 were confirmed dead last year. There was evidence of recent entanglements. In one instance, a whale was sighted gear-free in the morning, and was then seen a few hours later carrying gear.
Sightings included fin, humpback, blue, and North Atlantic right whales. In June, for example, the team recorded 79 fin whales, 4 blue whales, 21 humpback whales, and 301 right whales. Many of the right whale sightings are repeated sightings of the same whales.
Since right whales can be individually identified, preliminary photo identification indicates that 135 individual right whales were sighted by the NOAA team during the summer, almost a third of the population.
In addition to the surveys and the sonobuoy project, the NOAA Fisheries team also assisted Transport Canada with testing unmanned aircraft systems by providing up-to-date right whale sighting locations. The NOAA Fisheries team also trained several Department of Fisheries and Oceans Canada biologists in right whale survey methods. Canadian biologists worked with the aerial team most of the summer, learning about all aspects of the operation, including photo identification.
To learn more about the NEFSC aerial survey team and to see where whales are being sighted visit the NEFSC interactive right whale sightings map