Where are the North Atlantic right whales? The question is an urgent one for the future of both U.S. fisheries and the shipping industry because federal laws do not allow for the loss of a single right whale as a result of a human interaction.
A whale tagged with a LIMPET tag. NOAA photo.
As the Gulf of Maine has warmed, right whales have changed their movements. In recent years, researchers have documented portions of the right whale population feeding in Cape Cod Bay and the Gulf of St. Lawrence, and off the mid- and southeast-Atlantic coast where calves are born. More rare are individual right whale sightings in unusual places such as the Gulf of Mexico or off the European coast. Understanding where the rest of the right whale population can be found is imperative if we are to save the species.
On the other side of the world, whale researchers are asking the same questions about other large whale species.
In August 2020 researchers at the University of Auckland and the Cawthron Institute in New Zealand, part of the Southern Right Whale Consortium, successfully attached invasive satellite tags to six Southern right whales. The tag on one of the animals transmitted long past its typical span of six months. The scientists learned that this right whale went south into the Southern Ocean, meandered east along the Antarctic ice edge, and then returned to the Auckland Islands after nearly a year. The data indicated that right whales had turned to feeding grounds previously unidentified.
In September 2022 Consortium scientists at Macquarie University and the University of Western Australia attached these satellite tags to five Southern right whales off the Western Australia southern coast. Most of the satellite tags stayed on long enough for the researchers to learn that these right whales also headed south, to the area off Antarctica, and west; one whale traveled thousands of kilometers to the south of Madagascar before its tag failed.
The tag on one of the five whales, however, has lasted more than a year, providing the first-ever complete map of a Southern right whale’s annual migratory journey and identifying previously unknown habitats. In an interview with Australian Broadcasting Corporation, University of Western Australia researcher Kate Sprogis said mapping the whale’s travels was a milestone achievement. “With Southern right whales, we haven’t known where they’ve gone,” she said.
Increasing the number of tagged North Atlantic right whales to better understand where they travel and potentially discover unknown habitats would seem to be a logical action to take in order to reduce the whales’ interaction with shipping and fishing gear. But tagging a marine mammal, particularly an endangered right whale, is anything but simple.
All research on protected marine mammals in U.S. waters must be authorized under a NOAA Fisheries scientific research permit. Getting such a permit is a challenging and time-consuming process.
With a research permit in hand, scientists can then place a tag on a whale. Since right whales lack a dorsal fin, there are only two types of attachment methods to place tags on these whales. Non-invasive tags, such as suction cup tags, are attached on top of the animal’s skin. These tags are usually shed quickly by the animal. Invasive tags, such as LIMPET (Low Impact Minimally Percutaneous Electronic Transmitter), or blubber tags, can stay attached for weeks, months, or in some instances more than a year. Both invasive and non-invasive tags can track the whale’s location, behavior, movement, swim speed, habitat use, dive depth and health.
According to the New England Aquarium, between 1988 and 1997, 55 invasive satellite tags were deployed to track right whales. Health monitoring showed that 88% of these tagged whales had some form of scarring and 60% had observed swelling. Due to health concerns, NMFS ceased permitting these deep-penetrating tags. LIMPET tags were redesigned to tag right whales by penetrating just below the skin. The goal was to create a tag to last longer than a suction cup tag with minimal risk for health impacts. The state of Georgia successfully deployed LIMPET tags on right whales in 2014 and 2016. Of the seven right whales tagged, one tag transmitted for 50 days and another for 15 days; the remainder were attached for less than a week.
Placing any sort of tag on the back of a moving whale is dangerous, both to the whale and to the people applying the tag. To apply tags, researchers typically approach a right whale in a small boat to get close to the whale. Suction cup tags are placed on the whale using a long pole to push the suction cup tag onto its back. Invasive tags are shot into the animal’s skin with a bow or dart gun to allow the barbs or “petals” to penetrate the skin and take hold.
This summer NOAA Fisheries used a new technique for attaching a suction cup tag. It successfully flew drones to place a suction cup tag to the back of a right whale, part of a group of about 70 congregating on Georges Bank. While this technique has been used by researchers at Stellwagen Bank National Marine Sanctuary for the past two years to track sei whales, it was the first time it was attempted on a right whale.
Meanwhile, on the west coast, the use of implantable tags has provided critical insight on the North Pacific right whale population. In the mid-2000s, a tagging project helped identify previously unrecognized North Pacific right whale feeding and congregating areas in the Bering Sea. Furthermore, the tag data showed that the whales had different habitat use patterns based on temperature. In a year when the southeastern Bering Sea was particularly cold, the whales would aggregate in certain places. In a warmer year, the animals moved around much. Their behavior suggested that during the cold years they were congregating where copepod species were most abundant; during warmer years the copepods did not aggregate as densely, leading the whales to move more frequently in search of food.
In September, NOAA Fisheries, the Marine Mammal Commission, the Office of Naval Research, and Fisheries and Oceans Canada convened a North Atlantic right whale tagging workshop to bring together experts to inform potential future tagging of these whales. The first day of the workshop, which was open to the public, featured a series of presentations on research needs for North Atlantic right whale conservation, and a summary of the regulatory permitting environment in the United States and Canada, the history of telemetry tag development and use for large whales, and tagging best practices. Ultimately, the workshop proceedings will inform the risks and benefits of using various tagging methods, and identify which management and scientific questions could be answered through tagging studies of North Atlantic right whales. The workshop’s preliminary findings will be presented at the North Atlantic Right Whale Consortium meeting in October.
Many in the research community remain opposed to any invasive tagging of North Atlantic right whales. The recent commitment of $82 million dollars by the federal government to improve and expand tracking of right whales may help to add critical data vital to the conservation of the right whale population.