Researchers document offshore route of right whale

First published in The Savannah Morning News. Reprinted in Landings, May, 2015, with permission.

With a satellite tag attached to its shoulder, a young right whale has revealed the route of its seven-week migration from Cape Canaveral to Cape Cod. Before shrugging off its bright orange tracking device the whale zig-zagged more than 1,800 miles up the coast.

Georgia Department of Natural Resources (DNR) and other researchers tagged the animal in January as part of a trial in which up to five whales were to be fitted with the palm-sized satellite trackers. “Our goal was to develop a minimally invasive tag that works with right whales,” said Clay George, a biologist with the Georgia Department of Natural Resources.

So far, so good. Of the tags attached to three whales, two lasted the target duration of at least two weeks. The tags didn’t appear to harm the whales. Researchers observed two of the three whales after they’d lost their tags and noted only superficial scratches near the tag site. Some right whales, including breeding females, migrate each winter from northern foraging grounds to the waters off Georgia and Florida, where they give birth. They return north to New England and Canada in the spring.

On each journey migrating whales run a gauntlet of hazards including numerous large ports, busy shipping lanes, recreational vessel traffic and commercial fishing gear. Tagging could provide a more precise mapping of their route and help tailor regulations to keep them safe without unnecessarily burdening shippers, boaters and fishermen.

In particular, scientists want more information about the whales’ journey through the mid-Atlantic region, where they’ve proven tough to spot. “Studies have shown traveling right whales are the most difficult to find,” said Barb Zoodsma, a former DNR biologist now with NOAA Fisheries. “In fact, this whale that went up the East Coast, we haven’t gotten one sighting of this animal. It’s somehow sneaking by without any sighting or reporting.” How right whales pace themselves is not well understood, either. “Do they start swimming and not stop until they get to the Northeast, or do they dilly dally?” George said.

Numbers and location

Tags could also tell researchers where right whales go when they’re not seen in their known haunts, including the Bay of Fundy. They typically feed there in summer but have been scarce in recent years. “Where are the whales?” Zoodsma said. “This technology may be able to tell us.”

The new tags attach like a molly bolt, with titanium barbs that hook into the outer layer of blubber, said Russ Andrews, a scientist with the Alaska SeaLife Center and the University of Alaska Fairbanks. He customizes the tags for use on various species, using samples of cadaver whale blubber to stress test their holding power. The tags have helped track 21 species of whales and dolphins.

Surprisingly supple

Right whales provide several challenges for tagging efforts. Researchers can’t collar them or glue a tag to their sloughy skin. Suction cups don’t last. And even if researchers could capture the bus-sized baleen whales, they lack a dorsal fin, which provides a handy area on which to bolt tags on other species, including great white sharks.

On right whales, the tag must be anchored into a thin outer layer of blubber. Doing that requires an air rifle and a skilled marksman, in this case Andrews, who practiced aiming for a precise area on the surprisingly supple behemoths. “It might look I’m hitting the side of a barn, but I’m trying to aim for a particular place on the shoulder, an area it won’t move very much,” Andrews said.

The case of an 11-year-old female right whale nicknamed “Platypus” demonstrated the difficulty of the process. Her tag transmitted for only 20 hours. It’s unclear why it came off, though Zoodsma has some ideas.

Right whales are big, social animals that rub up against each other and scrape against the ocean floor, Zoodsma noted. “There’s not much that can stand up to getting smeared by a 50-ton object,” she said.

Magical migration

Still, the tags already have provided insight into whale behavior. The 15-day meanderings of the 6-year-old female known as 4092 indicated she swam 50 miles off the Georgia coast, a greater distance than expected. She eventually made it to Cape Hatteras before losing her tag.

The yet-to-be named juvenile that kept its tag for 50 days was the real superstar, though. A lifeguard initially spotted that whale just 100 yards off New Smyrna Beach, Fla., alerting the researchers on January 20. The young animal’s journey up the coast revealed its estimated position from there to just south of Martha’s Vineyard, a possible feeding area. “It’s one of the best insights we’ve had into the actual paths right whales take to migrate up the mid-Atlantic,” Zoodsma said, cautioning that more data from more tags are needed before they can reach a conclusion. Still, she found it interesting that this whale seemed to make it up the coast by going from cape to cape, “running into” these projections. “The capes used to be whaling stations, suggesting that (path) is not unique,” Zoodsma said. This calving season was slow, with bad weather limiting the survey effort and making it harder to find suitable whales to tag. Researchers plan to be back at it next year.

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