It’s Not That Easy Keeping Track Of Right Whales

With the sharp focus this summer on North Atlantic right whales, a logical question to ask is: why is it so hard to figure out where the whales are? Wouldn’t it make sense to tag them, as we do cod and sharks, so that scientists and fishermen can know where they are and, in the latter case, avoid them?
Russell Andrews of the University of Alaska and the Alaska SeaLife Center has tried to do just that. He and his colleagues attempted to tag right whales with a satellite tag to track their movements while migrating north from the southeast U.S. toward the northeast coast. He used a barnacle-style tag which attaches with little anchors to the whales, called a Low Impact Minimally Percutaneous External-electronics Transmitter, or LIMPET.
The physical characteristics of a right whale make the animals difficult to tag. Unlike other baleen whales, right whales do not have a dorsal fin. So when the whale rises to the surface, there’s nothing much to attach a tag to. Any tag must somehow stick to the animal’s wet skin. rising above the surface of the ocean. Attaching a LIMPET tag means using an air rifle to shoot the small tag into the whale’s thin layer of surface blubber, preferably on the shoulder, which doesn’t move as much as other parts of the body.
The project began in January 2015, when the researchers were able to attach tags on just three right whales. In December they tried again, this time managing to tag four whales in total before ending the tagging component of the project in January 2016.
Tagging a moving whale is not a simple matter. Whales generally do not spend a lot of time at the surface of the ocean. A whale must be seen, which requires observers on boats and in airplanes. Second, a vessel must be ready to immediately head to the last known location of the whale. Then the weather, time of day and condition of the seas factor into the probability of tagging success. It took researchers following one right whale off South Carolina more than an hour before they could get in place to successfully shoot the LIMPET into the whale. More than two hours elapsed before the researchers were able to tag another right whale off St. Augustine, Florida.
Although large, right whales can move fast when they want to. They are social animals and will bump against each other in groups of juveniles or when males contest with other males in search of a mate. They may rub and roll on the seafloor to remove parasites. So even attached with barbed anchors, the LIMPET tags did not stay on the right whales for very long.
The four whales tagged in January 2016 kept their tags on for 0.1, 1.2, 3.5 and 5.5 days. The two of the whales tagged earlier in 2015 retained their tags longer, 15 and 50 days respectively. Their movements while tagged, however, showed that the whales either remained in the southern calving grounds off Georgia and South Carolina or moved northward along the coast. One juvenile whale, whose tag lasted 50 days, moved from cape to cape along the East Coast and along the southern side of Long Island before its tag stopped broadcasting in the waters south of Nantucket. Though not extensive, scientists hope that the satellite data can give a better picture of where the whales travel and how quickly along the mid-Atlantic region, where they are particularly hard to spot.
Another method of tracking right whale movements involves underwater eavesdropping. Scientists have set up an array of underwater acoustic monitors along the East Coast to listen for the characteristic sounds made by different species of whales. Called passive acoustic monitoring, these underwater buoys now operate from Florida to the Canadian provinces.
Last year the results of a large-scale study of the movements of North Atlantic right whales during the past ten years were published. The study, “Long-term passive acoustic recordings track the changing distribution of North Atlantic right whales from 2004 to 2014,” was coordinated by NOAA. It drew on the data from hundreds of acoustic-based underwater monitoring devices to show that right whales have changed their migration habits in recent years.
Data were collected from 324 recording devices operated by 19 different organizations in the U.S. and Canada along the East Coast. Five types of bottom-mounted passive acoustic recorders were deployed during the study period, each able to listen to calls from multiple whale species at one time.
Analysis of the data revealed North Atlantic right whales have increased time spent in the Mid-Atlantic region since 2010 and decreased their presence in the northern Gulf of Maine. They were also less likely to be found in the waters off Cape Hatteras, North Carolina in summer and fall, and are widely distributed across most East Coast regions throughout the winter months. They seem to be visiting the Bay of Fundy less frequently than they used to and linger along the East Coast year-round rather than just passing through on their annual northern and southern migrations. Many more right whales are gathering in the late winter and early spring in Cape Cod Bay.
The acoustic monitors detected right whales from Jacksonville, Florida to Nova Scotia from late October through early April. The only exception was on the Scotian Shelf, where no whales were detected from December through February. Right whales were also heard near Iceland and Greenland from July through October. Individual right whales made journeys to European waters, including a 131-day round trip from U.S. waters to an old whaling ground off northern Norway.
Passive acoustic monitoring is a relatively inexpensive, long-term monitoring tool that gives researchers a better understanding of distribution shifts in populations occurring from year to year. In addition, acoustic monitoring systems can send out a signal when right whales are detected in an area, alerting mariners and fishermen about the approximate location of the whales.

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