BAR HARBOR — On Oct. 10, Allied Whale entered the image of the 8,000th humpback whale into its photographic database.
It’s a milestone for the marine mammal research organization, which created the North Atlantic Humpback Whale Catalogue in 1977 with only 120 photographs.
It’s also a good sign the endangered species has been rebounding since it began receiving legal protections in 1955, when commercial whaling was halted in the North Atlantic.
In 1977, estimates suggested there were fewer than 2,000 humpbacks in the North Atlantic. Today, said Allied Whale senior scientist Peter Stevick, a combination of known whales and further estimates based on sampling methods suggest there may be closer to 20,000 humpbacks roaming the North Atlantic.
Thirty-seven years ago, students and faculty at College of the Atlantic, where Allied Whale is located, published the first slim catalogue, which showed how natural patterns on each humpback’s flukes—the two lobes at the end of the tail—were unique to each animal. Since then, photo-identification has allowed researchers to track movement, behavior and lifespan patterns, based on subsequent photos snapped by researchers, yachters, whale watchers and the like.
Over the years, about 700 individuals and groups have contributed photos and data; hundreds of staff, students and volunteers have spent countless hours comparing new photos to those already in the collection. A cool entry occurred recently, when Allied Whale received its first new photo of a humpback that was entered into the catalogue in 1978. The catalogue was a pioneering concept; today, photo-identification is a commonly used technique for studying whales.
TRACKING NO. 8,000
No. 8,000 has a strong white marking running diagonally across the center of its tail. It was photographed twice, first in April 2010 in the waters of the Agoa Marine Mammal Sanctuary off Guadeloupe in the French West Indies. Humpbacks travel to these warm waters in the winter to mate and give birth. Widely distributed there, it’s hard to set up a survey. So an outfit called the Observatoire des Mammiferes Marins de l’Archipel Guadeloupeen encourages boaters to take pictures, and funnels the photos to Allied Whale.
In November 2013, the whale was photographed 5,000 miles away in the Arctic, off MusvÃ¦r Island, Norway. This is an area where humpbacks feed on schools of herring.
Although photographed three years apart, Allied Whale received both sightings at the same time. The sightings provide insight into the distances humpbacks travel.
The humpback is one of 13 great whale species worldwide, according to the International Whaling Commission (IWC). Humpbacks exist as separate populations in the North Atlantic, North Pacific and Southern Hemisphere. The North Atlantic population migrates south to the equator in the winter, and north to sub-polar regions in the summer. The Gulf of Maine is one of their feeding areas from late spring to late October; they generally hang out 10-15 miles offshore.
In the past, all whale species were targeted by commercial whaling and many populations were seriously depleted. But no species were driven to extinction, and some populations have substantially improved, thanks to legal protection.
Humpback populations worldwide today show signs of increase, as do other species, such as the finback and blue whale. The common minke is in a healthy state, but the Atlantic right whale remains rare. The IWC banned all commercial whaling in 1986, but other threats remain, including ship collisions, fishing gear entanglements, pollution, habitat loss, noise pollution, reductions in prey, ocean acidification and other effects of climate change.
According to the National Marine Fisheries Service, from 1997 through 2010, humpbacks accounted for the greatest number of observed serious-injury entanglements (35), followed by right whales (11); minkes (5); and finbacks (4). As to fatal entanglements during that same period, there were 31 minke deaths, 20 humpback, eight right whale, and six finback.
It’s difficult to tell what pre-industrial humpback population levels were, and researchers, using different models and inputs, have arrived at radically different answers, said Stevick. However, he said, it’s possible to say that, within the North Atlantic, humpbacks have increased substantially over their numbers in the mid-20th century.
“Beyond that, it becomes a case of evaluating what threats the population continues to face, against its ability to sustain itself,” he said. “In this part of the world, I see the North Atlantic humpback as, on the whole, quite a positive conservation success story. That isn’t to say there are no threats and everything is wonderful and perfect. But the protection they’ve been afforded really does seem to have allowed them to come back in numbers and establish themselves in a lot of places we know historically were their range.”
Protective measures for whales in general have evolved over time. Measures that address fishing gear entanglement impact the Maine lobster fishery; in 2009, lobstermen were required to switch out floating ground line to sinking line, and on June 1, 2015, they will be required to reduce the number of end lines in the water. The measures are intended to minimize the amount of rope whales might encounter.
But climate change and ocean acidification have the potential to alter the ocean’s food base, and thus predator patterns, in such a drastic way that other human impacts pale by comparison, said Stevick.
Awareness of whales and their role as large, easily observed animals, as sentinels of ocean health has grown as increasing numbers of people participate in whale-watching excursions. These include a partnership formed in 2013 between the Bar Harbor Whale Watch Company and College of the Atlantic, designed to promote awareness of whales and marine conservation in general.
“They are dependent upon having a whole series of processes in the oceans doing what they’re supposed to do when they’re supposed to do it,” said Stevick. “If there’s a shift in the timing of when certain prey species are available, especially if they’re ones we don’t fish for, nobody might notice. But if that led to a sudden shift in where the whales are or what they’re doing, we would notice. They’re dependent on having a healthy ocean, and they’re big and obvious, and we pay attention them.”