Tides Changing In Marine World

Humpback Whales Thriving Off N.E. Coast

By Andrew Blake, Boston Globe Staff, 09/19/99

GLOUCESTER - The whale population off the coast of New England and the North Shore, has its good years and lean years. But this year and last qualify as boom times.

While the success of whale society, with a focus on humpback whales, can't be measured with economic markers like the Dow-Jones average, population numbers and other indicators tell researchers much about whale welfare.

Tourists by the thousands see the awesome power and grace of the humpback whale with its fluke raised in a theatrical pose while cameras click. But there is more to whales than meets the eye.

Not only is the local humpback whale population reflecting healthy growth, but researchers at the Whale Center of New England here believe they have identified a new feeding pattern, primarily involving juveniles, as well as vocalization patterns that may help in cooperative feeding ventures.

The WCNE, a nonprofit group supported by foundation and government grants and its 2,000 members, plans to present the findings at an international whale conference in Hawaii in December and plans to offer papers on their research to marine scientific journals.

"Certainly 1998 and this year so far have been very good years for the humpback whales in our region," said Mason Weinrich, executive director and chief scientist at WCNE.

Last year, said Weinrich, "we identified 51 calves, which was more than a record year in 1997, and so far this year we have identified 28 more mother-calf pairs."

An increasing population, he explained, is a reflection of longer-living whales with more females maturing each year while a smaller number are dying. It also tells researchers that the food supply is good and that the humpback population is well within the numbers that can be sustained by the ecosystem.

"One of the things we found, which is really exciting, is that there appears to be a new kind of cooperative feeding going on which involves mostly juveniles but with some adults," Weinrich said.

The favorite food of humpback whales in this region is small fish known as sand lance, commonly referred to as sand eels. They are found on Stellwagen Bank, an upcropping 12 miles from Gloucester and about 20 miles due east of Boston.

Humpback whales, so called because of the way they hump their backs while diving, force schools of sand eels toward the surface where they trap them against the surface in their gaping jaws. It is the preferred method of adult humpback whales.

"But what we've seen since a year ago July are groups of three and sometimes groups of up to eight, mostly juveniles, swimming close to the bottom and vocalizing loudly as some bump the bottom to scare up sand eels," Weinrich said.

Juveniles, he speculated, may not have learned to trap their prey against the surface or may find feeding along the bottom easier than trying to compete with adults more skilled at surface-feeding.

As the groups, like formations of low flying bombers, WCNEise the bottom terrain, they eat the sand eels there instead of herding them to the surface.

"We think there are now about 40 humpback whales at Stellwagen who seem to be specializing in this technique," Weinrich said.

"If whales could sneer, those who feed at the surface in the traditional manner would sneer at the bottom feeders," Weinrich joked as he viewed photographs of humpbacks feeding on sand eels forced to the surface

Exactly what the bottom-feeding pattern means along with the relationship to vocalization is open to question. The WCNE, Weinrich said, is simply noting at this point that something different appears to be happening

Humpbacks, which grow to about 50 feet, are the whales most often sighted by commercial whale watch boats usually at Stellwagen Bank, where the water is only about 100 feet - or two whale lengths - deep.

Other nearby feeding grounds include Jeffrey's Ledge, which runs off Cape Ann to New Hampshire, and Maine waters and the Great South Channel off Cape Cod. Whales raised in one "neighborhood" tend to return to that area year after year "but food, prey, is the driving force," Weinrich said.

In lean years, such as 1992 through about 1995 at Stellwagen and last year at the Great South Channel, whale populations shifted. Many whales moved to Jeffrey's Ledge to feed on herring and some from the Great South Channel in recent years have been feeding at Stellwagen.

"Like humans, whales tend to feed where their mothers taught them to feed, but necessity will force them elsewhere. If you took a person who knows where to walk down the street for a quart of milk and you plunked that person down in the middle of Indiana, the person would still be able to find the milk but it would require a lot more time and work," Weinrich explained.

Similarly, whales who have fed at Stellwagen and Jeffrey's Ledge will return to those areas as need requires, even though their natural neighborhood may be the Great South Channel off Chatham.

As the whale watch season winds down for tourists, Weinrich also said, he believes that whale watch guidlines may soon give way to whale watch regulations because of the increasing number of whale-boat collisions.

Between August 1997 and September 1998, he said, there were three whale watch boat collisions with humpbacks, with one whale fatality, one non-fatal injury and a third result unknown.

"The guidelines worked well for a while, especially in the commercial whale watch fleet, although they have slipped recently. The big problem is getting the word out to recreational boaters. I think we are moving to regulations to prevent more whale mortality accidents," he said.

Current guidelines, he said, call for a vessel speed to be reduced to 13 knots at two miles from a whale, 10 knots at a mile, seven knots at a half-mile, and a no-wake barely-moving speed at closer range. No more than one boat at a time should be within 300 yards of a wh ale for a maximum of 15 minutes if other boats are waiting. He advised boaters to contact the US Department of National Marine Fisheries for more information. The agency has an office in Gloucester.

The humpback whales are joined in the region by finback whales and smaller minke whales, as well as the rare and endangered northern right whale on occasion. There are only about 300 right whales left, Weinrich said.

But the humpback whale population is thriving. There are about 10,200 humpback whales who call the North Atlantic home, from New England to Newfoundland and the St. Lawrence to Iceland, Greenland and Norway.

"That's a very accurate number. That's based on good data, not extrapolations," Weinrich said. There are six major feeding groups, with one group of 1,000 to 1,200 making up the humpback population in New England and the largest group of about 3,000 feeding off the coast of Newfoundland. In winter the pods move to the warmer waters in the south off the West Indies to breed before moving north again in the spring.

This year, Weinrich said, marks the 20th anniversary of the Whale Center of New England, and at the start of the new century will come a name change. As of January the WCNE will become the Whale Center of New England.

"We have been a well-kept secret but we didn't intend to be. We'd like to change that. Not too many people identify with a cetacean but everyone knows a whale," he added.

Donations to WCNE are tax deductible. The group sponsors an Adopt a Whale program. It also offers a complete teacher's curriculum free over the Internet. It can be reached by computer at www.whalecenter.org, or by telephone at 978-281-6351. The mailing address is 33 Bass Ave., Gloucester, MA 01930 or PO Box 159, Gloucester, MA 01930.

This story ran on page 01 of the Boston Globe's North Weekly on 09/19/99.
© Copyright 1999 Globe Newspaper Company.