On the tail of the humpback whale

While a book featuring a thousand photographs of whale tails may never be a best seller, researchers in this field say it has become a valuable scientific tool. It has added the personal touch to marine mammal study - allowing scientists to identify individual humpback whales by distinctive markings on their flukes, or tails, and thus track their movements around the Atlantic.

Using ''Humpback Whales: A Catalogue of Individuals Identified by Fluke Photographs,'' researchers are getting a better understanding of that species.

So far they have:

* Found that North Atlantic humpbacks seem to be divided into distinct ''stocks,'' each with its own breeding and feeding grounds.

* Discovered that the fluke patterns of the whales can change over time, but usually not enough to hinder identification.

* Identified an estimated one-third of the humpbacks in the North Atlantic.

This information will be valuable to scientists working to protect humpbacks, which are threatened by offshore development and pollution.

Even before Melville's tale of ''Moby Dick,'' the great white sperm whale, whalers and researchers had noticed that they could identify individual whales by distinctive markings. Not until 1975, however, did scientists make significant use of the markings for research purposes.

The effort is led by Allied Whale, a loosely knit organization of specialists and amateur researchers, which scientists call a model of scientific cooperation. The group, based at the College of the Atlantic (COA) in Bar Harbor , Maine, is led by Prof. Steven Katona.

''Allied Whale is a model for collaboration,'' says Dr. Charles Mayo, director of cetacean research at the Center for Coastal Studies in Provincetown, Mass. ''We don't see this kind of collaboration in other sciences, not even in other aspects of whale research.''

Professor Katona says the group's cooperative nature is partly due to practical considerations. Marine mammal research was a relatively new field when Allied Whale started in 1972, and ''we weren't competing with anybody for anything,'' Katona explains. ''Few people on the East Coast, or anywhere, were working on whales. And we do some very tedious work.''

Cooperation was also ''in the spirit of the times,'' he says. Started in 1972 - the year when Earth Day was first observed and when the Marine Mammal Protection Act was passed - the organization grew out of a workshop for students interested in studying whales and stopping whaling.

Today, the fluke photographs have become the centerpiece of the cooperative effort. Using the photographs, researchers are tracking the huge marine mammals on their twice-yearly 4,000-mile migrations.

While only about 1,000 different whales were included in the 1980 catalog, researchers at Allied Whale now have photos of almost 3,000 different humpbacks on file (possibly one-third of the humpback population in the Atlantic north of the equator).

Most of the photos have come from professional researchers like Mayo, but many of the 175 contributors have been sailors or amateur whale watchers. Since no single observer could cover the entire Atlantic, Allied Whale researchers welcome photographs from anyone who has photographed a humpback.

New photos trickle into Katona's office at the rate of five or six a week. ''It's a little like having a pen pal when you get a photograph from someone you don't know, and never heard of before,'' he says.

The new photos are compared with the others in the collection - a process that takes up to 45 minutes. If the whale has not been photographed before, it is given a catalog number and added to the collection.

Because of their markings, humpbacks are the easiest whales to identify individually, Katona says. The unique patterns on their flukes - which can be 15 -feet wide - are created by pigmentation patterns, the growth of marine organisms such as barnacles on the skin, and scars. While the markings can change over time, one humpback was identified by its fluke pattern after 14 years. Some humpbacks have unmistakable markings - like those that lose one side of their tail to a ship's propeller.

Findings from the fluke project suggest that whales live in groups that return to the same areas yearly to breed or feed. Humpbacks that breed in the shallow seas near the Dominican Republic, for instance, spend their summers feeding off the coast of New England in the Gulf of Maine.

With their numbers depleted after more than a century of whaling, the largest remaining population of humpbacks lives in the Atlantic north of the equator. Increasingly, however, these animals are facing problems created by pollution and offshore development. Scientists hope learning about individual whales will help them protect the species.

''The humpback may not really be endangered in 1984,'' says Professor Katona, ''but we have to take the long view. What happens in 2084 is what we worry about and what matters. We're talking about an animal that has been on earth for millions of years, and we'd like it to be here for a few more million.''