While many groups report a shortage of volunteers, one program, Earthwatch, is thriving.

More than 1,000 men and women age 16 to 70 gave up a week or two of their time last year and plunked down about $1,000 each for the privilege of doing research with leading scientists around the world. This year so far, 1,500 civilians plan to join Earthwatch expeditions.

"We are not looking for experts, just interesting people who want to help, have good sense and a sense of humor," says Brian Rosborough, 42, Earthwatch president.

"We teach you the rest. Our goals are straightforward. We encourage the pursuit of knowledge and involve more people in the search for answers which may improve the quality of life."

Since the Reagan administration's cutbacks in funds for scientific research, requests from scientists who want their projects sponsored by the organization have doubled, says Blue Magruder, 34, Earthwatch director of communications. Out of 200 to 300 requests, Earthwatch will be able to accept 50 to 60 projects during their next review.

"With Mr. Reagan's admonitions to the private sector to pick up some of the slack left by government cutbacks for research, we can only say we're doing our best," says Magruder.

"We feel a bit like Tom Sawyer trying to get 1,500 people to paint the fence, and help pay for the paint."

Non-profit Earthwatch began in 1971 when a group of Massachusetts friends came up with the idea of linking researchers with civilians who would offer financial support and work on field-research projects. In the search for financial support, the group approached Rosborough, then a successful New York mergers and acquisitions lawyer. Rosborough said he had no money to offer, but "would help out."

He not only helped out, but in the end of 1972 he decided to give up the corporate life to become president of the group.

Since then, Earthwatch has become the third largest private source of funds supporting field research (after National Geographic and World Wildlife Fund). On Earthwatch expeditions in 35 countries, housewives, businesspeople and students have joined researchers to study art, archeology, birds, insects, whales, dolphins, plants, ecology and animal behavior.

In addition, 12,500 people from 50 states and 27 countries support Earthwatch with $20 yearly memberships, which entitle them to publications on expeditions and news from the field.

Earthwatch expeditions run from nine days to three weeks, with the projects as varied as subjects and locations. In some cases, special skills, such as diving, backpacking and photography, are helpful. Volunteer team members learn to excavate, map, photograph, observe animal behavior, study flora and fauna, gather ethnographic data, conduct oral-history interviews, measure astronomical alignments, record natural sounds, assist diving research and share in all field chores of professional research expeditions.

With volunteers paying their own expenses--thus sharing in supporting the research--average prices for 1982 Earthwatch expeditions run from $900 to $1,500, not including transportation to the site. Because team members are donating their labor and money, all expenses, including transportation, are tax-deductible. In some cases, college credit can be earned through Antioch College. Some scholarships are available for needy students age 16 to 23.

Among the many research sites: New Jersey, Colorado, California, Canada, Nepal, Bermuda, Australia, Jamaica, France, Greece, Israel, Hawaii, Peru.

Breck Blalock, a Jefferson High School (Fairfax County) senior, spent 15 days last summer on an Earthwatch expedition studying whales off the coast of Newfoundland.

"The best part," he says, "was getting to know the local people and visiting Newfoundland, the most beautiful place on earth with rugged, rocky terrain and glacier lakes. I really had a good time. I didn't want to leave."

During the four-month squid season, Newfoundland fishermen can lose their entire year's income when whales, who are covered by marine-protection acts, get caught in and ruin their nets. To help the fishermen learn better placement of nets, the Earthwatch research team--headed by Tim Rumage, curator of the Nature Lab at the Rhode Island School of Design--observed and mapped the whales' activities from 400-foot-high rocky cliffs and on fishermen's boats in Trinity Bay.

"The expedition," says Blalock, "was a wonderful educational experience. Not only did I learn a great deal about whale anatomy and physiology, but I also became aware of the sizable amount of raw data a researcher must collect before he can even make hypotheses.

"The three students came to see if they wanted to pursue a career in animal research. Most of the older people were trapped in business jobs and wanted to try something different. One member was a poet. Team members shared all chores--I even had to cook squid."

The diverse backgrounds of Earthwatch volunteers have more than once helped institute new research ideas and methods. Because of Blalock's experiences in a rock band, he suggested that Rumage use a $300 graphic equalizer--rather than a $2,000 piece of electronic equipment--to make recordings to guide the whales away from the fishermen's nets.

"The totally fresh, unjaded perspective that volunteers bring often gives exciting results," says Belmore Browne, 29, Earthwatch manager of professional placement.

Describing the "evangelical spirit" that permeates Earthwatch, he says about 40 percent of team members are repeat attenders and many new members have been referred by previous Earthwatchers. Some people join a different type of expedition on each outing; others stick to one area.

The scientists, he says, try to break down all hierarchy among volunteers so that there is a great deal of camaraderie. Participants tend to stay in touch, and one researcher even writes his own newsletter for former team members.

Participants, Browne says, rarely are surprised by the experience because expedition briefings are very detailed. "Team members are prepared psychologically as well as physically."

He tells the story of one volcano dig, when the group was sitting around the campfire chatting informally. A teen-ager threw in an idea and talked for about five minutes. When he looked up, he was amazed to see the two researchers taking notes.

"For a 17-year-old kid, that's a pretty profound statement that education is a two-way street."