Who says you need a Ph.D. to do science?

As "First Flush" showed on Nov. 8, volunteers and amateurs can make significant contributions to scientific research.

Dozens of volunteers participate each year in the event organized by the National Oceanographic and Atmospheric Agency, to detect pollution in storm water draining into the Monterey Bay sanctuary. Previous years' monitoring has revealed significant amounts of bacteria and harmful chemicals entering the sanctuary.

But it's much more than "First Flush." During the past year, thousands in California have contributed to other scientific studies.

"What they are doing for the environment and our community is really huge," said Bridget Hoover, coordinator of the Monterey Bay National Marine Sanctuary's network of citizen watershed monitors. "They do so much more work over large areas than any agency monitors could ever do."

Time is money, as the saying goes, and it's expensive to hire professionals for time-consuming jobs, such as collecting field data. When facing budget constraints, universities, government agencies and nonprofits often turn to volunteers.

And in an age of instant communication, it doesn't take long to assemble a corps of willing amateurs for any worthy scientific enterprise. Environmental monitoring is especially popular.

Earthwatch Institute, a Massachusetts-based grass-roots environmental group started in 1987 with 39 volunteers, mobilized nearly 4,000 people from more than 50 countries this year to work on environmental studies worldwide. Volunteers pay part of the research cost, in addition to their own expenses.

Nearly 43,000 Americans participated in the Audubon Society's 105th Christmas bird count last December, tallying nearly 62 million birds. These numbers have steadily increased since the society's first bird count in 1900, in which 27 participants counted about 18,500 birds.

Closer to home, volunteers counted magpies for West Nile virus studies, reported beach erosion, tagged butterflies and monitored watersheds.

"They are kind of the eyes and ears to what is going on," said Chris Coburn, a Santa Cruz water quality specialist who has worked with volunteers. "They are interested in knowing what is going on with the creek that runs by their house. They are wondering, 'Gee, why are there no more fish here?' "

When it comes to water testing, volunteers make quite a splash.

Consider World Water Monitoring Day, an annual monthlong event culminating on Oct. 18. It attracted 42,000 volunteers last year from 50 countries, who monitored nearly 5,000 sites worldwide.

"Even with minimal training, they provide the first sight of problems and issues," said Ed Moyer, World Water Monitoring Day coordinator. Professionals can then "target and key in on the problems."

Volunteers also gain. Beyond the satisfaction of contributing to a larger cause, many come away with deeper insights and renewed interest in science.

"It made me aware of my surroundings," said Mike McNicholas, 18, who has volunteered in several ecological studies in Santa Cruz County. He said he gained "a great deal of knowledge and some friends."

The growth of volunteerism is part of a trend of increased amateur participation in science. Shawn Carlson, MacArthur genius award winner and founder of the Society for Amateur Scientists, calls it "citizen science."

"I don't see it as anything but a boon to modern science," Carlson said.

Virtually anyone with interest and passion can contribute to science, Carlson said, whether they are skilled amateurs, volunteer data collectors, or even science fair competitors.

Some are more cautious in their endorsement of citizen science. They acknowledge the value of amateurs as data collectors, but not as contributors to original scientific research.

"Participation in research is limited to an elite group of dedicated, quasi-professional amateurs," said George Musser Jr., editorial columnist at the Scientific American. "The average person in his or her backyard is unlikely to contribute."

Citizen science has a venerable history. Even in the old days, before the Ph.D. was invented, many scientists were amateurs. Benjamin Franklin toyed with electricity. Gregor Mendel tinkered with plant genetics. Thomas Jefferson studied climate change.

But as science advanced and became specialized, amateurs faced new challenges. Theoreticians used advanced mathematical tools. Experimenters used powerful, expensive instruments.

Amateurs increasingly found it hard to keep up.

Except, perhaps, in scanning the skies. When it comes to astronomical observation, amateurs have always held their own. To make a useful contribution, all an amateur stargazer may need, besides a simple telescope, are keen observation, patience and luck.

Robert Evans, a church pastor in New South Wales, Australia, has discovered more than 30 supernovae — a world record. Paul G. Comba of Prescott, Ariz. has found more than 50 new asteroids using a backyard telescope. These discoveries are a tiny fraction of the overall amateur contribution to astronomy.

In many other fields, amateurs lagged, but consumer technology could put them back in the picture.

Today's home computer has more power than advanced computers had a decade ago. Armed with data-processing software, it can easily crunch numbers for complex science — folding amino acid into proteins, decoding signals from space, visualizing the Martian surface. In the past, this would have been unthinkable.

Electronic gadgets flooding the consumer marketplace — such as digital cameras and measuring instruments — are likewise a boon for the amateur.

And who invents these gizmos?

"Most of the cute, clever inventions these days are not being made by professionals," Carlson said. He cited several amateur inventions, including a handheld instrument to measure the thickness of the ozone layer, called Total Ozone Portable Spectrometer, and a device for measuring the earth's magnetic field, called a torsion magnetometer.

On top of all this, amateurs now have the ultimate tool: the Internet. With practically the entire scientific knowledge of humanity available at the click of a button, the aspiring "amateur Nobelist" is no longer hobbled by lack of information or resources.

"It is a very exciting time for citizen science," said Carlson.

Some citizen scientists don't need high technology or slick gadgets.

For instance, World Water Monitoring Day volunteers need only a simple kit — collection jar, thermometer, test tube, vial and chemical tablets — to measure basic indicators of water quality: temperature, acidity, clarity and dissolved oxygen. These measurements show how healthy the water is for fish and other marine organisms. Ideally, the water should not be too warm or too cold, too acid or too alkaline. It should be clear, with plenty of dissolved oxygen.

These amateur water sleuths can't measure more complex parameters such as bacteria or toxic pollutants, Coburn said. Even here, however, they can help by collecting samples and sending them to a lab.

But amateurs shouldn't be given tasks that are tedious or risky, Coburn said. "They have to be enjoying what they do," he said. "You don't want to just send them out as you would send an employee."

Antonia D'Amore, a UC Santa Cruz biologist who organizes volunteers for amphibian studies, stresses the importance of training. "Make sure they understand why they are doing what they are doing," she said. "Make them feel they've owned a little piece of the project."

With enough passion and interest, citizen scientists can penetrate any field, said Carlson, except those requiring "a lot of money and a big lab," such as high-energy physics.

"To everything outside of big science, citizen scientists can make contributions," Carlson said. "Genius is not restricted to academics."

Even skeptics like Musser recognize the value of science as a hobby.

"A personal discovery can be deeply meaningful," he said. "You don't have to push back the frontier of knowledge in order to enjoy the landscape."