HARWICH PORT - It's been a decade since Harbormaster Tom Leach cobbled together some leftover PVC pipe and a few planks of wood from the highways and maintenance department and built the town's first shellfish laboratory at Wychmere Harbor. More than 20 million clams later, the lab is still going strong. Natural resources officer Heinz Proft, who has overseen the lab for the past six years, says the program helps seed the town's shellfish beds and provides an invaluable living laboratory to a handful of aquaculture internships every summer. "We usually have three to four kids depending on the number of kids applying, the funds available and the work we're doing that summer," he said. "They're exposed to a lot of things in a short period of time. For six weeks, they manage and maintain the laboratory and give tours."

The lab itself is located in a tiny, town-owned shed on the edge of Wychmere Harbor. Within its walls is a complex maze of pipes that pump nutrient-rich water into a series of color-coded silos with screens on the bottom. Each color represents a different batch of seedling clams. Every other day, interns or volunteers hose down the tanks, washing them out with freshwater. "They can survive up to 24 hours out of saltwater," Ben Latimer says as he sprays down a silo with a hose. "They lock up."

This year, Latimer, Liam Thomson and Matthew Brown, all 15, have been overseeing the lab's 2.4 million clams under the guidance of Robert Smeltzer. Smeltzer, a Latin teacher at Harwich High School, has been involved in the shellfish lab program for three years. "I was intrigued with the whole process," he says as the saltwater spray of the nearby harbor fills the lab. "Even after three years, I always find something new." Smeltzer's charges admit that they were not fully aware of the scope of their responsibilities when they signed on for the internships. "I thought it would be boring," Liam says, adding that he quickly discovered that the work easily beat out his other summer employment in terms of interest. "It's a lot better than any grocery store job."

Beyond cleaning the tanks, the trio records the water temperature every weekday, as well as the water's salinity, dissolved oxygen level and the growth rate of the clams. The group has visited the Aquacultural Research Center in North Dennis that supplied many of the lab's seedlings, and takes regular boat trips out to Nantucket Sound to take readings outside of the laboratory environment. "Once they have a good feel of the lab, they run it on their own with the teacher/ supervisor," Proft says. "They decide how they clean and drain and take care of the lab." The work will serve Matthew Brown well: he has volunteered with the water monitoring committee to help collect data for John Joseph Pond. The three young men have also been able to see the future fruits of their labor, visiting Round Cove and doing some clamming. "We went out and dug up 85 clams, 80 of which were legal sized," Matthew says, noting that the students returned all of the clams to the shellfish beds. "I had never done it before."

The students also serve as stand-by tour guides from 8:30 a.m. to 11:30 a.m., and have walked more than 100 visitors through the laboratory this summer alone. Early in the summer, the question on everyone's minds is the same: Where are the clams? "They think it's sand," Matthew says of the tiny seedlings. Proft says that the infant shellfish measure between 1 and 3 millimeters when they arrive in the lab. By the time they are released in October, they can measure upward of 12 to 15 millimeters. Ensuring that each clam has sufficient food has been a case of science and art, along with some trial and error, over the past decade. Proft recalls that in 1998, the lab hosted 6 million seedlings. But because they had to share a finite amount of food, the clams generally did not grow as large as hoped. "The larger the seed, the better the chance of survival in the wild," he says. "How many you start with hinges on how big you want them to grow."

This year, the lab is home to 2.4 million clams, which appears to be a good number, according to their hosts. The young men also have to occasionally provide definitions of little necks and quahogs. For many visitors, a clam is a clam is a clam. But the students seem to enjoy sharing their knowledge. "They are glad to have the opportunity to be a part of this," Smeltzer says, adding that although many interns would like to return for a second year, the program enlists new students each year to maximize participation. "These kids go back and tell others. It's messy and dirty, but that's the only downside. Most of them are fascinated by the entire process." He adds that the program also connects students to where they live, and helps them learn not to take the area's natural resources for granted.

After the internship concludes, volunteers will continue overseeing the program through late October or early November, when the seedlings will be distributed throughout Harwich's waterways, including Allen Harbor, Oyster Creek, Herring River, Wychmere Harbor, Round Cove and Pleasant Bay. Approximately 1,000 of the more immature seedlings may get a warm winter's vacation. For the past few years, Proft has been working with Harwich High School biology teacher Troy Hopkins to keep a fraction of the shellfish alive in the school's greenhouse. Although the program has yet to succeed, Proft says that each year brings them closer to figuring out the right balance to keep the shellfish alive. For the clams heading to shellfish beds, Proft says it will take approximately two years before the shellfish reach the legal taking size of 1-inch thick. Although each lab clam bears a distinctive identifying ring around the lip of the shell, Proft says that it is tough to assess just how valuable the program has been to local fishermen over the years.

The value to the interns is easier to ascertain. "When they're asked about unique experiences or a role where they were entrusted with responsibility, this experience stands out quite a bit," Proft says. "It is very hands-on. You are constantly learning something."