Collecting sea shells by the sea shore is tough from a wheelchair. And learning the difference between the call of a snowy egret and a great blue heron takes ome imagination when you're deaf.

But the two dozen handicpped high school students who are spending part of the summer scooping science from the sand of the Virginia coast near Chincoteague, don't want any pity. That sentiment, they will tell you, is to blame for making programs like theirs unusual.

"The biggest barrier is not really a flight of stairs or a heavy door. It's people's attitudes," says Heidi Johnson, a 16-year-old with bright blue eyes, brown hair and brittle bones that constantly ache from severe rheumatoid arthritis. "There aren't many people who treat you like a normal person. I am a normal person."

All of the students in the federally funded program are gifted science students from 13 states and the District of Columbia. And almost all have stories to tell of being barred from school laboratories and field trips either because of the paternal attitudes of teachers or the tyranny of poorly-designed buildings.

"We started this program because we found that outstanding handicapped kids rarely attempt to get into a science career," says Edward Keller, who founded the Marine Science School for the Handicapped five years ago. "Their counselors tell them there are too many obstacles to overcome, that science is not for you."

Keller knows better. When polio struck him in college 30 years ago, Keller was told by doctors he would never walk again. Now a rotund and affable biology professor at West Virginia University in Morgantown, Keller uses a cane during the summer only to help himself out of primeval muck or pounding surf.

But his five-week summer program is not so healthy.President Reagan's recent budget-cutting triumph was heard as a death knell by Keller and his staff on Wallops Island.Their $50,000-a-year budget, which pays for a full and part-time staff of 15 as well as the use of two boats and two buses with locomotion problems equal to any of the students, comes almost entirely from a National Science Foundation grant. Last week, the morning after the final congressional budget vote, Keller got a call from Washington offering condolences.

"The National Science Foundation told us it looks bleak for funding next year," said Keller, sitting over $500 in gasoline bills for the first weeks of the program. "That's pretty depressing news for us."

While Keller worried about next year, Craig Skeens a 17-year-old from Emory, Va., with cerebral palsy, struggled with the more immediate task of getting himself onto a dilapidated surplus Army bus for a field trip to a nearby wildlife center. Using his crutches with practiced care, he slowly walked himself up a steep ramp, pausing only to joke about his tortoise pace.

"I bet you're thrilled that I got to come on your bus," said Skeens, evading wheel chairs and lifting himself over scattered crutches to the back of the bus where he and his regular coterie of friends immediately began critiquing everything from the lunch menu (stuffed cabbage) to the bus driver's ability.

In most ways, the participants the summer program at Wallops are like any high school class on a summer foray. The most obvious difference is that these students communicate everything on at least two levels. Puns and profundities are constantly being translated from voice to sign language and back again. It is not unusual at Wallops to see a blind student pushing an orthopedically handicapped student in a wheelchair while a third student on crutches calls out directions.

"A real bond develops between the students here. They become each other's eyes and ears," says Mary Ellsworth, who spends her summers at Wallops and the rest of the year teaching a the Model School for the Deaf on the Washington campus of Gallaudet College.

The physical demands of heat, field work and mosquito swarms are compounded by individual handicaps. But the staff here refuses to accept any but the best excuses for failed work. Many of their students have been smothered by parents and slowed by overprotective teachers. At Wallops, handicaps are no excuse. They are the norm.

"We don't breast feed them," says Keller. As a result, there is both a level of expectation and an exhilaration from attaining it that is novel. That doesn't mean, however, that the age old battle between teacher and student takes a holiday at Wallops.

When Troy Wittren, an orthopedically handicapped student from Oregon is scolded for breaking one of the last thermometers in stock, Cynthia Higgins rolls her wheel chair to the rescue.

"Don't you know," says the college-bound chemist to her teacher, "that things like that happen all the time in science?"