WALLA WALLA, Wash. -- For Willie Swinerton, his classroom is South Caicos Island in the British West Indies. For Leila Behnampour, it's a small farm in Costa Rica's Central Valley. For Lisa Bean, it's Magdalena Bay in Baja California.

All three Whitman College students are spending the fall semester taking part in "foreign study" programs sponsored by the School for Field Studies (SFS), which operates educational and research centers in six environmentally-threatened locales around the globe.

Based in Beverly, Mass., SFS manages each of its centers with the same purpose in mind. The goal is to give college undergraduates the chance to live, study and work in some of the most beautiful and threatened ecosystems in the world, earning college credit while participating in real-life studies of challenging environmental dilemmas.

Each center, staffed by a director and three faculty members, is designed to accommodate between 25 and 34 students per semester. Classroom lectures are combined with the opportunity for hands-on, community-focused environmental field work. Each SFS team of faculty members and students addresses a variety of critical environmental issues, including efforts to preserve individual species as well as entire ecosystems, balance economic development and conservation, and manage and sustain wildlife, marine and agricultural resources.

Whitman students have been taking part in the SFS program since 1997, notes Whitman Director of International Programs Susan Holme Brick. The program, which also has field centers in Kenya, Australia and British Columbia, is "probably the best foreign study option for students interested in hands-on environmental studies."

Bean, a junior from Bellevue, Wash., who is majoring in geology and environmental studies at Whitman, is one of 14 students this fall at the Center for Coastal and Marine Mammal Studies at Bahia Magdalena, which stretches for 200 kilometers along the west coast of the Baja California peninsula. It is one of the most critically threatened ecosystems in Mexico, its fisheries near collapse, their stocks dangerously over-harvested. The bay, endangered by pollution from nearby industries and the town of Puerto San Carlos, is home to large populations of dolphins, sea lions, gray whales and turtles, and over 100 species of migratory and resident birds.

This particular center, which opened in 1997, has already directed a number of important studies. One example is a water quality analysis project that pinpointed the sources and impacts of contamination of local waters, and led to development of a monitoring program and alternative disposal recommendations. A study of gray whales, who use the bay as a calving area, generated information on how whales can be protected as local boat operations continue to provide whale-watching trips.

Swinerton, a Whitman junior from San Francisco who is majoring in history (with a minor in geology and environmental studies), is one 31 students this fall at the Center for Marine Resource Studies on South Caicos Island. The Turks and Caicos Islands (TCI), located at the southern end of the Bahamas, 100 miles north of the Dominican Republic, are a major exporter of spiny lobster and conch. The local waters provide habitat for more than 40 species of corals and 200 species of fish.

The most immediate concern facing the area is development of sustainable resources for fishing communities dependent on fluctuating lobster and conch harvests. Those resources are further threatened by residential and resort developers who are attracted by the area's spectacular and relatively unspoiled marine environment.

Students and staff at the SFS Center are involved in a number of projects, including one that is testing the effectiveness of artificial lobster shelters in critical nursery and feeding grounds. Students and staff also help review environmental impact assessments made by resort developers, offer environmental education programs and tutoring in local schools, and host or support public forums on communal issues.

Behnampour, a junior from Minneapolis, Minn., who is majoring in politics and environmental studies, is the latest Whitman student to study at the Center for Sustainable Development, which is located on a small hillside farm overlooking the Rio Grande River in Costa Rica's fertile Central Valley. The country is home to a variety of ecosystems, ranging from cloud forests and lowland rainforests to volcanic mountains and beaches on the Pacific Ocean and Caribbean Sea. Coffee, mangoes, bananas and pineapples are key commodities for an agriculture-based economy.

Costa Rica faces a struggle common to many developing countries: how to preserve natural resources while fostering its population's desire for greater prosperity. The struggle is evident in Costa Rica's land-protection efforts. Despite placing an impressive 27 percent of its land mass into preserved areas, unprotected areas are subject to some of the world's highest deforestation rates. Environmental problems include river pollution, pesticide build-up, soil protection, and the need for biological corridors for animal migration.

At the request of local farmers, the SFS center studied and recommended ways of controlling the economically devastating white fly, using integrated pest management options with natural extracts from local medicinal trees. Results were presented at an international meeting. Other recent SFS projects include development of an operational management plan for two protected areas within one of Costa Rica's most important watersheds, and a joint effort that documented the economic and environmental benefits of growing coffee in an "economically friendly" manner.