An international team of researchers will travel to the depths of the Pacific Ocean in November to explore deep-sea hydrothermal vents, and high-school classes are invited along. Hydrothermal vents are grooves or openings in the planet's crust from which hot water exits. This water has been heated from deep below the surface of the earth. Hydrothermal vents have been a source of interest to scientists such as marine biologists for many years now. This is because the areas around these vents are much more biologically productive than the surrounding seas and they support a unique and diverse ecosystem. During their expedition, the scientists will focus their research efforts on this ecosystem, paying particular attention to marine viruses and other tiny life-forms called protists. Craig Cary, professor of marine biosciences at the University of Delaware College of Marine and Earth Studies in the US spoke about the importance of the expedition. 'For many years, the vents have been explored with little to no attention to viruses and protists,' he said. 'Yet because these organisms eat bacteria, they have the most dramatic effect on the bacterial communities that support the vent system. Our research programmes are among the first to focus on these remarkable scavengers.' Professor Cary has embarked on over 20 such deep-sea research cruises and will also be the chief scientist on the expedition. Also onboard will be David Caron, who is professor of biological sciences at the University of Southern California, US. His role will be to lead the research team that will examine the single-celled organisms called protists. Professor Caron is an expert in the ecology of these species, which include the microalgae and protozoa, and will be conducting ground-breaking work to understand the species diversity and activities of these creatures at the vents. 'Protists are important consumers of bacteria and other microorganisms in all other aquatic environments,' Professor Caron said. 'We believe that they serve as an essential link in the bacterial-based food webs of hydrothermal vents, but surprisingly little work has been performed in deep-sea ecosystems to document and understand the activities of these species.' Schoolchildren from around the world will have the opportunity to participate in the expedition via the University of Delaware's 'Extreme 2008: A Deep-Sea Adventure' programme. Participating classes have the opportunity to design experiments and connect to the researchers through a 'Phone Call to the Deep' initiative. This will link classrooms with researchers working in real time on the seafloor. Classes will also receive free curricula, study guides, and other educational activities designed to boost students' understanding of the ocean and the process of scientific discovery. The researchers will be based on board the Atlantis, a research vessel owned by the US Navy and operated by the Woods Hole Oceanographic Institution (WHOI). One of the latest research vessels currently afloat, it contains six science laboratories, a seafloor mapping sonar, and satellite communications. Also on-board are three winches, three cranes, a machine shop, and specialised hangars. These have been specifically designed to support Alvin, a submersible which will dive around 3,000 metres to the ocean floor from time to time.