Undergraduate research is usually more exciting in groups and we have developed a teambased collaborative research course to investigate aspects of environmental restoration in estuarine environments. A class of 15 is divided into three teams with related objectives, and the teams work together in field work, laboratory analyses and frequent group presentations of research progress. For example, we have followed a restoration of a Hudson River estuarine cove severely polluted with metals and studied the loss of resistance of a genetically distinct species, the export of metals, and effects on the benthic community. Another course followed the potential for oyster restoration in an urban bay, considering nutrient limitation of phytoplankton, oyster function, and water quality. In both types of study, the work depended upon the presence of a research laboratory and field facilities, such as an Audubon field station on the Hudson. In all cases the small team size encouraged strong interactions and the objective of producing collaborative research was achieved. When one team was overwhelmed it was possible to induct the services of members of other teams, which greatly helped to knit the class together. On the other hand, students were accountable to each other, which occasionally generated conflict. Overall, interactions between students promoted interest in the subject, critical thinking and creativity. Moreover, student work inspired later research in the laboratory, which is a very desirable feedback for instructors.