The Biodiversity and Conservation program studies the distribution and abundance of marine organisms and their habitats, how they change over time and space, and how they are affected by natural changes and human activities. "Diversity" includes genetic and habitat diversity, and the ecological interactions and interdependencies of organisms, populations and communities. A key to studying biodiversity is the identification of species, by morphological, biochemical or molecular techniques. The reduction, removal, or addition of single species may initiate trophic or agonistic cascades that resonate throughout the community or ecosystem in many different ways, on a variety of time scales. Quantitative analyses are required to resolve patterns of species distribution and natural assemblages, to examine the influences of invasive (non-indigenous) species, and to recommend changes to policy and management to protect environmental integrity and promote wise stewardship of natural resources.