1. The variety and variability among living organisms from all sources, including terrestrial, marine, and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species, and of ecosystems. Diversity indices are measures of richness (the number of species in a system) and may reflect ecosystem stresses (such as those due to high fishing intensity); 2. Includes genetic diversity (within species), species diversity (within ecosystems), and ecosystem diversity.