Conference Title: Exploring patterns of compositional change along environmental gradients, and mapping expected patterns of biodiversity composition at regional scale. Abstract Environmental variables are increasingly used as indirect surrogates for mapping patterns of biodiversity because species survey data are scant, especially in the marine realm. This Census of Marine Life cross‐program synthesis quantified the shapes and magnitude of multiple species responses to >30 environmental gradients, and the extent to which these variables were useful as predictors for mapping patterns or biodiversity composition.