The Marine Education Society of Australasia (MESA) Inc. is a national organisation of marine educators that aims to bring together people interested in the study and enjoyment of coastal and marine environments. MESA representatives and members organise education and interpretation activities in support of schools and communities during a number of environmental calendar days and weeks: specifically Seaweek, and includes World Wetlands Day, Earth Day, World Environment Day, Threatened Species Day, Biodiversity Month, Water Week, and Coastcare Week. Each year, MESA runs Seaweek to promote educational issues of relevance to the marine environment. This article provides support for primary teachers looking for ways to integrate science across the curriculum and to increase children's awareness of marine life and their environments. It includes practical activities based on lessons the author has conducted with pre-service student teachers and primary school students during Seaweek. (Contains 8 figures.)