Batches of sand from a beach on the Delaware Bay are yielding insights into the powerful impact of temperature rise and evaporation along the shore that are in turn challenging long-held assumptions about what causes beach salinity to fluctuate in coastal zones that support a rich network of sea creatures and plants.The findings have implications for the migration and survival of invertebrates such as mussels and crabs as global warming drives temperatures higher.A first major study of the effects of evaporation on the flow of subsurface water and salinity, or salt content, in the beach intertidal zone — the section of the beach between the low and high tide marks — is being published today in Scientific Reports, an online affiliate of Nature.