An effective and safe method for sorting small molluscs from sediment

Abstract

A method is presented which enables infaunal juvenile bivalves to be separated from associated sediment with a combination of elutriation and flotation techniques. Simple elutriation is used to remove less dense organic detritus and a relatively new, nontoxic compound (sodium polytungstate) is used to create a heavy liquid that sorts the bivalves from sediment by relative density. The technique was applicable to 12 species of molluscs of various sizes and was 98–100% effective in separating juvenile Mya arenaria, ranging from 0.5 to 24 mm in shell length, from surrounding sediment.