ABSTRACT: Calanoid copepod nauplii hatched from intertidal sediment samples from 3 British estuaries, the Exe, the Humber and the Mersey. The Exe estuary is exposed to low levels of urban and agricultural pollution but the Humber and Mersey are subject to moreextensive urban and industrial pollution. Samples were taken from the Humber and the Exe in April and November 1995 and from the Mersey and the Exe in June and October 1995. The concentrations of polycyclic aromatic hydrocarbons (PAH) in the sedimentswere measured as an index of pollution. The PAH concentrations in sediment were lowest in the Exe (mean <100 µg g^-1 dry weight) with most values >200 µg g^-1 dry weight in the Humber and some >300 µg g^-1 dry weight in theMersey. Many more nauplii hatched from incubated sediments from the Exe than from the more polluted estuaries in April, June and November but larger numbers of nauplii hatched from the samples from the Mersey than from the Exe in October. Eggs wereextracted from the samples taken in October and November and incubated; 92% of those from the Exe, 48% of those from the Humber and 14% of those from the Mersey hatched. This is consistent with reduction in viability of eggs with increased pollution. Theviability of copepod eggs from sediments appears to have potential as a technique for in situ bioassay of fine sediments.