Viability of calanoid copepod eggs from intertidal sediments:a comparison of three estuaries

Abstract

Calanold copepod nauplu hatched from lntertldal s e d ~m e n t samples from 3 Brltlsh estuaries, the Exe, the Humber and the Mersey The Exe estuary is exposed to low levels of urban and a g ncultural pollution but the Humber and Mersey are subject to more extensive urban and industnal poll u t ~o n Samples were taken from the Humber and the Exe in Apnl and hovember 1995 and from the Mersey and the Exe in June and October 1995 The concentrations of polycyclic aromatic hydrocarbons (PAH) in the sediments were measured as an index of pollution The PAH concentrations In sediment were lowest In the Exe (mean < l 0 0 py g.' dry welght) with most values >200 pg g-' dry weight in the Humber and some >300 pg g ' dry weight in the Mersey hdany mole nauplll hatched from Incubated sediments from the Exe than from the more polluted estuanes In Apnl, J u n e and November but larger numbers of nauplll hatched from the samples from the Melsey than from the Exe In October Eggs were extlacted 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 vlablllty of eggs \ n t h increased pollut~on The viability of copepod eggs from sedlments appears to have potential as a technique for in situ bioassay of flne sedlments KEY WORDS. C a l a n o ~d . Egg .