Ecological significance of endocrine disruption in marine invertebrates

Anthropogenic chemicals which can disrupt the hormonal (endocrine) systems of wildlife species are currently a major cause for concern. Reproductive h ormone-receptor systems appear to be especially vulnerable. In the past few years, numerous effects of endocrine disrupting chemicals on wildlife have emerged including changes in the sex of riverine fish, reproductive failur e in birds and abnormalities in the reproductive organs of alligators and p olar bears. Much less is known regarding endocrine disruption in marine inv ertebrates, the key structural and functional components of marine ecosyste ms. In this paper, potential effects of different classes of endocrine disrupti ng chemicals are reviewed. The endocrinology of several major invertebrate groups is briefly examined to identify which phyla are most likely to be at risk. Gaps in our knowledge concerning the availability and uptake of endo crine disrupters are identified. For example, the relative importance of di fferent routes of chemical uptake (from seawater vs food) is considered. Fe eding strategies (herbivores, carnivores, deposit feeders, suspension feede rs) in relation to uptake of endocrine disrupters are also discussed. Examples of endocrine disruption in marine invertebrates in situ are provid ed, including imposer in gastropod molluscs exposed to organotin compounds and intersex in crustaceans exposed to sewage discharges. Laboratory data a re presented concerning the effects of endocrine disrupters on the growth a nd reproductive output of the deposit feeding amphipod Corophium valutator and the polychaete worm Dinophilus gyrociliatus. Recent findings are report ed which demonstrate reductions in settlement following exposure of barnacl e larvae to the xeno-estrogen, 4 nonyl phenol. The potential use of cyprid major protein as a biomarker of oestrogenicity is explored. The ecological significance of endocrine disruption in marine invertebrates is discussed. With regard to environmental management action, an evidence-based approach is advocated. A protocol for collecting evidence of ecologically significan t endocrine disruption is outlined, (C) 1999 Elsevier Science Ltd. All righ ts reserved.