Pedal mucus is deposited as a trail behind most mobile gastropods (for review seeDavies and Hawkins, 1998) and by virtue of its sticky properties may act as a trapfor microalgal particles that some marine molluscan grazers ingest (Davies et al.,1992). Further, given mucus production and degradation rates, and the densityand movement patterns of grazing gastropods, much of the benthos is covered formuch of the time with a layer of mucus (Davies and Hawkins, 1998). If thismucus is capable of adhering microscopic particles, can it also be capable ofadsorbing materials on a molecular scale?Mucuses from other groups have metal-adsorbing properties.Mucusexopolymers from various marine (Loaec et al., 1997) and freshwater (Friedmanand Dugan, 1968; Mittelman and Geesey, 1985) bacteria have been shown toadsorb various metals (for a review of earlier work see Brown and Lester, 1979)and at least for one species (Klebsiella aerogenes) mucus serves to reduce thetoxicity of a water-borne metal (Bitton and Freihofer, 1978). Mucus in fish canserve to protect the animal from its environment by accumulating metals andretarding metal transport (by over 50 %) from solution to the epithelial surface(Playle and Wood, 1991; Wilkinson and Campbell, 1993). The metal-adsorbingproperties of mucus have even prompted the suggestion that it be used in watertreatment and in the biodetoxification of polluted seas (Loaec et al., 1997). Wetherefore postulate that the mucus deposited by gastropods may also adsorbmetals from solution and that subsequent ingestion of the mucus may constitute asignificant route of uptake into the littoral food web.Here we present data on the ability of the mucus of the littoral gastropod molluscPatella vulgata L. (common limpet) to adsorb and thus concentrate Zn and Cufrom seawater. P. vulgata was chosen as it is extremely common on northEuropean shores, where it is often the dominant grazer and further because itspedal mucus production system has been well investigated (see Davies andHawkins, 1998). Zn and Cu were chosen as toxicants as these have been shownto affect mucus production rates in P. vulgata (Davies, 1992) and are commoncoastal pollutants, entering via freshwater influx (Bryan, 1984).