Transfer of gold nanoparticles from the water column to the estuarine food web

Within the next five years the manufacture of large quantities of nanomaterials may lead to unintended contamination of ter-restrial and aquatic ecosystems1. The unique physical, chemical and electronic properties of nanomaterials allow new modes of interaction with environmental systems that can have unex-pected impacts2,3. Here, we show that gold nanorods can readily pass from the water column to the marine food web in three laboratory-constructed estuarine mesocosms containing sea water, sediment, sea grass, microbes, biofilms, snails, clams, shrimp and fish. A single dose of gold nanorods (65 nm length3 15 nm diameter) was added to each meso-cosm and their distribution in the aqueous and sediment phases monitored over 12 days. Nanorods partitioned between biofilms, sediments, plants, animals and sea water with a recovery of 84.4%. Clams and biofilms accumulate