ABSTRACT Ivar do Sul, J.A. and Costa, M.F. Plastic pollution risks in an estuarine conservation unit. In: Conley, D.C., Masselink, G., Russell, P.E. and O’Hare, T.J. (eds.), Proceedings 12th International Coastal Symposium (Plymouth, England), Journal of Coastal Research, Special Issue No. 65, pp. 48-53, ISSN 0749-0208. Plastics enter the marine environment mostly from land-based sources, often via estuaries. However, studies related to plastic debris pollution remain rare within these environments. An estuarine beach comprised within a Marine Conservation Unit (MCU) in the Northeast coast of Brazil was studied during one year regarding plastic pollution. Petroleum derived products were >95% of all items, as commonly reported for other coastal and marine habitats. Monthly totals of marine debris presented an average of 10.8±1.63 items.100m-2, much lower than reported in the literature for other estuarine beaches. Three main sources were identified: fisheries, local users and human settlements along the river basin. The most frequent (56%) size category was 11-100cm2, but fragmented items alone were 83% of observed items. The main impact on the estuarine and visiting biota expected is the ingestion of plastic items and fragments, which was corroborated by recent works on estuarine fishes. Interactions with fishing gear are highlighted in the context of this MCU. To protect the traditional livelihoods in the Goiana Estuary, the guarantee of a healthy ecosystem, inclusive free from plastic pollution, must be included in management plans. ADDITIONAL INDEX WORDS: Environmental monitoring, pollution control, ecosystem management, fisheries, physical fragmentation, ingestion, nylon |