Mud depocentres on the continental shelf: a neglected sink for anthropogenic contaminants from the coastal zone

Autor(es)

de Mahiques, Michel Michaelovitch ^[1] ; Hanebuth, Till J. J. ^[2] ; Martins, Cesar C. ^[3] ; Montoya-Montes, Isabel ^[1] ; Alcantara-Carrio, Javier ^[1] ; Figueira, Rubens C. L. ^[1] ; Bicego, Marcia C. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Oceanog, Praca Oceanog 191, BR-05508120 Sao Paulo, SP - Brazil

^[2] Coastal Carolina Univ, Sch Coastal & Marine Syst Sci, POB 261954, Conway, SC 29528 - USA

^[3] Univ Fed Parana, Ctr Estudos Mar, POB 61, BR-83255976 Pontal Do Parana, PR - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ENVIRONMENTAL EARTH SCIENCES; v. 75, n. 1 JAN 2016.
• Citações Web of Science: 9

Resumo

In this study, published and unpublished data from the Santos Estuarine Complex and Bay and the adjacent continental shelf (Sao Paulo State, Brazil) were gathered in order to evaluate the entrapment of anthropogenic chemical contaminants (hydrocarbons, heavy metals) in a mid-shelf mud depocentre. Results show that these contaminants, produced by industrial activities in the adjacent coastal zone and released into the bay waters, are distributed far over the shelf since they are found in the mid-shelf mudbelt in locally significant concentrations. Two main aspects are highlighted by this study. The first underlines the fact that the material stored in the mudbelt is not related to a specific fluvial source discharging to the shelf. Instead, the contaminants, used as tracers, stem from multiple injection sources along the heavily used coastline of the Santos industrial zone. The second finding suggests that the anthropogenic compounds are not only accumulating in the surface sediments of fine-grained shelf depocentres. Rather, these substances are also already found several centimetres below the modern seabed. They can, thus, be easily reinjected into the water column by storms, benthic activity, and human disturbances such as seabed dredging and bottom trawling. (AU)

• Processo FAPESP: 10/06147-5 - Incremento da capacidade de pesquisa em oceanografia no estado de São Paulo
• Beneficiário: Michel Michaelovitch de Mahiques
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Regular
• Processo FAPESP: 03/09932-1 - A influência do complexo estuarino da Baixada Santista sobre o ecossistema da plataforma adjacente (ECOSAN)
• Beneficiário: Ana Maria Setubal Pires-Vanin
• Modalidade de apoio: Auxílio à Pesquisa - Programa PRONEX - Temático