Long-term effects of oil pollution in mangrove forests (Baixada Santista, Southeast Brazil) detected using a GIS-based multitemporal analysis of aerial photographs

Autor(es)

Maia Santos, Luciana Cavalcanti ^[1] ; Cunha-Lignon, Marilia ^[2] ; Schaeffer-Novelli, Yara ^[2] ; Cintron-Molero, Gilberto ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Biociencias, Lab Ecol Paisagem & Conservacao LEPaC, BR-05508090 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Inst Oceanog, BR-05508120 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Brazilian Journal of Oceanography; v. 60, n. 2, p. 159-170, APR-JUN 2012.
• Citações Web of Science: 7

Resumo

Oil spills are potential threats to the integrity of highly productive coastal wetlands, such as mangrove forests. In October 1983, a mangrove area of nearly 300 ha located on the southeastern coast of Brazil was impacted by a 3.5 million liter crude oil spill released by a broken pipeline. In order to assess the long-term effects of oil pollution on mangrove vegetation, we carried out a GIS-based multitemporal analysis of aerial photographs of the years 1962, 1994, 2000 and 2003. Photointerpretation, visual classification, class quantification, ground-truth and vegetation structure data were combined to evaluate the oil impact. Before the spill, the mangroves exhibited a homogeneous canopy and well-developed stands. More than ten years after the spill, the mangrove vegetation exhibited three distinct zones reflecting the long-term effects of the oil pollution. The most impacted zone (10.5 ha) presented dead trees, exposed substrate and recovering stands with reduced structural development. We suggest that the distinct impact and recovery zones reflect the spatial variability of oil removal rates in the mangrove forest. This study identifies the multitemporal analysis of aerial photographs as a useful tool for assessing a system's capacity for recovery and monitoring the long-term residual effects of pollutants on vegetation dynamics, thus giving support to mangrove forest management and conservation. (AU)

• Processo FAPESP: 06/57503-0 - Análise da variação espaço-temporal de bosques de mangue do rio Iriri (Baixada Santista, São Paulo, Brasil) antes e após o derrame de petróleo ocorrido em 1983
• Beneficiário: Luciana Cavalcanti Maia Santos
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica