The Port of Santos, the largest and fastest growing seaport in Brazil, lies within a sheltered, mangrove-lined estuary. The movement of dangerous chemicals is a hazardous activity which could generate severe negative socio-environmental impacts. From an ecosystem perspective, the port may be perceived as part of an integrated web of economic, ecological, legal, social systems and not as a mere industrial complex, isolated from the sensitive ecosystems surrounding it; or from the people who work in and reside in the region. We emphasize the integrated concept of humans-in-nature, adopting the view that the distinction between social and natural systems is artificial and arbitrary. This paper presents an assessment of the linkages between the causes and consequences of environmental incidents which occurred between 1980 and 2006; a period during which 108,934 ships berthed. Four hundred and twenty-four entries were compiled from CETESB's (the Environmental Agency of São Paulo State), CODESP's (the port authority) and ABTL's (the Brazilian Association of Liquid Bulk Terminals) database. The results demonstrate that maritime transport accounted for the great majority of the spills which were mainly provoked by operational failures. Marine fuel oils (bunkers) were released more frequently than any other chemical substance and in the majority of the cases, the oil spread well beyond the spill site, impacting the health and safety of people and ecosystems of the region. The preventive and corrective actions which were taken had positive effects, highlighting the importance of enhancing resilience to reduce impacts and accelerate recovery.