Mangrove forests are formed by mangrove trees and shrubs that grow in the intertidal zone at the sea-continent interface. They constitute major ecosystems of tropical to subtropical muddy coasts that perform several ecological functions, including: mitigation of coastal erosion and flooding hazards associated with storm waves, extreme tides and tsunami, providing nurseries for some estuarine and coastal species (e.g., shrimps, fishes), production and recycling of organic matter, carbon storage, functioning as long-term sinks for several contaminants. World mangroves face a number of threats with increasing habitat destruction caused by direct and indirect anthropogenic pressures coupled with global climate change. They are known to be extremely vulnerable to oil spills. Even if the fate and impact of oil spills in such ecosystems have been partially monitored and experimentally studied (e.g., 30-year TROPICS field experiment in Panama islands, replicated field trials conducted in central Queensland, Australia) significant gaps in knowledge remain. The oil dynamic in such ecosystem is complex and depends on the abiotic-biotic processes interactions. Understanding the fate and impact of the oil spill thus requires an integrated approach of the functioning of the whole mangroves system facing the pollution. The case of the French Guiana mangroves, subjected to intense hydromorpho-sedimentary dynamics under the direct influence of the massive discharge of suspended sediments from the Amazon River, will serve as conceptual model to highlight the importance of the need for a specific Ecosystem-based Management response in case of oil spill.