Environmental risk assessment of petrogenic hydrocarbon spills in mangrove ecosystems: the Tumaco case study as a baseline, Colombian Pacific

Abstract Petrogenic hydrocarbon spills (PHS) are harmful to mangrove ecosystems along tropical coastlines both in the short and long term. The aim of this study was to assess the environmental risk of recurrent PHS on mangrove ecosystems in Tumaco municipality, Colombian Pacific. Mangrove characteristics and management aspects led to subdividing the entire the study into 11 units-of-analysis (UA) for which threats, vulnerability, potential impacts, and risks were assessed based on environmental factors and the formulation and use of indicators in a rating scale with five categories, which are very low, low, moderate, high, and very high. The results showed that all UAs are highly (64%) or moderately (36%) threatened by PHS, highly (45%) or moderately (55%) vulnerable to this kind of pollution, and susceptible of high (73%) or moderate (27%) potential impacts. Environmental risk was high in 73% of the UAs, indicating likely irreversible damage to mangrove ecosystems by PHS, thus pointing to the need of urgent intervention by responsible authorities to ease their recovery and conservation. The methodology and results of this study become technical inputs that serve for environmental control and monitoring, which can be incorporated into contingency and risk management plans.