Water, Food and Ecosystem Nexus in the Coastal Zone of Northeast Pará, Eastern Amazon, Brazil

The aim of this research was to identify the challenges and opportunities associated with the Water-Food-Ecosystem (WFE) Nexus approach in coastal river basins in Northeastern Pará and Eastern Amazonia. The methodology considered Sustainable Development Goals (SDGs) axes 2, 6, 8, 10 and 13 through a Nexus indicator matrix. It involved a statistical analysis of distribution and correlation coefficients. The coefficient indicates the strength of the relationship and the presence of positive or negative correlations. The final distribution of the variables discussed was to zone the region into areas of higher and lower potential for water sustainability. The results showed significant variability in consumptive use along the water axis. Castanhal had the highest level of consumptive use due to its public water supply, which increased in line with population growth between 2000 and 2022 (r = 0.76), in accordance with SDG 6. In the food axis, fishing and aquaculture activities were prevalent in the coastal municipalities of Maracanã and São Caetano de Odivelas (SDGs 2 and 8). In the ecosystem axis, significant deforestation was observed (39.45% to 86.88%), accompanied by low environmental compliance. Regarding the relationship between water and food, only the proportion of rural properties with irrigation and temporary crops showed a significant negative correlation (r = −0.62). The results indicate the consolidation of measures pertaining to water security in the region, exerting a direct influence on food security and strategies employed for the administration of ecosystems imperative for the sustenance of multiple extractive communities in the region. The Nexus approach highlighted various challenges in the region, including poor environmental compliance, overuse of water and forest resources, degraded pastures, and underdeveloped socioeconomic indicators.