Mercury Contamination within Protected Areas in the Brazilian Northern Amazon-Amapá State

Abstract

Mercury contamination is a long-standing environmental and social problem, notably in the Amazon. The widespread use of mercury in artisanal and small-scale gold mining has driven contamination of the environment and the people, threatening biodiversity, human health and livelihoods of traditional populations. Along the border area between Brazil and French Guiana, illegal gold mining is considered a critical threat to biodiversity, a social and economic problem and a political and diplomatic issue. On the Brazilian side in Amapá state, stands the world's largest tropical forest National Park-Tumucumaque National Park (TNP). Despite its critical importance for the maintenance of ecosystem services, little is known about anthropic impacts in the area, including mercury contamination. The present study aims to assess the current levels of mercury contamination of carnivorous fish species in the TNP region as the starting point for the assessment of its impact over the integrity of protected areas and local communities. Fish samples were collected at 33 sampling sites within TNP and its surroundings. Samples of 187 most consumed local fish belonging to eight carnivore species were analyzed. Mercury was detected in 81% of the collected fish, the majority of them with individual levels above the WHO health safety limit (0.5 µg.g^-1). Furthermore, samples from all rivers assessed presented some level of contamination. The contamination of important locally consumed fish is widespread in the study area. Important river basins in the Northern Amazon area are affected and even protected areas might be impacted by mercury. Our results suggest mercury as a significant threat to biodiversity and human health in the region. Additional studies should be conducted towards identifying the extent of the problem in the region and mitigation strategies addressing the effects of contamination must be incorporated in decision makers' priority agenda.