Contamination and Toxicity of Surface Waters Along Rural and Urban Regions of the Capibaribe River in Tropical Northeastern Brazil

Abstract

The Capibaribe River provides water to a population of 1.7 million people in the Brazilian northeast, while receiving agricultural runoff and industrial and domestic effluents along its 280 km. The present study evaluated the ecotoxicity of surface waters along ten sites in rural and urban areas using zebrafish (Danio rerio) early‐life stages and related it to water quality indices and chemical abiotic variables. Lethality rates, delays in embryo‐larval development quantified by the general morphology score (GMS), and frequencies of developmental abnormalities were analyzed. A correlation was detected between zebrafish GMS and water quality index (WQI), sensitivity to domestic sewage contamination, and trophic state index, focused on eutrophication. These indices agreed in identifying a spatial pattern of smaller impact in terms of ecotoxicity, domestic sewage contamination, and eutrophication risk at three sites in rural areas (mean GMS 16.9), an intermediate impact at four sites with urban and agricultural influence (mean GMS 16.4), and greatest impacts at three more urbanized sites (mean GMS 14.9). Most frequent developmental abnormalities included noninflation of the swim bladder, delayed hatching, nonprotrusion of the mouth, blood stasis, and nondevelopment of pectoral fins. Toxic NH3 concentrations varied spatially, with higher concentrations in urban sites; and blood stasis correlated positively with NH3, suggesting a causal relationship. Polycyclic aromatic hydrocarbons were detected in both rural and urbanized sites, contributing to detected toxicity. The present study demonstrates the potential of zebrafish early‐life stages as an ecotoxicological model that may contribute to a better understanding of surface water quality and ecotoxicity in tropical river systems. Environ Toxicol Chem 2021;40:3063–3077. © 2021 SETAC

Investigation of pre and post environmental impact of the lockdown (COVID-19) on the water quality of the Capibaribe and Tejipió rivers, Recife metropolitan region, Brazil

“…Its basin has an area of 7454.88 km 2 and is considered one of the most important in the state. The Capibaribe River estuary, in the city of Recife, is highly impacted by anthropogenic activities, mainly domestic effluents, deforestation, and landfills ( Purificação et al, 2017 ; Holanda and Soares, 2019 ; Alves et al, 2021 ; Bertrand et al, 2021 ).…”

Genotoxic effect of heavy metals on Nile tilapia (Oreochromis niloticus) species in an urban river in northeastern Brazil

“…In addition, they are toxic and can interact with genetic material, causing damage to DNA. Therefore, they are also considered cytotoxic, genotoxic, and mutagenic agents (Alves et al, 2021;Carolin et al, 2017).…”

“…The current degradation of aquatic ecosystems is a re ection of urban and industrial development that contributes to the disposal of chemical pollutants, either by direct or indirect release into the environment (Alves et al, 2021, Lima et al, 2019. These contaminants originate from domestic, industrial, hospital, and agricultural wastes that are inappropriately released into the environment, compromising not only the ecological balance but also human health (Belchior et al, 2017;Ghisi et al, 2014).…”

“…It is approximately 195 km from Recife and is along its route. It passes through several urban centers that use it for e uent disposal and ows into the Atlantic Ocean (Alves et al, 2021). Artisanal shing is one of the primary activities practiced by riverside communities in this region, and one of the most consumed shing resource by these communities is Nile tilapia (Alves et al, 2021).…”

“…It passes through several urban centers that use it for e uent disposal and ows into the Atlantic Ocean (Alves et al, 2021). Artisanal shing is one of the primary activities practiced by riverside communities in this region, and one of the most consumed shing resource by these communities is Nile tilapia (Alves et al, 2021). Tilapia is an African origin sh that was introduced in Brazil to improve sh productivity and the development of aquaculture (Lèveque, 2002).…”