Early evidences of niche shifts in estuarine fishes following one of the world's largest mining dam disasters

• Published in: Marine pollution bulletin 2020-05, Vol.154, p.111073-111073, Article 111073
• Main Authors: Andrades, Ryan, Guabiroba, Helder C., Hora, Maik S.C., Martins, Rebeka F., Rodrigues, Vitor L.A., Vilar, Ciro C., Giarrizzo, Tommaso, Joyeux, Jean-Christophe
• Format: Article
• Language: English
• Subjects: Baseline studies; Brackishwater environment; Brackishwater fishes; Dams; Depletion; Disasters; Energy transfer; Environmental impact; Estuaries; Estuarine fisheries; Estuary; Fish; Fisheries; Food chains; Food webs; Habitat selection; Habitat utilization; Marine crustaceans; Mine spill; Niches; Resources; River basins; River pollution; Stable isotopes; Sustainability
• ISSN: 0025-326X; 1879-3363
• DOI: 10.1016/j.marpolbul.2020.111073

The Fundão dam collapse occurred on November 2015 in Mariana city (Brazil), provoking a series of ecological impacts over the Doce river basin and its nearshore environment. However many impacts over fishery target fauna (fish and shrimp) are still unknown or underestimated due to the lack of baseline data in the region. In the present study we assessed the isotopic niches modeled from δ13C and δ15N signatures of six estuarine fish species before and after the impact to assign potential shifts at the population- and community-level. We showed isotopic niche has altered in all studied species irrespective of its trophic group and habitat use. Niche community metrics indicated a depletion of trophic diversity and basal resources of the whole community after the impact. Food web changes as we reported here can impair the energy transfer through the food chain and put at risk the sustainability of small fisheries that rely upon local resources. •The Fundão dam collapse in Brazil is known as the worst environmental disaster involving mine ore tailings in the world•The passage of the contaminated mud through the Doce river estuarine environment altered the niche of fish species•Bayesian models indicated that fish species showed low or no niche overlap when comparing before and after impact•Community-wide measures indicated depletion of trophic diversity and basal resources of the food chain