Small-scale gold mining erodes fish assemblage structure in small neotropical streams

Abstract

The current gold rush experienced by the Guiana shield is profoundly disturbing freshwater ecosystems. Indeed, streams act as receptors for the water that drains gold mining sites and that contain a high load of sediment and toxicants. We here investigated how gold mining activities affect the structure of fish assemblages in small forest streams in French Guiana. We selected six streams subjected to different types of gold mining impact (reference, former gold mining and currently exploited sites) to measure the impact of gold mining on downstream fish assemblages, but also to determine the resilience of fish assemblages after stopping mining activities. Although overall descriptors of the assemblage such as species richness and fish biomass were not sensitive to gold mining, the fish taxonomic composition was strongly influenced. Furthermore, we showed that the functional structure of fish assemblages was significantly affected by the mining activities favouring smaller and ubiquitous fish at the expense of bigger and habitat specialist species. Even in areas where mining activities had stopped for some time, site resilience was incomplete.

Phylogenetic diagnosis and expanded description of the genus Mazarunia Kullander, 1990 (Teleostei: Cichlidae) from the upper Mazaruni River, Guyana, with description of two new species

“…This is particularly concerning as work in other regions of the Guiana shield has demonstrated the negative impacts of even small-scale gold mining on fish community structure (e.g. Brosse et al, 2011). The upper Mazaruni basin is contained within a comparatively small geographic range, it harbors an extraordinary number of endemic freshwater fish species, and is under a rapidly increasing threat of direct habitat alteration due to mining activities in the region.…”

Measuring ecosystem degradation through half a century of fish species introductions and extirpations in a large isolated lake

“…The most commonly used metrics are structural diversity indices, such as richness, Shannon index, Pielou's Eveness, or Simpson index. All these indices take into account species richness and/or evenness, but they are facing criticism for uncertain ecological interpretation, excessive data requirement, insensitiveness to disturbance, and oversimplification (Brosse et al, 2011;von Euler and Svensson, 2001).…”

Diversidad de insectos acuáticos en quebradas impactadas por agricultura y minería, Caldas, Colombia

“…Esto también ha sucedido en los Andes (Etter et al, 2006;Defensoría del pueblo Colombia, 2010), debido a la pérdida de la vegetación ribereña, la erosión y el uso de sustancias contaminantes (Ramírez, Pringle, & Wantzen, 2008;Brosse, Grenouillet, Gevrey, Khazraie, & Tudesque, 2011). Estas actividades tienen efectos negativos sobre las cadenas tróficas (Canton & Ward, 1981;Boudou, Maury-Brachet, Coquery, Durrieu, & Cossa, 2005;Pond, Passmore, Borsuk, Reynolds, & Rose, 2008) y el funcionamiento de los ecosistemas (Barbour et al, 1999;Ward, Tockner, & Schiemer, 1999).…”

“…En las últimas cinco décadas, la agricultura en Colombia ha tenido un crecimiento acelerado, debido a la intensificación de la producción y a la expansión de los cultivos (Etter et al, 2006), y se ha documentado que es una de las actividades antrópicas que más altera las dinámicas de los ecosistemas acuáti-cos (Maloney & Weller, 2011;Piggott, Lange, Townsend, & Matthaei, 2012;Chará-Serna, Chará, Giraldo, Zúñiga, & Allan, 2015). Por otro lado, la minería es una de las actividades que más impacta los ecosistemas lóticos, ya que estos actúan como receptores de los desechos provenientes de la explotación y extracción de minerales (Bernhardt & Palmer, 2011;Brosse et al 2011).…”

“…Establecer los efectos de la actividad agrí-cola y minera sobre la diversidad de insectos acuáticos y su potencial impacto sobre los ecosistemas dulceacuícolas, es relevante dado el incremento de estas actividades en Latinoamérica (Harvey et al, 2008;Brosse et al, 2011;Armenteras & Rodríguez, 2014;Chará-Serna et al, 2015). En la actualidad, no se conocen con certeza los efectos sobre las comunidades asociadas a ecosistemas acuáticos inmersos en matrices con presencia de actividades agrícolas y mineras (Pond et al, 2008;Hepp, Milesi, Biasi, & Restello, 2010;Piggott et al, 2012;De Jonge, Tipping, Lofts, Bervoets, & Blust, 2013;Mondal & Jana, 2015) en quebradas de los Andes tropicales, las cuales se caracterizan por ser pequeñas, correntosas y propensas a la erosión, debido a las fuertes lluvias (Chará-Serna et al, 2015).…”