Local fish extinction in a small tropical lake in Brazil

Abstract

Lagoa Santa is a shallow permanent lake, located in Belo Horizonte metropolitan region, Brazil. In this study, the loss in fish diversity of the lake over the past 150 years is evaluated. Local extinction of almost 70% of the original fish fauna is described. Probably, the main causes of this richness loss were: obstruction of natural communication with rio das Velhas, non-native species introduction, change in the water level, organic pollution, and elimination of littoral and submerged vegetation.Lagoa Santa é uma lagoa rasa e permanente, localizada na região metropolitana de Belo Horizonte, Brasil. Neste estudo, é avaliada a diminuição da diversidade de peixes na lagoa. Avaliações recentes indicam que cerca de 70% da ictiofauna nativa foi extinta na lagoa, durante os últimos 150 anos. As causas prováveis desta perda de espécies foram: obstrução da comunicação com o rio das Velhas, introdução de espécies exóticas, mudanças no nível da água, poluição orgânica e eliminação da vegetação marginal e submersa.

The roles of marginal lagoons in the maintenance of genetic diversity in the Brazilian migratory fishes Prochilodus argenteus and P. costatus

“…Notwithstanding, Pompeu & Godinho (2006) observed a gradual reduction in fish richness and an abundance of lagoons that did not receive annual flooding because of the water flow control by the Três Marias hydroelectric dam. Local extinction with a reduction of almost 70% of the native fish fauna was also observed in a lagoon from the rio São Francisco basin (Pompeu & Alves, 2003). Considering these fish nurseries in the rio São Francisco basin (Sato & Godinho, 2003) and upper rio Paraná (Agostinho et al, 2000), the Brazilian conservation policy should include these marginal lagoons in the floodplains as a priority for the maintenance of the genetic variability in migratory fishes.…”

Implementation of hydroacoustic for a rapid assessment of fish spatial distribution at a Brazilian Lake - Lagoa Santa, MG

“…Impacts on the diversity of fishes were detected by Pompeu and Alves (2003), who noted the disappearance of 70% of the 19 species recorded by Johannes Reinhardt, who made the first fish survey in 1850. The most famous was the extinction of Characidium lagosantense, a small fish typical of the region, probably due fishing sonars enable the continuous visualization of the pelagic zone and allow the study of aquatic organisms that have biological structures filled with gas and, therefore, reflect the sound waves depending on the density difference between these structures and the environment.…”

“…The total distance covered during the entire study was 8.7 km, representing a degree of coverage to: (a) obstruction of natural communication with rio das Velhas, formerly held by the stream Bebedouro (now channeled and heavily polluted), (b) introduction of exotic species, and (c) the elimination of marginal and submerged vegetation (Pompeu and Alves, 2003 …”

The role of ovarian steroids in reproductive plasticity in Hoplias malabaricus (Teleostei: Characiformes: Erythrinidae) in tropical reservoirs with different degrees of pollution

“…The impact of water pollution on fish and other aquatic communities has been well documented in various neotropical watersheds (Mangeaud, 1998;Pompeu and Alves, 2003;Cazenave et al, 2005;Hued et al, 2006;Kirschbaum et al, 2009;Fedato et al, 2010), and many laboratory studies have examined the effects of exposure to specific chemicals on fish physiology (Jones and Reynolds, 1997;Robinson et al, 2003;Correia et al, 2010;Simonato et al, 2011;Nascimento et al, 2012;Vieira et al, 2013). However, only few studies have evaluated the effects of pollution present in rivers and reservoirs on fish reproductive physiology.…”