Population and biological parameters of selected fish species from the middle Xingu River, Amazon Basin

Abstract

This study estimates the main biological parameters, including growth rates, asymptotic length, mortality, consumption by biomass, biological yield, and biomass, for the most abundant fish species found on the middle Xingu River, prior to the construction of the Belo Monte Dam. The specimens collected in experimental catches were analysed with empirical equations and length-based FISAT methods. For the 63 fish species studied, high growth rates (K) and high natural mortality (M) were related to early sexual maturation and low longevity. The predominance of species with short life cycles and a reduced number of age classes, determines high rates of stock turnover, which indicates high productivity for fisheries, and a low risk of overfishing.Keywords: amazon fishes, population dynamics, life history strategies, Belo Monte dam. Parâmetros biológicos e populacionais de peixes do meio Rio Xingu, Bacia Amazônica ResumoEste estudo estima os parâmetros biológicos tais como taxas de crescimento corporal, comprimento assintótico, mortalidade, consumo por biomassa, produção biológica e biomassa, para 63 espécies no médio rio Xingu, antes da construção da hidrelétrica de Belo Monte. Os espécimes foram coletados por capturas experimentais e foram analisados com equações empíricas através do programa FISAT com base nos comprimentos corporais. Altas taxas de crescimento (K) e altas mortalidades naturais (M) foram relacionadas com uma maturação sexual precoce e baixa longevidade. O predomino de espécies com ciclos de vida curta e um reduzido número de classes etárias determinou altas taxas de renovação dos estoques, que indica alta produtividade para as pescarias e baixos riscos de sobrepesca.Palavras-chave: peixes amazônicos, dinâmica populacional, estratégias de vida, hidrelétrica de Belo Monte.

O que dizem as pesquisas acadêmicas sobre os impactos das hidrelétricas na pesca artesanal?

“…Com relação a biologia e ecologia, os estudos focaram suas análises em aspectos de crescimento, mortalidade, reprodução, dinâmica alimentar, riqueza, diversidade, população, assembleia de peixes e distribuição (ALI, 1996;GOMES;MIRANDA, 2001;TORDECILLA-PETRO et al, 2005;JIMÉNEZ-BADILLO, 2006;AGOSTINHO et al, 2007;COLL et al, 2007;MAIA et al, 2007;ARAYA et al, 2008;ZHU;CHANG, 2008;TOS et al, 2009;KANTOUSSAN et al, 2009;MESSINA et al, 2010;GARCIA-LIZARRAGA et al, 2011;CARVALHO, 2011a;QUARCOOPOME et al, 2011;CARVALHO, 2012;ALVAREZ et al, 2013;GERASIMOV et al, 2013;HAMID;MANSOR, 2013;CAMARGO et al, 2015;SÁ-OLIVEIRA et al, 2015;AGOSTINHO et al, 2016;DAVID et al, 2016).…”

Distribution of economically important fish larvae (Characiformes, Prochilodontidae) in the Central Amazonia, Brazil

“…Understanding of the phenology of fish spawning in neotropical freshwater ecosystems, such as the Amazon basin, depends on the life history strategies of the species, the availability of resources and the interactions of regional environmental variation patterns related to the hydrological cycle and seasonality (Camargo, Giarrizzo & Isaac, 2015;Lima & Araújo-Lima, 2004;Ponte, Ferreira, Bittencourt, Queiroz & Zacardi, 2016;Ruffino & Isaac, 1995). These factors regulate the composition, abundance and distribution of species within and among biological communities (Gomes & Agostinho, 1997;Junk, Bayley & Sparks, 1989;Menge & Sutherland, 1987;Winemiller, 1989).…”

Naga people's (Tasikmalaya District, West Java, Indonesia) local knowledge of the variations and traditional management farm of village chickens

“…Based on the biological parameters estimated for the fishes of the study area, there was a clear indication of r strategist species, characterized by high growth rates (K) and high natural mortality (M), and strongly related to early sexual maturation and low longevity. These parameters could categorize as rapid replacement of generations (Camargo et al 2015). The relationship between spawning potential and age of the species suggests life-history uncertainty surrounding the status of the stocks, causing overfishing to go incognito until stocks have finally collapsed.…”