Population dynamics and stock assessment of Colossoma macropomum caught in the Manacapuru Lake system (Amazon Basin, Brazil)

Abstract

Colossoma macropomum is the second largest scaled fish in the Amazon basin. Reduced harvests in recent decades suggest that populations of this species are already overexploited in some areas. In this study, the population dynamics of C. macropomum was investigated using length and weight data for fish caught in the Manacapuru Lake system, a large ria lake located along the lower reach of the Solimões River. A total of 1270 individuals of C. macropomum with standard lengths varying from 17 to 62 cm and mean length of 31.0 ± 6.7 cm were sampled. Weights varied from 165 to 8195 g, and mean weight was 1148.3 ± 883.8 g. Maximum sustainable yield was estimated at 285.8 g recruit−1, corresponding to a fishing mortality of 0.51 year−1. A scenario analysis based on changes in fishing mortality and age at first capture, two parameters potentially addressed by fishing management strategies, suggested that any improvement in fishing yield depends on increases in age at first capture.

A diní­¢mica sazonal das pescarias de pequena escala na Amazônia é definida pelo pulso hidrológico

“…But, the rising in the fisheries on this order, already is supporting the fish stock overfishing PETRERE JR. et al, 2004) and the declining in natural fish stock at the Amazon basin is growing each year (GARCEZ and FREITAS, 2011;CAMPOS et al, 2015), achieving a estimative about 47% of the available fish stocks, also 18% became overfished and 10% depleted (AGOSTINHO et al, 2007). But, the absence of continued studies on fisheries in the Amazon basin, make difficult to obtain a precise results from fisheries production in this region (OLIVEIRA JÚNIOR et al, 2016).…”

“…Also, allowing a bigger crew onboard and can do meddle and large fisheries trip extending about 100 to 300 km, from their communities (BATISTA and PETRERE, 2007). These fish boats had success in their fisheries mainly when acts close or in the preserved areas, as occur in the Manacapuru Lago Grande System (GARCEZ and FREITAS, 2011), but nowadays this proceeds started to reflects the existence of some fish stocks depletions in the Amazon basin (AGOSTINHO et al, 2007;GARCEZ and FREITAS, 2011;CAMPOS et al, 2015) which is clearly viewed from the decreasing of target fish number landed in the urban centers, which forces the fishermen to figure out fisheries in remote fish zones (BAYLEY and PETRERE JR., 1989;BATISTA and PETRERE, 2007).…”

Sustainability of small-scale fisheries in the middle Negro River (Amazonas – Brazil): A model with operational and biological variables

“…This ecosystem is home to the world's highest diversity of fish (Reis et al, 2016). Several anthropogenic factors, such as dam building (Kahn et al, 2014), oil and gas development (Finer et al, 2008), overfishing (Campos et al, 2015), invasive alien species (Latini and Petrere, 2004), deforestation (Lobón-Cerviá et al, 2015), and droughts caused by deforestation and global warming (Castello et al, 2013;Freitas et al, 2013), threaten this system.…”

Condition factor variations over time and trophic position among four species of Characidae from Amazonian floodplain lakes: effects of an anomalous drought

“…After breeding, they move to floodplain areas for shelter and feeding in the flooded forests (Fernandes, 1997;Saint-Paul et al, 2000;Soares et al, 2007;Noveras et al, 2010). Colossoma macropomum is the second largest scaled fish in the Amazon basin, and its populations are already overexploited in some areas (Isaac and Ruffino, 1996;Freitas et al, 2007;Campos et al, 2015). Mylossoma duriventre is a smaller-bodied fish that forms large schools during reproductive migrations (Granado-Lorencio et al, 2005).…”