Urban market amplifies strong species selectivity in Amazonian artisanal fisheries

Abstract

Despite Amazonia possessing the highest freshwater biodiversity on Earth, urban landing data show how huge fishing pressure is placed on only a dozen species. However, truly characterising the fishery and understanding the drivers of species selectivity is challenging, given the neglect of artisanal fishing activity, who may catch most of the Amazon’s fish. We register the catch of 824 fishing trips by interviewing artisanal fishers in their rural riverside communities. We use these data to characterise the artisanal fishery of the Rio Purus, the main fish source sub-system for the Amazon’s largest city (Manaus), and investigate the factors determining catch composition. Fishers caught 80 fish species, yet just four species made up over half of the harvested biomass. Urban markets appear to drive greater selectivity, with a significantly lower species diversity in commercial compared to subsistence catches. Fish catch composition varied significantly both seasonally and with geographical remoteness from Manaus. The spatial turnover in catch composition appears to be driven by urban access, with more commercially important species dominating where Manaus-based fish-buyers frequent. Our data may partially explain observed overfishing in some commercially important species, particularly as most Amazonians now live in urban areas.

Biodiversity underpins fisheries resilience to exploitation in the Amazon river basin

“…Additionally, fishery subsectors in the Amazon exist, but these tend to target low-abundance and high-value species such as Arapaima spp. and migratory catfish [37,38]. However, effort among gear types and actors is distributed widely and often overlapping in space and time.…”

Spatial dynamics of Amazonian commercial fisheries: an analysis of landscape composition and fish landings

“…Accessing fishing information with fishers in the years after the fisheries were carried out can be useful, especially when there is no systematic data collection, as is the case with freshwater fisheries in Brazil. Other studies conducted via interviews with fishers to obtain the amount of fish caught and the composition of the species, which fish are more valued, and how fish abundance and sizes vary over time have shown that this methodology is accurate (Silvano and Hallwass, 2020;Tregidgo et al, 2021;Rabuffetti et al, 2022).…”

“…The use of fishing sites closer to the landing site by fishers on the lower Solimões River reflects how fishers use their traditional knowledge of the environment and species (Silvano and Hallwass, 2020;Tregidgo et al, 2021). Generally, fishers choose the fishing site located at the shortest distance and with a high density of fishery resources (Corrêa et al, 2012;Pereira et al, 2019).…”

“…The behavior of the commercial fishers and the capture of the species can be shaped according to the fluctuation of the river level, the preferences of the consumer market, the type of environment and the fishing site (Matos et al, 2021;Tregidgo et al, 2021). In addition, the use of certain Brazilian Journal of Biology, 2023, vol.…”

Updated species checklist of fishes from Lake Dongting in Hunan Province, South China: Species diversity and conservation

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