39 research outputs found
Participatory research with fishers to improve knowledge on small-scale fisheries in tropical rivers
Freshwater small-scale fisheries sustain millions of livelihoods worldwide, but a lack of monitoring makes it difficult to check the sustainability of these fisheries. We aim to compare and describe participatory research methods used in studies with fishers in the Tapajos River, a poorly known tropical river in the Brazilian Amazon. We address three interview approaches, two ways to do fisheries monitoring and two approaches for georeferenced mapping based on fishers’ knowledge, which can provide data about at least 16 topics related to fisheries. We highlight major advantages and shortcomings of these methods and illustrate their potential with examples of results on fisheries and fish biology of Peacock bass (Cichla spp. tucunaré in Brazil), an important commercial fish in the Brazilian Amazon. The interviews, participatory monitoring and mapping revealed which fish are more valued by local communities, how fish abundance and sizes varied over time, when fish are more often caught and show reproductive activity, and which sites or habitats fish need to reproduce. In addition to providing useful data from many sites in a cost-effective way, participatory methods can bring the additional benefit of including local stakeholders in the monitoring, management, and research activitie
Fishers' knowledge indicates extensive socioecological impacts downstream of proposed dams in a tropical river
Brazil’s hydroelectricity sector is rapidly expanding, and several dams are planned in Amazonian rivers. The impacts on the fisheries downstream of the dams have largely been overlooked by official impact assessments. Here, we gather fishery baseline data from interviews with 171 fishers in 16 communities along a 275-km stretch of the Tapajos River, located downstream of a proposed dam. The results indicate that fishing constitutes a key source of food and income for fishers and their communities and that the impact of the dam on the fisheries will potentially extend much further than the officially recognized affected area. By ignoring the effects of the dams on downstream communities, impact assessments have severely underestimated the number of people who would be affected by the dams. Therefore, a thorough evaluation of downstream fishers needs to be conducted prior to river impoundment and be considered by development plans
A Segurança Alimentar De Comunidades Pesqueiras Do Sudeste Do Brasil: Dimensões Complementares E Um Exemplo Com O Robalo
Este estudo inclui aspectos complementares da segurança alimentar através da ênfase na importância da trajetória do recurso, dentre outros. Os locais de estudo são Copacabana (Rio de Janeiro) e Paraty (RJ), bem como Bertioga (SP). Três exemplos (casos) ilustram esse estudo: 1) a escolha alimentar de populações da costa; 2) a extração de recursos marinhos considerados vulneráveis; e 3) a compreensão da biologia/ecologia dos recursos, ilustrada aqui através de dados primários sobre o robalo (Centropomus undecimalis). A escolha alimentar inclui a importância do tempo de manipulação no alimento (espécies de peixe, nesse caso). Peixes com menos espinhas são preferidos para consumo e venda; esses possuem também alta demanda no mercado. A extração de recursos vulneráveis é ilustrada através da pesca da garoupa (Epinephelus marginatus). Indivíduos imaturos de garoupa compõem a maioria da pesca de pequenas comunidades pesqueiras e demandas do mercado influenciam as decisões dos pescadores. O último caso, a extração de peixes que utilizam ambientes diversos, para reproduzir e para completar os seus ciclos de vida, é exemplificado através do peixe estuarino robalo (C. undecimalis), com base em dados primários. A importância do conhecimento sobre a reprodução de peixes no sentido de manter as comunidades pesqueiras e trabalhar na direção da segurança alimentar é uma conclusão desse estudo.211404-416Segurança Alimenta
Which fish is this? Fishers know more than 100 fish species in megadiverse tropical rivers
Ethnobiological studies on folk, common, or popular names that fishers use to identify fish can help improve fisheries monitoring and collaborations between fishers and researchers. This study investigates fishers’ knowledge (recognition, naming, and habitat use) on 115 and 119 fish species, respectively, in the Negro and Tapajos Rivers, two megadiverse rivers in the Brazilian Amazon, and investigates the relationship between such knowledge and fish importance to fisheries, fish abundance, and fish size. We also compared fishers’ perceptions on fisheries and fish abundance with literature data on fish harvests and fish sampling. We interviewed 16 fishers in 16 communities (one fisher per community, 8 communities along each river). These fishers recognized an average of 91 ± 10.4 species in the Negro River and 115 ± 7.2 species in the Tapajos River, but all fishers recognized 114 species in Negro and all species in Tapajos. The fishers’ knowledge of fish species was positively related to fishers’ perceptions on fish abundance, size, and importance to fisheries in the Negro, but only positively related to fish size in the Tapajos. Our results highlight the usefulness of fishers’ knowledge to providing data on use and cultural relevance of fish species in high diversity aquatic ecosystems
‘Taking Fishers’ knowledge to the lab’: an interdisciplinary approach to understand fish trophic relationships in the Brazilian Amazon
Trophic levels can be applied to describe the ecological role of organisms in food webs and assess changes in ecosystems. Stable isotopes analysis can assist in the understanding of trophic interactions and use of food resources by aquatic organisms. The local ecological knowledge (LEK) of fishers can be an alternative to advance understanding about fish trophic interactions and to construct aquatic food webs, especially in regions lacking research capacity. The objectives of this study are: to calculate the trophic levels of six fish species important to fishing by combining data from stable isotopes analysis and fishers’ LEK in two clear water rivers (Tapajós and Tocantins) in the Brazilian Amazon; to compare the trophic levels of these fish between the two methods (stable isotopes analysis and LEK) and the two rivers; and to develop diagrams representing the trophic webs of the main fish prey and predators based on fisher’s LEK. The fish species studied were Pescada (Plagioscion squamosissimus), Tucunaré (Cichla pinima), Piranha (Serrasalmus rhombeus), Aracu (Leporinus fasciatus), Charuto (Hemiodus unimaculatus), and Jaraqui (Semaprochilodus spp.). A total of 98 interviews and 63 samples for stable isotopes analysis were carried out in both rivers. The average fish trophic levels did not differ between the stable isotopes analysis and the LEK in the Tapajós, nor in the Tocantins Rivers. The overall trophic level of the studied fish species obtained through the LEK did not differ from data obtained through the stable isotopes analysis in both rivers, except for the Aracu in the Tapajós River. The main food items consumed by the fish according to fishers’ LEK did agree with fish diets as described in the biological literature. Fishers provided useful information on fish predators and feeding habits of endangered species, such as river dolphin and river otter. Collaboration with fishers through LEK studies can be a viable approach to produce reliable data on fish trophic ecology to improve fisheries management and species conservation in tropical freshwater environments and other regions with data limitations
A segurança alimentar de comunidades pesqueiras do Sudeste do Brasil: dimensões complementares e um exemplo com o robalo
Este estudo inclui aspectos complementares da segurança alimentar através da ênfase na importância da trajetória do recurso, dentre outros. Os locais de estudo são Copacabana (Rio de Janeiro) e Paraty (RJ), bem como Bertioga (SP). Três exemplos (casos) ilustram esse estudo: 1) a escolha alimentar de populações da costa; 2) a extração de recursos marinhos considerados vulneráveis; e 3) a compreensão da biologia/ecologia dos recursos, ilustrada aqui através de dados primários sobre o robalo (Centropomus undecimalis). A escolha alimentar inclui a importância do tempo de manipulação no alimento (espécies de peixe, nesse caso). Peixes com menos espinhas são preferidos para consumo e venda; esses possuem também alta demanda no mercado. A extração de recursos vulneráveis é ilustrada através da pesca da garoupa (Epinephelus marginatus). Indivíduos imaturos de garoupa compõem a maioria da pesca de pequenas comunidades pesqueiras e demandas do mercado influenciam as decisões dos pescadores. O último caso, a extração de peixes que utilizam ambientes diversos, para reproduzir e para completar os seus ciclos de vida, é exemplificado através do peixe estuarino robalo (C. undecimalis), com base em dados primários. A importância do conhecimento sobre a reprodução de peixes no sentido de manter as comunidades pesqueiras e trabalhar na direção da segurança alimentar é uma conclusão desse estudo
Fishers’ knowledge on abundance and trophic interactions of the freshwater fish Plagioscion squamosissimus (Perciformes: Sciaenidae) in two Amazonian rivers
Small-scale fisheries provide income and food security to local peoples around the world. In the Brazilian Amazon, the pescada (Plagioscion squamosissimus) is among the fishes that contributes most to catches in small-scale fisheries. Our main goal was to evaluate the abundance, size, relevance to small-scale fisheries and trophic ecology of P. squamosissimus in the Tapajós and Tocantins rivers, in the Brazilian Amazon. We combined data from fishers’ local ecological knowledge (LEK) and fish sampling. We expected that fishers in the Tapajós River, less altered by anthropic changes, would cite a higher abundance, larger size and more prey and predators of P. squamosissimus. We interviewed 61 and 33 fishers and sampled fish in nine and five sites in the Tapajós and Tocantins rivers, respectively. The comparison between fishers’ citations and fish sampled indicated a higher relevance of P. squamosissimus to fishers in the Tapajós River, where this fish had an average larger size and where the fishers mentioned more food items. This pattern could be partially related to the history of anthropogenic changes in the Tocantins River. These results indicated that P. squamosissimus is a generalist fish, which could be resilient to fishing and environmental pressures.A pesca de pequena escala fornece renda e segurança alimentar para as populações locais em todo o mundo. Na Amazônia brasileira, a pescada (Plagioscion squamosissimus) está entre os peixes que mais contribuem para as capturas em pescarias de pequena escala. Nosso objetivo principal foi avaliar a abundância, tamanho, relevância para a pesca artesanal e ecologia trófica de P. squamosissimus nos rios Tapajós e Tocantins, na Amazônia brasileira. Combinamos dados do conhecimento ecológico local dos pescadores (CEL) e amostragem de peixes. Esperávamos que os pescadores do rio Tapajós, menos alterado por mudanças antrópicas, citassem maior abundância, maior tamanho e mais presas e predadores de P. squamosissimus. Entrevistamos 61 e 33 pescadores e amostramos peixes em nove e cinco locais nos rios Tapajós e Tocantins, respectivamente. A comparação entre as citações dos pescadores e os peixes amostrados indicou uma maior relevância de P. squamosissimus para os pescadores do rio Tapajós, onde este peixe teve um tamanho médio maior e onde os pescadores mencionaram mais itens alimentares. Esse padrão pode estar parcialmente relacionado ao histórico de mudanças antrópicas no rio Tocantins. Esses resultados indicaram que P. squamosissimus é um peixe generalista, que pode ser resiliente à pesca e às pressões ambientais
Diet and feeding behavior of Kyphosus spp. (Kyphosidae) in a Brazilian subtropical reef
Pesca do apaiari, Astronotus ocellatus (Agassiz, 1831), e perfil socioeconômico dos pescadores artesanais de uma região da Amazônia brasileira
The artisanal fishery is an important economic and subsistence activity among traditional populations in the Amazon Region. Therefore, the aim of this study was to characterize the fishery of apaiari, Astronotus ocellatus (Agassiz, 1831), and to present a socioeconomic profile of artisanal fishermen in the region lakes of Pracuúba, Amapá, Brazil. From May to August 2011 interviews were conducted using standardized forms with fishermen selected by "snowball" method and aged above 18 years old. A total of 68 fishing workers were interviewed, of which 55 were men and 13 women. It was possible to observe that fishing workers have a wide knowledge of fishery in the Region, including apaiari fishery, and that social and economic lives of the Pracuúba population depend totally of the artisanal fishery