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The Neotropical region hosts 4225 freshwater fish species, ranking first among the world's most diverse regions for freshwater fishes. Our NEOTROPICAL FRESHWATER FISHES data set is the first to produce a large-scale Neotropical freshwater fish inventory, covering the entire Neotropical region from Mexico and the Caribbean in the north to the southern limits in Argentina, Paraguay, Chile, and Uruguay. We compiled 185,787 distribution records, with unique georeferenced coordinates, for the 4225 species, represented by occurrence and abundance data. The number of species for the most numerous orders are as follows: Characiformes (1289), Siluriformes (1384), Cichliformes (354), Cyprinodontiformes (245), and Gymnotiformes (135). The most recorded species was the characid Astyanax fasciatus (4696 records). We registered 116,802 distribution records for native species, compared to 1802 distribution records for nonnative species. The main aim of the NEOTROPICAL FRESHWATER FISHES data set was to make these occurrence and abundance data accessible for international researchers to develop ecological and macroecological studies, from local to regional scales, with focal fish species, families, or orders. We anticipate that the NEOTROPICAL FRESHWATER FISHES data set will be valuable for studies on a wide range of ecological processes, such as trophic cascades, fishery pressure, the effects of habitat loss and fragmentation, and the impacts of species invasion and climate change. There are no copyright restrictions on the data, and please cite this data paper when using the data in publications.

The fishery of mapará (Hypophthalmus marginatus) is of great economic importance in the Amazon region. Despite this, it is observed that the current norms of management disagree with the ethnoknowledge of fishermen of the Tocantins river. Therefore, there are many seizures and fines in the Tocantins Low region. This work appeared as a demand of the fishermen of the region and had as purpose to test the pertinence of the fishing legislation on the capture of the species and to provide subsidies for the adaptation of the norms to the local reality. For this, a mapará fishery was taken on the Pindobal Grande river, in the municipality of Igarapé-Miri, in the state of Pará. A sample of the captured individuals was collected, and identification, sexing and biometry were done. Fishing was described, and the sex ratio tested with the Chi-Square test and the mean length differences between the sexes with the Student's t-test. The results were compared with current legislation and literature data. The captured mapará individuals were mostly above 30 cm, as determined by legislation. It is concluded that, despite using a network that is prohibited, the capture of the species in the region acts selectively, due to the ethno-cognition and the fisherman's action ("taleiro"). Therefore, it is necessary that the legislation be revised, seeking the reconciliation between the conservation of ecosystems, the traditional knowledge and the socioeconomic development of the region. La pesca del sorgo (Hypophthalmus marginatus) tiene una gran importancia económica en la región amazónica. Sin embargo, se observa que las normas de gestión vigentes están en desacuerdo con los conocimientos étnicos de los pescadores del río Tocantins. Por lo tanto, hay un gran número de incautaciones y multas en la región del Bajo Tocantins. Este trabajo surgió como una demanda de los pescadores de la región y su objetivo era comprobar la pertinencia de la legislación pesquera sobre la captura de la especie y proporcionar subvenciones para adaptar la normativa a la realidad local. Así, seguimos una pesquería de mapará en el río Pindobal Grande, municipio de Igarapé-Miri, estado de Pará; donde se tomó una muestra de los individuos capturados y se procedió a su identificación, sexado y biometría. Se describieron las pesquerías y se comprobaron las proporciones de los sexos con la prueba de Chi Cuadrado y las diferencias de longitud media entre los sexos con la prueba t de Student. Los resultados se compararon con la legislación vigente y con los datos de la literatura. La mayoría de los ejemplares de mapará capturados superaban los 30 cm, tal y como exige la ley. Se puede concluir que, a pesar del uso de una red prohibida, la captura de la especie en la región es selectiva, debido al conocimiento étnico y a las acciones del pescador ("taleiro"). Por lo tanto, es necesario que se revise la legislación, buscando conciliar la conservación de los ecosistemas, los conocimientos tradicionales y el desarrollo socioeconómico de la región. A pescaria do mapará (Hypophthalmus marginatus) é de grande importância econômica na região amazônica. Apesar disso, observa-se que as normas de manejo vigentes estão em discordância com o etnoconhecimento dos pescadores do rio Tocantins. Logo, há uma grande quantidade de apreensões e multas na região do Baixo Tocantins. Este trabalho surgiu como demanda dos pescadores da região e teve como finalidade testar a pertinência da legislação de pesca sobre a captura da espécie e fornecer subsídios para a adequação das normas à realidade local. Para isso acompanhou-se uma pescaria do mapará no rio Pindobal Grande, município de Igarapé-Miri, estado do Pará. Retirou-se uma amostra dos indivíduos capturados, e foi feita a identificação, sexagem e biometria. A pesca foi descrita e a proporção sexual testada com o teste de Qui Quadrado e as diferenças do comprimento médio entre os sexos com o teste t de Student. Os resultados foram comparados com a legislação vigente e com dados da literatura. Os indivíduos de mapará capturados estavam em sua maioria acima dos 30 cm, determinado pela legislação. Conclui-se então, que apesar de utilizar uma rede que é proibida, a captura da espécie na região atua de forma seletiva, por conta do etnoconhecimento e da atuação do pescador (“taleiro”). Logo, faz-se necessário que a legislação seja revista, buscando a conciliação entre a conservação dos ecossistemas, o saber tradicional e o desenvolvimento socioeconômico da região.

WOS:000630750300001; 1. The Amazon basin hosts the Earth's highest diversity of freshwater fish. Fish species have adapted to the basin's size and seasonal dynamics by displaying a broad range of migratory behaviour, but they are under increasing threats; however, no study to date has assessed threats and conservation of Amazonian migratory fishes. 2. Here, the available knowledge on the diversity of migratory behaviour in Amazonian fishes is synthesized, including the geographical scales at which they occur, their drivers and timing, and life stage at which they are performed. 3. Migratory fishes are integral components of Amazonian society. They contribute about 93% (range 77-99%) of the fisheries landings in the basin, amounting to -US\436 million annually. 4. These valuable fish populations are mainly threatened by growing trends of overexploitation, deforestation, climate change, and hydroelectric dam development. Most Amazonian migratory fish have key ecological roles as apex predators, ecological engineers, or seed-dispersal species. Reducing their population sizes could induce cascading effects with implications for ecosystem stability and associated services. 5. Conserving Amazonian migratory fishes requires a broad portfolio of research, management, and conservation actions, within an ecosystem-based management framework at the basin scale. This would require trans-frontier coordination and recognition of the crucial importance of freshwater ecosystems and their connectivity. 6. Existing areas where fishing is allowed could be coupled with a chain of freshwater protected areas. Management of commercial and subsistence species also needs fisheries activities to be monitored in the Amazonian cities and in the floodplain communities to allow assessments of the status of target species, and the identification of management units or stocks. Ensuring that existing and future fisheries management rules are effective implies the voluntary participation of fishers, which can be achieved by increasing the effectiveness and coverage of adaptive community-based management schemes.

Flooding events in large rivers, termed flood pulses, expand and contract habitat available for fish populations, affecting fish abundance and catches. Here, we investigated if river hydrologic variability affected catch of curimata (Prochilodus nigricans), a widely distributed and economically important fish species of the Amazon Basin. Using fish catch and fishing effort data for the lower Amazon region collected between 1993 and 2004, we performed an (i) analysis of covariance (ANCOVA) to understand the intra-annual relationship, and (ii) a cross-correlation function (CCF) to assess the inter-annual lag associated between river water levels and catches. We found that the intra-annual relationship between monthly river water levels and monthly catches of P. nigricans was negative, resulting in greater catches during lower river water levels and vice versa. We also found positive correlations with an inter-annual lag of 15-months between river water levels and catch, indicating that years with more extensive flooding lead to greater than normal catches of P. nigricans 15 months later. Increased flooding can be hypothesized to lead to increased survival and growth rates of P. nigricans. This dependency of catches of P. nigricans on river hydrological cycles underscores the threat posed by ongoing hydrological alterations to fish-related food and income security in the region. Further research is necessary to assess the extent to which such hydrological effects can impact multispecies fisheries catches in light of growing levels of fishing pressure.

Virtual Population Analysis (VPA) is a diagnostic tool that providing valuable input for management decisions to sustainable catches for marine fisheries. Industrial shrimp trawling produces one of the most valuable export commodities in the Brazilian fishery sector. Due to the profitability, there is pressure on government agencies to increase the number of fishing licenses. The present study used the body-length data available for the industrial southern brown shrimp trawling fleet of the Amazon Continental Shelf (ACS), Brazil, to estimate the current maximum sustainable yield and test the potential effects of increased effort on the sustainability of this fishery. The available data encompasses 13 years of onboard monitoring of shrimp trawling. The VPA was run in an Excel spreadsheet. The results indicate that the ACS shrimp stock has high fishing (F) mortality rates, although exploitation levels can be considered adequate below the MSY. An increase of up to 40% in fishery effort – including the expansion of the number of vessels – would not result in overfishing, although we would not recommend an increase in effort, as this may increase impacts on the bycatch fauna and eventual economic losses in the event of the failure of recruitment. El Análisis de población virtual (VPA) es una herramienta de diagnóstico que proporciona información valiosa para las decisiones de gestión sostenible de las capturas para la pesca marina. La pesca de arrastre industrial de camarón produce uno de los productos de exportación más valiosos de la industria pesquera brasileña. Debido a la rentabilidad, existe presión sobre las agencias gubernamentales para que aumenten el número de licencias de pesca. El presente estudio utilizó los datos de longitud corporal disponibles para la flota de arrastre de camarón marrón del sur de la plataforma continental amazónica (ACS), Brasil, para estimar el rendimiento máximo sostenible actual y probar los efectos potenciales de un mayor esfuerzo sobre la sostenibilidad de esta pesquería. Los datos disponibles cubren 13 años de monitoreo a bordo de la pesca de arrastre de camarón. El VPA se ejecutó en una hoja de cálculo de Excel. Los resultados indican que el stock de camarón ACS tiene altas tasas de mortalidad por pesca (F), aunque los niveles de exploración pueden considerarse adecuados por debajo del RMS. Un aumento de hasta un 40% en el esfuerzo pesquero, incluida una expansión en el número de embarcaciones, no resultaría en una sobrepesca, aunque no recomendamos un aumento en el esfuerzo, ya que esto puede incrementar los impactos en la fauna de las capturas accesorias y eventuales pérdidas económicas en el caso de una contratación fallida. A Análise de População Virtual (VPA) é uma ferramenta de diagnóstico que fornece informações valiosas para decisões de gestão de capturas sustentáveis ​​para a pesca marinha. O arrasto industrial de camarão produz uma das commodities de exportação mais valiosas do setor pesqueiro brasileiro. Devido à lucratividade, há pressão sobre os órgãos governamentais para aumentar o número de licenças de pesca. O presente estudo usou os dados de comprimento do corpo disponíveis para a frota industrial de arrasto de camarão negro do sul da Plataforma Continental da Amazônia (ACS), Brasil, para estimar o rendimento máximo sustentável atual e testar os efeitos potenciais do aumento do esforço na sustentabilidade desta pescaria. Os dados disponíveis abrangem 13 anos de monitoramento a bordo da pesca de arrasto de camarão. O VPA foi executado em uma planilha Excel. Os resultados indicam que o estoque de camarão ACS apresenta altas taxas de mortalidade por pesca (F), embora os níveis de exploração possam ser considerados adequados abaixo do MSY. Um aumento de até 40% no esforço de pesca - incluindo a expansão do número de embarcações - não resultaria em sobrepesca, embora não recomendamos um aumento do esforço, pois isso pode aumentar os impactos sobre a fauna de capturas acessórias e eventuais perdas econômicas em o caso de insucesso do recrutamento.

A dourada, Brachyplatystoma rousseauxii (Castelnau, 1855), é um recurso pesqueiro muito explotado na região Amazônica e que não possui nenhuma regulação atualmente. O presente trabalho tem como objetivo descrever a diní­¢mica da pesca da dourada no Baixo Amazonas, analisando os desembarques pesqueiros no municí­­pio de Santarém-PA. No perí­­odo de janeiro de 1993 a dezembro de 2003 foram registradas 14.428 viagens de pesca, totalizando uma produção de 3.413 toneladas de pescado. A captura da dourada é praticada, principalmente, nos canais dos rios, com barcos motorizados e equipados com urnas de gelo. A principal arte de pesca utilizada é a rede de emalhe, com destaque para a "bubuia" rede de emalhe usada a meia água, colocada í­Â deriva no canal do rio. A captura por unidade de esforço (CPUE) estimada para a pesca desembarcada pelos barcos pescadores atuando com "bubuia” foi de 13,80 kg/pescador*dia. O preço médio de primeira comercialização do quilo da dourada desembarcada variou de R$ 2,40 a R$ 6,20. A pesca da dourada (B. rousseauxii) apresenta um padrão sazonal associado ao ciclo hidrológico, no qual os meses de redução do ní­­vel do rio correspondem ao perí­­odo de safra. Este estudo demonstra a importí­¢ncia desse recurso para a região e vem contribuir como subsí­­dio para um futuro ordenamento pesqueiro e manejo da espécie, que hoje em dia não possui nenhuma regulamentação.

Inland fisheries underpin food security in many tropical countries. The most productive inland fisheries in tropical and subtropical developing countries occur in large river–floodplain systems that are often impacted by land cover changes. However, few studies to date have assessed the effects of changes in floodplain land cover on fishery yields. Here, we integrated fisheries and satellite‐mapped habitat data to evaluate the effects of floodplain deforestation on fishery yields in 68 floodplain lake systems of the lower Amazon River, representing a wide range in relative amounts of woody, herbaceous and non‐vegetated land cover. We modelled relative fish yields (fish capture per unit effort [CPUE]) in the floodplain lakes as a function of the relative amounts of forest, shrub, aquatic macrophyte and bare/herbaceous habitats surrounding them. We found that forest amount was positively related (p = .0003) to multispecies CPUE. The validity of these findings was supported by rejection of plausible alternative causative mechanisms involving habitat‐related differences in amount of piscivores, fishing effort, lake area, and habitat effects on CPUE of the nine taxa dominating multispecies yields. Our results provide support to the idea that removal of floodplain forests reduces fishery yields per unit effort. Increased protection of floodplain forests is necessary to maintain the food, income and livelihood security services provided by large river–floodplain fisheries.

Este trabalho descreve os canais e as margens de comercialização de cinco espécies de peixes ornamentais capturadas no rio Xingu, estado do Pará, Brasil. A coleta de dados foi realizada de forma intencional e sequencial junto a 51 agentes da cadeia de comercialização, incluindo pescadores, atacadistas e varejistas nacionais e internacionais. Os resultados indicam que as espécies ornamentais podem passar por até seis agentes de comercialização antes do consumidor final. O acari picota-ouro (Scobinancistrus aureatus) é a espécie mais valorizada no mercado, chegando a ser vendida ao consumidor final pelo preço unitário de R$ 543,00, um aumento de 1.361% no mercado norte americano e 1.527% no mercado europeu em relação ao preço da exportação brasileira. As margens de comercialização são elevadas: 92,68% no mercado europeu e 89,24% no mercado norte-americano. Observando as distribuições de benefí­­cios, conclui-se que o mercado internacional se apropria da maior parcela do valor gerado pela atividade.

The North Brazil Shelf is a Large Marine Ecosystem (LME) that extends from the Caribbean Sea, in Central America, to the Parnaiba River in Brazil, and includes six countries. The area is dominated by the runoff of large rivers, including the Amazon and Orinoco, and by the intense disturbance of sediment transport, tides and currents. The sea bed is formed mainly by mud in shallow water, and by sand, mud, and gravel in deeper water. In terms of its biological productivity, this LME can be considered oligotrophic, with stratified habitats. The main source of nutrients of the euphotic layer is the local rivers and mangroves. Primary production has been limited by light and rising temperatures in recent years, factors associated with a decrease in marine primary productivity. However, the benthic fauna is very rich and unique, but poorly known. More than 500 fish species have been recorded in this LME. Demersal fish and shrimp are the main fishery resources in coastal and continental shelf waters. Fisheries account for more than 600 million USD a year with a considerable diversity of methods and scales ranging from very small to industrial. Seafood consumption is moderate to high in the local countries. Climate changes, dam building, deforestation, pollution, overfishing, tourism and aquaculture are the main threats to ecosystem productivity and habitat quality. Socioeconomic data are scant for this LME. Development is concentrated near the cities and mouths of rivers. Traditional communities in the coastal areas are culturally diverse, but invariably characterized by very low socioeconomic conditions. The Gross Domestic Product of the local countries ranges from 7,500 USD per capita in Guyana to 32,600 USD per capita in Trinidad and Tobago. Profound problems of governability are common to all six countries, and mean governance indicators reflect poor performances in all cases. The main issues are an absence of effective rule of law, political stability, and control of corruption. Fisheries are characterized by increasing effort and an absence of sustainability. Most of the fishery stocks are either fully or over exploited. This scenario can only be rectified by investments in marine protected areas and scientific research, as well as the increased participation of fishers in the development and implementation of management strategies and regulations.

One method with considerable potential for understanding fishing and environmental impacts on fish assemblages is size spectra (SS) and diversity size spectra (DSS) analysis—a regression of Ln abundance or Shannon diversity against the natural logarithm of body size of fish assemblages. But the usefulness of this method for application to tropical freshwater fish assemblages is uncertain. Here, we assessed the extent to which SS and DSS analyses explained changes in the exploited fish assemblage related to fishing effort and river droughts. To do this, we used correlation analyses on historical datasets of river water level, fishing effort, and fish length measurements for 56 fish species in three of the largest rivers of the Amazon Basin. In calculating the SS and DSS analysis statistics, we found that linear regressions adjusted well to the diversity and Ln(abundance) data plotted against Ln(fork length). In analysing SS and DSS statistics in relation to fishing and environmental impacts, we found that the slope of SS was negatively correlated to drought intensity with a lag of zero years in all rivers. The slope of SS also was negatively correlated to fishing effort with a lag of three years in two rivers and a lag of two years in one year. The slope of DSS was not correlated to drought intensity and fishing effort in any of the rivers. Our results provide support for the use of SS analysis to investigate fishing and environmental effects on exploited fish assemblages in tropical freshwater environments.

The study analyzed the fishery parameters and population dynamics of the silver croaker, Plagioscion squamosissimus, and its exploitation status, before the damming of the Xingu River by the Belo Monte hydroelectric dam. Silver croaker was caught throughout the year, with a total production of 239 tons. Estimated Catch per Unit Effort (CPUE) was 14.16 kg.fisher-1.day-1. The mean price paid to the fishers for a kilogram of silver croaker ranged from US$1.89 to US$3.28. Mean longevity estimated was 7.68 years. The total mortality (Z) was calculated at approximately 1.44 year-1, natural mortality (M) was 0.76 year-1, fishery mortality (F) was 0.68 year-1, and the current exploitation rate (E) was 0.47 year-1. The study highlights the importance of P. squamosissimus as a fishery resource in the Xingu region and provides important insights for the development of future fishery management strategies and conservation of the species stocks.

The giant catfishes Brachyplatystoma rousseauxii, Brachyplatystoma vaillantii and Brachyplatystoma filamentosum are important environmental, social and economic resources in the Amazon. However, anthropogenic environmental changes, such as climate change, deforestation, overexploitation of water resources and damming of rivers, threaten the conservation of this fishery. The aims of this study were to investigate temporal trends and elucidate global and regional environmental drivers of catch for these species of giant catfish in the Amazon. Using annualised catch data (1993–2010), we tested for linear trends using Mann–Kendall tests and built multilinear models of fish catch using effort and a variety of regional and global hydrological and meteorological series. We found a significant decline in the catches of B. rousseauxii and B. filamentosum, whereas the B. vaillantii catch increased. Total catch had a significant positive correlation with fishing effort, and variation in sea surface temperature (SST) explained an additional 19–38% of the variability of catches. Other hydrological and climate variables were weakly correlated or uncorrelated with catch. Overall, these results argue strongly for a resumption the collection of fishing statistics in the Amazon. In addition, associations between SST and catch suggest that conservation of these long-distance migrants must consider both regional and global drivers of fisheries change.

The assessment of fishery resources is key to the development of management strategies for exploited stocks. Analysis of specific parameters provides information regarding the state of the stock and indicators of exploitation levels. The aim of the present study was to analyse the growth and mortality parameters, as well as investigate the exploitation status, of Panulirus meripurpuratus caught on the Amazon coast, northern Brazil. Growth parameters and stock assessment were estimated using R with bootstrapping and FISAT II, based on cephalothorax length–distribution frequency. Specimens were collected by the commercial lobster fishery off the coast of the states of Pará and Amapá between 2001 and 2002. The results indicate that the P. meripurpuratus stock assessed is composed of individuals with low growth rates and high estimates of maximum asymptotic length, with relative longevity of 21.37 years. The exploitation rate was operating at near the maximum limit of sustainability in 2001 and 2002. This is the first estimate of the exploitation status of P. meripurpuratus on the Amazon coast. We strongly recommend new monitoring efforts and further studies to support the conservation and management of the spiny lobster stock.

River-floodplain fisheries are highly productive as seasonal water level changes, known as ‘flood pulses,’ increase the productivity of fish populations by providing them with feeding and reproductive opportunities in the floodplains. However, current understanding of flood pulse effects on fisheries activities at seasonal and interannual time scales remains deficient. Here, we analyze a comprehensive dataset of the Lower Amazon region to address the following questions: How flood pulses affect river-floodplain fishing strategies with respect to species composition and habitat? What is the interannual lag of hydrological effects on fisheries yields? And does that lag depend on the life-history strategy of the target fish species? A principal coordinates analysis indicated that fishing activities followed a clear seasonal pattern characterized by alternating habitat and species. Cross-correlation analyses indicated the existence of positive effects caused by mean water levels on fish catches roughly two or three years later. The lag of such water level effects on fish catches was proportional to species longevity, being 22 months for short-lived species with a mean age at catch of 21 months, 26 months for medium-lived species with a mean age at catch of 27.2 months, and 42 months for short-lived species with a mean age at catch of 33.7 months. The results of this study highlight the large seasonal and annual variability of tropical river-floodplain fisheries, and underscore the dependence of fish catches on natural river hydrological cycles. Because these fisheries are suffering increasing exploitation pressures, conservation measures are necessary to protect the hydrology of Amazonian rivers.

The shrimps Penaeidae represent one of the most frequent and exploited fishery resources in coastal regions worldwide. In the estuaries of the north coast of Brazil they are caught, even when juveniles, by artisanal fisheries and mostly serving local markets. The objective of this study was to determine the composition, abundance and spatio-temporal distribution of species of Penaeidae shrimp caught in the Curuca estuary, State of Para, north coast of Brazil. The samples were collected every two months from July 2003 to July 2004 in eight sampling sites using an otter trawl net when the tide was ebbing. Two profiles were selected to study this area: Muria tidal creek and the Curuca River, with four sampling points in each site. A total of 6,158 Penaeidae shrimps, belonging to three species, were obtained. Farfantepenaeus subtilis was the dominant species with 78.5% of the total of shrimps, followed by Litopenaeus schmitti and Xiphopenaeus kroyeri that corresponded to 11.5 and 9.8%, respectively. The highest density of F. subtilis and X. kroyeri was obtained during the rainy season (p

The objective of this study was to document the structure of the fish assemblages found in the aquatic environments affected by the Coaracy Nunes hydroelectric reservoir in Ferreira-Gomes, Amapa (B...

Urbanization causes environmental impacts that threaten the health of aquatic communities and alter their recovery patterns. In this study, we evaluated the diversity of intertidal fish in six areas affected by urbanization (areas with native vegetation, deforested areas, and areas in process of restoration of vegetation) along an urban waterfront in the Amazon River. 20 species were identified, representing 17 genera, 14 families, and 8 orders. The different degrees of habitat degradation had a major effect on the composition of the fish fauna; the two least affected sectors were the only ones in that all 20 species were found. Eight species were recorded in the most degraded areas. The analysis revealed two well-defined groups, coinciding with the sectors in better ecological quality and degraded areas, respectively. The native vegetation has been identified as the crucial factor to the recovery and homeostasis of the studied ecosystem, justifying its legal protection and its use in the restoration and conservation of altered and threatened environments. These results reinforce the importance of maintaining the native vegetation as well as its restoration in order to benefit of the fish populations in intertidal zones impacted by alterations resulting from inadequate urbanization.

Floodplains comprise a complex mosaic of seasonally-flooded forests, lakes and channels that support productive fisheries. These habitats and their fish populations are increasingly threatened by a variety of human pressures, including floodplain deforestation. However, the effects of multiple human pressures on these floodplain fisheries have not been studied in the Amazon River. Here, we investigated the combined effects of forest cover, river water level, fishing effort and distance from nearest urban center on the catch of the most exploited fish taxa. Our study integrated fisheries, hydrological, geographical, and satellite land cover change data for 21 floodplain lake systems over a ten-year period. We found that an ANCOVA model explained 91% of the variation in catch (p

The capture of ornamental fish is an important economic activity in Brazil. Most (79 %) of the live aquarium fish exported from this country are captured in the Amazon region, in particular in the basins of the Negro, Xingu, and Tapajos rivers. The capture of ornamental fish in the Xingu basin is now under threat from the impacts caused by the construction of the Belo Monte hydroelectric dam, which has resulted in habitat loss and changes in the river’s hydrological cycle. An economic assessment of this fishery is needed to determine the magnitude of the possible impacts for the fishers over the long term. The present study estimated the costs and profitability of the fisheries that target ornamental species prior to the impoundment of the river, based on the records of the catches and economic income of 36 vessels. The results were positive, indicating that this activity was economically viable at that time. The harvesting of ornamental fish requires a mean initial investment of US$ 2,640.14, with a net profitability of 28.63 % for wooden canoes and 18.47 % for aluminum boats, providing the fishers with a net income of US$16.80 per fishing day. However, this income is extremely unstable due to the fluctuations in the capturability of the target species over the course of the year, and unpredictable oscillations in the demand for the most commercially valuable species. The predicted changes in the hydrological systems following the construction of the dam will likely result in a decrease in the economic yield of the fishery. Studies of this type are fundamentally important for the establishment of effective public policies for the fishery sector, and the mediation of socio-environmental impacts in the Amazon region.

Amazonian fisheries in Brazil contribute to the food security of over 20 million people who are mostly poor. However, multiple examples suggest that freshwater fish stocks may be under the same overfishing threats observed in marine fisheries, in addition to all the risks imposed by infrastructure development projects. While such threats may push some of these vulnerable people to the edge as some fisheries collapse, others will be pushed toward makeshift or elaborated solutions which can help them to maintain or restore local fisheries. In this chapter, we first adopt a theoretical approach to explore the main threats to Amazonian small-scale fisheries and their direct impacts on people’s livelihoods. We then move on to an empirical solution-based comparison between different types of co-management initiatives, using case studies developed within a protected area framework and community-based arrangements. We expect to show how small-scale fishers themselves can be the best, and sometimes the only, alternative for management. The different kinds of management broaden the application of eventual patterns, discrepancies, limitations, and solutions identified for Amazon to inland fisheries.

The tropics contain the overwhelming majority of Earth's biodiversity: their terrestrial, freshwater and marine ecosystems hold more than three-quarters of all species, including almost all shallow-water corals and over 90% of terrestrial birds. However, tropical ecosystems are also subject to pervasive and interacting stressors, such as deforestation, overfishing and climate change, and they are set within a socio-economic context that includes growing pressure from an increasingly globalized world, larger and more affluent tropical populations, and weak governance and response capacities. Concerted local, national and international actions are urgently required to prevent a collapse of tropical biodiversity.

The present study characterises the commercial fisheries of the basin of the Xingu River, a major tributary of the Amazon River, between the towns of Gurupá (at the mouth of the Amazon) and São Félix do Xingu. Between April, 2012, and March, 2014, a total of 23,939 fishing trips were recorded, yielding a total production of 1,484 tons of fish, harvested by almost three thousand fishers. The analysis of the catches emphasizes the small-scale and artisanal nature of the region’s fisheries, with emphasis on the contribution of the motorised canoes powered by “long-tail” outboard motors. Larger motorboats operate only at the mouth of the Xingu and on the Amazon. Peacock bass (Cichla spp.), croakers (Plagioscion spp.), pacu (a group containing numerous serrasalmid species), aracu (various anostomids), and curimatã (Prochilodus nigricans) together contributed more than 60% of the total catch. Mean catch per unit effort was 18 kg/fisher–1.day–1, which varied among fishing methods (type of vessel and fishing equipment used), river sections, and time of the year. In most cases, yields varied little between years (2012 and 2013). The technical database provided by this study constitutes an important resource for the regulation of the region’s fisheries, as well as for the evaluation of future changes resulting from the construction of the Belo Monte dam on the Xingu River. Resumo Este trabalho teve como objetivo caracterizar a pesca comercial de consumo na bacia do rio Xingu, afluente do rio Amazonas, no trecho entre a cidade de Gurupá (localizada na foz do Rio Amazonas) até São Félix do Xingu, no estado do Pará, Brasil. No período de abril de 2012 a março de 2014 foram registradas 23.939 viagens de pesca, totalizando uma produção de 1.484 toneladas de pescado, obtidas por quase 3.000 pescadores. A análise dos dados oriundos do monitoramento dos desembarques demonstrou que a pesca na região tem caráter artesanal de pequena escala, destacando-se a participação de canoas motorizadas que utilizam um motor de popa chamado “rabeta”. Os barcos motorizados atuam somente na foz do rio Xingu e no rio Amazonas. Tucunaré (Cichla spp), pescada-branca (Plagioscion spp), pacu (várias espécies de Serrasalmidae), aracu (várias espécies de Anostomidae) e curimatã (Prochilodus nigricans) perfazem mais de 60% do total capturado. A captura média por unidade de esforço é de 18 kg.pescador–1.dia–1 e muda dependendo da modalidade de pesca (tipo de embarcação e arte de pesca), do pesqueiro utilizado e da época do ano. Na maior parte dos casos, não encontramos diferenças nos rendimentos de 2012 e 2013. As informações técnicas geradas são importantes para subsidiar ações de ordenamento pesqueiro, bem como para avaliar futuras mudanças que possam ocorrer na atividade frente à construção da barragem de Belo Monte no Rio Xingu.

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. Resumo Este 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.

Major hydroelectric dams are proliferating in tropical regions such as Amazonia, where extensive new hydropower developments are planned despite potentially severe ecological and social impacts. The status of freshwater biota in the vicinity of existing dams could be valuable to predict the effects of such developments, but detailed ecological monitoring before and after dam construction is frequently lacking. In the absence of these data, we used a space-for-time replacement to compare a key component of the aquatic biota at upstream and downstream sites, with the latter more closely resembling river channel conditions prior to the dam. We assessed the fish assemblages upstream and downstream of the Coaracy Nunes Dam in Amapa, Brazil, the first ecological study at this site since this dam was constructed 42 years earlier. We used gillnets during eight bimonthly field campaigns, covering both wet and dry seasons, and sampled the ichthyofauna (1819 individuals, 81 species) at four sites: Downstream Channel, Reservoir, Upstream Lake and Upstream Channel. We found clear negative impacts on the abundance, biomass, species richness, alpha diversity and species dominance upstream of the dam. The physical subdivision of the river channel and the upstream channel conversion from lentic to lotic habitats were strongly associated with differences in the composition and structure of fish communities. Notable changes include an increased contribution of small-bodied fish in the reservoir and an absence of long-distance migrants upstream of the dam. Downstream channel habitats, in particular, retained their fish diversity with high conservation value typical of eastern Amazonia, yet these areas now face the threat of new hydropower development farther downstream. The long-term impacts on aquatic biodiversity highlighted in this study are especially relevant in the face of burgeoning new hydroelectricity development plans for rivers across lowland Amazonia.

The exploitation of resources by closely related species with similar niches may be mediated by differences in activity patterns, which may vary in nycthemeral scale and seasonal scale. Piranhas Serrasalmus gibbus and Serrasalmus rhombeus are Neotropical predators that occur sympatrically in many environments of the Amazon basin. To evaluate the strategies adopted by these two species in a restricted environment (a reservoir), nycthemeral and seasonal samples were made, identifying the composition of the diet and their activity patterns. A total of 402 specimens were collected: 341 S. gibbus and 61 S. rhombeus. Both species fed themselves primarily on fish, with some seasonal variation being found in S. gibbus during the flood season, when plant material was consumed. There was considerable temporal overlap in the foraging behavior of the two species, although S. rhombeus presented a bimodal pattern of abundance over the 24-hour cycle. S. rhombeus was more active during the nighttime, between dusk and early morning, whereas S. gibbus was active throughout the nycthemeral cycle. These findings indicate low levels of competition between the two species, which allowed for a considerable overlap in nighttime foraging, following distinct nycthemeral patterns of foraging activity and allowing their coexistence.

O objetivo deste trabalho foi analisar a dieta de Ageneiosus ucayalensis do reservatório da Usina Hidrelétrica Coaracy Nunes, no município de Ferreira Gomes/AP. As amostragens foram feitas bimestralmente em três estações de coleta na área do reservatório entre julho/2009 e julho/2010. As coletas foram realizadas utilizando redes de espera, organizadas em baterias com sete redes cada e diferentes distâncias entre nós. Após a captura, foi realizada a biometria dos exemplares, sendo seus estômagos retirados, fixados e conservados para análise em laboratório. A proporção sexual foi realizada no intuito de verificar se houve diferença significativa entre os sexos. Os itens alimentares do conteúdo estomacal foram agrupados em categorias amplas e analisados através dos métodos de frequência de ocorrência e volumétrico, combinados no Índice de Importância Alimentar (IAi), por período sazonal. Os resultados evidenciaram que a proporção entre os sexos foi de 1:1, com uma leve predominância de fêmeas. Quanto à alimentação, a espécie mostrou-se carnívora, com a dieta baseada principalmente em microcrustáceos, crustáceos, peixes e material não identificável. Variações sazonais na dieta não foram nítidas e, provavelmente, estão relacionadas tanto à disponibilidade das presas na área quanto à manipulação do nível da água do reservatório pelo controle de comportas. Palavras-chave: alimentação, UHE, peixes, Siluriformes, IAi. DOI: http://dx.doi.org/10.18561/2179-5746/biotaamazonia.v4n3p73-82

In order to provide guidelines for the management of fish stocks in artificial reservoirs in the Amazon region, the present study analyzed the composition and structure of the fish communities of four sectors (upstream, lake, reservoir, and downstream) of the area affected by the Coaracy Nunes hydroelectric reservoir on the Araguari River in the Brazilian state of Amapa. Variation in ecological parameters was analyzed in the context of the impacts suffered since the damming of the river approximately 40 years ago. Standardized samples of fish were collected in gillnets during eight campaigns in 2009 and 2010. Abundance and biomass were initially evaluated by Analysis of Variance (ANOVA), and lognormal, log-series, geometric series, and broken stick models were then calculated. The K-dominance and Abundance-Biomass (ABC) curves were also analyzed, together with the size-spectrum of the specimens. The results indicated that the sector downstream from the dam had the highest species richness, and was most consistent with the broken stick model. The ABC and K-dominance analyses also confirmed that this sector was the most balanced, in ecological terms. The lake sector had the only community that fitted the geometric series model, and all the analyses indicated a predominance of small individuals, typical of impacted communities. The analyses of the reservoir sector indicated a disturbed environment, whereas the upstream sector was characterized by a more balanced community, reflecting its greater resilience to the impacts caused by the reservoir, and its potential of this area for the conservation of local fish communities. The results also confirmed the applicability of the analytical tools employed for the study of fish communities in reservoir environments.

O reservatório da UHE Coaracy Nunes, no Estado do Amapá, Brasil é o mais antigo da Amazônia e foi construído com fins de produção de energia elétrica. O objetivo deste trabalho foi investigar a pesca no reservatório de Coaracy Nunes e adjacências, descrevendo a produção pesqueira, as espécies de peixes de maior interesse e os aspectos sócio-econômicos dos pescadores. A metodologia utilizada foi fundamentada em questionamentos feitos diretamente a 53 pescadores utilizando formulários específicos que continham perguntas sobre os aspectos sócio-econômicos dos pescadores e sobre a pesca. Os resultados revelaram que a pesca na área de estudo é uma atividade de subsistência, mas com tendências à pesca artesanal. A principal arte de pesca empregada é a rede de espera, seguida de zagaia e arpão subaquático e anzol. A composição ictiofaunística da pesca estava composta de 13 espécies, com destaque, em termos de biomassa, para Cichla sp., Hoplias macrophthalmus, Tometes trilobatus e Leporinus sp., que juntos compuseram 47,55% da pesca total. A produção pesqueira foi considerada baixa comparada a de outros reservatórios mais recentes. Pescadores residentes há mais de 50 anos na região afirmam que no período pré-barramento do rio existia notável abundância de espécies de grande porte, o que sugere que o barramento do rio e a pesca foram os principais fatores na eliminação e redução dos estoques de algumas espécies na área do reservatório. Palavras-chave: rio Araguari, pesca de subsistência, produção pesqueira, recursos pesqueiros. DOI: http://dx.doi.org/10.18561/2179-5746/biotaamazonia.v3n3p83-96

To contribute to mass balanced trophic model parametrization, estimates of annual food consumption/biomass ratio (Q/B) were compiled for 37 selected fish species of the Curuçá Estuary in Northern Brazil using an empirical model. Samples were taken bimonthly between July 2003 and July 2004 in the main channel and intertidal creeks using an otter trawl and a fyke net, respectively. The aspect ratio of the caudal fin varied between 0.8 for Poecilia vivipara and 4.6 for Sciades herzbergii and the Q/B ranged from 2.3 for Epinephelus itajara to 67.3 for Cetengraulis edentulus. This study represents the first reference available on Q/B values of 29 fish species. This compilation of Q/B ratio presented here should be useful for construction of Ecopath models particularly in tropical conditions. Keywords: consumption/biomass; aspect ratio; trophic models; Ecopath. DOI: http://dx.doi.org/10.18561/2179-5746/biotaamazonia.v3n2p149-154

The stomach contents of 172 individuals of Hypostomus plecostomus and 94 specimens of Hypostomus emarginatus from the Coaracy Nunes reservoir in northern Brazil were analyzed in order to evaluate the feeding ecology of the two fish species from this site. Data were collected in eight campaigns conducted every two months between May, 2010 and July, 2011, four in the dry season and four during the flood period. The analysis of the stomach contents was based on the volumetric frequency (VF%) and frequency of occurrence (FO%), combined with the feeding index (FI). Nine different dietary items were identified: detritus, plant fragments, zooplankton, arthropods, chlorophytes, bacillariophytes, cyanobacteria, dinophytes, and unidentified material. Detritus was the principal component of the diet during both seasons, with all the other items representing only complementary or accidental portions of the diets of both species. Niche breadth was low overall, but slightly greater in H. plecostomus in comparison with H. emarginatus. Niche overlap was accentuated in both seasons, which indicates that seasonality is not a major factor influencing the characteristics of the niches of these species, possibly because of the marked abundance of detritus in the study area, specifically in the impounded sector. The two species can be characterized as detritivores, which share dietary resources with no clear evidence of any negative effects of interspecific competition on the coexistence of the two populations. Keywords: feeding ecology, niche breadth, Araguarí river, Amazonia. DOI: http://dx.doi.org/10.18561/2179-5746/biotaamazonia.v3n2p116-125

This paper aims to describe the spatial-temporal variability in catch of the main fishery resources of the Amazon River and floodplain lakes of the Lower Amazon, as well as relating the Catch per Unit of Effort with anomalies of some of the Amazon River, atmosphere and Atlantic Ocean system variables, determining the influence of the environment on the Amazonian fishery resources. Finfish landings data from the towns and villages of the Lower Amazon for the fisheries of three sites (Óbidos, Santarém and Monte Alegre), were obtained for the period between January 1993 and December 2004. Analysis of variance, detrended correspondence analysis, redundancy analysis and multiple regression techniques were used for the statistical analysis of the distinct time series. Fisheries production in the Lower Amazon presents differences between the Amazon River and the floodplain lakes. Production in the Amazon River is approximately half of the one of the floodplain lakes. This variability occurs both along the Lower Amazon River region (longitudinal gradient) and laterally (latitudinal gradient) for every fishing ground studied here. The distinct environmental variables alone or in association act differently on the fishery stocks and the success of catches in each fishery group studied here. Important variables are the flooding events; the soil the sea surface temperatures; the humidity; the wind and the occurence of El Niño-Southern Oscillation events. Fishery productivity presents a large difference in quantity and distribution patterns between the river and floodplain lakes. This variability occurs in the region of the Lower Amazon as well as laterally for each fishery group studied, being dependent on the ecological characteristics and life strategies of each fish group considered here.

A pesca artesanal na costa Norte do Brasil é caracterizado por um conjunto de modalidades de pesca diferentes. Utilizando uma abordagem multidisciplinar, 20 sistemas de produção pesqueira foram identificados, com características distintas em relação à tecnologia e finalidade. As características de cada sistema foram classificados em cinco dimensões (ecológicas, económicas, sociais, tecnológicos e políticos). A análise de escalonamento multidimensional revelou que alguns destes 20 sistemas têm semelhanças maiores. Assim, um total de 10 grupos distintos foram identificados. Artisanal fishing on the northern coast of Brazil is characterized by a set of different fishery modalities. Using a multidisciplinary approach, 20 fishery production systems were identified, with distinct characteristics regarding technology and purpose. The characteristics of each system were classified into five dimensions (ecological, economic, social, technological and political). Multidimensional scaling revealed that some of these 20 systems have greater similarities. Thus, a total of 10 groups were identified.

Rhinoclemmys punctularia punctularia is a semi-aquatic chelonian found in Northern South America. We analyzed the habitat use, size structure and sex ratio of the species on Algodoal-Maiandeua Island, a protected area on the Northeastern coast of the Brazilian state of Pará. Four distinct habitats (coastal plain lake, flooded forest “igapó”, interdunal lakes, and tidal channels) were surveyed during the rainy (March and April) and dry (August and September) seasons of 2009, using hoop traps. For the analysis of population structure, additional data were taken in March and August, 2008. A total of 169 individuals were captured in flooded forest (igapó), lakes of the coastal plain and, occasionally, in temporary pools. Capture rates were highest in the coastal plain lake, possibly due to the greater availability of the fruits that form part of the diet of R. p. punctularia. Of the physical-chemical variables measured, salinity appeared to be the only factor to have a significant negative effect on capture rates. The sex ratio was only slightly biased to females, and did not vary between habitats or seasons. Straight carapace length was significantly larger in females, but did not vary between habitats. Overall, the evidence indicates that both biotic and abiotic factors like food availability, low current and salinity, influence the habitats selection and use by R. p. punctularia on Algodoal-Maiandeua Island.Rhinoclemmys punctularia punctularia es un quelonio semi-acuático, con amplia distribución geográfica. El presente trabajo analiza la densidad relativa, proporción sexual y el uso de hábitat de esta especie en la isla de Algodoal-Maiandeua, en el litoral Norte de Brasil. Cuatro hábitats distintos fueron muestreados durante los períodos de lluvias y seco de 2009, en donde se utilizaron trampas de aro. Muestras de 2008 (marzo-agosto) también se emplearon para el análisis de la estructura de la población. Asimismo, fueron encontrados 169 ejemplares en el bosque inundado, lagunas de tierras bajas y, ocasionalmente, en lagunas temporales. Las tasas de captura fueron más altas en las lagunas costeras, posiblemente debido a la mayor disponibilidad de frutos, que sirven de alimento para esta especie. De las variables físico-químicas, la salinidad fue el único factor que se correlaciona inversamente con las tasas de captura. La proporción de sexos fue ligeramente superior en las hembras, pero no varió entre los hábitats o período del año. El tamaño promedio de los individuos fue mayor en las hembras, pero no varió entre hábitats. Los factores ambientales, como la disponibilidad de alimentos, la baja salinidad y la poca corriente, probablemente hayan favorecido la selección y el uso de estos hábitats por R. p. punctularia.

Data on macrofauna density and diversity, and the height and density of Spartina brasiliensis, were obtained from salt marsh beds of a tropical estuary in northern Brazil. Sampling was carried out at four distinct times of the year, during the wet and dry seasons and in the transition periods between these. Sampling was also carried out in salt marshes of three size classes, small, medium and large. Variables were analyzed in relation to time of year and salt marsh size class. Overall, 46 taxa were found, with polychaetes, isopods and the gastropod Neritina virginea dominating the fauna. Macrofauna density and diversity were positively correlated with culm density, indicating a possible role in protection from predation. All the three variables were higher during the transitional periods between the wet and dry seasons and seasonal changes in rainfall, salinity and light availability may influence mortality, food availability and settlement of the macrofauna. There was no effect of salt marsh size on either the macrofauna or the vegetation.Dados sobre a densidade e diversidade da macrofauna em relação à altura e densidade de Spartina brasiliensis foram obtidos em bancos de marismas em um estuário tropical no norte do Brasil. A amostragem foi realizada quatro vezes durante um ano, nas estações chuvosa, seca e nos períodos de transição entre estas. A amostragem foi realizada em marismas de três classes de tamanho: pequeno, médio e grande. As variáveis foram analisadas em relação às estações do ano e das classes de tamanho das marismas. Um total de 46 táxons foram encontrados, com os poliquetos, isopodos e o gastropódo Neritina virginea dominando a fauna, resultados similares a estudos realizados em marismas no sul do Brasil. A densidade e a diversidade da macrofauna foram correlacionadas positivamente com a densidade de colmos da vegetação, indicando um possível papel da vegetação em proteção contra predação. Todas as três variáveis foram maiores durante os períodos transicionais entre as estações chuvosa e seca e mudanças sazonais em precipitação, salinidade e disponibilidade de luz possam influenciar mortalidade, disponibilidade de alimento e assentamento da macrofauna. Não houve um efeito de tamanho da marisma sobre a macrofauna ou a vegetação. O efeito beneficial da vegetação sobre a macrofauna é apoiado por outros estudos de marismas brasileiras.

Summary The performance of 20 fishery production systems off the state of Para in the northern region of Brazil was compared using the ‘RAPFISH’ methodology, with 57 identified attributes distributed among five evaluation fields: economics, sociology, ecology, technology and politics. The results indicated the existence of three large groups of fishery sectors: (i) industrial (red snapper with traps, the Laulao catfish, shrimp trawl) and semi-industrial (lobster) fisheries; (ii) large-scale artisanal fisheries (acoupa weakfish, red snapper with lines, king mackerel, Spanish mackerel, coco sea catfish); and (iii) small-scale artisanal fisheries (shellfish, crab, estuarine longline, fish traps, etc.). While the industrial and large-scale artisanal systems demonstrated greater sustainability from an economic and social standpoint, small-scale fisheries appeared to be more ecologically sustainable. Based on the results, a reduction in industrial fishing efforts is recommended, along with the establishment of licensing quotas for fishing vessels, as well as an increased investment in research on proper guidance and management of the semi-industrial and large-scale artisanal fisheries sectors. For small-scale artisanal fisheries, economic incentives are suggested for the aggregate value of the products and to assist fishers in the development of an appropriate social organization. Finally, it is believed that a greater stakeholder involvement in the decision-making process would improve management actions for all modalities.