Abstract. The long-term impacts of large hydroelectric dams on small-scale fisheries in tropical rivers are poorly known. A promising way to investigate such impacts is to compare and integrate the local ecological knowledge (LEK) of resource users with biological data for the same region. We analyzed the accuracy of fishers' LEK to investigate fisheries dynamics and environmental changes in the Lower Tocantins River (Brazilian Amazon) downstream from a large dam. We estimated fishers' LEK through interviews with 300 fishers in nine villages and collected data on 601 fish landings in five of these villages, 22 years after the dam's establishment (2006)(2007)(2008). We compared these two databases with each other and with data on fish landings from before the dam's establishment (1981) gathered from the literature. The data obtained based on the fishers' LEK (interviews) and from fisheries agreed regarding the primary fish species caught, the most commonly used type of fishing gear (gill nets) and even the most often used gill net mesh sizes but disagreed regarding seasonal fish abundance. According to the interviewed fishers, the primary environmental changes that occurred after the impoundment were an overall decrease in fish abundance, an increase in the abundance of some fish species and, possibly, the local extinction of a commercial fish species (Semaprochilodus brama). These changes were corroborated by comparing fish landings sampled before and 22 years after the impoundment, which indicated changes in the composition of fish landings and a decrease in the total annual fish production. Our results reinforce the hypothesis that large dams may adversely affect small-scale fisheries downstream and establish a feasible approach for applying fishers' LEK to fisheries management, especially in regions with a low research capacity.

Analysis of Brazilian fishers' classifications of 24 marine (Atlantic coast) and 24 freshwater (Amazon) fish species reveals that fishers from the Atlantic coast identify fish mainly through generic names (primary lexemes), while riverine Amazonian fishers typically identify them through binomials. The similarity of Amazonian fish species seems to contribute to the detailed folk taxonomy used by riverine fishers. Highranking groups called "relatives" or "cousins" are sorted by fishers in terms of similarities of habitat, diet, and morphology and, secondarily, behavior. The general correspondence between the folk and scientific taxonomies reinforces the reality of both the supracategories used by these fishers and the biological groups as discontinuities in nature. Given the urgency of biological inventories and the lack of knowledge of high-biodiversity environments such as the Atlantic Forest and the Amazon, these results suggest that fisher knowledge and experience could contribute to scientific research. The reality of species has been the subject of debate since the early days of evolutionary biology. Darwin defined species as varieties that are well demarcated and defined and actually exist at a certain point in time, but his analysis left open the possibility that species might be arbitrary constructions of the human mind (Darwin 1859a [1982], 1859b; Coyne and Orr 2004). The term "species" is vague because it includes both

Interdisciplinary research and collaborations are essential to disentangle complex and wicked global socio-ecological challenges. However, institutional structures and practices to support interdisciplinary research are still developing and a shared understanding on how best to develop effective interdisciplinary researchers (particularly at early career stages) is lacking. Barriers to interdisciplinary approaches, which include diverse disciplinary 'languages', research time constraints and limited guidance on how to achieve interdisciplinarity in practice, further challenge this understanding. To help overcome these barriers, this paper provides practical advice for early career researchers and their mentors, as well as senior researchers and lab leaders, in the form of 10 tips: 'Develop an area of expertise'; 'Learn new languages'; 'Be open-minded'; 'Be patient'; 'Embrace complexity'; 'Collaborate widely; 'Push your boundaries'; 'Consider if you will engage in interdisciplinary research'; 'Foster interdisciplinary culture'; and 'Champion interdisciplinary researchers'. They are presented here to empower present and future generations of interdisciplinary researchers in their endeavour to solve contemporary socioecological challenges worldwide.

No abstract

Artisanal fisheries are of great importance in Brazil, as they are responsible for more than 50% of national fish production. This importance, associated with the necessity of conserving marine environments threatened by multiple competing uses, leads us to propose mechanisms for co-management of fisheries by users and public authorities. This proposal takes into account: a) local conflicts between artisanal and industrial fishers; b) local rules over the use of fishing areas established by artisanal fishers; c) the advent of protected areas that close access to some fishing areas used by artisanal fisheries; and d) co-management options being explored between government and fishers. This study suggests policy and technical alternatives under consideration to manage the artisanal fisheries of southeastern Brazil with a focus on Ilha Grande bay in Rio de Janeiro. In our case study, based on field research conducted in 2009, we show that artisanal fishers are squeezed into a marine space between protected areas and industrial fishing. We suggest that a combination of fishing agreements (FAs), based on experience in Amazonian fisheries and extractive reserves, and payment for environmental services (PES), based on forest and related water resource experience, could improve management and livelihoods for local artisanal fisheries by stimulating and rewarding fishers who participate in conservation efforts. The two instruments (FAs and PES) are the subject of considerable research and practical experience. Their integration in an instrument mix represents a contribution from transdisciplinary fields of human ecology and ecological economics.

No abstract

No abstract

No abstract