Basin-scale planning is needed to minimize impacts in mega-diverse rivers

Studies investigating the local ecological knowledge (LEK) held by fishermen about the fishing resources have indicated that fishermen's LEK may have the potential to improve fishery management, by providing new information about the ecology, behavior and abundance trends of fish and other aquatic animals. Our major aim is to undertake a brief review of published ethnoichthyological studies with a focus on coastal Brazilian fisheries and freshwater fisheries in both Brazil and Southeast Asia. Based on such review, we provide 29 hypotheses on fish ecology based on fishermen's LEK and compare them with what is already known from the biological literature, using an arbitrary 'likelihood' measure: ''Low likelihood'' corresponded to unexpected hypotheses, which contradict existing biological data. ''Medium likelihood'' corresponded to hypotheses that could not be compared to available scientific knowledge. Hypotheses that agree with scientific data were considered as ''High likelihood''. We therefore discuss these three categories of hypotheses about several distinct topics, such as migration, reproduction, feeding habits, abundance patterns, ecological relationships between fish and their predators, and fishing pressure. Our results may contribute to the fisheries management and research in the studied regions and other similar places, besides raising the interest of biologists to properly include fishermen's LEK when planning and conducting fisheries surveys.Keywords Amazon Basin Á Brazilian coast Á Ethnobiology Á Fish ecology Á Fisheries management Á Human ecology Á Mekong River Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.

Fishermen's local knowledge of fishing resources may be an important source of information to improve artisanal tropical fisheries management, such as those found in Brazil, where most data on fish biology is lacking. We aim to study the local ecological knowledge that Brazilian coastal fishers have about reproductive aspects (season, places and migration) of 13 coastal fish species of commercial importance. We selected fishermen with more than 30 years of fishing practice and we interviewed a total of 67 fishermen: 29 from the southeastern coast, from the communities of Puruba, Almada, Picinguaba and Bertioga, and 38 from the northeastern coast, from the communities of Valença, Arembepe and Porto Sauípe. In the interviews, we used standardized questionnaires and showed photos of fish species. Our results indicate some general patterns in fishes' reproduction according to fishermen knowledge: fish species spawn in open ocean, near reefs or in coastal rivers (estuaries); some fishes reproduce during the summer and others in winter, while some have more defined spawning months. The main fish migratory patterns mentioned by interviewees were: long migrations along the coast, usually in the South to North direction, short migrations among reefs, fishes that do not migrate, migrations between the shore and open ocean and migrations between the sea and coastal rivers. Fishermen's knowledge differed among fish species: most fishermen did not know spawning places or seasons of large pelagic fishes, which raised concerns of their possible depletion. We compared such ethnoichthyological information with available scientific data, indicating promising insights about reproduction and migration of Brazilian coastal fishes. Data gathered from local fishermen may provide inexpensive and prompt information, potentially applicable to fisheries management. Our approach might be useful to several other small-scale fisheries, especially the tropical ones, where there is a high diversity of target species and a low biological and ecological knowledge about these species.

Dusky grouper (garoupa, Epinephelus marginatus) is an important catch for several artisanal smallscale fisheries along the Brazilian coast. It is a sedentary, monandric, and late maturing protogynous species, which makes it vulnerable to overharvesting even though it is mainly caught through hook and line or spear fishing through free diving. Lack of information on the ecology and biology of this species in Brazil is astonishing. Much of the information found in the literature concerns Mediterranean dusky groupers. Studies compiling local knowledge (ethnoecology) about fish species complement biological data, and have been fundamental for effective fisheries management. In this study, our objectives are to obtain data about dusky grouper through fish catches and analysis of stomach contents and gonad maturation (macroscopic analyses), along with interviews from fishermen from six small-scales communities from the southern (Pântano do Sul, Florianópolis, Santa Catarina State) to the northern Brazilian coast (Porto Sauípe, Bahia State). We conclude that precautionary approaches and 'data-less' management approaches are needed in the coast of Brazil. Research on this species and on the potential of aquaculture for its cultivation, are urgent, due to the apparent vulnerability and decrease of dusky grouper along the coast of Brazil.

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.

We analyzed fishermen's local ecological knowledge (LEK) about the feeding habits, trophic interactions, habitats, fishing grounds, migration, and reproduction of nine coastal fishes in Búzios Island, southeastern Brazilian coast. We interviewed 39 fishermen using standardized questionnaires. Fishermen's LEK on habitat use and trophic interactions for the studied fishes agreed with the scientific literature, allowing the organization of reef and pelagic food webs. The interviewed fishermen mentioned that submerged rock formations would be important habitats for some large commercial fishes, such as Seriola spp., Caranx latus and Epinephelus marginatus. In some instances there was no scientific data to be compared with fishermen's LEK, and thus this kind of knowledge would be the only available source of information, such as for reproduction and migration of most of the studied fishes. We suggest herein ways to apply fishermen's LEK to develop and improve fisheries management measures, such as zoning of marine space, marine protected areas, and closed fishing seasons. Fishermen's LEK may be an important and feasible support to fisheries management and co-management.Analisamos o conhecimento ecológico local (CEL) dos pescadores sobre os hábitos alimentares, interações tróficas, habitats, locais de pesca, migração e reprodução de nove peixes costeiros na Ilha de Búzios, litoral sudeste do Brasil. Entrevistamos 39 pescadores, utilizando questionários padronizados. As informações sobre uso do habitat e interações tróficas entre os peixes estudados com base no CEL dos pescadores foram condizentes com a literatura científica, permitindo a organização de teias tróficas para os habitats recifal e pelágico. Os pescadores entrevistados mencionaram que formações de rochas submersas seriam habitats importantes para alguns peixes comerciais de grande porte, como Seriola spp., Caranx latus e Epinephelus marginatus. Em algumas circunstâncias, não haviam dados biológicos para serem comparados com o CEL dos pescadores, que, portanto seria a única fonte disponível de informação, por exemplo sobre a reprodução e migração de vários dos peixes estudados. Sugerimos aqui formas de aplicar o CEL dos pescadores para desenvolver e aprimorar medidas de manejo pesqueiro, como zoneamento do espaço marinho, áreas marinhas protegidas e épocas de defeso da pesca. O CEL dos pescadores pode ser um apoio importante e factível para iniciativas de manejo e co-manejo pesqueiro.

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

Bluefish (Pomatomus saltatrix) has a worldwide distribution, being targeted by fishers all along its range, which includes the Brazilian coast. We formulated and checked hypotheses regarding bluefish diet, migration, and reproduction based on fishers' local ecological knowledge (LEK). We interviewed 49 experienced fishers (40 years and older) from five communities along the Brazilian coast and analyzed the diet and reproduction of 185 fish. According to fishers' LEK, the bluefish spawn mainly during the winter, migrate throughout year (from the South to North), and eat mainly small fish (Clupeidae and Engraulidae), plus shrimp and squid. The biological survey confirmed the hypothesis on bluefish diet (78% of fish with stomach contents had fish in their stomachs) but not that on reproduction: we observed larger fish and more fish with visible eggs during summer and autumn. Migratory movements mentioned by fishers agreed with literature data. Besides providing data to support conventional management decisions in the absence of biological surveys, our results and approach could help involve fishers in management, thus contributing to development of co-management systems more suitable to local conditions and to complex tropical fisheries.