The use of optimal foraging theory in the understanding of fishing strategies: A case from Sepetiba Bay (Rio de Janeiro State,Brazil)

The community of Gamboa is located on Itacuruçá Island, Sepetiba Bay (State of Rio de Janeiro, Brazil) and includes 26 families, mostly of artisanal fishermen who use paddled or motor canoes, and encircling nets for fishing. In this study, predictions from optimal foraging theory (patch model), in particular of patch residence time, are compared to the observed behavior of fishermen on fishing trips. Fishermen's strategies differ depending on their intended prey. They spend more time in patches and use fewer patches for shrimp than for fish. Gamboa's fishermen tend to leave a patch later than predicted by the model. The difficulty in evaluating stock availability, the comparatively few patches available for shrimp, and the competitive aspects of fishing contribute to the explanation of this behavior.     

Ethnobotany of Atlantic Forest coastal communities: Diversity of plant uses in Gamboa (Itacuruçá island,Brazil)

Local plants are a very important resource for the community of Gamboa, located at Itacuruçá Island, Sepetiba Bay, State of Rio de Janeiro, Brazil Ninety species of plants, belonging to 40 families, are used for a variety of purposes, such as food, construction, handicraft, and medicine. In a survey medicinal uses for plants were the most quoted by the community. Uses of medicinal plants within Gamboa and with other coastal communities are analyzed using diversity indices. Use by different categories of people based on sex, age, and economic activity was compared and significant differences were found among the groups compared, except for economic categories (fishermen and non-fishermen). The theory of island biogeography is shown to be useful for analyzing different levels of resource uses on different islands.     

Fishers' Knowledge Reveals Ecological Interactions Between Fish and Plants in High Diverse Tropical Rivers

Ecosystems - Frugivory and seed dispersal by fish is an important mutualistic interaction in complex and species-rich tropical rivers. The local ecological knowledge (LEK) held by fishers can...     

Fishing spots and sea tenure: Incipient forms of local management in Atlantic forest coastal communities

Recent work has dealt with the local management of aquatic resources as an alternative to Hardin's (1968) tragedy of the commons. In communities with no formal management of resources, informal ownership of fishing spots or conflicts with outside competitors may determine the basis for future local management. In this study, I analyze the use of aquatic resources by five fishing communities on the Atlantic Forest coast of southeast Brazil: Búzios Island, Puruba, and Picinguaba in São Paulo State, and Jaguanum and Itacuruçá Islands at Sepetiba Bay in Rio de Janeiro State. Informal ownership of fishing spots, used for set gillnet fishing, is regulated by kin ties at Búzios Island. The artisanal fishers of Sepetiba Bay, especially those from Jaguanum Island, have a conflict with Bay intruders, such as the shrimp and herring trawlers. Two coastal communities, Puruba and Picinguaba, have conflicts with fishing regulations from a State Park (Parque Estadual da Serra do Mar),created in 1977. The transformation of populated areas of the Atlantic Forest to Extractive Reserves might be a way to avoid conflicts with intruders and with governmental agencies, and to involve local populations in management. Kinship rules at Búzios Island and the territorial behavior of fishers at Sepetiba Bay may form a basis for local organization.     

Medicinal Plants in the Atlantic Forest (Brazil): Knowledge, Use, and Conservation

This study focuses on knowledge of medicinal plants among the Caiçaras (rural inhabitants of the Atlantic Forest coast, Brazil). In particular, we examine the use of medicinal plants according to sex and age to reveal general patterns of Caiçara knowledge and use of plant resources. Data collected through 449 interviews at 12 Caiçara communities (Rio de Janeiro and São Paulo coastal sites) include citations of 249 plants and identification of 227 species. We show the importance of introduced as opposed to native plants and of key individuals for the conservation of the Caiçaras-Atlantic Forest.     

Cell wall proteomics of sugarcane cell suspension cultures

The use of cell walls to produce cellulosic ethanol from sugarcane bagasse is a new challenge. A better knowledge of proteins involved in cell wall remodelling is essential to improve the saccharification processes. Cell suspension cultures were used for this first cell wall proteomics study of sugarcane. Proteins extracted from cell walls were identified using an adapted protocol. They were extracted using 0.2 M CaCl₂ and 2 M LiCl after purification of cell walls. The proteins were then identified by the innovative nanoACQUITY UPLC MS/MS technology and bioinformatics using the translated SUCEST EST cluster database of sugarcane. The experiments were reproduced three times. Since Sorghum bicolor is the closest plant with a fully sequenced genome, homologous proteins were searched for to complete the annotation of proteins, that is, prediction of subcellular localization and functional domains. Altogether, 69 different proteins predicted to be secreted were identified among 377 proteins. The reproducibility of the experiments is discussed. These proteins were distributed into eight functional classes. Oxidoreductases such as peroxidases were well represented, whereas glycoside hydrolases were scarce. This work provides information about the proteins that could be manipulated through genetic transformation, to increase second‐generation ethanol production.     

Co-management and Spatial Features Contribute to Secure Fish Abundance and Fishing Yields in Tropical Floodplain Lakes

Empirical data are needed to show the efficacy of co-management, which is regarded as a promising approach to achieve conservation goals. In this study, we addressed the potential influence of fisheries co-management to increase fish abundance and fishing yields in the lower Tocantins River Basin (Brazilian Amazon), downstream from a large dam. We analyzed 590 fish landings (6.7 t of fish) from five fishing villages and 48 fish samples obtained using gillnets (10,378 fish from 101 species) in 12 floodplain lakes in four regions: two with incipient co-management and two unmanaged. The fish species richness did not differ among the regions, but the lakes in the regions that were co-managed had higher fish abundance (biomass and number of individuals) and a higher mean proportion of fish reproducing during the high water season. Fishers had higher catches per unit of effort in the co-managed regions than fishers in the non-managed regions. These results were also influenced by geographic factors (distance and accessibility of lakes), as fish biomass was higher in lakes that were distant from the main river and from the main city in the region. Managers should thus consider strategic selection of the geographic locations of managed sites, even in remote areas. However, the fish biomass sampled in lakes was more related to region than to the lakes’ geographical location. Therefore, co-management has at least partially contributed to increased fish abundance and fishing yields in the studied region, through the protection of an important fish habitat (lakes). We provide empirical evidence that co-management can contribute to the maintenance of fish abundance, sustainability of fisheries, and food security in large tropical rivers impacted by damming.     

Fishing at Rio Grande (Brazil): Ecological niche and competition

This study is an ecological analysis of the use of resources by two potentially competitive groups, the commercial and recreational fishermen of Rio Grande, located on the border of the States of SÃo Paulo and Minas Gerais. Tourism at Rio Grande was intensified after the construction of the hydroeletric plant of Marimbondo in 1974, and local fishermen have complained about its interference. Values of niche dimensions, such as fishing periods, grounds, and prey caught were obtained through data gathered at landing points. Local and recreational fishermen usually fish in different parts of the river and catch different fish, because they use different gear. However, in transition months between the wet and dry seasons, when fish are less abundant, there is conflict or competition related to fishing grounds, reinforced by the territorial fishing rights of local longline fishermen in this period. We show how ecological concepts, such as niche and competition, may help to understand strategies of exploitation by human groups, fundamental information for the management of tropical areas.     

Dynamics of artisanal fisheries in two Brazilian Amazonian reserves: implications to co-management

In this study we compare the dynamics of artisanal fishery in two adjacent reserves located in the Brazilian Amazon, Mamirauá (being managed for more than 12 years) and Amanã (initiating a management process), through the record of 485 fish landings in one fishing community in each reserve during high and low water seasons in 2003. Our goals were, first, to make a rapid and comparative assessment of some main aspects of fisheries in these two communities (fish species caught, CPUE, fishing gear and habitats exploited). Second, we used such data to evaluate if management strategies already in place in Mamirauá would be also valid for Amanã. Third, we compared fishing CPUE between the two communities, in order to check if co-management measures have contributed, at least partially, to preclude over-fishing, maintaining a higher fishing reward in Mamirauá reserve. We analyzed fisheries directed to the two most important marketable fishes in the region: the pirarucu (Arapaimas gigas) and the tambaqui (Colossoma macropomum), besides those fisheries aimed to subsistence and lower valued fishes. Our results indicated that the tambaqui was intensively fished year-round in Mamirauá, while Amanã fishers caught a higher variety of fishes, including catfishes and migratory scale fishes. Such differences might reflect differences in gear used and habitat exploited by fishers during the high water season. Mamirauá fishers caught a higher fish biomass considering both marketable and all fishes. Differences in gear used, habitats exploited and fishes caught during high water season indicate that distinct management initiatives might apply for each reserve. Notwithstanding their differences, both communities exploited the commercial fishes (tambaqui and pirarucu) in a similar way during the low water season. Therefore, the higher mean fishing yield (CPUE) observed in Mamirauá may be partially attributable to co-management measures, considering that Mamirauá has possibly been experiencing a higher fishing intensity than Amanã. Fishing related data are seldom available in Brazil and other tropical developing countries. We thus provided a framework of fast assessment of fishing dynamics, which may represent a first and useful step for management initiatives in the absence of more detailed data.