Environmental perception of gatherers of the crab'caranguejo-uçá'(Ucides cordatus, Decapoda, Brachyura) affecting their collection attitudes (original) (raw)
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Ecological Economics, 2017
The large mangrove crab Ucides cordatus ("caranguejo-uçá") is a key fisheries resource in Brazil, critical for the sustenance of livelihoods of thousands of people in coastal rural areas. Today's crab populations suffer from habitat degradation, disease, and increasing fishing pressure. Crabs are sold alive on local and regional markets, or traded as processed meat and the market chains typically involve intermediaries (i.e. traders). The present study examined the relationship between crab harvesters and the intermediaries, and the socio-ecological implications thereof. The research was performed between September 2013 and October 2014 in the Mamanguape River estuary, northeastern Brazil. Socioeconomic information and data regarding the catch (sex and carapace width of the crabs), the processing of U. cordatus meat and the commercial relationship between harvesters and intermediaries were obtained through structured (questionnaires) and semi-structured interviews and direct observations. The crab harvesters exist under precarious socioeconomic conditions that place them at the edge of society and therefore often seek loans offered by the intermediaries, generating loyalty and dependence that guarantees the intermediaries a stable supply of crabs needed to supply an avid market. Within this relationship, the intermediaries create pressure on natural crab populations by stimulating non-selective captures, as they buy specimens below the legal size limit (6 cm wide carapace) for processing. During crab meat processing, the intermediaries themselves report that the crabmeat is often mixed with cooked and shredded meat of marine vertebrates, such as spotted eagle ray (Aetobatus narinari) and nurse shark (Ginglymostoma cirratum), to increase the weight of the final product. As with the crab harvesters, the women involved in processing the crabmeat often accept loans, resulting in the same type of dependence and loyalty to the intermediaries. The intermediaries exercised a strong influence on crab harvesting and 3 are directly linked to the commercial, social and ecological implications of these harvesting activities together with the crab harvesters themselves. Hence, to ensure sustainability of the U. cordatus fishery and maintain (better improve) dependant livelihoods, all actors involved in the production chain of U. cordatus must be considered when developing management strategies, rather than the current approach of considering the crab harvesters only. We advise the development and implementation of fisheries associations to give the crab harvesters (and regulating bodies) greater control over and capital gains from their catches.
Habits and customs of crab catchers in southern Bahia, Brazil
Journal of ethnobiology and ethnomedicine, 2017
Brazilian mangrove forests are widely distributed along the coast and exploited by groups of people with customs and habits as diverse as the biology of the mangrove ecosystems. This study identifies different methods of extracting crabs that inhabit the mangrove belts; some of these activities, such as catching individual crabs by hand, are aimed at maintaining natural stocks of this species in Mucuri (south Bahia), Brazil. In the studied community, illegal hunting activities that violate Brazilian legislation limiting the use of tangle-netting in mangrove ecosystem were observed. According to our observations, fishermen, to catch individual crabs, use the tangle-netting technique seeking to increase income and are from families that have no tradition of extraction. This analysis leads us to conclude that catchers from economically marginalised social groups enter mangroves for purposes of survival rather than for purposes of subsistence, because the catching by tangle-netting is a...
Nauplius
The century-old mangrove crab Ucides cordatus Linnaeus, 1763 harvesting is a traditional activity of Northeastern Brazilian coastal communities, who use it as food, source of income and cultural reference. The extractivism and marketing of this crustacean is essential for the socioeconomic development of the states of Maranhão, Piauí and Ceará. The aim of this study was to carry out the monitoring of harvesting and landing of the mangrove crab in Ilha Grande, PI. Interviews were conducted with crab gatherers and transporters to obtain information about harvesting, landed volume, market price and destination of commercialized crab. The main capture spots were located at the Maranhão part of the Parnaíba River Delta. Crab gatherers are active 5.07 times a week and spend an average of 6 hours in mangrove. The average number of crabs collected per gatherer/day was 77.0. The quantity landed in daytime period was 63,628 crabs/month, totalizing 714,543 crabs/ year. The average price traded was USD 0.19/crab. The production chain
Ocean & Coastal Management, 2014
This study presents the ethnoecology of the crab Ucides cordatus Linnaeus, 1763 through the perception of traditional gatherers in a mangrove forest of northern Rio de Janeiro, south-eastern Brazil. The study also describes gathering techniques and assesses the development of traditional management actions. A total of 66 ethnographic interviews was performed, from which the gatherers' ability to correctly identify the target species and describe aspects of its biology, ecology and behavior was determined. The gatherers who collect U. cordatus in this mangrove forest are primarily female, and the techniques applied include the 'redinha' or net method, the 'braceamento' or arm method, and the 'mão' or hand method. Crab gatherers have developed a traditional management system based on selective gathering according to the sex and size of the animals and the establishment of fallow areas in the mangrove forest. This system facilitates the long-term sustainability of the gathering activity. The existence of a traditional management system in this crab-gathering activity illustrates the fact that traditional knowledge can be applied in the conservation process. Integration of traditional knowledge with scientific knowledge plays a critical role in the development and execution of management plans. This study established a network of relationships between research institutions, the Fishermen's Colony and the community. The acknowledgment of this traditional management system allowed the recognition of certain key individuals who will facilitate the elaboration of educational programs. These local actors can be community members who disseminate ideas and help with decisions related to fishery management. Traditional knowledge can help researchers to understand the environmental conflicts and interests of a community. The union of this knowledge with scientific information can provide support for defining conservation strategies and elaborating laws and thus might improve management plans.
Anais da Academia Brasileira de Ciências, 2012
The present study was undertaken in two traditional communities that are located on the margins of the estuary and mangrove complex of the Mamanguape River, Paraíba state (PB), Brazil. This work describes the crabs capture techniques tapamento and redinha, and identifies the negative socio-environmental impacts of redinha, using qualitative methods (open and semi-structured interviews, guided tours, direct observation and the administration of questionnaires). Results indicate that currently only two principle techniques are used to capture Ucides cordatus: redinha and tapamento. Tapamento has a low impact in relation to redinha. Redinha was pointed out by interviewees as a system that has social impact (social conflicts, breaking of traditions, substitution and extinction of techniques) and environmental impact (less selective captures and high productivity, mangrove pollution, death of crabs caught in traps, cutting of the roots of Rhizophora mangle, micro-habitat loss resulting from galleries destroyed and polluted). Knowledge of crab harvesting carried out using these two techniques and the possible social and environmental impacts caused by redinha, can lead to more effective planning and actions towards the conservation of the species.
The fishery of the mangrove crab (Ucides cordatus) is one of the oldest sources of food, income and extractive activity in the estuarine systems of Brazil. The state of São Paulo has the largest population of any Brazilian state, and the city of Cananéia, in the Brazilian southeast has the highest recorded level of exploitation of the uçá-crab. Since 1990, this species has been under intense exploitation pressure due to the unauthorized use of a type of trap called ’redinha’. This type of fishing gear is considered harmful and is prohibited by Brazilian law, although its use is very common throughout the country. This study aims to evaluate the exploitation patterns of U. cordatus based on landing data and monitoring of the crab fishermen to verify the population structure of the crab stock and to identify the factors that influence the catches. A general view of the sustainability of the fishery for this resource is also provided for five defined mangrove sectors (areas A to E) at Cananéia. For this purpose, fishery data were recorded during 2009-2010 by the Instituto de Pesca (APTA/SAA-SP), and monitoring of the capture procedures used by two fishermen was conducted to obtain biometry data (CW, carapace width) and gender data for the captured crabs. The redinha trap was very efficient (86.4%) and produced sustainable catches because the trapped crabs were legalsized males (CW>60 mm), although some traps are lost or remain in the mangrove swamps and can cause pollution by introducing plastic debris. The fishery data were evaluated with a General Linear Model (GLM) based on six factors: the characteristics of the crab fishermen, the time of capture (by month and year), the lunar phase, the productive sector and the reproductive period. The individual crab fishermen’s empirical knowledge, the year of capture and the productive sector were the strongest influences on the crab catch per unit effort (CPUE). Differing extraction patterns were found in the five sectors examined in the Cananéia estuary. These findings underscore the need for a reassessment of the prohibition of the trap's use, raising discussion as to its possible construction with biodegradable materials, thus ensuring profitable and sustainable catches through a local participatory management process.
Are Crab-collectors in Mangroves of Northern Brazil (PA) Optimal Foragers?
Wetlands
Intensive harvesting of the mangrove crab Ucides cordatus provides subsistence for food and main or additional income to many inhabitants of mangrove areas in Northern Brazil. In order to better understand the spatial patterns of use of this natural resource as basis for sustainable resource-management, we used a combination of GPS-tracking, field observations, semi-structured interviews and participatory mapping with crab-collectors. We quantified daily working hours, traveling distance and time to, as well as collecting time inside, the patches where crabs are collected. Based on preliminary findings for three different types of transportation to the fishing grounds, we conclude that crab-collectors in our study area act in accordance with the central place optimal foraging concept in that they invest more time in traveling to areas with higher catch. We hold these findings will prove relevant for sustainably managing the use of mangrove crabs as natural resource. The parallel occ...
Background: Blue Land Crab (Cardisoma guanhumi) is one of the most important crustacean species captured and commercialized in Brazil. Although this species is not considered to be threatened with extinction, populations of C. guanhumi are known to be rapidly diminishing due to heavy harvesting pressures and degradation of their natural habitats, highlighting the necessity of developing and implanting management and protection strategies for their populations. There have been no ethnozoological publications that have focused specifically on C. guanhumi, in spite of importance of this type of information for developing efficient management plans of resource utilization. So, the present work describes the ethnoecological aspects of the capture and commercialization of C. guanhumi by a fishing community in northeastern Brazil. Methods: Field work was carried out in the municipality of Mucuri, Bahia in Brazil, between the months of January and March/2011 through the use of open semi-structured interviews with all of the crustacean harvesters in city who acknowledged their work in capturing this species, totaling 12 interviewees. The informants were identified through the use of the "snowball" sampling technique. In addition to the interviews themselves, the "guided tour" technique and direct observations was employed. Results: According all the interviewees, the C. guanhumi is popularly called "guaiamum" and is collected in "apicum" zones. They recognize sexual dimorphism in the species based on three morphological characteristics and the harvesters also pointed two stages in the reproductive cycle during the year and another phase mentioned by the interviewees was ecdysis. All of the interviewed affirmed that the size and the quantities C. guanhumi stocks in Mucuri have been diminishing. All of the interviewees agreed that the species and other mangrove resources constituted their principal source of income. The harvesters dedicated three to five days a week to collect Blue Land Crabs and the principal technique utilized for capturing is a trap called a "ratoeira" (rat-trap).
Ecological Economics, 2007
The mangrove crab Ucides cordatus is considered by some authors as the keystone species in the mangrove ecosystem of the Caeté river estuary, North Brazil. In this region, crab fishery constitutes the main source of income for native households, and crab collectors are almost all men. The present study was carried out to characterize the role of women in the mangrove crab production process in the district of Caratateua (Pará, Brazil). Crabmeat processing and other activities, such as the construction of traps and other crab gathering artifacts used by the men in crab collection, clearly place the women in the crab production process.