Local ecological knowledge is not a useful source of information concerning impacts caused by non-native Nile tilapia on fishery stocks / Conhecimento ecológico local não é uma informação útil acerca dos impactos causados pela exótica tilápia do Nilo sobre os estoques pesqueiros

Exotic freshwater fish can have deleterious effects on local biodiversity, although these impacts often only become apparent many years after the introduction. Local Ecological Knowledge (LEK) may be a useful source of information in situations where formal technical studies are insufficient, but few works have examined the reliability of information generated through this approach. We examined the reliability of LEK by investigating the impacts of Nile tilapia on fishery stocks in an artificial reservoir in northeastern Brazil. We gathered LEK from 29 experienced fishermen and then confronted this information with official fishery statistics from the same site. Twenty-two fishermen stated that total catch in the Gargalheiras Reservoir had declined over the years, 68% (N=15) of them began fishing before 1976 (the year Nile tilapia was introduced into reservoir). Of those 15 fishermen, 87% (N=13) stated that tilapia has not negatively affected other species, which ran counter to analyses of fishery statistics. Our study suggests that the LEK of fishermen is not a useful source of information concerning the impacts caused by exotic tilapia. However, the LEK added an overfishing hypothesis of the decline in fishery stocks in the Gargalheiras reservoir.(AU)

Espécies exóticas de peixes têm causado efeitos deletérios sobre a biodiversidade local de lagos, porém esses efeitos podem tornar-se aparentes apenas anos após a introdução. Em situações onde informações técnicas são insuficientes, o Conhecimento Ecológico Local (CEL) pode fornecer informações úteis, mas existem poucos estudos que avaliam a confiabilidade da informação gerada por essa abordagem. No presente estudo, nós avaliamos a confiabilidade do CEL acerca dos impactos da introdução da tilápia do Nilo sobre os estoques pesqueiros em um reservatório do nordeste do Brasil. Nós coletamos CEL de 29 pescadores experientes, utilizando questionários e, posteriormente, comparamos as informações com os resultados das estatísticas de pesca do mesmo reservatório. Vinte dois pescadores afirmaram que as capturas totais no reservatório Gargalheiras declinaram ao longo dos anos, 68% (N=15) deles começaram a pescar antes da introdução da tilápia no reservatório. Destes 15 pescadores, 87% (N=13) afirmaram que a tilápia não afetou negativamente outras espécies, contrariamente aos resultados das estatísticas de pesca. Nosso estudo indica que o CEL não é uma fonte útil de informação acerca dos impactos causados pela tilápia. No entanto, o CEL forneceu a hipótese de que a sobrepesca pode ter contribuído também para as reduções nos estoques pesqueiros de Gargalheiras.(AU)

Local ecological knowledge is not a useful source of information concerning impacts caused by non-native Nile tilapia on fishery stocks / Conhecimento ecológico local não é uma informação útil acerca dos impactos causados pela exótica tilápia do Nilo sobre os estoques pesqueiros

Exotic freshwater fish can have deleterious effects on local biodiversity, although these impacts often only become apparent many years after the introduction. Local Ecological Knowledge (LEK) may be a useful source of information in situations where formal technical studies are insufficient, but few works have examined the reliability of information generated through this approach. We examined the reliability of LEK by investigating the impacts of Nile tilapia on fishery stocks in an artificial reservoir in northeastern Brazil. We gathered LEK from 29 experienced fishermen and then confronted this information with official fishery statistics from the same site. Twenty-two fishermen stated that total catch in the Gargalheiras Reservoir had declined over the years, 68% (N=15) of them began fishing before 1976 (the year Nile tilapia was introduced into reservoir). Of those 15 fishermen, 87% (N=13) stated that tilapia has not negatively affected other species, which ran counter to analyses of fishery statistics. Our study suggests that the LEK of fishermen is not a useful source of information concerning the impacts caused by exotic tilapia. However, the LEK added an overfishing hypothesis of the decline in fishery stocks in the Gargalheiras reservoir.

Espécies exóticas de peixes têm causado efeitos deletérios sobre a biodiversidade local de lagos, porém esses efeitos podem tornar-se aparentes apenas anos após a introdução. Em situações onde informações técnicas são insuficientes, o Conhecimento Ecológico Local (CEL) pode fornecer informações úteis, mas existem poucos estudos que avaliam a confiabilidade da informação gerada por essa abordagem. No presente estudo, nós avaliamos a confiabilidade do CEL acerca dos impactos da introdução da tilápia do Nilo sobre os estoques pesqueiros em um reservatório do nordeste do Brasil. Nós coletamos CEL de 29 pescadores experientes, utilizando questionários e, posteriormente, comparamos as informações com os resultados das estatísticas de pesca do mesmo reservatório. Vinte dois pescadores afirmaram que as capturas totais no reservatório Gargalheiras declinaram ao longo dos anos, 68% (N=15) deles começaram a pescar antes da introdução da tilápia no reservatório. Destes 15 pescadores, 87% (N=13) afirmaram que a tilápia não afetou negativamente outras espécies, contrariamente aos resultados das estatísticas de pesca. Nosso estudo indica que o CEL não é uma fonte útil de informação acerca dos impactos causados pela tilápia. No entanto, o CEL forneceu a hipótese de que a sobrepesca pode ter contribuído também para as reduções nos estoques pesqueiros de Gargalheiras.

Ethnotaxonomical considerations and usage of ichthyofauna in a fishing community in Ceará State, Northeast Brazil.

BACKGROUND: Artisanal fishery is one of the most important economic activities for human populations living in coastal areas. The traditional knowledge that fishermen have of fishes is of utmost importance for the establishment of conservation strategies for many species. This study aimed to analyse the knowledge of and utilization of fishes by the artisanal fishermen in a fishing community on the coast of Ceará State (Northeast Brazil). METHODS: In 2011, a number of semi-structured interviews were performed with fishermen with more than 20 years of fishery experience. The interviews were about fisheries (collecting spots, artefacts, etc.) and fish use. The fishes cited by the fishermen were identified scientifically and ethnotaxonomically. RESULTS: Considered masters of fishery, they cited 162 vernacular names of fishes, which corresponded to 290 different species, also including other animals such as dolphins, porpoises, whales and manatees. The criteria for the classification of the fishes were well known and utilised by the fishermen, and they were based on morphology, behaviour, habitat and the importance of commercial and fishing activities. Four hierarchical categories were identified in their classification system: kingdom, life-form, generic and specific. The fish nomenclature created by the fishermen was mostly composed of generic and monotypic names. The main uses of fish were for food and commercial purposes. CONCLUSIONS: The results stress the richness and complexity of the knowledge of the artisanal fishermen of Redonda Beach, and they provide support for the possibility of future studies and for the development of management plans and the management of wildlife resources.

O uso dos recursos pesqueiros no estuário do rio mamanguape, estado da Paraíba, Brasil / Use of fishing resources in the mamanguape river estuary, Paraiba state, Brazil / Utilización de los recusos pesqueros en el estuario del río mamanguape, estado de Paraiba, Brasil

O complexo estuário-manguezal possui um elevado capital natural, fornecendo diversos serviços ecológicos e recursos naturais para as comunidades costeiras, de uso na subsistência ou na economia local. O presente trabalho teve como objetivo inventariar os usos dos recursos pesqueiros provenientes do estuário do Rio Mamanguape localizado no Estado da Paraíba, Brasil. Para isto, foi utilizada uma proposta metodológica que envolveu a combinação de métodos qualitativos (entrevistas e observação direta) e quantitativos (valor de uso e concordância de uso principal corrigido). Foram entrevistadas 30 pessoas, sendo registrado o uso de 68 espécies, entre peixes, crustáceos e moluscos. As espécies mais importantes foram Opisthonema oglinum, Anomalocardia brasiliana, Mugil curema, Crassostrea rhizophorae, Ucides cordatus, Centropomus sp. e Panulirus argus. As espécies são utilizadas principalmente para comercialização e consumo local, entretanto, algumas delas são utilizadas para fins medicinais (usos zooterapêuticos) e como iscas para captura de outras espécies. A biodiversidade de recursos explorados registrada neste trabalho evidencia a importância dos manguezais para as comunidades que aí se desenvolvem e os dados obtidos podem servir de base para a elaboração de projetos de manejo que visem à conservação dos recursos e da diversidade cultural.

Estuary-mangrove complexes possess a rich natural capital and furnish diverse ecological services and natural resources to local coastal communities for both subsistence and economic ends. The present work presents an inventory of the uses of fishing resources at the Mamanguape River estuary, located in Paraíba State, Brazil. The inventory was prepared using a methodological approach that involved a combination of qualitative (interviews and direct observations) and quantitative (use-value and corrected principal-use concordance) approaches. A total of 30 people were interviewed and 68 species of fish, crustaceans and mollusks were identified as being used. The most important species were Opisthonema oglinum, Anomalocardia brasiliana, Mugil curema, Crassostrea rhizophorae, Ucides cordatus, Centropomus sp. and Panulirus argus. The species harvested are principally commercialized or consumed locally, although some are used for medicinal (zootherapeutic) purposes and as bait to capture other species. The biodiversity of the resources reported here is indicative of the importance of mangrove swamps for the local communities, and the data can be used for the design of management projects directed towards the conservation of both regional natural resources and cultural diversity.

El complejo estuario-manglar tiene un elevado capital natural, proporcionando varios servicios ecológicos y recursos naturales a las comunidades costeras, para el uso en la subsistencia o en la economía local. El presente trabajo tuvo como objetivo inventariar los usos de los recursos pesqueros provenientes del estuario del Río Mamanguape (ERM), localizado en el Estado de Paraíba, Brasil. Para ello fue utilizada una propuesta metodológica que incluyó la combinación de métodos cualitativos (entrevistas y observación directa) y cuantitativos (valor de uso y concordancia de uso principal corregido). Fueron entrevistadas 30 personas, registrándose el uso de 68 especies entre peces, crustáceos y moluscos. Las especies más importantes identificadas fueron Opisthonema oglinum, Anomalocardia brasiliana, Mugil curema, Crassostrea rhizophorae, Ucides cordatus, Centropomus sp. y Panulirus argus. Las especies son utilizadas principalmente para la comercialización y consumo local; sin embargo, algunas de ellas son utilizadas para fines medicinales (usos zooterapéuticos) y como cebo para la captura de otras especies. La biodiversidad de recursos registrada en este trabajo demuestra la importancia de los manglares para las comunidades que allí se desenvuelven y los datos obtenidos pueden servir de base para la elaboración del proyectos de manejo que persigan la conservación de los recursos e en la diversidad cultural.

Management of plant species for controlling pests, by peasant farmers at Lagoa Seca, Paraíba state, Brazil: an ethnoecological approach.

Ethnoecological knowledge may be understood as spontaneous knowledge, culturally referenced of any society's members, learned and transmitted through social interactions and that are targeted at resolution of daily routine situations. The traditional knowledge in small scale economy societies as well as the non-academic knowledge in urban-industrial societies might be included in this concept. An ethnoecological approach study was performed here on people living at the communities of Alvinho, Almeida, Chã do Marinho, Floriano, and Chã de Oiti, all located in the municipality of Lagoa Seca, Paraíba state, Northeast Brazil. The general objective pursued here was to study the knowledge that peasant farmers have on management of plant species utilized for pest control. For this, the methodological instruments employed here to investigate the ethnoecological knowledge were: direct observation, structured and semi-structured interviews, and tours conducted by local peasant farmers. We analyzed the data obtained under an emic/etic view and also by comparing the local knowledge with those obtained from the literature. The results showed that people in those communities utilize management alternatives for controlling pests, which are mainly: (i) fallowing; (ii) crop rotation; (iii) destruction of crop remains and fruits attacked by pests; (iv) alternations of crops with repellent plants; and/or (v) mixed cropping; (vi) insect's larvae covered with soil; (vii) crops irrigated abundantly; and (viii) soil preparation. The recovery and comprehension we get about this knowledge as well as the farmers' savoir faire, are extremely important to the revival of ancient agricultural practices, which have been forgotten due to advances in modern agriculture. The data obtained here showed that a huge body of knowledge the farmers have on many forms or strategies of management are generally compatible with scientific knowledge.