Navegando por Assunto "Manejo pesqueiro"

Agora exibindo 1 - 5 de 5

Acesso aberto (Open Access)
Genetic differentiation in the populations of red piranha, Pygocentrus nattereri Kner (1860) (Characiformes: Serrasalminae), from the river basins of northeastern Brazil
(Universidade Federal do Pará, 2015-11) LUZ, Luciana Alves da; REIS, Luana da Luz dos; SAMPAIO, Maria Iracilda da Cunha; BARROS, Maria Claudene; FRAGA, Elmary da Costa
The red piranha, Pygocentrus nattereri, is an important resource for artisanal and commercial fisheries. The present study determines the genetic differentiation among P. nattereri populations from the northeastern Brazilian state of Maranhão. The DNA was isolated using a standard phenol-chloroform protocol and the Control Region was amplified by PCR. The PCR products were sequenced using the didesoxyterminal method. A sequence of 1039 bps was obtained from the Control Region of 60 specimens, which presented 33 polymorphic sites, 41 haplotypes, һ =0.978 and π =0.009. The neutrality tests (D and Fs) were significant (P < 0.05) for most of the populations analyzed. The AMOVA indicated that most of the molecular variation (72%) arises between groups. The fixation index was highly significant (FST = 0.707, P < 0.00001). The phylogenetic analyses indicated that the specimens represented a monophyletic group. Genetic distances between populations varied from 0.8% to 1.9%, and were <0.5% within populations. The degree of genetic differentiation found among the stocks of P. nattereri indicates the need for the development of independent management plans for the different river basins in order to preserve the genetic variability of their populations.
Acesso aberto (Open Access)
O manejo comunitário de pirarucu (Arapaima gigas) como alternativa econômica para os pescadores das reservas Amanã e Mamirauá, Amazonas, Brasil
(Universidade Federal do Pará, 2009-10-14) AMARAL, Ellen Sílvia Ramos; ALMEIDA, Oriana Trindade de; http://lattes.cnpq.br/0325909843645279; MITSCHEIN, Thomas Adalbert; http://lattes.cnpq.br/7431424927108512
Acesso aberto (Open Access)
Perfil da piscicultura na mesorregião sudoeste Paraense
(Universidade Federal do Pará, 2011) OLIVEIRA, Adna Suany Cardoso de; FUJIMOTO, Rodrigo Yudi; http://lattes.cnpq.br/9538142371454660
This research aimed at characterizing the recent development of fish farming in southwestern Pará state in the Brazilian Amazon and how this economic activity is organized. Site visits were made to fish farms in the municipalities of Altamira, Brasil Novo, Medicilândia, Uruará, Vitória do Xingu, Itaituba, Aveiro, Jacareacanga, Novo Progresso, Rurópolis e Trairão. Data were obtained through the application of questionnaires with questions pertaining to characteristics of the production system and marketing. The sample included 143 fish farms, of which 65.9% practiced a semi-intensive system and 31.7% an extensive system. The employed labor force is drawn mostly from the immediate family. Fish farming is a complementary activity in 81% of the farms visited. The management of fish farms consists of several basic operations, such as rearing in ponds with locally produced feed (82%) and commercial fish ration (47.7%). The most commonly cultivated species are round fish (13%) as the preferred first cultivated species and tilapia (18%) as second choice. The average yearly yield was 8209 kg/ha for round fish and 3727 kg / ha for tilapia. The average yield of all species reached 14,339 tons/ha. The principle difficulties encountered by regional fish farmers are: lack of technical assistance, obtaining fingerlings, high feed prices, and lack of production incentives.
Acesso aberto (Open Access)
Os recursos pesqueiros marinhos e estuarinos do Maranhão: biologia, tecnologia, socioeconomia, estado da arte e manejo
(Universidade Federal do Pará, 2008) ALMEIDA, Zafira da Silva de; NAHUM, Victoria Judith Isaac; http://lattes.cnpq.br/3696530797888724
The state of Maranhão (Brazil) has considerable fishery potential. However, its fisheries have been excluded from governmental and scientific priorities. Considering the existing lack of knowledge, the aim of the present study was to carry out a survey on past and present available data regarding fisheries in Maranhão, addressing the state of the art; characterization of fishing vessels and gear; and analyzing yield, commercial value and socioeconomic status of the social actors involved. From this portrait, it was possible to delimit the existence of 21 units, heretofore denominated Fishery Production Systems, by means of a process of successive subdivisions of the fishery activity according to the following factors: fleet; practice or fishing gear; resources exploited; environment; residence, work relations and income of the fishermen; and degree of isolation of the fishing area. For such, questionnaires were administrated to different social actors and fieldwork was carried out. The systems were characterized according to economic, social, technological, ecological and management aspects, revealing a broad variety of practices and fleets that predominantly operate in coastal environments, with small vessels and simple gear, catching different target species, especially from the families Scianidae and Aridae. The socioeconomic status of the fishermen is of poverty and abandonment, with a low degree of social organization and low income level as well as precarious housing conditions, low levels of schooling and limited access to healthcare. The market and legislation have provided open access to resources and predatory practices, thereby compromising fishery resources, which are exploited without any concern for sustainability. This demonstrates the insufficiency of management actions. The Rapfish method was employed in an attempt to detect indicators for estimating the state of “health” of the systems, using a set of attributes grouped in five categories: ecology, economy, social aspects, technology and management. The results revealed the following as good indicators: social organization; number of fishermen exploiting the system; level of schooling; use of destructive gear; governmental and traditional management measures. Work relations and income were good criteria for differentiating three tendencies in the goals of the fisheries: subsistence, intermediate and semi-industrial. Some systems stood out a being less sustainable, such as the blue crab collecting, which has declined due to a lack of management, deficient social organization and the commercialization of ovate females; the lobster fishing, which use gear considered destructive. The system involving crabs other than the blue crab is characterized by the existence of traditional management measures and a better management of the resources on the part of government agencies. Thus, the present study allowed the use of a reference system for the analysis and monitoring of the sustainability of regional fisheries, using scientific and/or ethno-knowledge that led to the emergence of management proposals aimed at the fishery management, social organization and environmental education. A case study was also carried out on the production system using mid-sized vessels in the gillnet fishery targeting Cynoscion acoupa in order to give details on one of the production systems. This choice was based on the large catch volumes, large extension of the area of operations throughout the entire coast of the state of Maranhão and the large number of fishermen involved, representing a significant source of income for the state. The case study paid particular attention to the traditional knowledge of the population regarding the use and maintenance of the resource, complemented by studies on the fishery and reproductive biology of Cynoscion acoupa caught in the region of the São Marcos Bay and surrounding areas. Acoupa weakfish catches occurred throughout the year, with harvest at the beginning of the rainy season and a state production estimated at 10,600.00 kg/year. This system has undergone intensive, unorganized exploitation. It can be inferred from the biological characteristics of the species that the increasing fishery effort is not compatible with the capacity of environmental support or the needs of the fishermen. Regarding reproductive parameters, mean length at first sexual maturity (L50) for males was 39.9 cm and slightly higher for females (41.6 cm of total length). The sex proportion was 1:1.4, favoring males. This species completes its entire life cycle within the study area; reproduction occurs throughout the year, with two spawning peaks – one in November/December and another in March/May. It is believed that the information gathered can contribute toward the drafting of better sustainability proposals and actions regarding this fishery by combining ethnoknowledge and scientific knowledge on this system.
Acesso aberto (Open Access)
Temporal patterns in the occurrence of selected tropical fishes in mangrove creeks: implications for the fisheries management in north Brazil
(2009-06) GIARRIZZO, Tommaso; KRUMME, Uwe
To examine the temporal patterns in the occurrence of a tropical ichthyofauna, fisheries-independent samples were collected between September 2003 and July 2004 from intertidal mangrove creeks in the Curuçá estuary, Pará, north Brazil. Juveniles occurred year-round with the most intense occurrence during the wet/dry transition season (Anchovia clupeoides, Cetengraulis edentulus, Rhinosardinia amazonica, Mugil sp.). The occurrence of Colomesus psittacus and Anchoa hepsetus was continuous. Sciades herzbergii displayed two peaks (wet and dry season) while Cathorops sp. peaked only in the wet season. The continuous presence of juveniles in the tropical mangroves suggested that the fisheries management should be based on large no-take areas rather than closed seasons.