Survey sampling for fisheries monitoring in Brazil: implementation and analysis

Abstract

Census of fishing data about the landings carried out along the São Paulo coast during 2011 was used to evaluate and compare the survey sampling for fisheries monitoring, expecting reliable results along with an important cost reduction. Estimates of total catch for the São Paulo State as a whole and by municipality were relatively accurate (high precision and low bias). Estimated catch by month, by fish categories and both (factors not considered in the sampling design) demonstrated that, as the level of required detail increased, the catch estimates became more biased and less precise. However, when comparing to the 2011 true catches, the order of importance of fish categories based on estimated catches changed slightly in some positions after the fifth place. There was a minor cost reduction due to the sampling in comparison with the census methodology currently in use (15.4% at most). The results demonstrated that fisheries monitoring costs are directly proportional to the required level of details and data quality.

Risk assessment of small‐scale reef fisheries off the Abrolhos Bank: Snappers and groupers under a multidimensional evaluation

“…In Brazil, both small‐scale reef fisheries and medium‐scale offshore fisheries are not consistently monitored (Miranda, Kinas, Moreira, Namora, & Carneiro, ). Typically, the only register is catch data, while effort information is available only for some major stocks, such as for sardines (Freire & Oliveira, ).…”

Mitigação de Multipercurso por Estimação de Procrustes e Fatorização Khatri-Rao para Estimação de Atraso em GNSS

“…Sistemas Globais de Navegação por Satélites, do inglês Global Navigation Satellite Systems (GNSS), foram inicialmente projetados para oferecer posicionamento de precisão para aplicações militares enquanto aplicações civis teriam acesso apenasà aquisição de baixa resolução, do inglês coarse acquisition (C/A), mas poderiam ser aumentadas por sistemas auxiliares como sistema de aumentação baseado em solo, do inglês Ground Based Augmentations Systems (GBAS), para pouso e decolagem de aviões comerciais. Equipamentos de GNSS modernos oferecem boa acurácia graçasà melhorias Daniel Valle de Lima e João Paulo C. L. da Costa, Departamento de Engenharia Elétrica, Universidade de Brasília, DF, Brasil, E-mails: daniel.vallelima@gmail.com, joaopaulo.dacosta@ene.unb.br de sincronização mas, para aplicações de segurança crítica, do inglês Safety Critical Applications (SCA), como carros autônomos [1], e aplicações de responsabilidade crítica, do inglês Liability Critical Applications (LCA), como gestão de pescarias [2],é importante não apenas oferecer posicionamento preciso como também operação em ambientes exigentes onde multipercursos podem degradar o posicionamento.…”

The snapper and grouper fisheries of the Abrolhos Bank, East Brazil shelf: fleet patterns, exploitation status and risk assessment

“…In Brazil, some of the main challenges for fisheries assessments and management are the implementation of an effective system of fisheries monitoring throughout the various landing points (MATTOS et al, 2017;MIRANDA et al, 2016), as well as the implementation of a management effectively participatory (CASTELLO, 2008). The fishers' participation in both data collection and management plans may represent alternative approaches to obtain fishery data successfully (BERKES et al, 2001).…”

“…In Brazil, both the small-scale reef fisheries and medium scale offshore fisheries are not consistently monitored nor monitored over the long term (MIRANDA et al, 2016). Typically, the only registered data are catch data, while effort information is available only for some major stocks, such as for the sardines OLIVEIRA, 2007).…”