Comparisons between ethnooceanographic predictions by fishermen and official weather forecast in Brazil

Abstract

The ethnooceanographic knowledge can be understood as a body of information artisanal fishermen have acquired and developed from empiricism for perceiving and predicting conditions at the sea, which guarantee their safety. In this sense, the aim of the present study is to compare ethnooceanographic predictions from artisanal fishermen from the northern coast of Rio de Janeiro State, southeastern Brazil, with the official meteorological forecast from Brazilian institutes, identifying which one is more used by fishermen for their safety on board. From June to August 2018, we conducted 80 ethnographic interviews and compared their informations with predictions of the following institutes: National Institute of Meteorology (NIMET – Instituto Nacional de Meteorologia), the Weather Forecast and Climate Studies Center/National Institute for Space Research (WFCSC/NISR - Centro de Previsão de Tempo e Estudos Climáticos/Instituto Nacional de Pesquisas Espaciais) and the Hydrography and Navigation Board (HNB – Diretoria de Hidrografia e Navegação). Official ethnooceanographic predictions related to ‘waves height’ were concordant in 42.5% (n = 34) and discordant in 57.5% (n = 46) to interviews. Predictions related to the ‘wind speed’ were concordant in 58.7% (n = 47) and discordant in 41.3% (n = 33) to the interviews. Regarding tides height, most fishermen (82.5%; n = 66) consider 1.2 m or more as ‘favorable to the fishery’, and lower than 1.0 m as ‘unfavourable to fishery’. In Brazil, ethnooceanographic predictions are more used by fishermen to assure their safety on board and the success for their fishery.