Influência das variáveis climáticas na pesca artesanal na Baía de Pemba

Abstract

Artisanal fisheries along the northern Mozambique coast play a critical role in local livelihoods and food security, yet they are highly influenced by environmental variability. This study assesses the relationships between key environmental variables—precipitation, sea surface temperature (SST), and chlorophyll-a concentration—and artisanal fish catches (CPUE), while identifying lag times and trends over time. CPUE data were obtained from the Oceanographic Institute of Mozambique (INOM), rainfall data from the Climate Hazards Center (CHIRPS-2.0), and SST and chlorophyll-a data from the NASA Ocean Biology Processing Group. Interannual variability, trend analysis and correlation analyses were conducted to determine the associations between these variables and fish abundance. The results revealed significant positive correlations between CPUE and environmental variables, with distinct lag times: one year for precipitation and SST, and two years for chlorophyll-a. Precipitation plays a key role in delivering nutrients to coastal waters, stimulating primary production and supporting fish population growth. However, a declining trend in precipitation raises concerns about reduced nutrient fluxes and potential impacts on fisheries productivity. SST showed a strong positive correlation with CPUE, suggesting that warmer waters enhance fish growth and recruitment, although prolonged warming could pose risks to ecosystem stability. Chlorophyll-a, as a proxy for primary production, exhibited the strongest correlation with CPUE, highlighting the role of phytoplankton biomass in supporting higher trophic levels, despite its delayed influence over two years. The observed lag times underscore the importance of understanding delayed ecological responses when managing artisanal fisheries. In conclusion, this study highlights the complex and time-lagged relationships between environmental variables and fish abundance, emphasizing the need for integrated fisheries management approaches. Strategies should include monitoring freshwater inflows, thermal variability, and primary production to sustain artisanal fisheries amidst changing climatic conditions.