Teleconnection Impacts of Climatic Variability on Tuna and Billfish Fisheries of the South Atlantic and Indian Ocean: A Study Towards Sustainable Fisheries Management

Abstract

Climatic variability significantly impacts global fisheries by altering oceanographic conditions, potentially affecting fishing yields and species composition, and studying climate change's effects is crucial for understanding marine ecosystems, predicting disruptions and informing sustainable management strategies. Hence, this study examined the impact of climatic variability on pelagic predators like tunas, marlins and swordfish, using fishery data from 2005, January to 2016, December, focusing on nine commercially significant species each from the Indian and South Atlantic oceans. The hypothesis of the study was composed of two parts, that is, different populations of same species in the Indian and South Atlantic Ocean may respond differently to climatic variability, and the impact of teleconnections on fisheries may vary across these two oceans. The first part of the current study involved evaluating the importance of climatic variability on species using generalised additive modelling, while the second part involved analysing the unique effects of species-specific climatic variability using cross-spectral and cross-wavelet analysis. The current study revealed two significant findings: firstly, species in the Indian Ocean and South Atlantic Ocean had distinct response to climatic variability (first hypothesis), and secondly, the species in the Indian Ocean displayed a higher level of sensitivity to teleconnection impacts (second hypothesis). The study's findings can help fisheries communities to anticipate and adapt to changes in fish distribution and productivity, enhancing their practices and spatial management, thereby promoting sustainable global fisheries management.