The island of Clipperton, located in the Pacific Ocean, is a French territory that allows Mexican vessels to fish for tuna in the exclusive economic zone (EEZ). This area of the Eastern Pacific Ocean is managed by the IATTC and the International Dolphin Conservation Program (AIDCP), which provided the information for the analysis (catches per set and spatiotemporal data). The objective of this study was to analyze the data provided made by the Mexican tuna purse seiners around Clipperton Island of yellowfin tuna (Thunnus albacares) and skipjack (Katsuwonus pelamis) during the 2016-2021 period and correlate it to environmental variables downloaded from satellite data. Two delta-log models were used to describe the effect of the environmental and spatiotemporal variables (Presence-Absence GAM model and logCPUE model), and then were combined to create abundance indices for the yellowfin tuna. The skipjack delta-log models were not significant due to the lack of presence. Lastly a machine learning method, a Random Forest, was used to also obtain an abundance index, and was compared with the one obtained from the two delta-log models. Both methods may be useful for future studies and can be enhanced by adding more years of data.
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