Abstract: Biodiversity is a critical biological foundation for ecosystem stability, but long-term dynamic monitoring of marine biodiversity remains challenging. To study the biodiversity in the squid gigging fishery grounds of the Southeast Pacific, we employed jumbo squids (Dosidicus gigas) as samples to investigate the spatio-temporal distribution pattern of biodiversity in that area. We also applied GAMMs (Generalized Additive Mixed-Effects Models) to evaluate the relationship between biodiversity indexes and environmental condition. The results reveal that a total of 43 species were identified from 120 analyzed stomachs of D. gigas. The taxonomic composition included 27 Actinopterygii species, 8 Cephalopods, 7 Gastropods, and 1 Malacostraca. There was significant spatial heterogeneity in the biodiversity indexes, both Margalef and Shannon-Wiener indexes demonstrating an increasing trend from pelagic to coastal waters. While the seasonal variation in the biodiversity indexes were statistically insignificant, though relatively higher values were recorded in spring. The spatio-temporal distribution of biodiversity indexes exhibited significant negative correlations with chlorophyll a concentration and positive correlation with sea surface height and net primary productivity. By contrary, there was no significant relationship between biodiversity indexes and sea surface temperature. Thus, the results demonstrate obvious spatial patterns in biodiversity across the squid jigging fishery grounds in the Southeast Pacific, with relative seasonal stability. The observed spatio-temporal variations in biodiversity may be primarily driven by the habitat heterogeneity and dynamics of the marine environmental condition.