The authors analyzed data regarding the influences of environmental and spatial factors in shark bycatch in western and central Pacific longline fisheries from 2013-2021. Results suggest that several environmental factors, including oxygen concentration, sea surface temperature, and chlorophyll-a concentration, impact shark bycatch per unit effort (BPUE) for multiple shark species. Hotspots of bycatch were identified for bigeye thresher shark (Alopias superciliosus), longfin mako (Isurus paucus), silky shark (Carcharhinus falciformis), oceanic whitetip shark (Carcharhinus longimanus), blue shark (Prionace glauca) and shortfin mako (Isurus oxyrinchus). All species exhibited annual variations in BPUE, and bycatch risk trended eastward toward equatorial waters, likely due to a higher concentration of fishing effort in those areas.