We analyzed fishery data provided by Taiwanese fishermen between 1986 and 1996 to investigate seasonal and spatial distribution, abundance patterns, and environmental characteristics of three dominant tuna species (bigeye tuna, Thunnus obesus; yellowfin tuna, T. albacares; and albacore, T. alalunga) inhabiting the Indian Ocean using a GIS approach. Environmental preferences of these species were characterized by the data (sea surface temperature, pigment concentration, upwelling zone, etc.) from NASA's WWW sites. Results indicate that these species show distinct unique distribution patterns and seasonal variation. The peak abundance areas exhibit unique environment conditions. Our results show some promise on modeling species distribution using environmental variables.