Identification of large pelagic marine fish habitats and habitat utilization using ‘pop-up’ satellite archival tag and oceanic satellite remote sensing technologies and ‘SODA’ simple ocean data simulation model analyses

Large pelagic fishes (tuna, billfish, and sharks) are being tagged with `pop-up´ satellite archive electronic sensors (PSAT), which measure and log detailed data on the swimming environment of the fish, as well as light data, which are used to estimate the geographic locations of the fish. At predetermined periods the sensors are programmed to `pop-off´ the fish, float to the sea surface, and transmit the data collected to Argos satellites, which relay the data to ground stations on earth. Processing of these data provides detailed time-history information on the environment and estimated locations of individual free-swimming fish. The resulting information is then examined in conjunction with ocean measurements and data products derived from various satellite ocean sensors including sea surface temperature, ocean color, and ocean winds, as well as SODA ocean data assimilation model analyses. The fish habitats are thus defined in the context of surrounding ocean conditions, measured contemporaneously by oceanic satellite remote sensing and derived from outputs from the SODA ocean simulation model. An important aspect of this approach is that it provides the opportunity to identify, and subsequently monitor with satellite remote sensing, ocean features, processes, and properties that may play important roles in determining spatial and temporal variations in marine fish habitats. Data are presented that demonstrate this approach for blue shark, Prionace glauca.