Our objective is to provide the inter-american tropical tuna commission (IATTC) an operational information system to incorporate satellite imagery and output from a circulation model into their…

Our objective is to provide the inter-american tropical tuna commission (IATTC) an operational information system to incorporate satellite imagery and output from a circulation model into their stock assessment model. IATTC manages the tuna fishery of the eastern tropical pacific. This fishery is one of the largest and most valuable fisheries in the world and its fleets are registered in over 12 nations. Specifically, the tuna stock assessment support system (TSASS) that we propose to develop will merge satellite imagery of sea surface temperature, chlorophyll and height as well as output from the ecco 2 global circulation model with fishery data to provide spatial-temporal information to IATTC S stock assessment team on fish habitat, recruitment, and the movements and impact of fish aggregation devices. As is the case for many fisheries, sustainable management of tuna fisheries faces 3 main problems. First, the process of recruitment is extremely dynamic, poorly understood, and inadequately treated in stock assessment models. Stock assessment models currently ignore environmental factors that are known to be the major determinants of successful spawning and survival of young. In addition, recruitment rates for tuna are based upon data on the age distribution of adult fish, and thus lag events by at best 1 to 2 years. Second, the dramatic increase in fish aggregation devices since the early 90S has disrupted the fishery and compromised the ability of the stock assessment models to estimate adult stock size. Third, fishery scientists and managers recognize that fishing grounds are not uniform and that the resource should be managed with more spatial and temporal detail. However, they have lacked automated and efficient tools to do so. On one level the significance of our tuna stock assessment support system (TSASS) is that IT addresses all 3 of these problems by providing an operational system consisting of GIS tools and algorithms that link NASA ocean imagery and its global ocean circulation model to stock assessment. Need for improved management is clear not only because of climate change but also because of the food demands of an over populated planet. On another level we feel that once TSASS has become operational and proven its value other agencies that manage tuna fisheries around the world will follow suit and demand a continued supply of NASA products to better manage the resource. Our approach to develop TSASS is to build upon the pelagic habitat analysis module (PHAM), which was recently developed under NASA S decision support system program. The goal of PHAM was to provide fishery scientists with a satellite-based decision support system to map the distribution and define species habitat. The information system, which was built with system science applications easy marine geographic information system, matches in time and space fisheries data with satellite imagery of sea surface temperature, chlorophyll, and height as well as NASA S ecco 2 global ocean circulation model in order to extract information on the physical and biological characteristics of the habitat of commercial fish populations. At the same time IT extracts general information on the oceanographic properties that shape the temporal and spatial characteristics of the fishing effort. During the PHAM project we have developed with our collaborators both the software tools and the scientific insight necessary to address the problems described above that have challenged tuna stock assessment models: automated processing of spatial/temporal data, a new algorithm for predicting recruitment based upon EOF analysis of satellite imagery, tracking of fish aggregation devices with the ecco 2 model, and dynamic mapping of tuna habitat.