OCEANIC PROCESSES THAT CONCENTRATE ZOOPLANKTON AND FORAGE FISH IN SO-CALLED HOTSPOTS (AREAS OF ENHANCED SPECIES ABUNDANCE, DIVERSITY AND/OR TROPHIC INTERACTIONS) HAVE CHALLENGED THE PARADIGM THAT PRIMARY PRODUCTION ALONE DRIVES THE ABUNDANCE OF UPPER TROPHIC LEVELS. ZOOPLANKTON INCLUDING EUPHAUSIIDS (KRILL) AND COPEPODS ARE IMPORTANT GRAZERS OF PHYTOPLANKTON AND PREY SPECIES FOR A DIVERSE ARRAY OF PREDATORS; THEREFORE, THEY REPRESENT A KEY LINK IN MARINE FOOD WEBS. THE DISTRIBUTION OF ZOOPLANKTON IS PATCHY AND OFTEN DECOUPLED FROM PHYTOPLANKTON IN SPACE AND TIME. CONSEQUENTLY, IT HAS BEEN DIFFICULT TO PREDICT THE ABUNDANCE AND DISTRIBUTION OF FISH, SEABIRDS AND MARINE MAMMALS, WHICH DEPEND DIRECTLY ON ZOOPLANKTON FOR GROWTH AND REPRODUCTION, FROM REMOTELY-SENSED VARIABLES SUCH AS CHLOROPHYLL OR PRIMARY PRODUCTION. IMPROVED UNDERSTANDING OF THE CONNECTIONS BETWEEN PRIMARY PRODUCTION, ZOOPLANKTON AND LIVING MARINE RESOURCES WOULD BE OF GREAT SCIENTIFIC, MANAGEMENT AND CONSERVATION VALUE. THE GOAL OF THIS PROJECT IS TO FURTHER OUR KNOWLEDGE OF THE FUNDAMENTAL PHYSICAL AND BIOLOGICAL PROCESSES THAT DETERMINE THE LOCATION AND INTENSITY OF ZOOPLANKTON HOTSPOTS. WE PROPOSE TO COMBINE REMOTE SENSING PRODUCTS, ECOSYSTEM MODELS AND IN SITU DATA TO INVESTIGATE ZOOPLANKTON HOTSPOTS ALONG THE U.S. WEST COAST AND THEIR RELATIONSHIP WITH ENVIRONMENTAL FORCING, LOWER AND HIGHER TROPHIC LEVELS. WE WILL SIMULATE THE DISTRIBUTION OF HOTSPOTS USING TWO DIFFERENT, COMPLEMENTARY APPROACHES THAT CAPTURE THE AVERAGE LOCATION OF KNOWN HOTSPOTS: 1) A HIGH-RESOLUTION COUPLED BIOPHYSICAL MODEL, AND 2) A SIMPLE COMBINATION OF SATELLITE-BASED WINDS AND CURRENTS WITH PLANKTON GROWTH AND GRAZING EQUATIONS. OUR SIMULATIONS WILL BE EVALUATED AGAINST IN SITU OBSERVATIONS OF KRILL FROM FISHERIES SURVEYS AND DISTRIBUTIONS OF KRILL PREDATORS (E.G., SEABIRDS AND MARINE MAMMALS). ONCE VALIDATED, THE SIMULATIONS WILL BE USED TO IDENTIFY SPECIFIC REMOTELY-SENSED FEATURES THAT FAVOR ZOOPLANKTON AGGREGATION AND THE POTENTIAL FORMATION OF MULTI-SPECIES ECOSYSTEM HOTSPOTS. THESE FINDINGS WILL BE USED TO DEVELOP ALGORITHMS THAT CAN PREDICT ZOOPLANKTON HOTSPOTS FROM SATELLITE DATA. PRODUCTS FROM THIS EFFORT WILL BE TWO-FOLD: 1) IMPROVED FUNDAMENTAL UNDERSTANDING OF THE CONNECTION BETWEEN OCEAN CIRCULATION, PRIMARY PRODUCTION, AND LIVING MARINE RESOURCES IN COASTAL UPWELLING REGIONS; AND 2) ROUTINE PRODUCTS FOR THE PREDICTION OF ZOOPLANKTON HOTSPOTS ALONG THE U.S. WEST COAST FROM REMOTELYSENSED VARIABLES.