BACKGROUND: CORAL REEF ECOSYSTEMS ARE CRITICALLY IMPORTANT TO COMMUNITIES LIVING AROUND AND DEPENDENT UPON THEM PARTICULARLY BY PROVIDING ECOSYSTEM SERVICES THROUGH AQUATIC BIODIVERSITY RECREATION AND TOURISTIC VALUE. COUNTRIES IN CENTRAL AMERICA FACE GREAT CHALLENGES IN PROPERLY MONITORING AND SUSTAINABLY MANAGING THESE VAST AND DISPARATE ENVIRONMENTS ESPECIALLY IN THE CONTEXT OF CLIMATE-INDUCED THREATS SUCH AS THROUGH INCREASED NUTRIENT RUNOFF AND LOAD. THE BELIZE BARRIER REEF RESERVE SYSTEM (BBRRS) THE WORLD S SECOND LONGEST BARRIER REEF SYSTEM AND A UNESCO WORLD HERITAGE SITE IS A CRITICALLY IMPORTANT AREA IN THIS REGARD AND THEREFORE AN APPROPRIATE CASE STUDY ON THE IMPACTS OF NUTRIENT FLOWS ON ALGAL GROWTH AND CORAL REEF BIODIVERSITY. A 2009 STUDY LED BY THE WORLD RESOURCES INSTITUTE FOR INSTANCE INDICATED THAT THE BBRRS WAS RESPONSIBLE FOR 12-15% OF BELIZE S GROSS DOMESTIC PRODUCT. IN THAT CONTEXT EARTH OBSERVATIONS FROM NASA MULTISPECTRAL IMAGERS PROVIDE A VIABLE SOLUTION TO COMPLEMENT CURRENT EFFORTS TO MONITOR CORAL REEFS IN THE REGION AND ASSESS THE IMPACT OF POLICIES AND ACTIONS IMPLEMENTED. MAJOR GOALS: THE MAIN OBJECTIVE OF THIS PROPOSAL IS TO STUDY THE IMPACTS OF ERODED SEDIMENTS AND NUTRIENTS FROM BELIZE S SIXTEEN MAJOR WATERSHEDS ON THE CORAL REEF HEALTH AND BIODIVERSITY WITHIN THE BROADER BELIZE BARRIER REEF LAGOON SYSTEM. WE WILL USE A TIME SERIES APPROACH FOR STUDYING MODERATE RESOLUTION NASA OPTICAL DATASETS ATMOSPHERIC CORRECTION ALGORITHMS DEVELOPED BY THIS RESEARCH TEAM FOR HIGH ACCURACY OVER WATER BODIES AND IN SITU MEASUREMENTS OF BOTH CORAL REEF EXTENT AND WATER QUALITY AND NUTRIENT LOAD. WHILE SIMILAR ACTIVITIES HAVE BEEN ATTEMPTED IN PIECEMEAL FASHION PREVIOUSLY THIS PROPOSED EFFORT SEEKS BOTH TO LEVERAGE EARTH OBSERVATION DATA IN A WAY THEY HAVE NOT PREVIOUSLY BEEN USED BUT ALSO TO DEVELOP SUSTAINED LOCAL CAPACITY TO UTILIZE SUCH DATA FOR DECISION-MAKING. THE PROJECT WILL LEVERAGE STRONG EXISTING NETWORKS WITHIN THE COUNTRY OF BELIZE INCLUDING THROUGH A NETWORK OF NGOS AND GOVERNMENTAL AGENCIES FOCUSED ON SUSTAINABLE COASTAL ZONE MANAGEMENT. FINALLY THE PROPOSED WORK WILL ENTAIL CAPACITY BUILDING OF KEY INSTITUTIONS IN BELIZE IN THE THEME OF NASA EARTH OBSERVATIONS FOR AQUATIC ECOSYSTEM MONITORING. SPECIFIC TASKS: 1) HISTORICAL ASSESSMENT WHILE THERE ARE NOW ALMOST TWO DECADES OF OCEAN COLOR DATA FROM NASA S MULTISPECTRAL IMAGERS THIS DATA HAS NOT BEEN ANALYZED SPECIFICALLY WITH REGARD TO THE IMPACTS OF SEDIMENTS AND NUTRIENTS ON THE BELIZE BARRIER REEF. THUS A MAJOR EFFORT WILL BE TO ANALYZE THE TIME SERIES OF DATA TO BETTER UNDERSTAND WATER QUALITY DYNAMICS WITHIN THE BELIZE BARRIER REEF LAGOON SYSTEM INCLUDING SEASONAL CHANGES IN NUTRIENTS TEMPERATURE AND OCCASIONAL ALGAL BLOOMS. 2) FORECASTING BUILDING ON EARLIER EFFORTS LOOKING AT THE TRANSPORT OF SEDIMENTS AND NUTRIENTS UAH AND ITS PARTNERS WILL DEVELOP A COUNTRY-SPECIFIC MODEL FOR ESTIMATING THE QUANTITIES OF NUTRIENTS BEING DISCHARGED FROM THE MAJOR RIVERS AND BEING TRANSPORTED OUT TO THE BELIZE BARRIER REEF COMPLEX. SUCH A MODEL WILL HELP LOCAL DECISION-MAKERS TO GUIDE EFFORTS TO REDUCE NUTRIENT LOADS. 3) FIELD CALIBRATION / VALIDATION WCS AND PARTNERS WILL CONDUCT PHYSICAL AND ECOLOGICAL MONITORING ACTIVITIES TO ASSESS IMPACT OF NUTRIENTS ON CORAL REEF SYSTEMS ACROSS BELIZE IN ORDER TO CONFIRM / VALIDATE DATA GATHERED VIA SATELLITE REMOTE SENSING AND CALIBRATE THE MODELS AS NECESSARY. 4) CAPACITY BUILDING UAH WILL WORK CLOSELY WITH GIS STAFF FROM LOCAL ORGANIZATIONS (WCS AND COASTAL ZONE MANAGEMENT AUTHORITY&INSTITUTE) TO INCREASE CAPACITY IN REMOTE ASSESSMENT OF AQUATIC ECOSYSTEM MONITORING. 5) INFORMATION DISSEMINATION DATA ANALYSIS WILL BE SYNTHESIZED FOR PRESENTATION TO NATIONAL AUTHORITIES FOR RECOMMENDATIONS AS NEEDED TO INFORM FOR IMPROVED CORAL REEF MANAGEMENT IN BELIZE GIVEN ANTHROPOGENIC THREATS INCREASING VULNERABILITY TO THE IMPACTS OF CLIMATE CHANGE.