Spatiotemporal Patterns of Coral Bleaching and Disease along the Florida Reef Tract Brian K. Walker & Amanda Costaregni
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Objectives 1. Identify areas where spatial clustering of significantly high percent coral bleaching and disease and mean total mortality occur in the FL Keys and SE FL region.
Objectives 1. Identify areas where spatial clustering of significantly high percent coral bleaching and disease and mean total mortality occur in the FL Keys and SE FL region. 2. Evaluate overlap of spatial clustering between years to determine if some areas had more frequent clustering than others.
Method Hot Spot Analysis (Getis-Ord GI*)
Hot Spot Analysis (Getis-Ord GI*) Looks at each site within the context of neighboring sites. A site with a high value is interesting but may not be a statistically significant hot spot.
Hot Spot Analysis (Getis-Ord GI*) A statistically significant hot spot is a feature with a high value surrounded by other features with high values.
Hot Spot Analysis (Getis-Ord GI*) The local sum for a feature and its neighbors is compared proportionally to the sum of all features; when the local sum is very different from the expected local sum, and when that difference is too large to be the result of random chance, a statistically significant z-score results.
Hot Spot Analysis (Getis-Ord GI*) In other words What is the probability that the spatial distribution of values is random?
Temporal Accumulation of Clusters The accumulation of clustering through time can be evaluated to determine more-affected areas.
Preliminary Results FL Keys % Bleaching Obvious spatiotemporal clustering. Near Key Largo, Marathon, and Dry Tortugas.
Preliminary Results FL Keys % Total Disease Obvious spatiotemporal clustering. Near Key Largo and Key West.
Preliminary Results FL Keys Mean Total Mortality Obvious spatiotemporal clustering. Near North Key Largo and Key West.
Preliminary Results St. Lucie Reef had 3 years of spatiotemporal hotspots. 2015 had the most of any year. Between Gov. Cut and Hollywood. SEFCRI % Bleaching
Preliminary Results SEFCRI % Total Disease Obvious spatiotemporal pattern. 2015 had the most of any year. Between N. Miami and Fort Lauderdale.
Preliminary Results Obvious spatiotemporal pattern. Between N. Miami and Pompano. 2015 had the most of any year. SEFCRI Mean Total Mortality
What is Decision Support? Preliminary Results Summary - Keys 1. Areas near Key Largo had spatiotemporal hot spots for percent Bleaching and Disease and Mean Total Mortality. 2. Key West had spatiotemporal hot spots for percent Disease and Mean Total Mortality. 3. Dry Tortugas has increased in hotspot frequency since 2011.
What is Decision Support? Preliminary Results Summary SE FL 1. St. Lucie Reef had bleaching hotspots for 3 years: 2008, 2009, and 2012. 2. Spatiotemporal hot spots for percent Disease occurred between N. Miami and Fort Lauderdale. 3. Spatiotemporal hot spots for mean Total Mortality occurred between Pompano and Fort Lauderdale.
Next Steps What is Decision Support? 1. Define spatiotemporal hot spot areas. 2. Determine if the frequency of hotspots is increasing through time. 3. Use spatiotemporal hot spot areas as a strata to analyze FRRP data comparing to adjacent less-affected areas. 4. Try to identify possible stressors unique to the affected areas.
What is Decision Support? Thank You