Crown of Thorns Starfish on the Great Barrier Reef
This animation was created by the AIMS Long Term Monitoring Project. Data was collected using using the manta tow method at various reefs. These data were interpolated using ArcInfo's IDW (Inverse Distance Weight) function to create a grid for each year. The interpolation used a fixed radius of 1 degree. Any cell in the grid which contained less than three points was assigned a no data value. No data cells were then assigned the average of the preceding and following years if these were available. If one of these was not available, the cell was assigned the value of the other year.