Table 1. Environmental predictor variables included in the boosted regression tree analysis.

Variable Name	Source	Units	Range
Moon phase	calculation from date	days from new	0–29
Time of Day	Index from sequential dive #	#	1–6
Temperature	in situ (SBE39)	°C	23.43–30.35
Wave Energy	calculation from NOAA WW32	kW/m	13.76–517.99
Depth	in situ (SBE39)	m	1.6–26.5
Distance to 50 m contour	NOAA PIBHMC3 bathymetry	m	1–500
Quadrant	calculation	categorical	NE, SE, SW, NW
Human Population/Reef Area	Calculation (2000 US Census)	#/km2	0–2445
Complexity	benthic towed-diver visual estimate	index	0–6
Reef Structure	NOAA BHM (Benthic Habitat Maps)4	categorical	Reef, Sand, etc
Benthic Cover	NOAA BHM4	categorical	Coral, Algae, etc
% Cover – Coral	benthic towed-diver visual estimate	%	0–68.8
% Cover – Macroalgae	benthic towed-diver visual estimate	%	0–87.5
% Cover – Crustose coralline algae	benthic towed-diver visual estimate	%	0–68.75
% Cover – Sand	benthic towed-diver visual estimate	%	8.0–87.5
% Cover – Rubble	benthic towed-diver visual estimate	%	0–56.3
Variety of Cover Types	Calculation from BHM4 data	#	1–4
Variety of Structure Types	Calculation from BHM4 data	#	1–4

¹Pathfinder satellite data - http://www.nodc.noaa.gov/SatelliteData/pathfinder4km/.

²NOAA WaveWatch 3 - http://polar.ncep.noaa.gov/waves/main_int.html.

³Pacific Islands Benthic Habitat Mapping Center - http://www.soest.hawaii.edu/pibhmc.

⁴NOAA Benthic Habitat Maps - http://ccma.nos.noaa.gov/ecosystems/coralreef/us_pac_mapping.html.