Table 1

Comparisons of threats to reefs from human impacts in the top 10% highest scoring cells versus the bottom 90% of cells. Threat scores for each grid cell were calculated with data from Bryantet al. (3, 12) and range from 1 (low threat) to 3 (high threat). Figures show mean scores. For all taxa, the top 10% most species-rich cells were significantly more threatened than the rest. For the top 10% of range-rarity scores, this was the case only for corals and snails.

Top 10% of cellsBottom 90% of cellsSignificance (Mann-Whitney U test)
Fish species richness2.381.77P<0.0001
Coral species richness2.541.75P<0.0001
Snail species richness2.291.78P<0.0001
Lobster species richness2.411.76P<0.0001
Fish range rarity1.941.82NS
Coral range rarity2.231.79P <0.0001
Snail range rarity2.141.80P <0.0001
Lobster range rarity1.891.83NS