WSSTAs per year 0 1 to 5 5 Mean number of corals with white syndrome per 1500 m 0 24 0 9 3 6 4 7 Coral cover 25 49 0 9 9 8 4 5 50 75 10 4 23 3 80 1 that week between 1985 and 2004 If the sea surface temperature was 1 C or more above the mean this was recorded as a weekly sea surface temperature anomaly WSSTA The number of WSSTAS was calculated for the twelve months preceding the date on which a reef was surveyed for white syndrome On each reef the number of cases of white syndrome in a 1500 m sample area was surveyed once per year The table shows these cases in relation to numbers of WSSTAS and coral cover on the reef Low coral cover was 0 24 and high coral cover was 50 75 b i Describe the evidence that is provided by the data in the table for the harmful effects of rising sea temperatures on corals 2 D ii The researchers concluded that there was a threshold coral cover percentage below which infection rates ended to remain fairly low Using the data in the table identify this threshold level 1 O WSSTAS per year iii Suggest a reason for a larger percentage of corals being infected with white syndrome on reefs with a