Ecotourism affects breeding in sergeant major damselfish (Abudefduf saxatilis).

We studied the effect of tourist activity on the reproductive success of sergeant major damselfish (Abudefduf saxatilis). We snorkeled at two sites - one with a bridge over the reef allowing access to the reef from the seaside (Princess beach) and further south where the number of tourists is low (Taba beach). We identified 36 (65.5%) nests on the Princess reef and 19 (34.5%) on the Taba reefs. Average nest size at Princess was 11.8 cm2 (±2.68 SD) vs 19.6 cm2 (±3.9) at Taba. Further, at Princess although the number of nests was not correlated to the distance from the bridge (R2  = 0.352), average nest size increased with distance from the bridge (R2  = 0.861). At Taba, nests on the continuous reef averaged 21.8 cm2 (±1.8, N = 13) while those on the loose aggregation reefs averaged 14.8 cm2 (±2.02, N = 6). Although reef tourism is increasingly being regarded a major source to generate income for human coastal communities, a better understanding of the consequences of human activities to the reef system can enhance conservation initiatives and facilitate management implementation.