Tourist compliance to a Code of Conduct and the resulting effects on whale shark (Rhincodon typus) behavior in Donsol, Philippines

This study examines tourist compliance to the Code of Conduct for whale shark (Rhincodon typus) interactions and assesses impacts of tourists on whale sharks in Donsol, Philippines. Whale sharks feed in Donsol's nutrient rich waters between November and June, drawing up to 7100 visitors annually. Tourist, tour operator, and whale shark behavior were examined during human-whale shark interactions (n = 777) on 117 boat trips (March, April and May) in 2004, and on 76 boat trips in 2005 (n = 620). Average compliance to Code of Conduct regulations in 2004 and 2005 was 44% for the minimum distance kept; 82% for no touching, no path obstruction and a maximum of six swimmers per whale shark; 89% for a maximum of one boat per shark, 99% for no flash photography and no SCUBA, scooters, and jet-skis. Significant predictors of whale shark's directional changes were path obstruction and proximity of swimmer to whale shark, while for whale shark's dive response it was first-time sighting and whale shark feeding. The significant predictor of a violent shudder behavior was touching. Generalized linear modeling evaluated change in direction, dive response and violent shuddering variables, and found that touching, flash photography, and swimmer diving towards the whale shark significantly affected the magnitude of disturbance. Tourism impacts on whale sharks can be minimized through adaptive management that monitors tourism and alters interaction regulations to reflect tourist and tour operator actions that have detrimental effects on whale sharks. (c) 2006 Published by Elsevier B.V.