| Popis: |
Background Whale shark watching and swimming are two of the most popular activities for tourists in the northern Mexican Caribbean. Each year since 2002, these activities have had an exponential growth, which could represent a hazard for whale sharks. It is important to monitor the tourism effect on whale shark behavior to take sustainable management measures concerning the use of this natural resource. Approach Whale shark behavior monitoring was conducted from June to September in 2014 and 2015. In order to know the effects of tourism activities and their influence on feeding behaviors and diving paths shown by whale sharks, we conducted surveys to observe whale shark behavior with and without tourism activities (swimmers and boats). Results The monitoring effort in 2014 and 2015 for whale shark surface behavior includes 571 minutes on video, of which 414 minutes include whale shark behavior during tourism activities, and 157 minutes without tourists present. In 2014, 26 whale sharks were observed without tourism activity, and 56% of these sharks showed ram feeding behavior near the surface from the beginning to the end of the observation. 42 whale sharks were observed with tourism; at the beginning of the observation 48% of these sharks presented ram feeding behavior near the surface, but this behavior decreased to 29% to the end of the observation. In 2015, only 7 whale sharks were observed without tourism interactions; 57% had ram feeding behavior from the beginning to the end of the observations. 51 whale sharks were observed with tourism interactions, where 31% of these sharks had ram feeding behavior at the beginning of the survey, but it decreased to 27% by the end of the survey. For 2014, the main behavior was ram feeding behavior. In 2015, the main behavior showed by whale sharks during tourism interactions was diving path behavior (37%). Conclusions Tourism activity might have an effect on whale shark behavior and on surface sightings, indicating a decrease in the surface feeding time in one of the most important feeding aggregations for whale sharks in the northern Mexican Caribbean. Precautionary measures are necessary for adaptive management of tourism activities and the whale sharks in this area. |
