Long-Term Photo-Identification Reveals the Population Dynamics and Strong Site Fidelity of Adult Whale Sharks to the Coastal Waters of Donsol, Philippines

摘要: Donsol in the Philippines is longest running community-based whale shark (Rhincodon typus) ecotourism site Southeast Asia, with peak visitation 2012 of over 27,000 tourists. In order to understand this aggregation and importance area sharks, dedicated photographic identification (photo-ID) research began 2007. In-water photo-ID surveys were conducted from tourism boats, weather operator permitting, December June between 2007 2016. Visual matches unique spot patterns each individual validated by pattern-recognition software Interactive Individual Identification System (I3S), on online database Wildbook for Whale Sharks (www.whaleshark.org). A total 1,985 trips 895 survey days resulted 6,786 encounters R. typus. Combined both citizen science dating back 1998, 479 sharks identified, making up 44% known population (n = 1,095). Of these, photographs pelvic region confirmed sex 158 males 22 females. size estimates ranged 2 10 m (mean ± S.D 6.5 ±1.6 m). Maturity (LT50) was estimated at 6.8 0.2 length, 53% considered mature. Annually, number individuals sighted varied 15 185 ( mean 104 55.53), a recruitment 3-90 new yearly 46.8 36.29). Modelled residency using maximum likelihood methods suggested spent 49.8 S.E. 14.5 (95% CI [32.3 – 78.6]) season, 47.1 60.8 any one time during season. Twenty recorded through other sites across Philippines. The extended Donsol, paired presence sexually mature animals economic value industry, highlights endangered species.