No abstract

Perceived crowding is an important measure in assessing the social impacts of tourism activities. The goal of this study was to determine if the method used to measure perceived crowding in the marine environment (numerical vs. visual approach, boat vs. swimmer crowding) affects the crowding outcome and to apply the concept to a high-density marine wildlife tourism site, viewing whale sharks in Oslob, Philippines. The influence of various variables, including specialization, gender, nationality, swimmer behaviors, and proximity, was also tested to see if they affected crowding levels. Results indicate that a visual approach is more accurate in measuring reported encounters and encounter norms, and that boat and swimmer crowding are not interchangeable. Boat crowding is a serious problem in Oslob (95.6% crowded). Specialization, nationality, and swimmer behaviors and proximity all affected perceived crowding. Individuals who reported feeling crowded were more likely to perceive negative impacts of tourism activities on the local community, whale sharks, and wider environment. They also showed higher levels of support for management interventions to limit the number of people and boats at the site and to better regulate or ban whale shark provisioning activities. This study provides important insights regarding how to measure perceived crowding in the marine environment and management implications for a mass tourism wildlife site experiencing overcrowding.

1. The ornate eagle ray Aetomylaeus vespertilio (Bleeker, 1852) is a rare and Endangered species of eagle ray, with a patchy distribution across the Indo-West Pacific region, for which data are scarce. 2. Citizen science-sourced data from online social media platforms were used to shed light on the distribution and ecology of the ornate eagle ray. 3. A total of 53 reports of A. vespertilio were found on Facebook, Instagram, Twitter, and YouTube, including four reports of dead specimens. All live reports occurred in shallow reef or lagoon ecosystems. Two individual A. vespertilio specimens were re-sighted in the same general area following initial identification within 9 and 13 months at Ningaloo Reef and at Lady Elliot Island, Australia, respectively, as confirmed through their dorsal spot patterns. One report was at Richard's Bay in South Africa, the southernmost known location for this species in the Indian Ocean (28°S). Live reports were also reported from the Maldives, the Seychelles, Egypt (Red Sea), Philippines, Palau, and elsewhere on the Great Barrier Reef, Australia. 4. Results indicate that citizen-collected data can shed light on the occurrence and distribution of cryptic species, as well as complement monitoring programmes.

Marine plastic abundance has increased over the past 60 years and microplastics (< 5 mm) constitute a primary component of such litter. Filter-feeding megafauna, such as the whale shark, might be particularly affected by microplastic pollution as their feeding mode requires filtration of up to thousands of cubic meters of water. In addition, the habitat range of whale sharks intersects with several recognized microplastic pollution hotspots, among which is the Coral Triangle. Direct evidence for microplastic ingestion in whale sharks however, has not yet been presented. Here we show that whale shark scat collected in the Philippines from 2012 to 2019 contained a mean of 2.8 microplastics g− 1. Contrary to our expectations, the microplastic concentration in the scat remained consistent from 2012 to 2019. Water samples from the study site in 2019 indicated that the local microplastic pollution (5.83 particles m− 3) was higher than in surface waters in other whale shark habitats, but well below other pollution hot-spots found in Southeast Asia and China (range: 100–4100 particles m− 3). With the predicted growth in plastic use, leading to increased plastic marine pollution, whale sharks are expected to become more exposed to this form of pollution. To what extent microplastic ingestion impacts the overall health status of this endangered species remains an open question.

The whale shark is the world's largest fish that forms predictable aggregations across its range, many of which support tourism industries. The largest non-captive provisioned whale shark destination globally is at Oslob, Philippines, where more than 500 000 tourists visit yearly. There, the sharks are provisioned daily, year-round, allowing the human–shark interaction in nearshore waters. We used in-water behavioural observations of whale sharks between 2015 and 2017 to understand the relationship between external stimuli and shark behaviour, whether frequency of visits at the site can act as a predictor of behaviour, and the tourist compliance to the code of conduct. Mixed effects models revealed that the number of previous visits at the site was a strong predictor of whale shark behaviour, and that provisioned sharks were less likely to exhibit avoidance. Compliance was poor, with 93% of surveys having people less than 2 m from the animal, highlighting overcrowding of whale sharks at Oslob. Given the behavioural implications to whale sharks highlighted here and the local community's reliance on the tourism industry, it is imperative to improve management strategies to increase tourist compliance and strive for sustainable tourism practices.