Format

Send to

Choose Destination
Environ Manage. 2019 Feb;63(2):282-291. doi: 10.1007/s00267-018-1125-3. Epub 2018 Dec 4.

Whale Shark Tourism: Impacts on Coral Reefs in the Philippines.

Author information

1
The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Hong Kong Special Administrative Region, China.
2
University of Guam Marine Laboratory, UOG Station, Mangilao, GU, 96923, USA.
3
Department of Earth Sciences, The University of Hong Kong, Hong Kong Special Administrative Region, China.
4
Large Marine Vertebrates Research Institute Philippines, Cagulada Compound, Barangay Tejero, Jagna, Bohol, 6308, Philippines.
5
The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Hong Kong Special Administrative Region, China. dmbaker@hku.hk.

Abstract

Reef-based tourism has been developing rapidly in recent decades yet its impacts on reef ecosystems are often overlooked. In Tan-awan, Oslob, Philippines, whale sharks are attracted to the shallow reefs where they are provisioned up to 50 tons y-1 of feed and this phenomenon in turn attracts >300,000 y-1 visitors. Given the intensive provisioning and concentrating tourism activities, we hypothesized that the whale shark tourism-impacted site (IS) will have greater impacts on reef degradation and higher anthropogenic nitrogen pollution level compared to its reference site (RS). Ecological surveys revealed that relative to the RS, the IS had 36% higher relative abundance of Pocillopora and Porites coral over other genera, >2.5-fold lower coral density, and 20% higher macroalgal cover, which we concluded are signs of reef degradation. Also, we conducted stable nitrogen isotope analysis on gorgonian skeletons to trace nitrogen sources at both sites through time. Although an average 1‰ isotope enrichment found in the IS relative to the RS could indicate anthropogenic nitrogen inputs in the IS, this enrichment was consistent over time and existed before the tourism developed. Despite that, we cautioned against the imminent threat of local eutrophication caused by the continued inputs of nitrogen derived from provisioning and tourism activities. In summary, this study provided the first documentation of the impacts of provisioned whale shark tourism on the local reefs in Tan-awan and established an ecological baseline for future comparisons. Such assessments can offer important information on reef health, coastal development, and tourism management.

KEYWORDS:

Coastal development; Eutrophication; Reef degradation; Retrospective isotope analysis; Tourism management; Whale shark tourism

PMID:
30515531
DOI:
10.1007/s00267-018-1125-3

Supplemental Content

Full text links

Icon for Springer
Loading ...
Support Center