Spatial patterns of shark-inflicted injuries on coastal bottlenose dolphins in the Mesoamerican Reef System

ABSTRACT

Understanding predator–prey relationships is critical in ecology, but relatively challenging when investigating elusive marine megafauna. In this study, we document the presence of shark-inflicted injuries on coastal bottlenose dolphins (Tursiops truncatus) in the Mesoamerican Reef System using photo-identification methods. We analyzed data from a total of 533 photo-identified bottlenose dolphins in Mexico (Ascención Bay, Espíritu Santo Bay, and Chetumal Bay), Belize (Turneffe Atoll, Drowned Cayes, Barrier Reef, and Placencia), and Honduras (Utila). We identified 16 individuals with shark-inflicted injury scars consistent with attacks by large sharks of the Family Carcharhinidae. Additionally, two bottlenose dolphins were encountered with round-shaped crater wounds, likely inflicted by a cookiecutter shark (Isistius spp.). The prevalence of shark-inflicted wounds in bottlenose dolphins varied markedly between sites, with the highest prevalence in Placencia and Ascención Bay (Mexico), and lowest in Turneffe Atoll and Drowned Cayes (Belize). Further research is required to evaluate how predation risk shapes the ecology of bottlenose dolphins in the Mesoamerican Reef region.

KEYWORDS:

• Shark bites
• Tursiops truncatus
• cetaceans
• carcharhinids
• cookiecutter sharks
• Caribbean

Acknowledgments

The authors wish to thank the institutions and people that made possible the long-term collection of photo-identification data of bottlenose dolphins in the MARS: Elderhostel and TIDE. We owe thanks to Earthwatch and Oceanic Society for in-kind support through boat-based ecotourism and citizen monitoring programs.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was partially supported by the Comisión de Áreas Naturales Protegidas of Mexico (PROCER/CER /153/2018 and PROREST/CER/55/2019).