Foraging habits and levels of mercury in a resident population of bottlenose dolphins (Tursiops truncatus) in Bocas del Toro Archipelago, Caribbean Sea, Panama. (August 2019)

• Record Type: Journal Article
• Authors: Barragán-Barrera, Dalia C.; Luna-Acosta, Andrea; May-Collado, Laura J.; Polo-Silva, Carlos J.; Riet-Sapriza, Federico G.; Bustamante, Paco; Hernández-Ávila, María Paula; Vélez, Natalia; Farías-Curtidor, Nohelia; Caballero, Susana
• Is Part Of: Marine pollution bulletin. Volume 145(2019)
• Page Start: 343
• Page End: 356
• Publication Date: 2019-08
• Subjects: Tursiops truncatus -- Inshore form -- Bocas del Toro -- Bioaccumulation -- Stable isotopes; Marine pollution -- Periodicals; Marine Biology -- Periodicals; Water Pollution -- Periodicals; Mer -- Pollution -- Périodiques; Publications périodiques; Pollution des mers; Lutte antipollution; Electronic journals; 363.7394
• DOI: 10.1016/j.marpolbul.2019.04.076
• Languages: English
• ISSNs: 0025-326X

Abstract

Abstract: A small and genetically isolated bottlenose dolphin ( Tursiops truncatus ) population resides year-round in the Bocas del Toro Archipelago-Panama (BDT). Photo-identification and genetic data showed that this dolphin population is highly phylopatric and is formed exclusively by individuals of the "inshore form". This study aimed to investigate the trophic ecology and mercury concentrations of bottlenose dolphins in BDT to assess their coastal habits. We collected muscle samples ( n = 175) of 11 potential fish prey species, and skin samples from free-ranging dolphins in BDT ( n = 37) and La Guajira-Colombia ( n = 7) to compare isotopic niche width. Results showed that BDT dolphins have a coastal feeding habit, belong to the "inshore form" (δ 13 C = −13.05 ± 1.89‰), and have low mercury concentrations (mean = 1637 ± 1387 ng g −1 dw). However, this element is biomagnified in the BDT food chain, showing a marginal dolphins health risk ( RQ = 1.00). We call for a monitoring pollutant program and conservation strategies aimed to protect the dolphin population at BDT. Highlights: The bottlenose dolphin population in Bocas del Toro (BDT, Panama) is vulnerable to anthropogenic activities. Dolphins in BDT are isolated in the Caribbean and have strictly coastal habits. Mercury (Hg) is bioaccumulating and magnifying in the BDT marine food chain. Dolphins show a marginal health risk due to Hg exposure. Monitoring temporal trends of Hg concentration in BDT is needed to assess potential effects on biota.