[MARMAM] New publication on Persistent Organic Pollutants and mercury in bottlenose dolphins from the Gulf of Guayaquil, Ecuador

Juan Jose Alava jj_alava at yahoo.com
Thu Jun 18 14:50:02 PDT 2020

DearMarmam colleagues,

II trust this message finds you well.

In behalf of my co-authors, I pleasedto share a new paper on “PersistentOrganic Pollutants and Mercury in Genetically Identified Inner EstuaryBottlenose Dolphin (Tursiops truncatus)Residents of the Guayaquil Gulf, Ecuador: Ecotoxicological Science in Supportof Pollutant Management and Cetacean Conservation,” which is the first contribution on the ecotoxicological assessment of persistent organic pollutants (POPs)and mercury in a small cetacean species in Ecuador’s continental coast, and oneof the first ones along the Pacific coast of South America. 


This article is an Open Access paper and can be found at the following links;




Fulldetails and abstract:

Citation: Alava JJ*, Calle P,Tirapé A, Biedenbach G, Alvarado Cadena O, Maruya K, Lao W, Aguirre W, JiménezPJ, Domínguez GA, Bossart GD and Fair PA (2020) Persistent Organic Pollutantsand Mercury in Genetically Identified Inner Estuary Bottlenose Dolphin (Tursiopstruncatus) Residents of the Guayaquil Gulf, Ecuador: EcotoxicologicalScience in Support of Pollutant Management and Cetacean Conservation. Front.Mar. Sci. 7:122. doi: 10.3389/fmars.2020.00122 


*Correspondence: Juan José Alava, j.alava at oceans.ubc.ca; jalavasa at sfu.ca


Published: 20 March 2020.



Thebottlenose dolphin is one of the most common cetaceans found in the coastal waters,estuaries, and mangroves of Ecuador. However, its population size is graduallydeclining in the Gulf of Guayaquil, and anthropogenic factors including habitatdegradation, uncontrolled dolphin watching, dredging activities, increasingmaritime traffic, underwater noise, bycatch, and marine pollution have beenimplicated in their decline. Very little is known about contamination bypersistent organic pollutants (POPs) and mercury in bottlenose dolphins fromthe Pacific coast of South America. To address this research gap, the firstassessment of total mercury (THg) and POPs, including polychlorinated biphenyls(PCBs), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers(PBDEs), in free-ranging bottlenose dolphins in mangroves (El Morro MangroveWildlife Refuge) of the Gulf of Guayaquil, was conducted in Ecuador in 2018.Dolphin samples (i.e., skin and blubber; n = 9), were obtained usingdart biopsy field methods for contaminant analysis. POP concentrations rangedfrom 0.56 to 13.0 mg/kg in lipid weight, while THg ranged from 1.92 to 3.63mg/kg in dry weight. The predominant POPs were OCPs (50% of ΣPOP), followed byPCBs (46%) and PBDEs (6.0%); particularly, p,p′-DDE, the main DDTmetabolite and a potent anti-androgenic, accounting for 42% of ΣPOP, rangingfrom 0.12 to ∼7.0 mg/kg lw, followed by PCB 153 (8.0%)and PCB 180 (5.0%). PBDE 47 accounted for 2.0% of ΣPOP. While the POPconcentrations are lower than those found in dolphins from many other regionsof the world, some of the THg concentrations are within the concentration rangefound in dolphins from the southeastern coast of the United States. Theecotoxicological risk assessment showed that some of the sampled dolphins areexposed to immunotoxic and endocrine disruption effects by POPs and mercury.The low genetic diversity of this distinctive dolphin population, likelyexhibiting genetic isolation and a unique evolutionary heritage, could be lostif the population continues to decline in the face of anthropogenic threats,including chemical pollution. Our finding shows that bottlenose dolphins incoastal Ecuador are exposed to environmental contaminants and can be used assentinel species for ecosystem health to monitor pollution in the region and tosupport ecotoxicological risk assessment and regional pollutant management.

Keywords: contaminants, POPs, organic mercury, marine mammals,toxicological risk assessment, mangroves, Gulf of Guayaquil, South America
Wishingyou all well and stay safe.
JuanJose Alava-------------------- 
 Juan Jose Alava, PhD.
 Research Associate, Nippon Foundation-Ocean Litter Project
   Principal Investigator, Ocean Pollution Research Unit (OPRU)
 Institute for the Oceans and Fisheries 
 Faculty of Science, The University of British Columbia 
 AERL 2202 Main Mall | Vancouver, BC V6T 1Z4 Canada
Adjunct Professor
Resource and Environmental Management, Faculty of Environment, 
Simon Fraser University
8888 University Drive, 
Burnaby, British Columbia V5A 1S6,Canada
E-mail: jalavasa at sfu.ca 

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