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Anthropogenic Contaminants and Histopathological Findings in Stranded Cetaceans in the Southeastern United States, 2012–2018

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Anthropogenic contaminants in the marine environment often biodegrade slowly,

bioaccumulate in organisms, and can have deleterious effects on wildlife immunity,

health, reproduction, and development. In this study, we evaluated tissue toxicant

concentrations and pathology data from 83 odontocetes that stranded in the

southeastern United States during 2012–2018. Mass spectrometry was used to

analyze blubber samples for five organic toxicants (atrazine, bisphenol-A, diethyl

phthalates, nonylphenol monoethoxylate [NPE], triclosan), and liver samples were

analyzed for five non-essential elements (arsenic, cadmium, lead, mercury, thallium),

six essential elements (cobalt, copper, manganese, iron, selenium, zinc) and one

toxicant mixture class (Aroclor1268). Resultant data considerably improve upon the

existing knowledge base regarding toxicant concentrations in stranded odontocetes.

Toxicant and element concentrations varied based on animal demographic factors

including species, sex, age, and location. Samples from bottlenose dolphins had

significantly higher average concentrations of lead, manganese, mercury, selenium,

thallium, and zinc, and lower average concentrations of NPE, arsenic, cadmium, cobalt,

and iron than samples from pygmy sperm whales. In adult female bottlenose dolphins,

average arsenic concentrations were significantly higher and iron concentrations were

significantly lower than in adult males. Adult bottlenose dolphins had significantly higher

average concentrations of lead, mercury, and selenium, and significantly lower average

manganese concentrations compared to juveniles. Dolphins that stranded in Florida had

significantly higher average concentrations of lead, mercury, and selenium, and lower

concentrations of iron than dolphins that stranded in North Carolina. Histopathological

data are presented for 72 animals, including microscopic evidence of Campula spp.

and Sarcocystis spp. infections, and results of Morbillivirus and Brucella spp. molecular

diagnostic testing. Sublethal cellular changes related to toxicant exposure in free-ranging

odontocetes may lead to health declines and, in combination with other factors, may

contribute to stranding.

Keywords: dolphins, endocrine disrupting


About the author

Dr. Howard Dryden

Dr. Howard Dryden

Dr. Dryden has unique knowledge combination of biology, chemistry and technology and is the inventor of the activated, bio-resistant filter media AFM®. Dr. Dryden is one of the world`s leading experts in sustainable water treatment.

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Life on earth depends upon healthy Oceans, we have 10 years to stop toxic chemical pollution, or life on earth may become impossible

Dr. Howard Dryden, CSO

Goes Foundation

Roslin Innovation Centre
The University of Edinburgh
Easter Bush Campus
Midlothian EH25 9RG