Craig A. Harms

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.

Fibropapillomatosis is a debilitating tumor disease of sea turtles that is sometimes
fatal. This disease is a key concern for sea turtle rehabilitation facilities due to its infectious nature,
as it is associated with a virus called chelonid alphaherpesvirus 5. This is the first study to analyze
antibodies to this virus in loggerhead sea turtles and represents the most complete dataset on
viral detection in sea turtles encountered in the more northern latitudes of their habitat in the
western Atlantic.

Fibropapillomatosis (FP), a debilitating, infectious neoplastic disease, is rarely reported
in endangered Kemp’s ridley sea turtles (Lepidochelys kempii). With this study, we describe FP and
the associated chelonid alphaherpesvirus 5 (ChHV5) in Kemp’s ridley turtles encountered in the
United States during 2006–2020. Analysis of 22 case reports of Kemp’s ridley turtles with FP revealed
that while the disease was mild in most cases, 54.5% were adult turtles, a reproductively valuable
age class whose survival is a priority for population recovery. Of 51 blood samples from tumor-free
turtles and 12 tumor samples from turtles with FP, 7.8% and 91.7%, respectively, tested positive for
ChHV5 DNA via quantitative polymerase chain reaction (qPCR). Viral genome shotgun sequencing
and phylogenetic analysis of six tumor samples show that ChHV5 sequences in Kemp’s ridley
turtles encountered in the Gulf of Mexico and northwestern Atlantic cluster with ChHV5 sequences
identified in green (Chelonia mydas) and loggerhead (Caretta caretta) sea turtles from Hawaii, the southwestern Atlantic Ocean, and the Caribbean. Results suggest an interspecific, spatiotemporal
spread of FP among Kemp’s ridley turtles in regions where the disease is enzootic. Although FP is
currently uncommon in this species, it remains a health concern due to its uncertain pathogenesis
and potential relationship with habitat degradation.