Arctic – Mammals (poster)
Skull Shape and Morphometry of ~ 1800-Year-Old Alaskan Polar Bear
Skull: Evidence for a New Polar Bear Subspecies?
Raphaela Stimmelmayr
North Slope Borough,
Aaron Morris
North Slope Borough,
Billy Adams
North Slope Borough,
Anne Jensen
North Slope Borough,
The evolutionary history of the polar bear is not well known and fossil records of the
polar bear are scarce. Very few specimens have been found in North America. The
general scarcity is attributed to polar bears “for the most part live and die on the pack
ice, making their preservation in terrestrial sediments exceptional”. In 2014, a well preserved
skull of a polar bear (Ursus maritimus Phipps, 1774) was discovered after a
cave in and wash out at Walakpa, Alaska. Carbon dating places the skull at ~ 1850 years
BP (before present). This is to our knowledge the oldest complete polar bear skull
remains ever discovered in Alaska. Genetic sexing is pending but we speculate the skull
is from a fully-grown male based on well-known sexual dimorphism in polar bears. Our
findings on skull morphometrics and comparative skull shape analysis suggest marked
differences between this skull and modern day and last century SBS and Chukchi polar
bear skull specimens. Our specimen is among the largest polar bear skulls ever reported.
Briefly, the skull is overall slender and it differs in height of the sagital crest, nasal width,
breadth at canines, breadth of palatine, length of the maxilla, the palatine and sphenoid
bone to name a few of the differences. Inuvialuit TEK discusses differences in polar bear
types namely “stubby bears versus Weasel bears”. The latter are rarely encountered and
characterized by great size > 11 ‘ and slender built of head and neck. Evidence for
geographic variations in polar bears skull size has been put forth by Manning (1969) for
circumpolar stocks and subsequently by Wilson (1974) for Alaskan stocks, but discussion
on subspecies recognition of polar bear stocks remains an open discussion. Phylogenetic
DNA analysis of the Alaskan specimen is needed to further clarify the relationship to
modern day polar bears.
Arctic – Mammals (poster)
Cryptorchidism and Associated Testicular Cancer in an Adult Male Spotted Seal: A Case Report
Hannah Braden
Lincoln Memorial University College of Veterinary Medicine,
Raphaela Stimmelmayr
North Slope Borough,
Andrea Rios Gonzalez
Tufts University Conservation Medicine Masters Program,
The incidence of neoplasia in marine mammals continues to be low, but as previously
reviewed by Smith and Newman (2006) “the literature documenting marine mammal
neoplasia is expanding gradually”. Among the pinnipeds, case reports about Arctic ice
seals are scarce, with only one case of an adenocarcinoma being reported in a ringed
seal (Phoca hispida). We report the first case of a unilateral testicular cancer in a
cryptorchid adult male spotted seal (Phoca largha). Briefly, in 2015, the animal was
found freshly dead at Peard Bay, Alaska (70°50′43″N 158°48′39″W.). As part of our
Arctic Marine Mammal Stranding Response efforts, the seal carcass was brought back to
Barrow for post-mortem examination. The animal was in excellent body condition and
had completed molt. During necropsy the right greatly enlarged testicle was located in
the abdominal cavity. Associated retroperitoneal lymph nodes and intra-thoracic lymph
nodes were enlarged. In humans, cryptorchidism is an established risk factor for the
development of testicular germ cell tumors (TGCT). We will present an overview of gross
and histopathological findings of this unique case report.
Arctic – Seabirds
Assessing Hydrocarbon Sensitivity and Measuring Current CYP1A Activity in Arctic Marine Birds and Waterfowl
Ann Riddle
University of Alaska Fairbanks,
Tuula Hollmen
University of Alaska Fairbanks,
Robert Suydam
North Slope Borough,
Robert Sarren
North Slope Borough,
Raphaela Stimmelmayr
North Slope Borough,
With prospects of development of oil and gas resources and commercial shipping in the
Chukchi and Beaufort seas, establishing reference data and assessing sensitivity of Arctic
wildlife to hydrocarbon exposure will provide essential information needed for
management and conservation for species potentially impacted by an oil spill. Targeting
a broad selection of Arctic marine birds and waterfowl, we used species-specific cell
culture to assess hydrocarbon sensitivity by measuring liver cytochrome P450 (CYP1A).
We have established reference CYP1A enzyme responses for liver cell lines in ten Arctic
marine bird species and a control bird species (mallard, Anas platyrhunchos) by exposing
cells for 24 hours to positive control reference reagents (e.g. the hydrocarbon
chrysene). We also exposed cell lines from five Arctic marine bird species and mallard
control to various amounts of Alaska North Slope crude oil to determine CYP1A activity
in a compound mixture. Results show differences in species response to control
reagents and crude oil. To measure levels of current CYP1A activity in Arctic birds we
validated field protocols for collecting liver samples from three bird species of
subsistence importance; king eiders (Somateria spectabilis), common eiders (Somateria
mollissima), and greater white-fronted geese (Anser albifrons). Birds were sampled near
Barrow, Alaska during spring and fall hunts over three years. Results suggest differences
in CYP1A enzyme activity levels among species and years. Cell culture sensitivity and
liver CYP1A activity results from this project provides valuable tools and information for
monitoring Arctic bird populations, identifying sensitive species, and future assessments
in the event of an oil spill.
Arctic – Mammals (oral presentation)
Frequency of Injuries from Line Entanglements, Killer Whales, and Ship Strikes On Bering-Chukchi-Beaufort Seas Bowhead Whales
J. Craig George
North Slope Borough,
Gay Sheffield
University of Alaska Fairbanks,
Dan Reed
Alaska Department of Fish & Game,
Barbara Tudor
North Slope Borough,
Raphaela Stimmelmayr
North Slope Borough,
Brian Person
North Slope Borough,
Todd Sformo
North Slope Borough,
Robert Suydam
North Slope Borough,
We analyzed scarring data for Bering-Chukchi-Beaufort (BCB) Seas bowhead whales
(Balaena mysticetus) harvested by Alaska Native hunters to quantify the frequency of
line entanglement (fishing gear), ship strikes, and killer whale inflicted injuries. We had
904 records in our long-term database for whales landed between 1990 and 2012, and
after data quality screening, found 521 records containing information on scarring.
Logistic regression was used to evaluate different combinations of explanatory variables
(i.e., body length, year, sex) to develop a prediction model for each scar type. We also
provide a list of bowheads entangled in commercial fishing gear that were harvested,
found dead, or observed alive. Our findings suggest that ~12% of harvested bowheads
show entanglement scars. The frequency of entanglement scars is highly correlated with
body length where ~50% of large bowheads (>17 m) exhibit entanglement scars while
whales < 9 m rarely show such scars. Scars associated with ship strikes are infrequent
and occur on ~2% of all harvested whales; body length was not a significant factor.
Scarring from attempted killer whale predation was evident on ~8% of landed whales.
As with entanglement injuries, the frequency of killer whale scars was much higher (>
40%) on whales >16 m and statistically more frequent in the second half of the study
(2002-2012). Increased killer whale injuries in the recent decade are consistent with
studies conducted on Eastern Canada-West Greenland bowheads. The findings
presented here reflect the most thorough analysis of injury rates from entanglement,
ships, and killer whales for the BCB bowheads conducted to date. They indicate that: (1)
entanglement rates from pot fishing gear (crab/cod) are relatively high (>40%) for very
large and presumably older bowheads, (2) collisions with ships are infrequent at
present, and (3) scarring from killer whales is frequent (~50%) on very large adult whales(> 17 m). Considering that bowhead habitat is changing rapidly (e.g., sea ice reduction),
industrial ship traffic in the Arctic is increasing, and commercial fishing operations are
expanding north, we strongly recommend that monitoring of scarring/injuries on
harvested bowheads continue into the future.
Arctic – Mammals (oral presentation)
Exposure Risks and Health Effects of Algal Toxins in Marine Mammals Using both Environmental Surveillance and Biomedical Laboratory Models
Kathi Lefebvre
NOAA Northwest Fisheries Science Center,
David Marcinek
University of Washigton,
Kathy Burek Huntington
Alaska Veterinary and Pathology Services,
Lori Quakenbush
Alaska Department of Fish & Game,
Anna Bryan
Alaska Department of Fish & Game,
Raphaela Stimmelmayr
North Slope Borough,
Gay Sheffield
University of Alaska Fairbanks,
Heather Ziel
NOAA Alaska Fisheries Science Center,
Tracey Goldstein
University of California, Davis,
Jonathon Snyder
U.S. Fish and Wildlfie Service,
Tom Gelatt
NOAA Alaska Fisheries Science Center,
Frances Gulland
The Marine Mammal Center,
Bobette Dickerson
NOAA Alaska Fisheries Science Center,
Verena Gill
Bureau of Ocean Energy Management,
The Wildlife Algal-Toxin Research and Response Network (WARRN-West) provides
environmental surveillance for the presence of algal toxins in marine wildlife from the
Arctic Ocean to Southern California. Over the last decade the program has analyzed
several thousand samples from stranded and harvested animals from more than a
dozen species. Additionally, the biomedical diagnostics part of this program has
performed controlled laboratory studies using mammalian models to identify health
effects of exposure to the algal toxin domoic acid. Data on the prevalence of algal toxins
in marine mammals as well as results from controlled laboratory studies will be
presented. The effects of acute high level exposure and chronic low-level exposure to
domoic acid will be compared. A new paradigm of chronic low-level toxicity has been
identified in which a reversible impairment of spatial memory, learning, and activity
occurs in the absence of gross morphological lesions in the brain of mammals.
Arctic – Mammals (poster)
Yesterday is Gone, Tomorrow Has Not Yet Come: Compound-Specific
Stable Isotopes of Polar Bear Bone Collagen over 2000 Years
Raphaela Stimmelmayr
North Slope Borough,
Lara Horstmann
University of Alaska Fairbanks,
Matthew McCarthy
University of California, Santa Cruz,
Polar bears (Ursus maritimus) are the internationally recognized face of Arctic climate
change and sea ice related habitat loss. In Alaska, two polar bear stocks are recognized,
the Southern Beaufort Sea (SBS) and the Chukchi Sea stock. The SBS stock is currently in
decline, and poor body condition, reduced fecundity, and survival have all been noted.
Sea ice loss, population recruitment, and increased land use by bears in response to the
rapidly changing Arctic are ongoing management concerns. We analyzed bone collagen
of SBS polar bears obtained from subsistence harvests (2006-2016; n=14), University of
Alaska Museum (1906-1971; n=7), and archeological digs (1850BP-1180BP; n=4) for bulk
stable isotopes (SI) and compound specific SI (CSI) of 12 individual amino acids (AA).
d15N of bulk collagen did not differ among present-day, historic, and ancient bears
(P=0.08), while 13C was significantly depleted in modern bears compared with historic
and ancient bears (P<0.0001, after Suess correction). This phenomenon has also been
observed in other Arctic marine mammals, e.g., pinnipeds, and may suggest an
increased sourcing of carbon from open-water phytoplankton over ice-associated
primary production. d15N of essential “source” AA (e.g., phenylalanine that change only
minimally in trophic transfer) did not differ among bears of the three gross time
groupings (P=0.60) indicating that baseline d15N values in the Arctic food web have
remained virtually unchanged. Threonine is a unique AA in its d15N systematics. Alone
among protein AA, threonine deamination involves an enzyme system, where the
catabolism leads to depletion rather than enrichment of 15N. This effect is more
pronounced in marine than terrestrial food webs. Interestingly, threonine was
significantly enriched in 15N of modern bears over historic and ancient animals
(P=0.008). There could be three reasons: 1) modern bears are in better body condition
than in the past; 2) the modern food web is shorter leading to less reworking of
nitrogen; and 3) modern bears rely more heavily on terrestrial food webs.
Arctic – Mammals (poster)
Prenatal Development of the Bowhead Whale and its Evolutionary
Implications
Hans Thewissen
Ohio Medical School,
Raphaela Stimmelmayr
North Slope Borough,
Craig George
North Slope Borough,
Robert Suydam
North Slope Borough,
Gay Sheffield
University of Alaska Fairbanks School of Fisheries,
This study reviews and characterizes fetal developmental landmarks of bowhead whales
(Balaena mysticetus). The subsistence harvest of bowhead whales in Northern Alaska
takes place during the Spring and Fall, and, occasionally, pregnant females are taken.
Bowheads gestation is approximately 14 months, and hence, prenatal specimens
collected from this harvest sample three ontogenetic periods: around 2 months, 8
months, and near full-term. These specimens elucidate morphological development that
is reminiscent of the evolution of cetaceans. For instance, the tail of the smallest
specimens in our collection is circular in cross-section, similar to the tail of land
mammals as well the tail of ancestral whales such as Pakicetus. In slightly older fetuses,
the tail expands laterally, and forms a diamond-shape. This is not a shape that is found
in in fossil whales, where some early cetaceans, such as Kutchicetus, had a long, narrow,
and flattened tail. Fetuses caught in fall as well as full term fetuses have a triangular
fluke, similar to postnatal animals. In evolution, this shape of fluke originated
approximately 45 million years ago, in the family Protocetidae. Spring caught Bowhead
whale fetuses show that more than 40 tooth buds are present in each jaw. These tooth
buds develop and are probably mineralized (as indicated by other baleen whales), but
are then resorbed. Adults of the fossil mysticete Aetiocetus polydentatus had a similar
numbers of teeth when it lived 35 million years ago. After the tooth buds disappear,
baleen forms, and bowheads are born with baleen approximately 10 cm long. In most
cetaceans, hind limb buds are formed early in ontogeny. Our early fetuses already show
the presence of internal cartilaginous precursors of pelvis, femur, and tibia. In adult
bowhead whales, pelvis and femur ossify, and a synovial joint occurs between them,
whereas the tibia usually remains cartilaginous. Occasionally, in postnatal bowhead
whales, the hind limb remnants are visible on the abdominal skin, which may show a
low welt, or an aberrant pigmentation pattern. Hind limbs were fully developed in most
Eocene cetaceans, and underwent a quick reduction in size and numbers of elements in
the late Eocene basilosaurids.
Arctic – Mammals (poster)
Out of Ice and Time – PATOU, the Mummified Ice Seal
Anne Jensen
North Slope Borough,
Aaron Morris
North Slope Borough,
Andrea Gonzalez
Tufts Conservation Medicine Masters Program,
Lara Horstman
University of Alaska Fairbanks School of Fisheries,
Raphaela Stimmelmayr
North Slope Borough,
Mummified specimens of pinnipeds are extremely rare and have only previously been
reported from the Antarctic. During the 2016 summer archeological excavation of the
Walakpa site, Alaska (Walakpa-Archaeological-Salvage-Project) several mummified
ringed seals were discovered in an traditional Inupiaq Sigiuaq [ice cellar). We report on
the initial forensic necropsy findings of “Patou”, as they relate to cause of death, carcass
desiccation patterns, in-situ and x-ray anatomy. Laboratory diagnostic findings including