[MARMAM] Plastic pollution within a marine protected area identifies threats for endangered northern bottlenose whales

[Laura Joan Feyrer]

>
> For those tracking trends in microplastic pollution and the impacts on
marine mammals, our latest collaborative publication: "Long term trends in
floating plastic pollution within a marine protected area identifies
threats for endangered northern bottlenose whales" is now available online
and is open access at: https://doi.org/10.1016/j.envres.2023.115686

Kelly, N.E., Feyrer, L., Gavel, H., Trela, O., Ledwell, W., Breeze, H.,
Marotte, E.C., McConney, L. and Whitehead, H., 2023. Long term trends in
floating plastic pollution within a marine protected area identifies
threats for endangered northern bottlenose whales. Environmental Research,
p.115686.

*Highlights*

• Plastics from multiple sources pollute an offshore marine protected area.
• The amount of large plastics decreased while small plastics increased
over time.
• Oceanographic features may trap plastics increasing encounter rates for
whales.
• Whales are ingesting plastics consistent with the types found in surface
waters.
• Plastic ingestion should be considered in recovery plans for endangered
whales.

*Abstract*

“The Gully”, situated off Nova Scotia, Canada, is the largest submarine
canyon in the western North Atlantic. This unique oceanographic feature,
which became a Marine Protected Area (MPA) in 2004, is rich in marine
biodiversity and is part of the critical habitat of Endangered northern
bottlenose whales (Hyperoodon ampullatus). To understand the potential
impact of plastic pollution in the MPA and on this endangered cetacean, we
evaluated trends over time in the abundance and composition of plastics and
compared these to the stomach contents of recently stranded northern
bottlenose whales. From the 1990s–2010s, the median abundance of
micro-sized (<5 mm) and small plastics (5 mm–2.5 cm) increased
significantly, while the median abundance of large plastics (>2.5 cm)
decreased significantly. Plastic abundance from the 2010s for micro-sized
and small plastics varied from 5586–438 196 particles km−2, higher than
previously measured estimates for surrounding offshore areas. Polymers
identified using FTIR spectroscopy included polyethylene, polypropylene,
polyethylene terephthalate polyester, nylon, alkyds (paint), and natural
and semi-synthetic cellulosic fibers. The abundance of large debris ranged
from 0 to 108.6 items km−2 and consisted of plastic sheets and bags, food
wrappers and containers, rope, fishing buoys, and small plastic fragments.
Whale stomach contents contained fragments of fishing nets, ropes, bottle
caps, cups, food wrappers, smaller plastic fragments, fibers, and paint
flakes, consistent with the composition and character of items collected
from their critical habitat. Despite being far from centres of human
population, the unique oceanographic features of The Gully (i.e., currents
and bathymetric complexity) may concentrate plastic debris, increasing
exposure rates of whales to plastic pollution. The increase in micro-sized
and small plastics over time suggests associated health and welfare impacts
of ingested plastics should be accounted for in future recovery plans for
this endangered species.
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[MARMAM] Publication: PhotoID Reveals the Threat of Entanglement for Endangered Northern Bottlenose Whales (Hyperoodon ampullatus)

[Laura Joan Feyrer]

Dear colleagues,

We would like to to share our new paper "Origin and Persistence of Markings
in a Long-Term Photo-Identification Dataset Reveal the Threat of
Entanglement for Endangered Northern Bottlenose Whales (Hyperoodon
ampullatus)" recently published as open access in Frontiers in Marine
Science.

Feyrer, L. J., Stewart, M., Yeung, J., Soulier, C., & Whitehead, H. (2021).
Origin and persistence of markings in a long-term photo-identification
dataset reveal the threat of entanglement for endangered northern
bottlenose whales (Hyperoodon ampullatus). Frontiers in Marine Science, 8,
349.

ABSTRACT
Photo-identification methods depend on markings that are stable over time.
Using a large dataset of photographs taken over a 31-year period, we
evaluate the reliability, rate of change and demographic trends in
different mark types on northern bottlenose whales (Hyperoodon ampullatus)
in the Endangered Scotian Shelf population, and assess the prevalence and
severity of anthropogenically caused markings. Only fin notches and back
indentations were stable over long timescales, leading to 48% of the
overall population being assessed as reliably marked. Males and mature
males were found to have higher incidence of most mark types compared to
females and juveniles. The proportion of reliably marked individuals
increased over time, a trend that should be accounted for in any temporal
analysis of population size using mark-recapture methods. An overall
increase in marked individuals may reflect the accumulation of scars on an
aging population post whaling. Anthropogenic markings, including probable
entanglement and propeller-vessel strike scars, occurred at a steady rate
over the study period and were observed on 6.6% of the population. The
annual gain rate for all injuries associated with anthropogenic
interactions was over 5 times the annual potential biological removal (PBR)
calculated for the endangered population. As entanglement incidents and
propeller-vessel strike injuries are typically undetected in offshore
areas, we provide the first minimum estimate of harmful human interactions
for northern bottlenose whales. With low observer effort for fisheries
across the Canadian Atlantic, photo-identification offers an important line
of evidence of the risks faced by this Endangered whale population.

Best,
Laura

https://www.frontiersin.org/articles/10.3389/fmars.2021.620804/full?_source=Email_to_authors__medium=Email_content=T1_11.5e1_author_campaign=Email_publication==Frontiers_in_Marine_Science=620804
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[MARMAM] New OA publication: Prolonged maternal care in northern bottlenose whales alters our understanding of beaked whale life history

[Laura Joan Feyrer]

New open access publication from the Northern Bottlenose Whale Project /
Whitehead Lab

Feyrer LJ, Zhao ST, Whitehead H, Matthews CJ. Prolonged maternal investment
in northern bottlenose whales alters our understanding of beaked whale
reproductive life history. PloS one. 2020 Jun 23;15(6):e0235114.

Nursing and weaning periods are poorly understood in cetaceans due to the
difficulty of assessing underwater behaviour in the wild. However, the
onset and completion of weaning are critical turning points for individual
development and survival, with implications for a species’ life history
including reproductive potential. δ15N and δ13C deposited in odontocete
teeth annuli provide a lifetime record of diet, offering an opportunity to
investigate variation and trends in fundamental biology. While available
reproductive parameters for beaked whales have largely been inferred from
single records of stranded or hunted animals and extrapolated across
species, here we examine the weaning strategy and nursing duration in
northern bottlenose whales (Hyperoodon ampullatus) by measuring stable
isotopes deposited in dentine growth layer groups (GLGs). Using a
collection of H. ampullatus teeth taken from whales killed during the
whaling era (N = 48) and from two stranded specimens, we compared
ontogenetic variation of δ15N and δ13C found in annual GLGs across all
individuals, by sex and by region. We detected age-based trends in both
δ15N and δ13C that are consistent across regions and males and females, and
indicate that nursing is prolonged and weaning does not conclude until
whales are 3–4 years old, substantially later than previous estimates of 1
year. Incorporating a prolonged period of maternal care into H. ampullatus
life history significantly reduces their reproductive potential, with broad
implications for models of beaked whale life history, energetics and the
species’ recovery from whaling.

A copy is freely available at: https://doi.org/10.1371/journal.pone.0235114

Cheers,

Laura Joan Feyrer
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[MARMAM] New publication on population structure and historical demography in northern bottlenose whales

[Laura Joan Feyrer]

For those interested in genetic assessments of population structure and
historical demography in cetaceans we have recently published our open
access study:

 Feyrer, L.J., Bentzen, P., Whitehead, H., Paterson, I.G. and Einfeldt, A.,
2019. Evolutionary impacts differ between two exploited populations of
northern bottlenose whale (Hyperoodon ampullatus). Ecology and Evolution.

https://onlinelibrary.wiley.com/doi/full/10.1002/ece3.5813

Abstract

Interpretation of conservation status should be informed by an appreciation
of genetic diversity, past demography, and overall trends in population
size, which contribute to a species' evolutionary potential and resilience
to genetic risks. Low genetic diversity can be symptomatic of rapid
demographic declines and impose genetic risks to populations, but can also
be maintained by natural processes. The northern bottlenose whale
Hyperoodon ampullatus has the lowest known mitochondrial diversity of any
cetacean and was intensely whaled in the Northwest Atlantic over the last
century, but whether exploitation imposed genetic risks that could limit
recovery is unknown. We sequenced full mitogenomes and genotyped 37 novel
microsatellites for 128 individuals from known areas of abundance in the
Scotian Shelf, Northern and Southern Labrador, Davis Strait, and Iceland,
and a newly discovered group off Newfoundland. Despite low diversity and
shared haplotypes across all regions, both markers supported the Endangered
Scotian Shelf population as distinct from the combined northern regions.
The genetic affinity of Newfoundland was uncertain, suggesting an area of
mixing with no clear population distinction for the region. Demographic
reconstruction using mitogenomes suggests that the northern region
underwent population expansion following the last glacial maximum, but for
the peripheral Scotian Shelf population, a stable demographic trend was
followed by a drastic decline over a temporal scale consistent with
increasing human activity in the Northwest Atlantic. Low connectivity
between the Scotian Shelf and the rest of the Atlantic likely compounded
the impact of intensive whaling for this species, potentially imposing
genetic risks affecting recovery of this population. We highlight how the
combination of historical environmental conditions and modern exploitation
of this species has had very different evolutionary impacts on structured
populations of northern bottlenose whales across the western North Atlantic.
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[MARMAM] First record of XXY in marine mammals and intersex sequencing method: new publication

[Laura Joan Feyrer]

On behalf of my co-authors I'm excited to announce our publication in the
Journal of Mammalogy which describes: (1) the first records of genetically
intersex cetaceans and (2) the sequencing method for determining XXY
chromosome condition in mammals.

Please contact Dr. Einfeldt (tony.einfe...@gmail.com) for a PDF.

Einfeldt, A. Orbach, D., & Feyrer, L.J. A method for determining sex and
chromosome copy number: sex-by-sequencing reveals the first two species of
marine mammals with XXY chromosome condition, Journal of Mammalogy, gyz131,
https://doi.org/10.1093/jmammal/gyz131

Abstract

Molecular assays of sex determination typically rely on qualitative
evaluation of sex-linked markers, which can lead to uncertainty when
results contradict morphological identifiers of sex. To investigate whether
disagreement between phenotypic and genotypic assays of sex could be
underpinned by variation in sex chromosome copy number, we developed a
quantitative genetic method to determine sex that is broadly applicable to
mammals with XY sex determination. We sequenced a region of the zinc-finger
gene ZF, which has fixed genetic differences between the X and Y
chromosomes, and screened 173 cetacean specimens for ZFX–ZFY haplotype
identity and read depth. Using a subset of 90 male specimens, we
demonstrate that haplotype read depth is an accurate estimator of
chromosome copy number. We identified three specimens representing two
different cetacean species that had external female morphological traits, Y
chromosome haplotypes, and ratios of ZFX:ZFY haplotypes that were above the
1:1 value expected for genetic males. These results provide the first
evidence of XXY aneuploidy in cetaceans. Investigation of the reproductive
tract of one specimen, a True’s beaked whale (Mesoplodon mirus), revealed
an intersex phenotype; despite having external characteristics typically
diagnostic for the female sex, a penis and testes were present. Our results
suggest that intersex phenotypes may be associated with XXY aneuploidy, and
that this phenomenon may be underestimated due to it not being detectable
by qualitative assays for determining sex.
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[MARMAM] new publication on beaked whale acoustics

[Laura Joan Feyrer]

For those interested in beaked whale acoustics, we are pleased to announce
our publication "Click characteristics of northern bottlenose whales
(Hyperoodon ampullatus) and Sowerby's beaked whales (Mesoplodon bidens) off
eastern Canada," has been published in The Journal of the Acoustical
Society of America (Vol.146, No.1). It can be found online at
https://doi.org/10.1121/1.5111336 DOI: 10.1121/1.5111336

ABSTRACT
Passive acoustic monitoring (PAM) is crucial to expanding the knowledge of
beaked whales, including the northern bottlenose whale (Hyperoodon
ampullatus) and Sowerby's beaked whale (Mesoplodon bidens). Existing
descriptions of clicks produced by these species are limited by sample
size, number of individuals recorded, and geographic scope. Data from
multiple encounters in the western North Atlantic are used to provide a
quantitative description of clicks produced by these species. Recordings
from nine encounters with northern bottlenose whales in Nova Scotia and
Newfoundland were analyzed (N = 2239 clicks). The click type described had
a median peak frequency of 25.9 kHz (10th–90th percentile range: 22.9–29.3
kHz), and a median inter-click interval (ICI) of 402 ms (N = 1917,
10th–90th percentile range: 290–524 ms). Recordings from 18 Sowerby's
beaked whale encounters from Nova Scotia were analyzed (N = 762 clicks).
The click type described had a median peak frequency of 65.8 kHz (10th–90th
percentile range: 61.5–76.5 kHz), and a median ICI of 237 ms (N = 677,
10th–90th percentile range: 130–315 ms). These results will contribute to
the development of methods to detect and classify beaked whale clicks to
the species level, improving the effectiveness of PAM and enhancing
scientific understanding and conservation efforts for cryptic and at-risk
cetaceans.


Cheers,

Laura Feyrer, PhD Candidate
Dalhousie University
Northern Bottlenose Whale Project
https://northernbottlenosewhale.weebly.com/

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[MARMAM] New Publication of first Mitogenome for Sowerby's and True's Beaked whales

[Laura Joan Feyrer]

A technical note that may be of interest for the marine mammal science
community:

"Complete mitochondrial genomes and phylogeny of two rare whale species:
True’s (Mesoplodon mirus: True 1913) and Sowerby’s (Mesoplodon bidens:
Sowerby 1804) beaked whales"

Beaked whales of the genus Mesoplodon are rarely encountered and
information on their basic biology is lacking. We sequenced the complete
mitochondrial genomes of True’s (Mesoplodon mirus) and Sowerby’s
(Mesoplodon bidens) beaked whales to high depth (>120X). The length of the
de novo assembled genomes was 16,342 bp (M. mirus) and 16,347 bp (M.
bidens), with GC compositions of 37.7 and 39.2%, respectively. A
maximum-likelihood phylogeny supports the hypotheses that M. mirus is most
closely related to Mesoplodon europaeus, and that M. bidens is the basal
species of the genus. These data provide molecular resources that will aid
in further understanding population genetics and evolution in this rare and
poorly understood group of cetaceans.


Anthony L. Einfeldt, Ian G. Paterson & Laura J. Feyrer (2019) Complete
mitochondrial genomes and phylogeny of two rare whale species: True’s
(Mesoplodon mirus: True 1913) and Sowerby’s (Mesoplodon bidens: Sowerby
1804) beaked whales, Mitochondrial DNA Part B, 4:1, 275-276, DOI:
10.1080/23802359.2018.1541719

Available at:
https://www.tandfonline.com/doi/full/10.1080/23802359.2018.1541719

Cheers,

Laura Feyrer
@deepdivewhales

Whitehead Lab
Biology Dept.
Dalhousie University
Halifax, NS
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