[MARMAM] New publication on killer whale calls around Iceland

[Anna Selbmann]

Dear colleagues,

We are pleased to share the publication of a new paper on killer whale calls 
around Iceland.

Selbmann A, Deecke VB, Filatova OA, Fedutin ID, Miller PJO, Simon M, Bowles AE, 
Lyrholm T, Lacey C, Magnúsdóttir EE, Maunder W, Wensveen PJ, Svavarsson J, 
Samarra FIP. Call type repertoire of killer whales (Orcinus orca) in Iceland 
and its variation across regions. Marine Mammal Science 
https://doi.org/10./mms.13039 

Abstract
Killer whales (Orcinus orca) have group-specific call repertoires that can be 
used to track groups and populations using passive acoustic monitoring. To 
provide a detailed description of the Icelandic killer whale repertoire and its 
variation, we analyzed acoustic data collected in five locations between 1985 
and 2016. Calls were classified manually, and CART and random forest analyses 
were employed to validate the manual classification. A total of 91 call 
categories (including call types and subtypes) were defined. Most call 
categories were recorded in more than one location, with the highest proportion 
shared between herring grounds in Vestmannaeyjar (South) and Breiðafjörður 
(West). However, both locations included call categories that were not recorded 
elsewhere in Iceland. Recordings from past herring wintering grounds in eastern 
Iceland included few call categories that matched other locations. Sample sizes 
from Reykjanes (Southwest) and Skjálfandi (North) were small and did not 
include unique call categories. The relative occurrence of call categories in 
Vestmannaeyjar changed little over a 14-year period (2002–2016), although 
shorter-term changes between years were observed that appeared to correlate to 
changes in individuals identified. This comparison of acoustic repertoires 
provides valuable information on the social structure and movement patterns of 
herring-eating killer whales around Iceland.

Available at: https://onlinelibrary.wiley.com/doi/full/10./mms.13039
Soon to be Open Access but in the meantime feel free to get in touch for a PDF.

Anna Selbmann

PhD Candidate
Faculty of Life and Environmental Sciences
University of Iceland
Sturlugata 7
101 Reykjavík, Iceland
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[MARMAM] New publication: Cheap gulp foraging of a giga-predator enables efficient exploitation of sparse prey

[Simone Kristine Alexandra Videsen]

Dear MARMAM community,

We are pleased to share our recent publication in Science Advances:

Videsen SK, Simon M, Christiansen F, Friedlaender A, Goldbogen J, Malte H, 
Segre P, Wang T, Johnson M, Madsen PT. Cheap gulp foraging of a giga-predator 
enables efficient exploitation of sparse prey. Science Advances. 9 (25) : 
eade3889.
https://www.science.org/doi/10.1126/sciadv.ade3889

Abstract
The giant rorqual whales are believed to have a massive food turnover driven by 
a high-intake lunge feeding style aptly described as the world's largest 
biomechanical action. This high-drag feeding behavior is thought to limit dive 
times and constrain rorquals to target only the densest prey patches, making 
them vulnerable to disturbance and habitat change. Using biologging tags to 
estimate energy expenditure as a function of feeding rates on 23 humpback 
whales, we show that lunge feeding is energetically cheap. Such inexpensive 
foraging means that rorquals are flexible in the quality of prey patches they 
exploit and therefore more resilient to environmental fluctuations and 
disturbance. As a consequence, the food turnover and hence the ecological role 
of these marine giants have likely been overestimated.

Best regards,

Simone K. A. Videsen
Postdoctoral Researcher
Department of Biology - Zoophysiology
Aarhus University
Marine Bioacoustics lab
simone.vide...@bio.au.dk

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[MARMAM] New Paper Available

[Thomas Jefferson]

Dear MARMAMers,  My co-authors and I are pleased to announce the publication of 
the following paper:
 Jefferson, T. A., M. A. Smultea and E. J. Ward. (2023). Distribution and 
Abundance of California (Zalophus californianus) and Steller (Eumetopias 
jubatus) Sea Lions in the Inshore Waters of Washington, 2013-2016. Aquatic 
Mammals, 49, 366-381. https://doi.org/10.1578/am.49.4.2023.366ABSTRACT:  
Two species of sea lions occur in the inlandwaters of Washington State, the 
California sea lion (Zalophus californianus) and Steller sea lion (Eumetopias 
jubatus). Both species breed elsewhere, but typically moveinto Puget Sound and 
adjacent waters of the Salish Sea from autumn throughspring months.  There is a 
need forinformation on their current abundance and seasonal use patterns, as 
bothspecies prey heavily on threatened/endangered stocks of salmon and 
steelheadtrout (Oncorhynchus spp.), andempirical abundance estimates of these 
species are lacking for inlandWashington waters. From 2013-2016, we conducted 
39,399 km of aerial surveys formarine mammals in this area, sighting 255 groups 
of sea lions.  We used a subset of 7,841 km of effort and165 sea lion sightings 
made during surveys in good sighting conditions toestimate in-water abundance 
using line-transect methods.  Historical tagging data collected in 
PacificNorthwest waters were used to evaluate the proportions of time that 
eachspecies spent on land and conducting dives, and then to develop 
correctionfactors to derive total abundance for both sea lion species, 
providing the firstempirical abundance estimates for these waters. We estimated 
that between 33 and 442 California sea lions were found inPuget Sound/Hood 
Canal in different seasons, with nearly 3,000 being found in thebroader inland 
Washington waters in the peak season (spring).  Steller sea lions occurred in 
much smallernumbers, with a peak of 219 animals in Puget Sound/Hood 
Canal/Strait of Juan deFuca in autumn (and possibly as many as 600-700 in the 
entire study area). Whilesome estimates suffer from low precision, this study 
demonstrates thatsubstantial numbers of sea lions use waters of the study area 
throughout muchof the year.  Our results provide animportant step toward better 
understanding of these two species in the inlandwaters of Washington, as well 
as their potential effects on protected salmonidprey species.

  The paper is available upon request or from the Aquatic Mammals website.
Tom Jefferson
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[MARMAM] Aquatic Mammals - issue 49.4 is available online

[Kathleen Dudzinski]

Dear MARMAM Subscribers,
 
Happy Summer! 
The 4th issue of volume 49 (49.4) of Aquatic Mammals journal is available 
online and will be officially published on Saturday (15 July). 
 
Further information about the journal can be found at: 
http://www.aquaticmammalsjournal.org/
To submit a manuscript for publication consideration, please visit: 
http://am.expressacademic.org/actions/author.php
 
With regards,
 
Kathleen M. Dudzinski, Ph.D.
Editor, Aquatic Mammals Journal
busin...@aquaticmammalsjournal.org 

Articles with ** are open access:

Jing Sun, Fangting Lu, Baolin Liao, Baohua Xiao, Min Li, Linyun He, Ling Bai, 
and Bingyao Chen. (2023). A Young Eden’s Whale (Balaenoptera edeni edeni) 
Wandering in a Busy International Container Port. Aquatic Mammals, 
49(4),321-328.
 
**David A. Waugh, Jennifer D. Sensor, John C. George, and J. G. M. Thewissen. 
(2023). Auditory Health of Bowhead Whales. Aquatic Mammals, 49(4), 329-335.

**Don R. Bergfelt, Maria Vences, Meghan Smallcomb, Roberto Sanchez-Okrucky, and 
Rocio Canales. (2023). Circulating Concentrations of Cortisol Encompassing 
Controlled Cessation of Suckling During Weaning Under Managed Care in Cow and 
Calf Bottlenose Dolphins (Tursiops truncatus). Aquatic Mammals, 49(4), 336-346.

Shannia Iskandar, Julia Adelsheim, and David A. S. Rosen. (2023). The Effects 
of Age and Sex on the Energy Intake of Captive Sea Otters (Enhydra lutris): 
Implications for Captive Management and Species Conservation. Aquatic Mammals, 
49(4), 347-355.
 
Wojtek Bachara, Mika Kuroda, Shin Nishida, Hajime Ishikawa, and Takashi Fritz 
Matsuishi. (2023). Northernmost Record of the Ginkgo-Toothed Beaked Whale 
(Mesoplodon ginkgodens). Aquatic Mammals, 49(4), 356-365.
 
**Thomas A. Jefferson, Mari A. Smultea, and Eric J. Ward. (2023). Distribution 
and Abundance of California (Zalophus californianus) and Steller (Eumetopias 
jubatus) Sea Lions in the Inshore Waters of Washington, 2013-2016. Aquatic 
Mammals, 49(4), 366-381.
 
**Cristina Castro, Marcia H. Engel, and Anthony R. Martin. (2023). First 
Humpback Whale Movement Between Ecuador and the South Sandwich Islands: 
Redefines the Easternmost Migration Point of Breeding Stock G. Aquatic Mammals, 
49(4), 382-387.
 
Victoria Luong, Kevin L. Woo, Kristy L. Biolsi, Bjoern Kils, and Preethi 
Radhakrishnan. (2023). Directional Orientation of Harbor (Phoca vitulina) and 
Gray (Halichoerus grypus) Seals at Haul-out Locations in New York City. Aquatic 
Mammals, 49(4), 388-394.
 
Alexandra M. McGowan, Jennifer M. Seddon, Janet M. Lanyon, Nicholas Clark, and 
Justine S. Gibson. (2023). Identification of Antimicrobial Resistance in Faecal 
Microbes from Wild Dugongs (Dugong dugon). Aquatic Mammals, 49(4), 395-405
 
**MaryEllen Mateleska. (2023). Book Review: We Are All Whalers: The Plight of 
Whales and Our Responsibility. Aquatic Mammals, 49(4), 406.
 
**Martin Böye. (2023). Letter to the Editor: EAAM Symposium: Marine Mammals in 
Need: Let People Know that We Are Part of the Solution. Aquatic Mammals, 49(4), 
407-408.
 
**Kathleen Dezio. (2023). Letter to the Editor: 2023 AMMPA Annual Meeting. 
Aquatic Mammals, 49(4), 409-410.


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[MARMAM] Shining light on dolphin physiology

[Andreas Fahlman]

Dear MarMamers
We would like to share our new open-access publication that investigated the 
use of Near Infrared Spectroscopy as a non-invasive tool to study physiology in 
the bottlenose dolphin. We report preliminary data which indicate that this 
technology allows us to measure blood flow and tissue and blood oxygenation in 
this dolphins. The details about the paper can be found below, and please send 
me or Alex Ruesch (arue...@andrew.cmu.edu) an email if you have any questions.
Sincerely,
Andreas

Title: Evaluating feasibility of functional near-infrared spectroscopy in 
dolphins
Authors: Ruesch, A., Acharya, D., Bulger, E., Cao, J., McKnight, J. C., Manley, 
M., Fahlman, A., Shinn-Cunningham, B. G. and Kainerstorfer, J. M.
Journal: Journal of Biomedical Optics
doi: 10.1117/1.JBO.28.7.075001
Abstract: Significance: Using functional near-infrared spectroscopy (fNIRS) in 
bottlenose dolphins (Tursiops truncatus) could help to understand how 
echolocating animals perceive their environment and how they focus on specific 
auditory objects, such as fish, in noisy marine settings.
Aim: To test the feasibility of near-infrared spectroscopy (NIRS) in 
medium-sized marine mammals, such as dolphins, we modeled the light propagation 
with computational tools to determine the wavelengths, optode locations, and 
separation distances that maximize sensitivity to brain tissue.
Approach: Using frequency-domain NIRS, we measured the absorption and reduced 
scattering coefficient of dolphin sculp. We assigned muscle, bone, and brain 
optical properties from the literature and modeled light propagation in a 
spatially accurate and biologically relevant model of a dolphin head, using 
finite-element modeling. We assessed tissue sensitivities for a range of 
wavelengths (600 to 1700 nm), source-detector distances (50 to 120 mm), and 
animal sizes (juvenile model 25% smaller than adult).
Results: We found that the wavelengths most suitable for imaging the brain fell 
into two ranges: 700 to 900 nm and 1100 to 1150 nm. The optimal location for 
brain sensing positioned the center point between source and detector 30 to 50 
mm caudal of the blowhole and at an angle 45 deg to 90 deg lateral off the 
midsagittal plane. Brain tissue sensitivity comparable to human measurements 
appears achievable only for smaller animals, such as juvenile bottlenose 
dolphins or smaller species of cetaceans, such as porpoises, or with 
source-detector separations ≫100 mm in adult dolphins.
Conclusions: Brain measurements in juvenile or subadult dolphins, or smaller 
dolphin species, may be possible using specialized fNIRS devices that support 
optode separations of >100 mm. We speculate that many measurement repetitions 
will be required to overcome hemodynamic signals originating predominantly from 
the muscle layer above the skull. NIRS measurements of muscle tissue are 
feasible today with source-detector separations of 50 mm, or even less..

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