[MARMAM] New publication on biomarkers for decompression stress in marine mammals

[Fahlman, Andreas]

Dear MarMam-ers,

We are proud to announce our new publication on biomarkers for decompression 
stress in Steller sea lions in American Journal of Physiology-Regulatory, 
Integrative and Comparative Physiology

Title: Dive, food, and exercise effects on blood microparticles in Steller sea 
lions (Eumetopias jubatus): exploring a biomarker for decompression sickness

Authors:  Andreas Fahlman, Michael J. Moore, Andrew W. Trites, David A. S. 
Rosen, Martin Haulena, Nigel Waller,  Troy Neale,  Ming Yang, and Stephen R. 
Thom

Journal: American Journal of Physiology-Regulatory, Integrative and Comparative 
Physiology
Volume: 310
Pages: R596–R601, 2016.

Abstract: Recent studies of stranded marine mammals indicate that exposure to 
underwater military sonar may induce pathophysiological responses consistent 
with decompression sickness (DCS). However, DCS has been difficult to diagnose 
in marine mammals. We investigated whether blood microparticles (MPs, measured 
as number/μl plasma), which increase in response to decompression stress in 
terrestrial mammals, are a suitable biomarker for DCS in marine mammals. We 
obtained blood samples from trained Steller sea lions (Eumetopias jubatus, 4 
adult females) wearing time-depth recorders that dove to predetermined depths 
(either 5 or 50 meters). We hypothesized that MPs would be positively related 
to decompression stress (depth and duration underwater). We also tested the 
effect of feeding and exercise in isolation on MPs using the same blood 
sampling protocol. We found that feeding and exercise had no effect on blood MP 
levels, but that diving caused MPs to increase. However, blood MP levels did 
not correlate with diving depth, relative time underwater, and presumed 
decompression stress, possibly indicating acclimation following repeated 
exposure to depth.

For reprints please e-mail Andreas Fahlman: 
andreas.fahl...@tamucc.edu
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[MARMAM] New Publication: Estimating energetics in cetaceans from respiratory frequency: why we need to understand physiology

[Fahlman Andreas]

Dear All
We are pleased to share our new publication “Estimating energetics in cetaceans 
from respiratory frequency: why we need to understand physiology” that was 
recently published in Biology Open. The study takes a closer look at the 
possibility of obtaining reasonable estimates of metabolic rates from breathing 
frequency in bottlenose dolphins. 
A copy of the paper can be found at: 
http://bio.biologists.org/content/biolopen/early/2016/03/16/bio.017251.full.pdf 

or by sending a request to afahl...@whoi.edu 

Title:Estimating energetics in cetaceans from respiratory frequency: why we 
need to understand physiology
Authors: Fahlman, A., van der Hoop, J., Moore, M.J., Levine, G., Rocho-Levine, 
J., Brodsky, M.
Journal: Biology Open
Year: 2016

Abstract: The accurate estimation of field metabolic rates (FMR) in wild 
animals is a key component of bioenergetic models, and is important for 
understanding the routine limitations for survival as well as individual 
responses to disturbances or environmental changes. Several methods have been 
used to estimate FMR, including accelerometer-derived activity budgets, isotope 
dilution techniques, and proxies from heart rate. Counting the number of 
breaths is another method used to assess FMR in cetaceans, which is attractive 
in its simplicity and the ability to measure respiration frequency from visual 
cues or data loggers. This method hinges on the assumption that over time a 
constant tidal volume (VT) and O2 exchange fraction (ΔO2) can be used to 
predict FMR. To test whether this method of estimating FMR is valid, we 
measured breath-by-breath tidal volumes and expired O2 levels of bottlenose 
dolphins, and computed the O2 consumption rate (V̇ O2) before and after a 
pre-determined duration of exercise. The measured V̇ O2 was compared with three 
methods to estimate FMR. Each method to estimate V̇ O2 included variable VT 
and/or ΔO2. Two assumption-based methods overestimated V̇ O2 by 216-501%. Once 
the temporal changes in cardio-respiratory physiology, such as variation in VT 
and ΔO2, were taken into account, pre-exercise resting V̇ O2 was predicted to 
within 2%, and post-exercise V̇ O2 was overestimated by 12%. Our data show that 
a better understanding of cardiorespiratory physiology significantly improves 
the ability to estimate metabolic rate from respiratory frequency, and further 
emphasizes the importance of eco-physiology for conservation management efforts.___
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[MARMAM] New publication on cardiac responses before and after exercise in dolphins

[Fahlman, Andreas]

Dear marmers,

We are proud to announce our new publication in cardiac function in bottlenose 
dolphins published in Journal of Experimental Biology.

Title: Evaluating cardiac physiology through echocardiography in bottlenose 
dolphins: using stroke volume and cardiac output to estimate systolic left 
ventricular function during rest and following exercise

Authors: Stefan Miedler, Andreas Fahlman, Mónica Valls Torres, Teresa Álvaro 
Álvarez, Daniel Garcia-Parraga

Journal: Journal of Experimental Biology  2015  218: 3604-3610;  doi: 
10.1242/jeb.131532

Abstract: Heart-rate (fH) changes during diving and exercise are well 
documented for marine mammals, but changes in stroke volume (SV) and cardiac 
output (CO) are much less known. We hypothesized that both SV and CO are also 
modified following intense exercise. Using transthoracic ultrasound Doppler at 
the level of the aortic valve, we compared blood flow velocities in the left 
ventricle and cardiac frequencies during rest and at 1, 3 and 4 min after a 
bout of exercise in 13 adult bottlenose dolphins (Tursiops truncatus, six male 
and seven female, body mass range 143–212 kg). Aortic cross-sectional area and 
ventricle blood velocity at the aortic valve were used to calculate SV, which 
together with fH provided estimates of left CO at rest and following exercise. 
fH and SV stabilized approximately 4–7 s following the post-respiratory 
tachycardia, so only data after the fH had stabilized were used for analysis 
and comparison. There were significant increases in fH, SV and CO associated 
with each breath. At rest, fH, SV and CO were uncorrelated with body mass, and 
averaged 41±9 beats min−1, 136±19 ml and 5514±1182 l min−1, respectively. One 
minute following high intensity exercise, the cardiac variables had increased 
by 104±43%, 63±11% and 234±84%, respectively. All variables remained 
significantly elevated in all animals for at least 4 min after the exercise. 
These baseline values provide the first data on SV and CO in awake and 
unrestrained cetaceans in water.

For reprints please e-mail Andreas Fahlman: 
andreas.fahl...@tamucc.edu
or download at: http://jeb.biologists.org/jexbio/218/22/3604.full.pdf


Andreas Fahlman
Department of Life Sciences
Texas A Corpus Christi
6300 Ocean Dr Unit 5892
Corpus Christi, TX 78412
Ph. +1-361-825-3489
Fax +1-361-825-2025
mail: andreas.fahl...@tamucc.edu
web: http://www.comparative-physiology.tamucc.edu/



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[MARMAM] New Paper: Lung function in Cetaceans

[Fahlman, Andreas]

Dear All
We would like to announce the publication of our recent paper on lung function 
and mechanics in cetaceans.

Title: Fahlman, A., Loring, S. H., Levine, G., Rocho-Levine, J., Austin, T. and 
Brodsky, M. (2015). Lung mechanics and pulmonary function testing in cetaceans 
Journal of Experimental Biology 218, 2030-2038.

Abstract: We measured2 and CO2 in six adult bottlenose dolphins (Tursiops 
truncatus) during voluntary breaths and maximal (chuff) respiratory efforts. 
The data were used to estimate the dynamic specific lung compliance (sCL), the 
O2 consumption rate () and CO2 production rates () during rest. Our results 
indicate that bottlenose dolphins have the capacity to generate respiratory 
flow-rates that exceed 130 l Ÿ sec-1 and 30 l Ÿ sec-1 during expiration and 
inspiration, respectively. The esophageal pressures indicated that expiration 
is passive during voluntary breaths, but active during maximal efforts while 
inspiration is active for all breaths. The average sCL of dolphins was 0.31 ± 
0.04 cmH2O-1, which is considerably higher than that of humans (0.08 cmH2O-1) 
and that previously measured in a pilot whale (0.13 cmH2O-1). The average 
estimated  and  using our breath-by-breath respirometry system ranged from 
0.857 l Ÿ O2 min-1 to 1.185 l Ÿ O2 min-1 and 0.589 l Ÿ CO2 min-1 to 0.851 l Ÿ 
CO2 min-1, respectively, which is similar to previously published metabolic 
measurements from the same animals using conventional flow-through 
respirometry. In addition, our custom-made system allows us to approximate 
end-tidal gas composition. Our measurements provide novel data for respiratory 
physiology in cetaceans, which may have significant value for clinical medicine 
and conservation efforts.

Please send an e-mail to Andreas Fahlman: 
andreas.fahl...@tamucc.edumailto:andreas.fahl...@tamucc.edu if you would like 
a re-print.

Thank you
Andreas



Andreas Fahlman
Department of Life Sciences
Texas AM- Corpus Christi
6300 Ocean Dr Unit 5892
Corpus Christi, TX 78412
Ph. +1-361-825-3489
Fax +1-361-825-2025
mail: andreas.fahl...@tamucc.edumailto:andreas.fahl...@tamucc.edu
web: http://www.comparative-physiology.tamucc.edu/



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[MARMAM] Recently published paper comparing breath-hold diving capacity in marine mammals and humans

[Fahlman, Andreas]

Dear colleagues,
We are pleased to announce the publication of our recent paper:

Title: Fahlman, A., E. Schagatay (2014). Man’s Place Among the Diving Mammals. 
Human Evolution, 29:1-3, 47-66.

Abstract: A theory was forwarded in 1960 that humans significantly deviate in 
anatomy, physiology and behavior from their closest relatives, the great apes, 
and instead resemble diving mammals, as a result of a period of selective 
pressure to enter the water (Hardy, 1960). Humans can learn how to dive and in 
many aspects resemble diving mammals, but how similar is man when compared with 
aquatic species? To evaluate this, we compared diving performances in a number 
of aquatic, semiaquatic, and terrestrial species. As an index of aquatic diving 
specialization, we used maximal and average dive depth and duration, and 
proportion of time spent under water during repeated dives. Our analysis 
indicates that aquatic “deep divers” form a separate group, to which humans – 
and most aquatic and semi aquatic mammals – do not compare in diving 
specialization. Several species perform dives of intermediate duration and to 
intermediate depths, and form a group of “moderate divers”. A great number of 
species show more modest diving skills, despite being dependent on an aquatic 
life or food sources, and form a group of “shallow divers”. Humans fit well in 
this latter group and their maximum diving capacity is well within the typical 
ability performed by shallow near shore foragers. It may be the case that, as 
most accessible food is present near the shores, a great number of air 
breathing species have specialized to utilize this niche, while only a smaller 
group have developed the specialized extreme physiology necessary for extended 
deep diving. While foraging in shallow water, humans may repeatedly dive to 20 
m and spend as much as 60% of the time submerged in shallow diving, and trained 
individuals have reached depths of 100 m on single maximal dives. From this 
perspective, human diving capacity is well within that of typical diving 
mammals.

If you would like a pdf copy of the paper, please send an e-mail to: 
andreas.fahl...@tamucc.edumailto:andreas.fahl...@tamucc.edu .

Sincerely,
Andreas
Andreas Fahlman
Department of Life Sciences
Texas AM- Corpus Christi
6300 Ocean Dr Unit 5892
Corpus Christi, TX 78412
Ph. +1-361-825-3489
Fax +1-361-825-2025
mail: andreas.fahl...@tamucc.edumailto:andreas.fahl...@tamucc.edu
web: http://www.comparative-physiology.tamucc.edu/



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[MARMAM] New publication on lung function in pinnipeds

[Fahlman Andreas]

Dear colleagues,
We are pleased to announce the publication of our recent paper: 
Title: Fahlman, A., S. H. Loring, S. Johnson, M. Haulena, A. W. Trites, V. A. 
Fravel and W. Van Bonn (2014). Inflation and deflation pressure-volume loops 
in anesthetized pinnipeds confirms compliant chest and lungs. Frontiers in 
Physiology 5.


Abstract: We examined structural properties of the marine mammal respiratory 
system, and tested Scholander’s hypothesis that the chest is highly compliant 
by measuring the mechanical properties of the respiratory system in five 
species of pinniped under anesthesia (Pacific harbor seal, Phoca vitulina; 
northern elephant seal, Mirounga angustirostris; northern fur seal Callorhinus 
ursinus; California sea lion, Zalophus californianus; and Steller sea lion, 
Eumetopias jubatus). We found that the chest wall compliance (CCW) of all five 
species was greater than lung compliance (airways and alveoli, CL) as predicted 
by Scholander, which suggests that the chest provides little protection against 
alveolar collapse or lung squeeze. We also found that specific respiratory 
compliance was significantly greater in wild animals than in animals raised in 
an aquatic facility. While differences in ages between the two groups may 
affect this incidental finding, it is also possible that lung conditioning in 
free-living animals may increase pulmonary compliance and reduce the risk of 
lung squeeze during diving. Overall, our data indicate that compliance of 
excised pinniped lungs provide a good estimate of total respiratory compliance.

An open access copy of the article can be found at: 
http://www.frontiersin.org/Journal/Abstract.aspx?s=54name=aquatic_physiologyART_DOI=10.3389/fphys.2014.00433
 
http://www.frontiersin.org/Journal/Abstract.aspx?s=54name=aquatic_physiologyART_DOI=10.3389/fphys.2014.00433

If you have any questions, please do not hesitate to contact me.

Sincerely,
Andreas

Andreas Fahlman
Department of Life Sciences
Texas AM- Corpus Christi
6300 Ocean Dr Unit 5892
Corpus Christi, TX 78412
Ph. +1-361-825-3489
Fax +1-361-825-2025
mail: andreas.fahl...@tamucc.edu
web: http://www.comparative-physiology.tamucc.edu/



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[MARMAM] Recent publications on the dive response and lung function

[Fahlman, Andreas]

Dear All
We are pleased to announce the recent publication of the following papers. The 
first article is open access, and a link is provided below to the journal web 
site where the article can be downloaded. A pdf copy of the second article will 
be provided upon request. We realize that the first paper is not directly 
related to marine mammals, but it may be of interest to those interested in the 
physiological ecology of these animals.

Fahlman, A. B.L. Bostrom, K.H. Dillon, D.R. Jones. 2011. The genetic component 
of the forced diving bradycardia response
in mammals. Frontiers in Physiology. 2: 63 doi: 10.3389/fphys.2011.00063

We contrasted the forced diving bradycardia between two genetically similar 
(inbred) rat strains (Fischer and Buffalo), compared to
that of outbred rats (Wistar). The animals were habituated to forced diving for 
4 weeks. Each animal was then tested during one
40-sec dive on each of 3 days. The heart rate (fH) was measured before, during, 
and after each dive. Fischer and Buffalo exhibited
marked difference in dive bradycardia (Fischer: 120.9 ± 14.0 beats • min-1 vs. 
Buffalo: 92.8 ± 12.8 beats • min-1, P  0.05). Outbred
rats showed an intermediate response (103.0 ± 30.9 beats • min-1) but their 
between-animal variability in mean dive fH and pre-diving
resting fH were higher than the inbred strains (P  0.05), which showed no 
difference (P  0.05). The decreased variability in fH in
inbred rats as compared with the outbred group indicates that reduced genetic 
variability minimizes variability of the diving bradycardia
between individuals. Heritability within strains was assessed by the 
repeatability (R) index and was 0.93 ± 0.05 for the outbred, 0.84 ± 0.16
for Buffalo, and 0.80 ± 0.12 for Fischer rats for fH during diving. Our results 
suggest that a portion of the mammalian diving bradycardia
may be a heritable trait.

http://www.frontiersin.org/aquatic_physiology/10.3389/fphys.2011.00063/abstract

Fahlman, A. S.H. Loring, M. Ferrigno, C. Moore, G. Early, M. Niemeyer, B. 
Lentell, F. Wenzel, R. Joy, M. 2011. Moore. Inflation
and deflation pressure-volume loops in breath-hold diving marine mammals. In 
Press Journal to Experimental Biology. 214:
3822-3828.

 Excised lungs from eight marine mammal species [harp seal (Pagophilus 
groenlandicus), harbor seal (Phoca vitulina), gray seal
(Halichoerus grypus), Atlantic white-sided dolphin (Lagenorhynchus acutus), 
common dolphin (Delphinus delphis), Rissoʼs
dolphin (Grampus griseus), long-finned pilot whale (Globicephala melas) and 
harbor porpoise (Phocoena phocoena)] were used
to determine the minimum air volume of the relaxed lung (MAV, N=15), the 
elastic properties (pressure–volume curves, N=24) of
the respiratory system and the total lung capacity (TLC). Our data indicate 
that mass-specific TLC (sTLC, l kg–1) does not differ
between species or groups (odontocete vs phocid) and agree with that estimated 
(TLCest) from body mass (Mb) by applying the
equation: TLCest=0.135Mb0.92. Measured MAV was on average 7% of TLC, with a 
range from 0 to 16%. The pressure–volume curves
were similar among species on inflation but diverged during deflation in 
phocids in comparison with odontocetes. These
differences provide a structural basis for observed species differences in the 
depth at which lungs collapse and gas exchange
ceases.

If you have any questions, please do not hesitate to send me an e-mail.
Sincerely,
Andreas

Department of Life Sciences
Texas AM University-Corpus Christi
6300 Ocean Drive, Unit 5892
Corpus Christi, TX 78412
Ph. +1-361-825-3489
Fax. +1-361-825-2025
e-mail: andreas.fahl...@tamucc.edumailto:andreas.fahl...@tamucc.edu

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