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Fahlman A. Cardiorespiratory adaptations in small cetaceans and marine mammals. Exp Physiol 2024; 109:324-334. [PMID: 37968859 PMCID: PMC10988691 DOI: 10.1113/ep091095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 10/25/2023] [Indexed: 11/17/2023]
Abstract
The dive response, or the 'master switch of life', is probably the most studied physiological trait in marine mammals and is thought to conserve the available O2 for the heart and brain. Although generally thought to be an autonomic reflex, several studies indicate that the cardiovascular changes during diving are anticipatory and can be conditioned. The respiratory adaptations, where the aquatic breathing pattern resembles intermittent breathing in land mammals, with expiratory flow exceeding 160 litres s-1 has been measured in cetaceans, and where exposure to extreme pressures results in alveolar collapse (atelectasis) and recruitment upon ascent. Cardiorespiratory coupling, where breathing results in changes in heart rate, has been proposed to improve gas exchange. Cardiorespiratory coupling has also been reported in marine mammals, and in the bottlenose dolphin, where it alters both heart rate and stroke volume. When accounting for this respiratory dependence on cardiac function, several studies have reported an absence of a diving-related bradycardia except during dives that exceed the duration that is fuelled by aerobic metabolism. This review summarizes what is known about the respiratory physiology in marine mammals, with a special focus on cetaceans. The cardiorespiratory coupling is reviewed, and the selective gas exchange hypothesis is summarized, which provides a testable mechanism for how breath-hold diving vertebrates may actively prevent uptake of N2 during routine dives, and how stress results in failure of this mechanism, which results in diving-related gas emboli.
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Affiliation(s)
- Andreas Fahlman
- Global Diving Research SLValenciaSpain
- Fundación Oceanogràfic de la Comunidad ValencianaValenciaSpain
- Kolmården Wildlife ParkKolmårdenSweden
- IFMLinköping UniversityLinköpingSweden
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Elmegaard SL, Teilmann J, Rojano-Doñate L, Brennecke D, Mikkelsen L, Balle JD, Gosewinkel U, Kyhn LA, Tønnesen P, Wahlberg M, Ruser A, Siebert U, Madsen PT. Wild harbour porpoises startle and flee at low received levels from acoustic harassment device. Sci Rep 2023; 13:16691. [PMID: 37794093 PMCID: PMC10550999 DOI: 10.1038/s41598-023-43453-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Accepted: 09/24/2023] [Indexed: 10/06/2023] Open
Abstract
Acoustic Harassment Devices (AHD) are widely used to deter marine mammals from aquaculture depredation, and from pile driving operations that may otherwise cause hearing damage. However, little is known about the behavioural and physiological effects of these devices. Here, we investigate the physiological and behavioural responses of harbour porpoises (Phocoena phocoena) to a commercial AHD in Danish waters. Six porpoises were tagged with suction-cup-attached DTAGs recording sound, 3D-movement, and GPS (n = 3) or electrocardiogram (n = 2). They were then exposed to AHDs for 15 min, with initial received levels (RL) ranging from 98 to 132 dB re 1 µPa (rms-fast, 125 ms) and initial exposure ranges of 0.9-7 km. All animals reacted by displaying a mixture of acoustic startle responses, fleeing, altered echolocation behaviour, and by demonstrating unusual tachycardia while diving. Moreover, during the 15-min exposures, half of the animals received cumulative sound doses close to published thresholds for temporary auditory threshold shifts. We conclude that AHD exposure at many km can evoke both startle, flight and cardiac responses which may impact blood-gas management, breath-hold capability, energy balance, stress level and risk of by-catch. We posit that current AHDs are too powerful for mitigation use to prevent hearing damage of porpoises from offshore construction.
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Affiliation(s)
- Siri L Elmegaard
- Zoophysiology, Dept. of Biology, Aarhus University, 8000, Aarhus, Denmark.
- Marine Mammal Research, Dept. of Ecoscience, Aarhus University, 4000, Roskilde, Denmark.
| | - Jonas Teilmann
- Marine Mammal Research, Dept. of Ecoscience, Aarhus University, 4000, Roskilde, Denmark
| | - Laia Rojano-Doñate
- Zoophysiology, Dept. of Biology, Aarhus University, 8000, Aarhus, Denmark
- Marine Mammal Research, Dept. of Ecoscience, Aarhus University, 4000, Roskilde, Denmark
| | - Dennis Brennecke
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, 25761, Büsum, Germany
| | - Lonnie Mikkelsen
- Marine Mammal Research, Dept. of Ecoscience, Aarhus University, 4000, Roskilde, Denmark
- Norwegian Polar Institute, 9296, Tromsø, Norway
| | - Jeppe D Balle
- Marine Mammal Research, Dept. of Ecoscience, Aarhus University, 4000, Roskilde, Denmark
| | - Ulrich Gosewinkel
- Environmental Microbiology, Dept. of Environmental Science, Aarhus University, 4000, Roskilde, Denmark
| | - Line A Kyhn
- Marine Mammal Research, Dept. of Ecoscience, Aarhus University, 4000, Roskilde, Denmark
| | - Pernille Tønnesen
- Zoophysiology, Dept. of Biology, Aarhus University, 8000, Aarhus, Denmark
| | - Magnus Wahlberg
- Marine Biological Research Centre, Dept. of Biology, University of Southern Denmark, 5300, Kerteminde, Denmark
| | - Andreas Ruser
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, 25761, Büsum, Germany
| | - Ursula Siebert
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, 25761, Büsum, Germany
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Cole MR, Ware C, McHuron EA, Costa DP, Ponganis PJ, McDonald BI. Deep dives and high tissue density increase mean dive costs in California sea lions (Zalophus californianus). J Exp Biol 2023; 226:jeb246059. [PMID: 37345474 DOI: 10.1242/jeb.246059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 06/14/2023] [Indexed: 06/23/2023]
Abstract
Diving is central to the foraging strategies of many marine mammals and seabirds. Still, the effect of dive depth on foraging cost remains elusive because energy expenditure is difficult to measure at fine temporal scales in wild animals. We used depth and acceleration data from eight lactating California sea lions (Zalophus californianus) to model body density and investigate the effect of dive depth and tissue density on rates of energy expenditure. We calculated body density in 5 s intervals from the rate of gliding descent. We modeled body density across depth in each dive, revealing high tissue densities and diving lung volumes (DLVs). DLV increased with dive depth in four individuals. We used the buoyancy calculated from dive-specific body-density models and drag calculated from swim speed to estimate metabolic power and cost of transport in 5 s intervals during descents and ascents. Deeper dives required greater mean power for round-trip vertical transit, especially in individuals with higher tissue density. These trends likely follow from increased mean swim speed and buoyant hinderance that increasingly outweighs buoyant aid in deeper dives. This suggests that deep diving is either a 'high-cost, high-reward' strategy or an energetically expensive option to access prey when prey in shallow waters are limited, and that poor body condition may increase the energetic costs of deep diving. These results add to our mechanistic understanding of how foraging strategy and body condition affect energy expenditure in wild breath-hold divers.
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Affiliation(s)
- Mason R Cole
- Moss Landing Marine Laboratories, San Jose State University, 8272 Moss Landing Rd, Moss Landing, CA 95039, USA
| | - Colin Ware
- Center for Coastal and Ocean Mapping, University of New Hampshire, Durham, NH 03924, USA
| | - Elizabeth A McHuron
- Cooperative Institute for Climate, Ocean, and Ecosystem Studies, University of Washington, Seattle, WA 98105, USA
| | - Daniel P Costa
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95064, USA
| | - Paul J Ponganis
- Scripps Institution of Oceanography, University of California San Diego, Center for Marine Biodiversity and Biomedicine, 8655 Kennel Way, La Jolla, CA 92037, USA
| | - Birgitte I McDonald
- Moss Landing Marine Laboratories, San Jose State University, 8272 Moss Landing Rd, Moss Landing, CA 95039, USA
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Williams CL, Ponganis PJ. Diving physiology of marine mammals and birds: the development of biologging techniques. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200211. [PMID: 34121464 PMCID: PMC8200650 DOI: 10.1098/rstb.2020.0211] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/14/2021] [Indexed: 11/12/2022] Open
Abstract
In the 1940s, Scholander and Irving revealed fundamental physiological responses to forced diving of marine mammals and birds, setting the stage for the study of diving physiology. Since then, diving physiology research has moved from the laboratory to the field. Modern biologging, with the development of microprocessor technology, recorder memory capacity and battery life, has advanced and expanded investigations of the diving physiology of marine mammals and birds. This review describes a brief history of the start of field diving physiology investigations, including the invention of the time depth recorder, and then tracks the use of biologging studies in four key diving physiology topics: heart rate, blood flow, body temperature and oxygen store management. Investigations of diving heart rates in cetaceans and O2 store management in diving emperor penguins are highlighted to emphasize the value of diving physiology biologging research. The review concludes with current challenges, remaining diving physiology questions and what technologies are needed to advance the field. This article is part of the theme issue 'Measuring physiology in free-living animals (Part I)'.
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Affiliation(s)
- Cassondra L. Williams
- National Marine Mammal Foundation, 2240 Shelter Island Drive, Suite 200, San Diego, CA 92106, USA
| | - Paul J. Ponganis
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093-0204, USA
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Williams CL, Czapanskiy MF, John JS, St Leger J, Scadeng M, Ponganis PJ. Cervical air sac oxygen profiles in diving emperor penguins: parabronchial ventilation and the respiratory oxygen store. J Exp Biol 2021; 224:jeb230219. [PMID: 33257430 DOI: 10.1242/jeb.230219] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 11/18/2020] [Indexed: 11/20/2022]
Abstract
Some marine birds and mammals can perform dives of extraordinary duration and depth. Such dive performance is dependent on many factors, including total body oxygen (O2) stores. For diving penguins, the respiratory system (air sacs and lungs) constitutes 30-50% of the total body O2 store. To better understand the role and mechanism of parabronchial ventilation and O2 utilization in penguins both on the surface and during the dive, we examined air sac partial pressures of O2 (PO2 ) in emperor penguins (Aptenodytes forsteri) equipped with backpack PO2 recorders. Cervical air sac PO2 values at rest were lower than in other birds, while the cervical air sac to posterior thoracic air sac PO2 difference was larger. Pre-dive cervical air sac PO2 values were often greater than those at rest, but had a wide range and were not significantly different from those at rest. The maximum respiratory O2 store and total body O2 stores calculated with representative anterior and posterior air sac PO2 data did not differ from prior estimates. The mean calculated anterior air sac O2 depletion rate for dives up to 11 min was approximately one-tenth that of the posterior air sacs. Low cervical air sac PO2 values at rest may be secondary to a low ratio of parabronchial ventilation to parabronchial blood O2 extraction. During dives, overlap of simultaneously recorded cervical and posterior thoracic air sac PO2 profiles supported the concept of maintenance of parabronchial ventilation during a dive by air movement through the lungs.
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Affiliation(s)
- Cassondra L Williams
- National Marine Mammal Foundation, 2240 Shelter Island Dr. #200, San Diego, CA 92106, USA
| | - Max F Czapanskiy
- Hopkins Marine Station, Department of Biology, Stanford University, Pacific Grove, CA 93950, USA
| | - Jason S John
- Center for Ocean Health, Long Marine Laboratory, University of California, Santa Cruz, 115 McAlister Way, Santa Cruz, CA 95060, USA
| | - Judy St Leger
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093-0204, USA
| | - Miriam Scadeng
- Department of Anatomy and Medical Imaging, Faculty of Health and Medical Sciences, University of Auckland, Auckland 1142, New Zealand
- Center for Functional Magnetic Resonance Imaging, University of California, San Diego, La Jolla, CA 92093, USA
| | - Paul J Ponganis
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093-0204, USA
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Hermann-Sorensen H, Thometz NM, Woodie K, Dennison-Gibby S, Reichmuth C. In Vivo Measurements of Lung Volumes in Ringed Seals: Insights from Biomedical Imaging. J Exp Biol 2020:jeb.235507. [PMID: 34005800 DOI: 10.1242/jeb.235507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 12/11/2020] [Indexed: 11/20/2022]
Abstract
Marine mammals rely on oxygen stored in blood, muscle, and lungs to support breath-hold diving and foraging at sea. Here, we used biomedical imaging to examine lung oxygen stores and other key respiratory parameters in living ringed seals (Pusa hispida). Three-dimensional models created from computed tomography (CT) images were used to quantify total lung capacity (TLC), respiratory dead space, minimum air volume, and total body volume to improve assessments of lung oxygen storage capacity, scaling relationships, and buoyant force estimates. Results suggest that lung oxygen stores determined in vivo are smaller than those derived from postmortem measurements. We also demonstrate that-while established allometric relationships hold well for most pinnipeds-these relationships consistently overestimate TLC for the smallest phocid seal. Finally, measures of total body volume reveal differences in body density and net vertical forces in the water column that influence costs associated with diving and foraging in free-ranging seals.
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Affiliation(s)
- Holly Hermann-Sorensen
- University of California Santa Cruz. Department of Ocean Sciences, 115 McAllister Way, Santa Cruz CA 95060, USA
| | - Nicole M Thometz
- University of San Francisco, Department of Biology. 2130 Fulton Street, San Francisco, CA 94117, USA
- University of California Santa Cruz. Institute of Marine Sciences, 115 McAllister Way, Santa Cruz CA 95060, USA
| | - Kathleen Woodie
- Alaska SeaLife Center, 301 Railway Ave, Seward, AK 99664, USA
| | | | - Colleen Reichmuth
- Alaska SeaLife Center, 301 Railway Ave, Seward, AK 99664, USA
- University of California Santa Cruz. Institute of Marine Sciences, 115 McAllister Way, Santa Cruz CA 95060, USA
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