Estimating energetics in cetaceans from respiratory frequency : why we need to understand physiology
van der Hoop, Julie
Moore, Michael J.
MetadataShow full item record
KeywordField metabolic rate; Marine mammal; Oxygen consumption rate; Exercise; Recovery; Eco-physiology; Energy budget; Oxygen debt
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 (V̇O2) before and after a pre-determined duration of exercise. The measured V̇O2 was compared with three methods to estimate FMR. Each method to estimate V̇O2 included variable VT and/or ΔO2. Two assumption-based methods overestimated V̇O2 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 V̇O2 was predicted to within 2%, and post-exercise V̇O2 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.
© The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Biology Open 5 (2016): 436-442, doi:10.1242/bio.017251.
Suggested CitationBiology Open 5 (2016): 436-442
The following license files are associated with this item:
Showing items related by title, author, creator and subject.
Response to ‘On the importance of understanding physiology when estimating energetics in cetaceans’ Fahlman, Andreas; van der Hoop, Julie; Moore, Michael J.; Levine, Gregg; Rocho-Levine, Julie; Brodsky, Micah (Company of Biologists, 2017-02-15)We are grateful for the interest in our paper by two eminent physiologists and hope this response to their comments will clarify the objectives of our paper. The analysis in Fahlman et al. (2016) was not intended to provide ...
Oxygen metrics for retinal function in marine invertebrate larvae determined with electroretinograms Levin, Lisa A; Oesch, Nicholas (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: email@example.com, 2019-11-01)Oxygen metrics for retinal function in marine invertebrate larvae determined with electroretinograms For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_descr ...
Levin, Lisa A; Oesch, Nicholas (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: firstname.lastname@example.org, 2019-11-01)Retinal responses during exposure to decreasing oxygen partial pressure (pO2) in marine invertebrate larvae determined with electroretinograms. For a complete list of measurements, refer to the full dataset description ...