An international team of researchers has found that the physical condition of beluga whales affects their capacity to store oxygen in their blood and muscle tissues, likely impacting their ability to dive. In a paper published in the Journal of Experimental Biology, concentrations of muscle myoglobin and blood hemoglobin, proteins responsible for the storage and delivery of oxygen, were found to be 12 and 27 per cent higher, respectively, in beluga whales in peak physical condition compared to those of lower condition.
“We estimate that these differences equate to at least a three minute reduction in maximum dive time of the whales with the lowest body condition,” says lead author Dr. Emily Choy (PhD/17), a University of Manitoba alumna, now a researcher at McGill University.
The study started in response to a 2014 report that found inferred growth rates of Beaufort Sea beluga whales had declined over the past 20 years, which were hypothesized to be the result of environmental change. As diving depth in toothed whales is related to body size, the team wondered if diving ability might be compromised by the smaller size of the whales. MORE
Header image: Wikimedia Commons.