A new study focusing on the naturally high levels of carbon monoxide in marine mammals’ breath and blood could be used to understand human exposure to the odourless gas.
Scientists from the Scripps Institution of Oceanography at the University of California are measuring levels of carbon monoxide in the breath of killer whales, pilot whales, beluga whales and dolphins at SeaWorld California in San Diego – and are finding that carbon monoxide isn’t all that bad. The study already indicates results of elevated carbon monoxide levels in marine mammals, thought to be deadly at high levels, which has potential to serve as a model for understanding safe levels of carbon monoxide exposure to human organs and tissues.
Carbon monoxide is known for being present in car exhaust and cigarette smoke. The gas is also produced naturally in the bodies of humans and other organisms from the breakdown of red blood cells and hemoglobin. However high levels of carbon monoxide are toxic because the gas binds to hemoglobin and prevents the transport of oxygen in the blood.
Mike Tift, a graduate student at Scripps Institution of Oceanography who is leading the study, said, “In some marine mammals, carbon monoxide levels can actually be quite high. A lot of the marine mammals that dive deep, will shut blood flow off to organs and tissues in order to conserve oxygenated blood for the organs that matter – like the heart and the brain. And so because they do that, because they shut the flood flow off, this carbon monoxide actually could prevent injuries from happening in those other tissues.”
By working with these animals and seeing what higher levels of carbon monoxide they produce, the scientists and SeaWorld trainers hope that they can build a model to measure what levels of carbon monoxide can be used safely and therapeutically in humans associated with certain illness or medical procedures.
SeaWorld’s senior veterinarian Todd Schmitt, continues, “In humans, with stroke, heart attack, organ transplants, asthma, there’s a number of clinical conditions that we think carbon monoxide may be therapeutic.”
"It's currently impossible to get a blood sample or a breath sample from a large whale or dolphin in the wild," Tift added.
A previous study by Tift which looked into carbon monoxide levels in elephant seals uncovered that around 10 percent of carbon monoxide is bound to hemoglobin in that species, which is 10 times higher than in healthy humans, and similar to chronic cigarette smokers. These results led Tift to explore levels in other species.
Many of the breath tests took place at SeaWorld California in front of guests who had the rare opportunity to see science in action
Access to SeaWorld’s collection of marine mammals is invaluable to the study. SeaWorld’s marine mammals are trained to participate in their own care and are accustomed to producing samples from their blowholes. Not only would it be virtually impossible to measure breath and blood gases from wild marine mammals, this research advances the scientific understanding of diving physiology in cetaceans and has application for advancing medical care in humans. Furthermore, diagnostic applications used on SeaWorld animals can be further modified for future use with wild populations to aid with their health assessment.