Recent research has shown that southern resident killer whales, also known as orcas, which range from California to British Columbia, are subject to a variety of bacteria and fungi that may pose a health risk to the whales, and the source of which is still unknown.
Because they range so far, orcas are exposed to a wide variety of pollutants like agricultural runoff, and some of the bacteria show antibiotic-resistant tendencies, perhaps caused by the increased use of antibiotics in agriculture and animal husbandry.
Understanding the health of southern resident killer whales is essential, as they’ve been endangered for some time. In the 1990s alone, their numbers dropped from around 108 to about 70, making it all the more important to protect those who remain.
But giving such animals a checkup has long been very difficult, but the researchers who are concerned about these bacteria and fungi have developed a new way to do exactly that.
They found the bacteria by testing droplets and exhaled breath caught from the blowholes of orcas, allowing them to see what kinds of microbial passengers they have.
“We wanted to find out what sort of bacteria and fungi represent in healthy whales and the potential pathogens they are being exposed to in their environment,” said study lead author Stephen Raverty, an adjunct professor at the University of British Columbia. “In some circumstances, these pathogenic microbes could pose a threat to the animals and contribute to clinical disease.”
This technique allows researchers to study the health of the whales now instead of waiting until they beach themselves or are otherwise found dead, after which a necropsy can be performed. While necropsies can tell us a lot about the dead animal, data collected from live specimens can be more important because it can allow us to react to sickness among those animals.
By collecting this “whale breath,” researchers will be able to get a better handle on what disease threats these whales face in the wild. Unlike more obvious dangers like depleted prey or increased water traffic disrupting their sonar, microbes are hard to detect in the first place, so it can be hard to keep them from causing harm.
“Assessing whether animals are healthy or sick is virtually impossible to do for live animals as big as whales,” said UBC professor Andrew Trites, who was not involved in the study. “Raverty and his colleagues found a way to assess health by collecting microbiota and pathogens when the whales exhaled between dives. It is an ingenious way to give whales a checkup.”