A new study published in the journal Scientific Reports suggests that infectious diseases in Puget Sound orcas might be another risk factor for the endangered species. The whales spray a lot of bacteria and fungi in their breath when they exhale, and some of them might be dangerous for the whales’ health.
The researchers took breath samples from orcas and discovered they housed microbes that might cause diseases. What is even worse is the fact that most of them were found resistant to many human and animal antibiotics. This suggests that the microbes spread after human waste contaminated the oceans.
Taking breath samples from the orcas
To obtain material for their research, scientists followed a group of whales swimming in Washington state waters. When they surfaced to exhale, they used long poles with petri dishes attached to capture the water droplets sprayed from their blowholes.
They had been capturing breath samples for a period of four years. After they analyzed them, they discovered a variety of bacteria and fungi hiding in the air exhaled by the orcas. The result was significant for the small population of killer whales living in the southern extremity of the northeast Pacific Ocean.
The bacteria in their breaths are a bigger threat than we would think
Puget Sound orcas have had fluctuating populations over the past few decades. This happened because of various factors. The whales have been threatened by the constant lack of prey, pollution, or by the ships which disturbed their environment. They were added on the endangered list in 2005, and now they number only 78 specimens.
This is why finding harmful bacteria in their breaths is so worrisome. Besides the healthy microorganisms the researchers found, there were also some drug-resistant ones, such as salmonella or Staphylococcus aureus.
While swimming through urbanized waterways, the whales encounter many factors that put them at risk. Most of them are caused by humans, and they include the dangerous agricultural residues or everything that is flushed down the toilet. Thus, orcas can get infected, and those with weak immune systems are in even more danger.
“They’re recruiting the bacteria in their habitats. These animals are subject to many stressors, which reduce the competence of their immune systems.”
This is the first study which shows how dangerous can these pathogens be for orca populations. Also, it can help scientists keep track of the whales’ health condition, and see what they can do to stop harming them, or at least reduce the risk they are into.
Image Source: Wikimedia Commons