The microbiological study of killer whales along the Pacific coast has proved to be significant. Marine biologists from the University of British Columbia are now able to assess the health of Orca with a straightforward breath test and they have increased knowledge about which microbes prose a risk to the whales. In a similar way to advancements in the study of the human microbiome are providing valuable information about health and disease, so too the microbiome of various animals provides important clues about the health of the animal. A microbiome is a term applied to the collection of microorganisms
in a given ecological niche (such as the gut).
The killer whales studied were southern resident killer whales
. These are classed as an endangered species and they reside in the Pacific Ocean, covering the area off the coast of California north to the Salish Sea off the western coast of British Columbia. Threats to the killer whales come from habitat changes, shipping traffic and a decline in food sources. The southern resident killer whales represent the smallest of four resident communities within the Northwestern portion of North America Pacific Ocean. It is the only killer whale population listed as endangered by the U.S. Fish & Wildlife Service.
The microbial data collected by the biologists provides a baseline. From this starting point the relative health of the whales provides clues as to which microbes signal good health and which indicate poor health.
According to lead researcher Stephen Raverty
the study of the microorganisms has proved to be of great importance: "In some circumstances, these pathogenic microbes could pose a threat to the animals and contribute to clinical disease."
The organisms of concern and which signal poor health are similar to those that present problems on land, such as Salmonella, Staphylococcus aureus and fungi like Penicillium, and Phoma. At present it is uncertain if the harmful microbes occur naturally in the ocean or whether they are coming from land. Genetic testing may, as more data is accumulated, provide the answer. The land connection is a strong possibility, given that some of the organisms are antibiotic resistant.
The findings are published in
the journal Scientific Reports
under the title “Respiratory Microbiome of Endangered Southern Resident Killer Whales and Microbiota of Surrounding Sea Surface Microlayer in the Eastern North Pacific.”