Scientists at the Raincoast Conservation Foundation are sifting through killer whale poop to search for DNA that will shed light on the health of their populations, individual specimens and the ecosystems they live in.
The work is underway at what the foundation describes as a “cutting edge” genetics lab at the Pacific Science Enterprise Centre in West Vancouver — a facility it shares with Fisheries and Oceans Canada.
In partnership with the federal department, the foundation has sequenced the entire genomes of 142 northern resident killer whales, finding insight on their genetic diversity, immune system strength, food choices, and more.
The team is now comparing that dataset to one for endangered southern resident killer whales that was compiled by the U.S. National Oceanic and Atmospheric Administration. That set suggested a link between high levels of inbreeding and reduced lifespan in the population.
“With the kind of genetic techniques that we use, we can look at mating systems, we can look at the impact of inbreeding, we can look at the status of the expression of various genes to give us a sense of how healthy the whales are and what challenges they’re facing,” Lance Barrett-Lennard, director of Raincoast’s cetacean conservation research program, told Global News.
Barrett-Lennard said the lab has so many skin samples as well, the team is sometimes able to match them with a fecal sample and determine which group the individual belongs to. Within the poop, there’s also a wealth of information about its prey, he added.
Fecal matter can even reveal where the prey — salmon, for example — came from off the coast of B.C., added Raincoast research scientist Adam Warner.
“We know that (southern resident killer whales) really prefer Chinook salmon as as their food source of choice,” Warner explained, “but we do see … some other species consumed at different times of the year.
“A sample I was working with just the other day — it looked like it consumes quite a bit of sablefish. That’s something that came up a few years ago from some observational studies and we’re seeing that through the fecal material as well.”
Conservationists, scientists and whale watchers estimate there are just 74 southern resident killer whales left, compared to more than 300 northern residents and 400 Bigg’s killer whales — their mammal-eating cousins.
To collect their poop, crews essentially follow them around at a distance and later, scoop it up out of the water.
The team hopes their findings could contribute to meaningful policy changes to help conserve these whales — particularly the southern resident.
“We’re hoping to do some more studies using DNA to look at how genes are affected from different contaminant responses and environmental changes,” said Warner.
“There’s some sort of newer DNA sequencing technology that’s out there now where you can look at methylation of DNA and see how that’s changed — basically how genes are expressed or how much protein product is made of a gene.”
Methylation is a chemical modification of the DNA and other molecules, which may be retained as cells that then divide to make more cells.
“From some of our samples, we can look at contaminant levels that are in the killer whale and then match that to methylation levels, so that’s something that we’re hoping to investigate with a future study,” Warner said.
— with files from Paul Johnson
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