You have to be looking at the whole ecosystem and not just one species at a time. Kristi Miller,
Technology provides a better way to assess marine biodiversity
DNA tests of water samples from Canada’s three coastlines are providing unique and fascinating insights into the nation’s marine biodiversity.
Scientists aboard the MV Polar Prince, the Canada C3 expedition’s 67-metre icebreaker exploring the Atlantic, Arctic and Pacific coastlines over 150 days, have collected water samples at 93 sites, and run the samples through a genetic sequencer to see what lives there.
Preliminary results of the first 14 samples showed major signs of pink salmon — as well as their predators, grizzly and black bears and bald eagles — in Khutze Inlet in B.C.’s Great Bear Rainforest, the only such discoveries to date.
Elsewhere in Canada, the results showed capelin off Terra Nova National Park in Newfoundland, Arctic cod and narwhal at Pond Inlet in Nunavut, Atlantic herring at Louisbourg, N.S., and salmon shark in Nome, Alaska.
Animals leave DNA evidence behind as they move through the water, shedding their hair, skin or scales, or leaving behind slime and mucous.
“When those cells are shed, most of them float to the surface,” said Kristi Miller, a C3 participant and head of the molecular genetics lab at the federal Pacific Biological Station in Nanaimo. The tests reveal the genetic fingerprint for that patch of water or even farther depending on currents.
“This is really exciting,” Miller said. “You have to be looking at the whole ecosystem and not just one species at a time. This technology can get you there.”
Among the potential applications for environmental DNA technology: the detection of species shifts due to climate change, such as southerly species displacing northern ones; determining the types of prey and predators in a given location; and the detection of invasive species such as in ports due to international shipping.
The emerging science could help resolve long-standing questions about the impact of fish farming on wild salmon in the Pacific.
“We can ask, are marine species attracted to active farming or not?” Miller said. “We can also look at the distribution of infectious agents in the water column. What kind ... do we find around active salmon farms, and how far away do we have to go before they dissipate? That kind of information is critical for developing regulations.”
Research could also determine the extent to which salmon farms are being affected by wild fish, including herring that also carry salmon diseases.
“This is just a snapshot of what we can do,” said Ben Sutherland, a post-doctoral fellow working with Miller. “The samples we have are super valuable. You can give them to a virologist or someone who studies marine mammals. There are multiple PhDs in analyzing the data.”
Sampling water is a relatively cheap method of determining biodiversity and doesn’t require killing marine life for research purposes, Miller said.
The C3 expedition began June 1 in Toronto and is now on its 15th and final leg, a 10-day voyage from Campbell River to Victoria.
Sixty people are on board the former Canadian Coast Guard research vessel, including crew and participants, who include scientists, politicians, chefs, journalists, explorers, artists and youth ambassadors.
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■ from the C3 expedition every day this week. For more information on Canada C3, visit canadac3.ca.
This is just a snapshot … the samples we have are super valuable.