Three of the largest animals on Earth just got their first DNA test
August 12, 2026, Vancouver, BC — Blue, fin, and sei whales are among the largest animals ever to have lived, and some of the hardest to find. They range across thousands of kilometres of open ocean, spend most of their lives underwater, and are rarely found in large numbers, even in places they’re known to frequent. Until now, no genetic test existed that could tell scientists which of these three species had passed through a stretch of water.
A new study by Ocean Wise and Whale Research Collective closes that gap, and the results include a detection visual observers missed entirely.
Published in the journal Environmental DNA, the study introduces the first species-specific genetic markers for blue, fin, and sei whales, then puts them to the test in one of the roughest environments for whale research anywhere: the Scotian Shelf and Labrador Sea, where fog and high winds routinely shut down visual surveys. Similar markers already existed for humpback, bowhead, and Rice’s whales. For these three species, researchers had nothing comparable until this study.
Blue whales are the largest animals on Earth, yet scientists have historically struggled to detect and monitor them across vast ocean habitats. New eDNA tools developed by Ocean Wise and the Whale Research Collective can identify the genetic traces these giants leave behind in seawater.
The method relies on environmental DNA, or eDNA, the skin cells, waste, and mucus that whales shed continuously into the water around them. Filter a sample of seawater and, in principle, that genetic trace can reveal which species passed through, without a whale ever needing to surface in sight of a boat.
During a four-week expedition in 2024, researchers from the Whale Research Collective collected seawater samples from 23 offshore stations, along with flukeprint samples (the DNA-rich slicks of water left behind after a whale dives) from blue and fin whales. Back in the lab, Ocean Wise scientists designed and validated qPCR assays, a genetic test that can detect and measure tiny amounts of a species’ DNA in a sample, for all three species. They then determined the minimum amount of whale DNA each test needed to return a reliable result.
A fin whale dives beneath the surface, leaving behind a flukeprint rich in environmental DNA. Researchers used samples like these to develop and validate the first species-specific eDNA tests for blue, fin, and sei whales.
In the field, the fin whale assay delivered the study’s clearest finding: it detected fin whale DNA at open-water stations where no whale had been sighted by observers on deck. That is the result that matters most for future monitoring, a case of eDNA registering an animal that a visual survey would have missed.
Picture 3: Co-author David Gaspard collects seawater samples aboard the research vessel Andromède during a 2024 expedition to the Scotian Shelf and Labrador Sea. The samples were used to test new genetic tools for detecting elusive whale species.
Picture 4: Researcher Katy Gavrilchuk filters seawater samples on board the Andromède, isolating environmental DNA shed by marine life. The approach allows scientists to detect whales even when poor weather and low visibility make visual surveys impossible.
‘The Scotian Shelf and Labrador Sea are known for their difficult conditions with strong winds and thick fog limiting our efforts to visually detect whales. eDNA gives us an additional tool and easy way to sample these waters even when visual surveys just aren’t possible.’ Bertrand Charry, Biologist, Whale Research Collective.
The study is equally direct about where the method falls short. Blue whales were sighted during the expedition but did not appear in any station sample, suggesting a detection limit tied to distance or density. Sei whales were not detected by either method, a result consistent with the species being scarce or absent in the area at the time, though it doesn’t confirm it. Researchers note that eDNA, like visual survey, cannot establish that a species is truly absent, only that it wasn’t detected.
A fin whale surfaces in Atlantic Canadian waters. In the study, researchers detected fin whale DNA at locations where no whales were observed visually, highlighting the potential of environmental DNA to reveal animals traditional surveys can miss.
“When using eDNA for whale monitoring, it’s essential to know with confidence which species you’re detecting, so that we don’t falsely report or miss them,” said Dr. Chloe Robinson, Director of the Ocean Wise Whales Initiative. “Through extensive laboratory and field testing, we’ve developed three robust, species-specific eDNA assays that we hope will help researchers and conservation practitioners monitor these elusive and endangered whales, not only in Canadian waters, but around the world.”
Researchers see eDNA as one piece of a broader shift in whale conservation, one that increasingly draws on drone imagery, acoustic monitoring, and artificial intelligence alongside genetic sampling. Used together, these tools aim to help scientists spot risks to whale populations, from shifting habitat to vessel traffic, before those risks become crises rather than after.
“eDNA gives us a new monitoring tool that requires very little effort in the field while enabling us to sample waters in all conditions” finished Charry. “While more research and efforts are needed before this method can directly inform management decisions, it offers a novel perspective on how we detect and monitor these species.”
This research was supported by Fisheries and Oceans Canada (Habitat Stewardship Program, 23-HSP-NFL-003), the Animal Welfare Foundation of Canada, and the Ocean Wise Killer Whale Adoption Program.
Posted August 12, 2026 by Nic Schulz
