Raasay, a young border collie, leans over the edge of a kayak, to catch a whiff. It’s not a ball she’s sniffing out. Rather, she’s hunting down a potential ecological threat hidden beneath the surface. Her target during this training session: an invasive aquatic plant, known as common cordgrass (Spartina anglica), that has found its way into many Australian lakes, mud flats, mangrove forests, and salt marshes. Once established, Spartina is notorious for pushing out native species and threatening otherwise biodiverse ecosystems. Raasay’s job is to find the weed before it can spread.
Tracy Lyten, Raasay’s handler and one of the founders of Skylos Ecology, knows that the most impactful conservation decisions are based on strong data. And in her eyes, the six dogs who work at Skylos are the ultimate data collectors. “They can tell us things that no other monitoring method can,” says Lyten.
You’ve got to pick the right dog for the right odor based on their personality.
Thanks to their acute sense of smell, estimated to be thousands of times more sensitive than a human’s, dogs have been employed to find illicit substances, missing people, and forensic evidence since the 19th century. Now conservationists are beginning to take advantage of that olfactory potential. In addition to sniffing out invasive plants underwater, Lyten’s dogs have been trained to find bird and bat carcasses hidden across sprawling wind farms. Some of the canines can even locate scat left behind by particular animals, clueing researchers in to where endangered species, like the tiger quoll (Dasyurus maculatus), are still present.
“You’ve got to pick the right dog for the right target odor based on their personality,” says Lyten. Dogs that have shorter attention spans might have a hard time finding plants, which have subtler scents than animal remains—especially when the plants are underwater. On walks, Raasay’s curiosity, patience, and urge to methodically sniff almost everything in sight convinced Lyten that she would be a great candidate for finding invasive weeds.
Common cordgrass, Raasay’s usual search target, is particularly challenging for land managers to contend with because it can be hard to find and reproduces quickly. Cordgrass can colonize entire wetlands by sending out fast-growing, sub-surface stems, called rhizomes, in various directions. Habitats once rich in biodiversity can become so-called “Spartina meadows,” with devastating results. Research has shown that cordgrass invasions threaten breeding habitats for fish, and scientists suspect that the weed is having an impact on local crustacean, mollusk, and shorebird populations as well.
But these ecosystems can rebound. Cordgrass infestations have been successfully reversed, and Skylos Ecology is working with local government agencies across eastern Australia to continue the detection effort. Toward that end, whenever Raasay finds a patch of Spartina, she will sit, lay down, or—if atop a kayak—point with her nose to alert her handler. Lyten will then log their location with GPS coordinates, and that data point will be added to a detailed map of common cordgrass sightings, slated for removal. It’s important work, but for Raasay, it’s just another day on the job—one that ends with a much-needed bath. 
Douglas Gimesy is a conservation and wildlife photojournalist who focuses on Australian issues. A senior fellow of the International League of Conservation Photographers, his work has been published in National Geographic, BBC Wildlife, and Audubon, along with other mainstream newspapers and magazines.
This story originally appeared in bioGraphic, an independent magazine about nature and regeneration powered by the California Academy of Sciences.
