Researchers track Arctic char around Nunavut

Les Harris of Fisheries and Oceans Canada readies a pair of acoustic receivers for an Arctic char-tagging project in Cambridge Bay, used to track migration patterns of the fish in Wellington Bay, just west of the hamlet. (PHOTO COURTESY OF JEAN-SÉBASTIEN MOORE)

If you’re out fishing around Cambridge Bay, be on the lookout for tagged fish in your Arctic char catch: the local hunters and trappers association is offering a reward to fishers who find tags and turn them in.

Researchers with the Ocean Tracking Network and Fisheries and Oceans Canada tagged 60 fish in Ekalluk River, some 60 kilometres northwest of the western Nunavut community, with floy tags in mid-July. The short yellow plastic strands, also known as “spaghetti tags,” are attached to the backs of the fish, and include phone numbers to report the tags to the Ekaluktutiak Hunters and Trappers Organization in Cambridge Bay.

Half of these fish have acoustic transmitters — small black pegs about one to two inches long implanted into the belly area of the fish — which allow researchers to track their movements.

The HTO offers $20 for each floy tag found on the char, and $40 for each acoustic peg found in the fish.

Acoustic tags send a sound signal through the water every few seconds, said Jean-Sébastien Moore, a Université Laval researcher who heads up the Cambridge Bay project for the Ocean Tracking Network. He and fellow researcher Les Harris of Fisheries and Oceans have set up acoustic receivers in Wellington Bay, just west of the community, to track movement of the tagged char.

“Every time a fish goes by one of those receivers it sends a signal,” Moore said. “Next year when we go and retrieve the receivers, we’ll know which fish swam by the location. So we can then infer things about the movement behaviour of the fish.”

Moore and Harris will tag more fish this month on the Halovik River, 100 km west of the community.

The project is part of a global study by the tracking network, which examines the migratory behaviour “of dozens of marine species across all three Canadian oceans,” Moore said.

“We hope to learn more about how far char move during the summer, whether char from different rivers mix in the ocean, and whether all char return to their natal streams [where they hatched] in the fall,” Moore said.

Similar projects have been conducted in Pangnirtung, and others are underway this summer in Clyde River and Resolute, Moore said.

The research fits in with a larger effort by the Ocean Tracking Network to chart the effects of global warming and industrialized fishing on sea life. Information on fish movements will make it easier “to designate new marine protected areas, set shipping routes, and approve oil and gas exploration,” according the network’s website.

The network is a collaboration between various research groups. Moore and Harris are in Cambridge Bay until September to tag the fish and collect the results from the HTO.

Of the 60 fish tagged in the Ekalluk River July 10 to July 13, three were reported found by Aug. 8, Moore said. Two of these were had both acoustic and floy tags, and one floy only. One of these was recaptured within 12 hours of its release.

“We were told that the fish we tagged the night before was recaptured 20 kilometres away the next morning,” Moore said. “That to me was super-exciting, to know that char could travel so far in such a short period of time, and be captured in another river.”

The two acoustically tagged fish were found within two weeks of their release, in a shoreline area of Cambridge Bay, Moore said.

Moore and Harris left the community for Halovik River on Aug. 8, where they will tag another 30 fish with acoustic transmitters, and “a few hundred” with floy tags.

Les Harris of Fisheries and Oceans Canada returns Arctic char to the water in Ekalluk River, northwest of Cambridge Bay, after researchers implanted the fish with acoustic receivers. (PHOTO COURTESY OF JEAN-SÉBASTIEN MOORE)