By Véronique Dubos, Johnny Nassak and Noah Eetook
Tracking the fish
Last summer, in August 2021, eight fish entering the Tasirjuarusik system were tagged with acoustic transmitters. Uumajulirijikkut Kangirsumi (LNUK of Kangirsuk) was leading this project to understand where the Arctic char of the lake Tasirjuarusik (Virgin Lake) were spending the winter. Indeed, numerous Arctic char migrate towards this large lake, located 20 km from the community. However, Kangirsummiut barely find them in winter. The char reappear only in late spring.
Eleven acoustic receivers were installed all over the lake to get some signals from the tagged fish. They have recorded the potential signals for a year, including during the winter 2021-2022. We retrieved the receivers from the lake in September 2022, to download the detected signals.
Where did the fish spend the winter?
From the eight fish tagged, one was caught just after the tagging, before even entering the lake. The seven remaining fish were all detected at least once in Tasirjuarusik Lake. Five of them were detected in the lake all winter long.
The char were more active in early winter, before mid-December since each fish was detected swimming in different areas of the lake by several receivers. During the winter months, the fish remained in different areas of the lake, showing very little movement. They became active again in late spring, around mid-May. Two of the fish remained in the lake during summer 2022 and were still in the lake in September when we retrieved the instruments. The others had left the lake before mid-June 2022.
What’s next?
Since the tags will continue to send a signal for a year, we have reinstalled the receivers. Five of them were reinstalled in the main lake Tasirjuarusik, and three others will be installed in the upstream lakes when there will be a solid ice cover. The receivers will be retrieved next summer. The instrumentation will allow us to see:
– If the tagged Arctic char are coming back in Tasirjuarusik again;
– If each fish is using the same overwintering area from one year to another;
– If some fish are migrating in the upstream lakes.
This study allows us to document the importance of the lake and the river for local subsistence fishing since the area of Tasirjuarusik is of interest for potential mining projects.
This project is led by Uumajulirijikkut Kangirsumi and is funded by the program Inuit Qaujisarnirmut Pilirijjutit, supported by ArcticNet and Inuit Tapiriit Kanatami. For any questions on the project: anguvigak@kangirsuk.ca or Veronique.Dubos@inrs.ca.
