Regions: South Slave Region
Tags: contaminants, mercury, biology, fish
| Principal Investigator: | Cote, Jason E (5) |
| Licence Number: | 14784 |
| Organization: | Cambria Gordon Ltd. |
| Licensed Year(s): |
2010
|
| Issued: | Aug 10, 2010 |
| Project Team: | Jason Cote B.Sc., R.P.Bio (Principal Investigator, Cambria Gordon Ltd.), Joseph MacLeod (Field Technician, Cambria Gordon Ltd.), Jeremy Findlay (Field Technician, R. Marshall & Associates), Eric White (Field Technician, Sole Proprietor), John Fitzsimons (Lead Biologist, Department of Fisheries and Oceans), Residents of Lutsel K'e (Community representative, Community of Lutsel K'e) |
Objective(s): To quantify egg deposition by depth on available habitat for fourteen known or suspected representative shallow reefs and ten representative deep water reefs in Nonacho Lake; also, to conduct mercury sampling in lake trout.
Project Description: The objectives of the field program are to quantify egg deposition by depth on available habitat for fourteen known or suspected representative shallow reefs and for ten representative deep water reefs in Nonacho Lake, also to conduct mercury sampling in Lake Trout from this lake. At each of the known or suspected lake trout spawning reefs, a total of 10 numbered egg nets will be buried in cobble substrate at 1-m spacing immediately adjacent to the drop-off in shallow water (e.g. < 2 m) by scuba divers using standard protocols. If the depth range within an individual reef at the drop-off exceeds 1 m, an additional 10 nets will be used. At each known or suspected shallow reef scuba divers will also undertake limited reconnaissance of the immediate area using scooters to assess the availability and type of deepwater (e.g. > 2 m) spawning habitat and the potential for installation of egg nets. All nets will be deployed in early August prior to spawning by lake trout estimated to occur in early to mid-September. The depth of each net at its rim will be determined immediately after burial. Relative lake level at the time of net burial will be related to a fixed water level gauge established on the lake. In late September after lake trout spawning has ceased, all egg nets will be removed from the substrate by scuba divers and the contents of each net examined. Each net will be evaluated for the number of natural eggs (dead or alive) and their stage of development, the number of artificial eggs, and the number, size (weight (gm) and length (mm)) and species of all fish (e.g. sculpins) and large macroinvertebrates (e.g. crayfish) present. All numbers will be converted to abundance expressed as numbers per 2 metre using the open area of the egg net to calculate area. Twenty lake trout will be caught and dead sampled for mercury testing. A report of the findings will be prepared and provided to the community of Lutsel K'e. The fieldwork for this study will be conducted from August 10, 2010 to September 30, 2010.
