Regions: South Slave Region
Tags: contaminants, mercury, biology, food web, fish, water chemistry, benthic invertebrates
| Principal Investigator: | Evans, Marlene S. (54) |
| Licence Number: | 14783 |
| Organization: | Environment Canada |
| Licensed Year(s): |
2010
2009
|
| Issued: | Aug 09, 2010 |
| Project Team: | Derek Muir (Environment Canada), Jonathan Keating (Environment Canada), Ray Griffith (Lutsel K'e Dene FN), Rosy Bjornson (Deninu Kue FN), Shawn Buckley (Hay River) |
Objective(s): To study contaminant levels in lake trout and burbot in Great Slave Lake.
Project Description: For several years, studies have been conducted to find out if contaminant levels are changing in lake trout and burbot in Great Slave Lake. The researchers have been seeing some changes with mercury levels increasing and HCH levels declining in these fish. However, there have been other changes in the fish, especially lake trout which appear to contain less fat and to be feeding closer to shore than in the 1990s. Because contaminant levels in lake trout and burbot can be affected by changes in their biology and in the lake in which they live, more studies are necessary to find out what is affecting contaminant trends. Specifically, contaminant inputs to the lake have been changing and this study is necessary to learn more about contaminants in the Great Slave Lake food web. Food web sampling will be conducted during summer 2010, and will include collections of mysids, amphipods, plankton, benthic invertebrates, and forage fish (whitefish and cisco) and, ideally, will continue in 2011 to provide a 2-year data base for more effective 1994-1995 comparisons. Most food web samples will be collected using plankton (plankton, mysids, amphipods) or seine (forage fish) nets towed behind a boat. Benthic invertebrate samples will be collected using a dipnet (nearshore) or PONAR grab (offshore). Some benthic invertebrate and plankton samples will be collected quantitatively (and preserved) so that species abundance/composition can be determined. All other samples will be freeze-dried, and subsamples analysed for stable isotopes, mercury, and possibly organochlorines and other emerging contaminants of concern. Water samples will also be collected for mercury and nutrient (DOC, TP, etc.) analyses. Communities and agencies will be kept informed of the results through telephone, email, and other communications. Community visits may also take place, depending on interest and schedules. The fieldwork for this study will be conducted from August 7, 2010 to September 30, 2010.
