The Tłı̨chǫ Aquatic Ecosystem Monitoring Program (TAEMP) was back in Wekweètì on March 7-8, 2017 and met with community members on the results from last September’s fish camp held on September 19-23, 2016. The team also visited students at Alexis Arrowmaker School and shared information about the fish camp and about fish.
The 2016 camp was the second fish camp held at Wekweètì. The TAEMP first visited the area in 2012 to take fish, water and sediment samples for analysis. Returning to the area to take new samples, participants chose a camp location that was close to the 2012 site but more sheltered from the wind, with a good beach for boats. Snare Lake is a narrow 80 km inland lake that drains into the Marion River system and eventually flows into the North Arm of Great Slave Lake. Its waters provide habitat for Łı̀h (Lake Whitefish) and Łıwezǫǫ (Lake Trout), as well as Įhdaa (Northern Pike or jackfish).
The 2012 results provide a baseline of information that can be compared with future sampling, to see if there are any changes to fish or water over time. The September 2016 TAEMP team was able to collect samples to provide follow-up data on mercury levels and other metals in łıh and łıwezǫǫ, fish typically consumed by community members. They also recorded information on the fish that are present in Snare Lake, including their size, age, maturity, life stage, and a general assessment of overall health. And the five-day on-the-land camp provided an ideal setting for an exchange of traditional Tłı̨chǫ knowledge and fisheries science, through cultural and educational activities.
Preparing dry fish at camp (Photo: Paul Vecsei, Golder Associates Ltd.)
Comparing the 2016 results with the results from 2012, there appears to be no appreciable changes in the fish, water or sediments in the Wekweètì area, and fish and their habitat in Snare Lake are in good shape –where “good” means that results weren’t considered to be abnormal or unexpected.
Fisheries Biologist Paul Vecsei, Golder Associates Ltd., described the fish sampling that took place, some interesting observations, and the test results from the fish tissue samples. Elders and community members familiar with the land, lake and fish, guided where to set fish nets for sampling. In total, Tłįchǫ community participants and scientists caught three species of fish at the Snare lake sites (24 łıwezǫǫ, 22 łıh, 11 ı̨hdaa). Of these, 20 łıh and the 20 łıwezǫǫ were processed for biological information and testing for metals.
WRRB Board Member Jonas Lafferty and one of the Tłı̨chǫ translators at fish camp with a Łıwezǫǫ (Lake Trout) for sampling (Photo: Paul Vecsei, Golder Associates Ltd.)
As part of the processing, fish were measured and weighed and observations were made on the overall health of each fish, if there were any deformities or growths, its sex, and stage of maturity –whether or not a fish had spawned or whether it was a juvenile, for example—and tissue samples were taken for contaminants testing to find out what concentrations of metals were present in the tissue. Looking inside a fish’s stomach can provide insights into the ecology of a fish and how it fits into the aquatic ecosystem it lives in. An examination of the stomach contents of each sampled fish yielded some interesting findings. Łı̀h typically feed on snails and insects, but sometimes on tiny fish. Some of the larger łıh had Dahts’a (Ninespine Sticklebacks) in their stomachs. These small fish, about 5 cm in size, feed on tiny invertebrates (animals without backbones like copepods and insects) found in the shallow water where they live. Observations of the stomach contents of łıwezǫǫ showed that these fish were feeding on dahts’a and Łı̀htsoa (Ciscoes). Typically found in deep, cold, clear lakes with rocky bottoms, Łı̀htsoa, in turn, feed on microscopic animals (“zooplankton”), insects and smaller fish.
Dahts’a (Nine-spine sticklebacks) were found in fish stomachs (Photo: Paul Vecsei, Golder Associates Ltd.)
Paul also removed structures known as otoliths, small ear bones, from each fish, to send to the lab. Biologists can estimate a fish’s age by counting the rings that can be seen when the otoliths are sliced thinly and viewed under a microscope, similar to counting the annual growth rings in a tree. Some very old fish were caught. The oldest was a 37-year-old łı̀h, with a 36-year-old łıwezǫǫ not far behind! The age ranges for both fish species were similar too: 8-37 for łı̀h and 7-36 for łıwezǫǫ. Knowing the ages of the fish helps biologists understand the growth rate of fish species in the lake, whether they are growing at the rate normally expected for a certain age of fish, and how age related to the concentration of metals in the tissue. This is another one of the ways biologists can tell if fish are healthy.
Fisheries biologist Paul Vecsei demonstrated how to remove the otolith to send out for aging the fish (Photo: Boyan Tracz, WRRB)
Below: Close-up of otolith supplied by Paul Vecsei, Golder Associates Ltd.)
Concerns are often raised related to fish health and mercury. Paul explained that mercury is known to naturally occur in small amounts in lakes throughout the North. Levels of mercury differ from lake to lake and can be due to human activities such as burning fuel or industry, and from natural events like forest fires and erosion (the wearing away of the earth’s surface, including rocks, by wind, water and ice).
Mercury levels are generally lower in species like łı̀h which feed on aquatic insects and other organisms near the bottom of the food chain. Levels are usually higher in predatory species such as łıwezǫǫ because they are more likely to eat smaller fish and mercury becomes more concentrated with each step up the food chain (“biomagnification”). Larger, older fish may also have higher levels of mercury because they have been exposed to it longer and accumulate it in their tissues (“bioaccumulation”). As expected, the sample results showed very low mercury levels in łı̀h. Though łıwezǫǫ were found to have higher levels than łı̀h, this was not unexpected because they are predatory fish. Future sampling will provide further indications of any changes in mercury levels over time.
Often around the processing table, people at camp ask about the parasites frequently seen inside fish –and whether the fish are still good to eat. Paul explained that parasites in fish are common, and that even within the same lake, parasite infestation can vary seasonally or from place to place. Fish can get tapeworms by eating copepods (tiny creatures floating around in water) that are infected with the parasite larvae. One type of tapeworm seen at Snare Lake migrates into the muscle tissue. Two other species move into the stomach area and become enclosed with cysts. Parasites are killed when fish are cooked thoroughly.
Water samples were taken near the sites sampled earlier in 2012 and sent to a lab for testing. Three new locations were added west of the camp on the request of community members. A variety of fish habitats were sampled, ranging from shallow rocky areas to deeper sandy bottom holes. In this way, there was a good representation of the aquatic environment and the living conditions for the lake’s fish populations. In general, water and sediment quality in Snare Lake is good—where “good” means results were not considered abnormal.
Nutrient and physical parameters such as the amount of dissolved organic carbon and the turbidity (cloudiness) respectively were measured at all sample sites in 2012 and 2016 sampling programs. No noticeable difference was noted between the two sampling years. All nutrients and physical parameters were found to be similar at all sites. Snare Lake water is typical of water originating on the Precambrian Shield and would be classified as an oligotrophic lake. Oligotrophic lakes have deep, clear water, and rocky and sandy bottoms. Common in the North, these lakes are “nutrient-poor and oxygen-rich”. They contain relatively little plant life or nutrients, but are rich in dissolved oxygen. The fish found in oligotrophic lakes –like łıh and łıwezǫǫ-- like cold, high oxygenated water.
The water was tested for 27 metals, including mercury. Most metal concentrations in Snare Lake were very low with many measuring below method detection limits (MDL). 2012 water samples had a few metal concentrations greater than FAL guidelines, but 2016 water samples were all better than FAL guidelines. (Canadian Council of Ministers of the Environment Water Quality Guidelines for the Protection of Freshwater Aquatic Life). In 2012, weather conditions restricted the water sampling by boat and samplers waded out into the water to collect water samples from at a few sites, and in 2016, sampling at locations closest to Wekweètì were also sampled by wading out. Collecting water samples by wading into the water may increase the amount of particulate matter that is captured in a sample by disturbing the bottom substrate (the material that rests at the bottom of the lake) which may result in higher readings of various metals.
Snare Lake (Photo: Paul Vecsei, Golder Associates Ltd.)
Overall, the results of the sediment analyses suggested that there were no appreciable differences between 2012 and 2016, similar to the results found for water. Sediment samples were compared to Canadian Council of Ministers of the Environment Sediment Quality Guidelines for the protection of Aquatic Life interim sediment quality guidelines (ISQG) and Probable Effects Levels (PEL) which define the levels above which adverse effects are expected to occur frequently. The few exceedances (where the concentration is above a standard limit) observed at some sampling locations may have been influenced by sampling and lab techniques, possible contamination of samples, and field conditions, as well as the nature of the sampling location. For example, the sediment sample sites included four different types of sediment: sand, silt, silt loam and sandy loam (See description in Fact Box at the end of this story). Exceedances in chromium may be related to the type of sediment, chromium being associated with the silty sediment.
The TAEMP team ended their presentation to the community with the comment that repeat sampling is key to detecting changes in fish or fish habitat over time. Also, taking a number of samples every year, along with taking more than one sample at each location of interest, can help with understanding the variation in results which may be observed.
Learning traditional fish preparation techniques from elders at fish camp (Photo: Boyan Tracz, WRRB)
Elders Jimmy and Noella Kodzin were two of the community members at the 2016 fish camp. Speaking in Tłįchǫ, they shared their experiences and knowledge with the students. James Rabesca and Jonas Lafferty, translators at the fish camp, translated Jimmy and Noella’s words afterwards. Jimmy spoke about how the water and fish in Wekweètì are healthy, which makes him happy. He noted that there are no mines near the community and that the water and sediment were good. Jimmy also talked about his experience with the youth who were at fish camp and how safety was an important topic for everyone there. As soon as the students arrived at camp, they talked about safety because safety is so important out on the land. He also described how morning and evening prayers were held each day at camp. Jimmy told the students that he was thankful for the good weather and for how the fish camp allowed people to work together and understand each other. He closed his talk by saying how important school is so a person could be strong like two people. If you have a good education, he said, you will succeed and have a successful life.
Noella Kodzin also talked to the students, sharing about how she dries fish and meat and sews all the time. She told the students that they are welcome to come into her home whenever they want to learn. Noella said that she really enjoyed being on the land with the students and being able to teach them their way of life. She also mentioned how she wished the students could have fully participated in drying the fish, but that it takes a long time and the group didn’t have that much time out at the camp. Having the elders visit the students was very appreciated.
Fisheries Biologist Paul Vecsei also gave an engaging presentation to the students. He showed them a slideshow with some of his photos of fish underwater. Paul explained that the fish are so used to him in the water taking pictures that he could just reach in the water and pull their tails so that he could get a closer shot of them! They didn’t even seem to mind, he said. Paul described different fish species in Snare Lake from big to small. Jackfish, he told them, are very large fish that often blend into their surroundings to quickly eat their prey in one bite. Even when these fish are babies, they eat a lot and even eat each other if some are smaller than they are. He also described smaller fish and how they blend into their surroundings to try to protect themselves. One strategy, for example, is living within the rocks of the shoreline, out of sight. The children were interested in the images Paul showed and what he had to say.
Thank you, Rachel Reesor, teacher, and the staff and students of Alexis Arrowmaker School, for making the TAEMP team welcome!