The Pelican Lake Healthy Water and Fish Committee (also called The Healthy Lake Committee) a committee of the Rural Municipality of Prairie Lakes, was formed in the fall 2012. We are an organization that promotes water stewardship and fish habitat maintenance, and implements projects and activities to improve the water quality and overall health of Pelican Lake and her watershed in the RM of Prairie Lakes. Key areas of focus include (but are not limited to) Pelican Lake recreational fishing, and overall healthy fish / aquatic habitat in Pelican Lake. 

 

Water stewardship is the main premise of our organization. One of our main goals is to determine the most efficient and effective ways for us to responsibly manage our lake waters, and improve the health of Pelican Lake and therefore the eco-system that is dependent upon the quality of the water in the lake.  

 

Pelican Lake is a 7000 acre body of water with an average depth of approximately 10 feet, located in Southwestern Manitoba. In recent years, this lake has suffered blue green cyanobacteria algae blooms, as well as significant fish die-offs. Both of these events have had significant impact on the health of the lake as well as the economic health of the area. This prompted the Healthy Lake Committee to form to attempt to do something to remedy the situation, and to continue to work towards a healthier lake going forward.

 

The method we are using to meet this goal is year round aeration. After consulting with professionals and doing plenty of our own research, we decided to use a micro-bubbler aeration system consisting of many individual bubbler heads that sit on the bottom of the lake and are connected to an on-shore air supply. These bubbler heads produce micro bubbles that resemble soda pop fizz. Our goal with year round aeration is to improve the health of the lake by increasing the oxygen levels. High levels of nutrients in the lake lead to algal blooms. Some algae is a food source for fish and gets consumed, however the toxic blue-green algae (which is a bacteria called Cyanobacteria) is not a food source and therefore accumulates, dies and decomposes. The decomposition of this extra accumulated matter depletes the oxygen levels in the lake. When oxygen levels get too low, decomposition of vegetation and excess nutrients slows down and is often incomplete which leads to the thick layer of ‘muck’ at the bottom of the lake, and the rotten egg smell. Therefore, through the addition of oxygen with aeration, the more decomposition we can facilitate, and the fewer nutrients there will be available for algae blooms. 

 

We installed an aeration field in the Northern Basin of Pelican Lake, starting out with 8 micro-bubblers running through the winter of 2012/2013. We monitored the oxygen levels periodically throughout the following months and saw a significant increase in oxygen levels within 800 feet of the bubbler field, and a general increase in oxygen levels in the Northern basin compared to the other areas of the lake. These positive results prompted us to redesign the aeration field into a larger, permanent bubbler field. By line boring and installing the air supply lines beneath the lake bottom we would avoid snagging and damages from boat traffic. For the winter 2013/2014 we increased the number of micro-bubblers to 26. We are now supplying 150 CFM to this aeration field in the winter months, which is approximately a 300% increase over the first winter.  

 

Over the summer and fall of 2015 we successfully built and installed a second aeration field at a mid-way point in Pelican Lake at Marina Terrace. This new field is much larger than the Northern Basin field, with 98 micro-bubbler heads installed in a fan pattern on the lake bottom over an area of 42 acres. Like our Northern Basin aeration system, this new system is supplied with air by compressors located in a shed onshore. At full capacity this field is able to supply 350 cfm of air to the lake. The total cost of the Marina Terrace aeration project was approximately $100,000, with $46,500 covered by the federal Recreational Fisheries Conservation Partnerships Program Grant, and the rest covered by local fundraising and volunteer labour. We can’t thank our volunteers enough!  

 

This addition of a second aeration field will help us to further build on the improvement in water quality and fish habitat that we’ve already started to see in the last few years. Running at full capacity in winter, the aeration systems add oxygen to the water to prevent fish die-offs. Running at a reduced capacity during the summer, they work to de-stratify the water column and accelerate the breakdown of the organic material on the bottom of the lake.