Comments Off on Musselman’s Lake Is Healthy And Vibrant
While none of us like to see the amount of algae mats that are in the lake this spring, it is important to understand why they are there and to look at the long term trends in water quality that fortunately are positive.
A synopsis of what is happening in our lake, by Dr. Brian Laing.
So, why are we seeing more algae this Spring?
This winter has been long and hard and the spring late in coming. This has delayed the normal slow blooming of algae and had made it come all at once. Algae cells are able to rise into the warmer water at the surface of the lake and consequently take advantage of the sudden warming of the water. This has been one of the harshest winters in living memory so it stands to reason that it will have a transitory effect on the ecology of the lake.
Of greater concern are the trends in water quality in our lake. As detailed in Dr Hutchinson’s water quality study of the lake, the overall health of the lake is good, and improving.
As we have suspected, Dr Hutchinson determined that one of the major problems controlling algae blooms and plant growth is the internal loading of phosphorus. Phosphorus is the primary nutrient that controls growth of plants and algae in most lakes. When plants and algae die and decompose on the bottom they release phosphorus into the water. Under aerobic conditions (plenty of oxygen) the phosphorus is bound up and unusable for plant or algae growth but under anaerobic conditions (little or no oxygen) this phosphorus is released back into the water in usable form. This is called internal phosphorus loading an it is largely responsible for the algae blooms and plant growth. In the winter the bottom of the lake becomes particularly anoxic and results in extra phosphorus being available for algae and plant growth in the spring. This winter was harder than usual likely resulting in greater phosphorus being available. The other ingredient for algae growth is warm water. Because this was delayed this spring, when it did come there was plenty of phosphorus available for eager algae to use.
Past studies have shown that the phosphorus level in Musselman’s Lake have decreased by 50% between 1989 and 2006. Dr Hutchinson’s results show that it has reduced further in 2013. This is good news. Our lake’s total phosphorus concentration is below the Provincial Water Quality Objective ‘for protection against nuisance growth and algae, and would not be indicative of impaired water quality, particularly for a lake in Southern Ontario’. Because of this, Dr. Hutchinson has recommended that we not pursue phosphorus sediment inactivation techniques such as phospholock at this time. He did however recommend that we continue to monitor water quality to track the inter-annual variability and if the internal phosphorus loading is in an up trend then the community should consider phosphorus sediment inactivation techniques at that time.
So in conclusion, while the algae mats are unsightly, they do not mean that the health of our lake has suddenly a turn for the worse. Fortunately Geranium homes generously supported the detailed professional analysis of the Lake by Dr. Hutchinson which gives us a baseline of the lake’s water quality.
It is our belief that we as a community should organize and raise money for ongoing monitoring of the lake so that trends can be identified and informed decisions can be made on if and when remedial action is necessary. The monitoring also enables us to gauge the effects of the actions we institute.