History of Lake Scugog

History of Lake Scugog

Edited: October 31, 2023

A special request about the marshlands south and east of the causeway.  SCUGOG MARSHLANDS: the Creation of the Syndicate Game Preserve, by J. Peter Hvidsten.  https://scugoglakestewards.com/wp-content/uploads/2019/10/scugogmarsh.pdf

New Post: march 29, 2020 — Reprint of an article from the Port Perry Star, July 12, 1949 discovered by Peter Hvidsten, during his historical research. Mud Lake Article, July 1949  You will be absolutely astounded at how things have hardly changed for Lake Scugog and its suggestions for improvement in all those years. The science is a little odd, the language old fashioned and funny, but incredibly connected to today.  Thank you Peter for finding this!

Also: Ice out this year, Mar. 29, 2020.

New Post: Oct. 07, 2019 — Information regarding the Osler Marsh (also known as the Scugog Marsh, Syndicate Lands or Cartwright Lands). J. Peter Hvidsten, prominent local historian, wrote the following comprehensive small document about the history of what he called the Scugog Marsh.  See PDF scugogmarsh: Creation of the Syndicate Game Preserve

The History of Lake Scugog

The history of Lake Scugog can be traced back to the last ice-age approximately 12,000 years ago. Ice, hundreds of meters deep, pushed down from the north scraping and excavating deep valleys in the soft limestone of the area. At one point, this Laurentide ice sheet split into two lobes leaving a deep crevasse which, over thousands of years, received huge blankets of stratified sands, gravel and silt out-wash from the glacier.  The ridge it created is now called the Oak Ridges Moraine. In some places, it has elevations of 150 meters.

The Oak Ridges Moraine prevented water runoff from the receding glaciers from running south to Lake Ontario.  Thus Lake Scugog and the Scugog River were formed. Originally the lake was much deeper than it is now.

As the glaciers retreated, Lake Scugog and Lake Simcoe formed in regional basins. Thick sequences of lacustrine sediment were then deposited in these lakes above the glacial units. These lake-associated deposits are observed extensively in the Lake Scugog basin. After these meltwaters retreated, erosion has been the dominant force with some sedimentation associated with river channels, stormwater outlets and shoreline runoff, as well as the accumulations of organic material in poorly drained areas as deposits of peat and muck.

When the first European settlers and surveyors arrived, Lake Scugog had filled in so that there were just two sluggish rivers running north to the Scugog River, on either side of what is now called ‘Scugog Island”.  There were some areas of open water in the deeper areas and in the channels.  The rest was varied wetland with large expanses of wild rice, cattails and, deep in the acidic older areas, vast areas of cranberries.  The current tract to the south, now called the “Cartwright Lands,” was a large tamarack swamp beloved by deer and, in the early days, southern caribou.

In the 1830’s, permission was granted to build a mill at Lindsay.  This required a “head” of water so the Scugog River was dammed bringing the lake up ten feet.  This first dam was destroyed and the new dam, built further along the river, only brought the lake up four feet. Without the dam at Lindsay there would be no Lake Scugog as we know it now.  History was changed on Lake Scugog and its watershed from then on.

Many areas of forest, plowed fields, indigenous settlements, and even newly-built settlers’ cabins, were inundated by the new water level. Then years of decomposition and swamp gas within the Scugog basin proved a great area for breeding disease-carrying mosquitoes.

A native malaria made many ill with what they called “ague” at the time.  The native malaria was less vigorous than tropical malaria and did not result in as many deaths, but it spread widely in newly populated, wet areas such as that found in the labour camps for the construction of the Rideau Canal and around the newly flooded Lake Scugog.

The condition of the new lake increased the types of European-originated diseases that were spreading malignantly through indigenous populations.  When quinine became available, symptoms of malaria declined. This disease was eradicated in Ontario by the 1890s.

In the meantime, the new depths of Lake Scugog allowed the transport of goods and settlers north and huge quantities of logs and other goods south to the railhead in Port Perry. Scugog’s dense maple, beech, pine and oak forests gave way to agriculture which became, and still is, the backbone of our economy.

The 1930s, 40s and 50s saw Lake Scugog as a convenient and pleasant vacation area, with hundreds of small summer cottages in tight, fun-loving summer communities around the lake.  Slowly that changed. Cottages became permanent residences and desirable shoreline communities.      Life on the lake was good!

Eurasian Water Milfoil:  Lake Scugog started aging once again when the invasive exotic water plant, Eurasian milfoil, exploded onto the scene.  It choked the lake with an over-abundance of plant life making life on the lake unattractive. The winter decomposition of all that plant life increased muck levels, covering spawning areas and even beaches. It peaked in the 1980s but for some reason, milfoil levels decreased dramatically after about 15 years. There was speculation that this was due to the proliferation of the native milfoil weevil, which normally just lived on the native milfoil in the lake. However, this is unproven.

This happy circumstance for the lake continued until approximately 2005 when, once again, milfoil ‘weed’ proliferated in the lake. Scugog Lake Stewards Inc. became very concerned about this new development. Through an association with an American distributor of native milfoil weevils, we obtained a DNA analysis. It proved that the milfoil now in the lake was a hybrid cross between native milfoil and the Eurasian. This seemed to give the new type of milfoil ‘hybrid vigor’ making it grow more densely and vigorously.  (Photo at left.)

Management with chemicals is out of the question. Cutting is counter-productive because it destroys both the good and the bad, leaving the area open to the more rapid growing hybrid milfoil. All cut pieces can create new plants as well.

It was at this point that the Stewards started a project to purchase native milfoil weevils to help combat the problem.  These new weevils were hand-planted in a large milfoil bed in King’s Bay. This project was abandoned after one year because of cost and because in Lake Scugog, it appeared that the weevil numbers did not expand as promoted by the supplying company.

Zebra Mussels arrive in Scugog:  Sometime in the latter years of 1900, the invasive zebra mussel arrived in Lake Scugog.  At first it did not seem to be a problem because they are filter feeders and therefore need hard surfaces to grow on above mucky areas.

Curly-Leaf pondweed arrives:  Once again, sometime in the later years of 1900, early 2000s, this next major invasive plant species arrived, first being seen just upwind/up current of boat launches. This aquatic plant, also from Eurasia, grows under the ice from vegetative pieces deposited in the bottom the previous summer. It comes up and flowers in thick surface patches in June. Then it dies back, allowing another species such as Eurasian water milfoil or starry stonewort to grow up as a second round of plant growth.

Starry stonewort: In 2014, the Scugog Lake Stewards’ research team began investigating a very strange new growth in the boat slips at Goreski’s Marina on Scugog Island. This growth appeared to be so thick that it made the water seem only inches deep whereas it was actually about 4 feet deep. Pulling it out to examine it, it appeared to be a network of thin green filaments that reached in billowy growth right to the bottom in areas where there was no boat traffic. This growth was then found in King’s Bay where the successful weevil implants had opened the area of milfoil. It was identified by Dr. Eric Sager of Trent University as an invasive macroalga called starry stonewort.  It is a Eurasian/Japanese relative of our native charra. Its distinguishing characteristic  is that it has fruiting bulbils on root-like anchors that look like tiny stars.  At approximately the same time, the walleye population was crashing and the reasons were unknown.

In 2016, the Scugog Lake Stewards’ research team,  led by Dr. Ron Porter, a director of the Stewards and members, Dr. Josh Thienpont and Dr. Jennifer Koros, applied for and obtained a three-year $395,000 grant from the Ontario Trillium Foundation to study the limnology of the lake. They hoped to find the reason for this reduction in the walleye population.

They engaged the biology laboratory of Dr. Andrea Kirkwood at Ontario Tech. University and many of her highly qualified students. They also involved Kawartha Conservation and York University.  (For an excellent video giving all the detail of the results of that study see: https://www.youtube.com/watch?v=JcAAcQvgNLs&t=89s)

Starry stonewort continues (at this writing in 2021) to be a profound problem. In general, it has displaced most other plant growth because it forms a lower-story growth layer throughout 90% of the lake.

Unfortunately, its architecture creates an ideal environment for the proliferation of zebra mussels. These two invasive species together are having a very deleterious effect on the lake including oxygen depletion leading to the much greater likelihood of toxic microcystis blooms (commonly, but erroneously called blue green algae).  Under the auspices of this OTF funded study with Ontario Tech University, it was also found that starry stonewort was present and a problem in most southern Ontario lakes and the northern states of the United States.