Dystrophic - Aylesford Lake EarthCache

Dystrophic - Aylesford Lake

Location:

Aylesford Lake is a natural, fresh-water, dystrophic lake located in Kings County, Nova Scotia, Canada, and is part of the Gaspereau Watershed. The lake encompasses approximately 190 hectares, and is surrounded by the South Mountain Rolling Plain area. Aylesford lake is one of  numerous lakes dotting Nova Scotia that resulted from the vigorous scouring activity of the glaciers.

Geological Information:

During the Quaternary Period, which covers the last 1.6 million years of earth history. The climate cooled and large glaciers periodically covered the earth’s surface. Nova Scotia was affected by at least four ice advances from 75,000 to 10,000 years ago (called the Wisconsinan Glacial Stage).

Aylesford Lake was formed as  glaciers moved over the surface of Nova Scotia gouging and scraping out the earth’s surface to the humic layer.  Glacial deposits including till and glacial lake mud were deposited over older peat bogs from a preceding warm period. As the glacial lakes filled and later they drained to become bogs and swamps, organic material accumulated at the bottom.

The main non-mineral resources resulting from the last glacial advance are clay, peat, soil, sand and gravel. After this and many other climate fluctuation, the climate warmed rapidly in Nova Scotia. There have been at least five documented major ice ages during the 4.6 billion years since the Earth was formed — and most likely, many more before humans came on the scene about 2.3 million years ago.  

How Dystrophic Lakes were formed

Lakes are born in topographic depressions and filled with water and it this case caused from glacier gougings. The speed at which the lake ages and goes through its stages of succession depends on the amount of water, nutrients and sediment being put in or taken out of it.

Dystrophic lakes, also known as humic lakes are lakes that contain high amounts of Humic substances  and organic acids. The presence of these substances causes the water to be brown in colour and have a generally low Ph of around 4.0-6.0. Due to these acidic conditions, there is little biodiversity able to survive, consisting mostly of algae, phytoplankton, picoplankton, and bacteria.

Dystrophic lakes are associated with areas underlain by hard, acid rock types (e.g. granite, schist and gneiss), with nutrient poor soils, and typically with high rainfall. These rocks are often associated with upland areas.  Generally they are small (with surface areas of between 1 and 5 ha), have peat stained water and may also have peat substrates. They generally show little habitat variation and their species diversity is very low, typically limited to one or two species, such as bog mosses Sphagnum spp.s. Humic substances are organic compounds that are important components of humus, the major organic fraction of soil, peat, and coal (and also a constituent of many upland streams, dystrophic lakes, and ocean water).

To log this Earthcache visit the viewing location.  Please answer the following questions and send in a timely manner to my geocaching profile or email. Answers not received will result in deleted logs.

1. Colour of the water?

2. What direction does the lake run, North/South or East/West?

3. What created the shape of the lake?

4. Elevation of the lake?

5. Post a picture of you and/or the lake.

[REQUIRED] In accordance with the updated guidelines from Geocaching Headquarters published in June 2019, photos are now an acceptable logging requirement and WILL BE REQUIRED TO LOG THIS CACHE. Please provide a photo of yourself or a personal item in the picture to prove you visited the site.