What's that in the water?
Pollen may appear as a yellow film visible on a lake’s surface and commonly accumulates in coves. The appearance of pollen on lake surfaces typically occurs in the spring and early summer and is often pollen from pine and other trees.
Courtesy of the American Society of Limnology and Oceanography
Photo courtesy of the University of Maine
Courtesy of the Lake Champlain Committee
Green algae can grow on the bottom of rivers and in the shallow areas of lakes and can attach to submerged objects such as rocks, branches and docks. As the water temperature rises throughout the summer, green algae can become more prevalent. When algae become detached from their substrate they can form clumps that appear brown or green and may be stringy. These can float to the surface and form mats.
Courtesy of the University of Utah
Courtesy of the NB Department of Environment and Local Government
Bryozoans (also known as moss animals) are underwater colonies of tiny, colonial animals which filter water for their food. They grow attached to sticks or rocks, prefer slow moving water and can range in size from golf balls to footballs.
Courtesy of the University of Massachusetts
Courtesy of Tim Vechter
The appearance of blue-green algae blooms can vary.
Example of a whole lake in New Brunswick turning green from a blue-green algae
bloom.
Courtesy of the NB Department of Environment and Local Government
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Example of colonies of blue-green algae accumulating along the shoreline.
Courtesy of the NB Department of Environment and Local Government
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Example of a blue-green algae bloom starting to die off and changing color from green to blue green.
Courtesy of the NB Department of Environment and Local Government
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Examples of blue-green algae mats in a river and along the shoreline in New Brunswick. These benthic algal mats can also have a spongy appearance as they float to the surface because of the oxygen that is produced during photosynthesis (top right photo).
Courtesy of the NB Department of Environment and Local Government
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Examples of blue-green algae mats along the NB shoreline look like clumps and can appear black, brown or dark green in colour. When these mats dry, they can also have a bleached appearance (top right photo).
Courtesy of the NB Department of Environment and Local Government
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Additional examples of blue-green algae mats:
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Rosen, B.H., and St. Amand, A. (2015). Field and laboratory guide to freshwater cyanobacteria harmful algal blooms for Native American and Alaska Native Communities. U.S. Geological Survey Open-File Report 2015-1164. Retrieved from: https://www.mfe.govt.nz/sites/default/files/nz-guidelines-cyanobacteria-recreational-fresh-waters.pdf
Aquatic plants have roots, leaves and stems and can vary in size. Some species float on the surface of the water while others can grow attached to the bottom of a lake.
Duckweed - Courtesy of the Westchester County Department of Planning
Aquatic plants - Courtesy of the Québec Ministère de Développement durable, Environnement et Parcs
Duckweed
Courtesy of the BNET
Aquatic plants - Courtesy of the Québec Ministère de Développement durable, Environnement et Parcs
Foam collecting on windward lake shorelines or streaking along lake surfaces is typically a natural occurrence triggered by organic matter contained in the water mixing with air through wind and wave action. The foam can have an earthy or fishy smell and can range from white to a greyish, yellowish or brownish colour.
Courtesy A. Thurnherr. Source: A Field Guide to Aquatic Phenomena – U of Maine
Foam