Algae in Lake Water
Algae is present in all lakes and ponds. It is important to note that algae are natural, essential and expected components of aquatic habitats. The presence of algae does not necessarily indicate degradation of water quality. We generally only become aware of it when it reaches nuisance levels that negatively impact aesthetics, recreation, water quality and ecological balance. Algae can appear in many forms and colors. It has no true leaves, stems or roots and reproduces by means of spores, cell division or fragmentation. It thrives on excess nutrients in the water and requires sunlight for growth.
Typical forms of algae are Filamentous, Planktonic and Macro-Algae:
Here on Contoocook Lake we generally experience sightings of filamentous algae. It is a harmless green algae that grows in the water, often forming large bundles or slimy masses that can be seen by eye. Recent samples (August 2020) have been extracted and forwarded to the NHDES and their response was not to worry as it was a harmless form of green algae identified as Zygnema.
However, if you suspect presence of a blue-green cyanobacteria bloom, please report this condition and location on the lake to CLAPA via email at [email protected].
Algae is present in all lakes and ponds. It is important to note that algae are natural, essential and expected components of aquatic habitats. The presence of algae does not necessarily indicate degradation of water quality. We generally only become aware of it when it reaches nuisance levels that negatively impact aesthetics, recreation, water quality and ecological balance. Algae can appear in many forms and colors. It has no true leaves, stems or roots and reproduces by means of spores, cell division or fragmentation. It thrives on excess nutrients in the water and requires sunlight for growth.
Typical forms of algae are Filamentous, Planktonic and Macro-Algae:
- Filamentous algae patches are typically long, stringy and slimy. The patches are often bright green, but can be bleached by the sun underwater and turn brown or yellow when dying. Lake shorelines can be overcome with filamentous algae due to stagnation or high nutrient load.
- Planktonic algae microscopic organisms that range in color from light blue, green, golden, to red. They are made up of one cell or colonies of single cells. When blooming or visually dense, plank tonic algae appears more like dye in the water and cannot be pulled our of the water like filamentous algae. Blooms of planktonic algae will often blow across the lake with wind and concentrate in corners or shorelines. High concentrations can result in oxygen depletion and lead to fish kills and natural die-off. Likewise, some species like cyanobacteria (blue-green algae) are found to be toxic to humans, fish and wildlife.
- Macro-Algae are a group of algae more common in marine than freshwater systems. Seaweeds are a type of macro-algae.
Here on Contoocook Lake we generally experience sightings of filamentous algae. It is a harmless green algae that grows in the water, often forming large bundles or slimy masses that can be seen by eye. Recent samples (August 2020) have been extracted and forwarded to the NHDES and their response was not to worry as it was a harmless form of green algae identified as Zygnema.
However, if you suspect presence of a blue-green cyanobacteria bloom, please report this condition and location on the lake to CLAPA via email at [email protected].
Click the file below to get more information from the DES on Algae in New Hampshire lakes.
| des_algae.pdf |