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Cladophora

Cladophora Along the Great Lakes Shorelines

Cladophora is a type of stringy (filamentous) algae that grows on rocks, wood, logs, and other hard underwater surfaces in freshwater ecosystems, including the Great Lakes basin.

If you spot this type of stringy algae along New York's Great Lakes beaches and shorelines, DEC wants to know. Use this online reporting tool (web browser: https://arcg.is/0r4Cue; mobile device: https://arcg.is/u195T) to submit observations of accumulating Cladophora along the New York shorelines of Lakes Erie and Ontario, and the Niagara and Saint Lawrence Rivers. Or, use this fillable PDF to make your report and e-mail the form to GLCladophora@dec.ny.gov. The information collected will complement ongoing monitoring and modeling efforts that aim to provide a better understanding of where, when, and the extent to which, Cladophora is accumulating along the Great Lakes shorelines.

The following categories will help you determine the level of Cladophora accumulation in your area:

No visible growth | Minimal | Moderate | Extensive | Other Types of Algae

While Cladophora typically accumulates along shorelines during the summer and fall, conditions can persist through the winter and spring as the algae continues to dry/decay. Report instances of Cladophora accumulation at any time of the year along New York's Great Lakes shorelines, as well as those along the Niagara and St. Lawrence rivers.

Large amounts of cladophora can wash up along a shoreline and may lead to an unfavorable recreational experience.
Large amounts of cladophora can wash up along a shoreline
and may lead to an unfavorable recreational experience.
Living cladophora will grow on hard underwater substrates, such as rocks, wood or logs. (Photo credit: USGS)
Living Cladophora will grow on hard underwater surfaces,
such as rocks, wood or logs.(Photo credit: USGS)

Cladophora and Water Quality

New York's Great Lakes Action Agenda Goal #2 recognizes that water quality in some nearshore areas of Lakes Erie and Ontario remain a concern, in part due to seasonal widespread occurrences of nuisance algae (e.g., Cladophora). While Cladophora serves beneficial ecological purposes in natural amounts, excessive growth can occur under certain conditions. When a large amount of Cladophora detaches from the lake bottom, it can wash up along the shoreline and begin to decompose, potentially leading to undesirable odors, an environment suitable for the growth of bacteria, and an unfavorable recreational experience.

Cladophora growth and distribution in the nearshore waters of the Great Lakes are being assessed by U.S. and Canadian agencies and researchers under the Great Lakes Water Quality Agreement. This includes the role that nutrients (phosphorus and nitrogen) and invasive Dreissenid (zebra and quagga) mussels play in promoting the growth of Cladophora.

We currently have limited understanding of exactly where and when excessive amounts of Cladophora are accumulating along New York's Great Lakes shorelines after detaching from the nearshore lake bottom surface where it grows. Information collected through public observations will help better inform agencies and researchers.

Identifying Cladophora Accumulations

The images shown here are typical of conditions that may be observed along the Great Lakes shoreline.

Relative amounts of Cladophora to be used as guidance when completing the observation form:

No visible Growth
None: No visible growth or accumulation.
None: No visible growth or accumulation.
Minimal Growth
Minimal: Small amount of accumulation along waterline.
Minimal: Small amount of accumulation along waterline.
Moderate Growth
moderate algae coverage
Moderate: Accumulation over a substantial portion of the shoreline;
in this image, both fresh algae in water and along wet beach and
drying/decaying algae on dry beach are visible.
Extensive Growth
extensive algal growth
Extensive: Area-wide coverage. (Photo credit: ECCC)
Other Types of Algae

The images here show various types of aquatic vegetation that may be observed along the Great Lakes shoreline but are not Cladophora.

Dense growth of submerged aquatic vegetation (SAV).
Dense growth of submerged aquatic vegetation (SAV).
Lily pads (large plants in photo).
Lily pads (large plants in photo).
Duckweed (very small individual plants that typically are found in dense populations covering larger areas). (Photo Credit: Ohio EPA)Duckweed (very small individual plants that typically are found in dense populations covering larger areas). (Photo credit: Ohio EPA)
Duckweed (very small individual plants that typically are found in dense populations
covering larger areas). (Photo credit: Ohio EPA)

Cyanobacteria (harmful algal bloom).