Harmful Algae Blooms on Seneca Lake
In 2015, for the first time, Seneca Lake had three laboratory-confirmed, blue-green algae blooms along its shores at levels that were above the DEC threshold-criteria of concern. The confirmed blooms were from Kime Beach, Seneca County; Severne Point, Yates County and Serenity Road, Yates County.
SLPWA received 17 reports of suspicious algae blooms in 2015. With the approval of the NYS Department of Environmental Conservation (DEC), SLPWA volunteers submitted five sets of samples to the SUNY -EFS lab for testing; two were negative for BGA.
Based on review of photographs, report descriptions, site visits, and discussions with DEC, SLPWA believes that, of the 17 reports, 15 were BGA. Not all could be submitted for testing as the bloom had disappeared before the sample could be collected.
The widespread occurrence of the HABs around the lake, along with its fugitive nature, means that residents and users of the lake must be aware of what to look for and how to respond to suspicious algae blooms, for their own safety as well as the safety of people and animals in their care. The DEC website provides current and useful information about these blooms and how to handle them. DEC warns: “Because it is hard to tell a harmful algae bloom from other algae blooms, we recommend avoiding contact with any floating rafts, scums, and discolored water.”
The occurrence of algae blooms is directly related to the increasing nutrient concentrations in Seneca Lake. SLPWA’s program of monitoring and identifying pollution sources of phosphorus and nitrogen in streams that feed the lake is an important component of a strategy to mitigate and reduce algae, bacteria, and weed growth in the lake.
According to the New York State Department of Environmental Conservation (DEC):
“Most algae are harmless and are an important part of the food web. Algae are naturally present in slow moving streams, lakes, marine waters and ponds in low numbers. Certain types can become abundant and form blooms under the right conditions. Some algae can produce toxins that can be harmful to people and animals. These are collectively called harmful algal blooms (HABs).”
“Algae blooms most frequently occur in nutrient-rich waters, particularly during hot, calm weather.”
“Because it is hard to tell a harmful algae bloom from other algae blooms, we recommend avoiding contact with any floating rafts, scums, and discolored water.”
When blooms are formed, the risk of toxin contamination of surface waters increases especially for some species of blue-green algae with the ability to produce toxins and other noxious chemicals. These are known as Harmful Algal Blooms (HABs). Blue-green algae, also known as cyanobacteria, are of special concern because of their potential impacts on drinking and recreational waters. Blue-green algae can form blooms that discolor the water or produce floating rafts or scums on the surface of the water. These can cause health risks to people and animals when they are exposed to them.
The health impacts of blue-green algae, according to the New York State Health Department:
“Some blue-green algae produce toxins that could pose a health risk to people and animals when they are exposed to them in large enough quantities. Health effects could occur when surface scums or water containing high levels of blue-green algal toxins are swallowed, through contact with the skin or when airborne droplets containing toxins are inhaled while swimming, bathing or showering.
Consuming water containing high levels of blue-green algal toxins has been associated with effects on the liver and on the nervous system in laboratory animals, pets, livestock and people. Livestock and pet deaths have occurred when animals consumed very large amounts of accumulated algal scum from along shorelines.
Direct contact or breathing airborne droplets containing high levels of blue-green algal toxins during swimming or showering can cause irritation of the skin, eyes, nose and throat and inflammation in the respiratory tract.”
DEC says our pets are at the most risk:
“Because of their behavior, dogs are much more susceptible than humans to cyanobacterial poisoning. When toxins are present, dogs can be exposed to toxins by drinking the water, by eating washed up mats or scum of toxic cyanobacteria and by having skin contact with water. Dogs are often attracted to algal scum odors. After leaving the water, dogs can also be poisoned by grooming their fur and paws.”
Identifying Harmful Algae Blooms
Large populations of blue-green algae may produce toxins at a high enough level to affect those using the water for drinking or recreational use. Individual cyanobacteria cells and green algae cannot be seen with the unaided eye. However, they may cluster together to form visible algae blooms. The photos below illustrate what possible Blue-green harmful algae blooms may look like. A laboratory analysis of a water sample must be completed to determine if toxins are present.
|Examples of Harmful Blue-green Algae Blooms|