Harmful algal bloom predicted for western Lake Erie
The U.S. National Oceanic and Atmospheric Administration, and its partners, predicted a significant harmful algal bloom for the western end of Lake Erie this summer. The scientific agency, part of the U.S. Department of Commerce, says the 2017 bloom could reach levels last seen in 2013 and 2014, but smaller than the record bloom of 2015. File photo
While the western end of Lake Erie will always be hit hardest by harmful algal blooms, it doesn’t mean the eastern end is immune, says Brock University earth science professor Francine McCarthy.
“It could certainly happen here,” says McCarthy.
But, she says, the eastern basin of the lake is deeper and colder, giving it a layer of protection over the much shallower western basin. The eastern basin starts from the Long Point area, while the western basin stops in the Point Pelee area. The central basin of the lake is in between those two points.
“The western basin is very warm throughout the water column,” she says. “Warmth is one of the things that correlates with harmful algal blooms.”
The U.S. National Oceanic and Atmospheric Administration, and its partners, predicted a significant harmful algal bloom for the western end of Lake Erie this summer. The scientific agency, part of the U.S. Department of Commerce, says the 2017 bloom could reach levels last seen in 2013 and 2014, but smaller than the record bloom of 2015.
In a release, it says the bloom “is expected to measure 7.5 on the severity index, but could range between six and 9.5. An index above five indicates a potentially harmful bloom. The severity index is based on a bloom’s biomass – the amount of its harmful algae – over a sustained period. The largest blooms, 2011 and 2015, were 10 and 10.5, respectively.”
In 2014, the city of Toldeo, Ohio saw its municipal water supply shutdown and a two-day ban on drinking or cooking with tap water due to an bloom in the western basin.
Algal blooms are caused by cyanobacteria, says McCarthy, adding it used to be called blue-green algae. The cyanobacteria creates microcystins, a neurotoxin that can affect everything living thing in the water and those that drink it.
She says the cyanobacteria are found across the lake, but it takes the right conditions - like warm waters and ample, available nutrients - to see them increase and cause a harmful bloom.
Nutrients that feed cyanobacteria include nitrogen and phosphorus found in agricultural fertilizer, and human activity such as effluent from wastewater treatment plants.
“Back in the 80s and 90s, people began to become aware and decreased the use of fertilizer. The Great Lakes Water Quality Agreement (between Canada and the U.S.) had an impact,” says McCarthy.
She says farmers on both sides of the border started to change the way the plowed their fields and applied fertilizer more judiciously, measures suggested by scientists to reduce phosphorus and other nutrients from entering the lake.
“Over time though, the population in the Great Lakes increased … the number of people that need to be fed.”
McCarthy says Ohio and Michigan are an agricultural heartland for the region, and even with best-use farming practices, there are factors beyond farmers’ control that will cause fertilizer to run-off into the lake.
Weather events, such as large storms, erode fields no matter how well plowed.
“The warming we’ve experienced over the last several decades make more of these large storm events less rare.”
McCarthy says large rain events that take place during the spring months have a bigger impact, because that is time of year farmers are fertilizing their fields.
And with the amount of rivers, and tributaries that feed those rivers, on the U.S. side of the border the run-off from agricultural lands into the lake will continue to feed the cyanobacteria.
“We’ve taken steps as a society as much as we can, but still the odds are against us.”
Information on harmful algal blooms can be found at oceanservice.noaa.gov/hazards/hab/ and Lake Erie forecasts at tidesandcurrents.noaa.gov/hab/lakeerie.html.
Harmful Algal Bloom Health Information
Effects on Humans
• Contact with skin can cause rash, hives, or skin blisters (especially on the lips and under swimsuits).
• Inhalation of water droplets can cause runny eyes and nose, a sore throat, asthma-like symptoms, or allergic reactions
• Ingestion of the water can cause abdominal pain, headache, sore throat, nausea and vomiting, dry cough, diarrhea, blistering around the mouth, and pneumonia.
• What you can do: Contact your healthcare provider OR regional health department.
Effects on Animals
• Ingestion of the water can cause lethargy, vomiting, diarrhea, weakness, pale mucous membranes, death.
• What you can do: Seek medical treatment immediately if you suspect your pets or livestock have been exposed.
How can you Avoid Exposure?
• Drinking Water: Health officials conduct routine monitoring to ensure that public drinking water is safe.
• What you can do: Follow drinking water advisories and contact your regional health department with questions.
• Recreational Water Safely: You can still boat and recreate in Lake Erie waters, but be aware that HABs may be present.
• What you can do: If you can, plan your trip by checking NOAA's HAB Bulletin before you go; Respect any waterbody closures announced by local public health authorities; Avoid activities in areas where the water is discolored by algae or scums are visible; Thoroughly wash yourself and pets after suspected contact with a HAB.
• Recreational Fishing: Commercial fish from local restaurants and markets is safe to eat because it is tested for HAB toxins before it is sold.
• What you can do: Fillet the meat, thoroughly removing the skin, gills, and guts (which may have accumulated toxins from the HAB); Rinse the fillet meat with clean water; Thoroughly wash hands after filleting fish.