The Impact of Lake Erie Algal Blooms on the Quality of Drinking Water
Photo of City of Toledo, Ohio Water Intake During a Harmful Algal Bloom in 2014 by Ty Wright for The Washington Post via Getty Images
By: Tori Metzger, Intern
Approximately eleven million people across the United States and Canada are dependent on Lake Erie as their main source of water - the quality and safety of which can be put into jeopardy due to algal blooms. Algal blooms are a rapid increase in the population of algae in a body of water. Algae is a natural aquatic plant that provides nutrients for marine species and is a staple for the food chain; however, when algae grows excessively, it causes a “harmful algal bloom,” or “HAB,” which causes harm to an aquatic system.
Algal blooms in Lake Erie are caused by many poor land-based practices, including failed septic tanks leaking nitrates into bodies of water, failed plumbing allowing lead to contaminate the water, and the most prevalent factors being overuse of fertilizers containing nitrogen and phosphorus. Rain washes any fertilizer that hasn't been absorbed into plants off of the land and into near-by water bodies. When this excess fertilizer enters the water, the abundant amounts of nitrogen and phosphorus produce an overabundance of algae and disrupt the ecosystem as a whole and produce a thick, blue-green colored HAB.
Figure showing a comparison of total phosphorus (TP) tributary loading to Lake St. Clair and the western Lake Erie. Sources: Michigan Sea Grant, M. Maccoux, Contractor ECCC, S. Wortman, USEPA, D. Obenour, NCSU, M. Evans, USGS. Credit: IJC
While small amounts of algae are natural and healthy for ecosystems, the abundance of it causes many problems for marine species. One problem is the lack of sunlight that is able to penetrate through the thick algae. Sunlight is important to marine species because it provides the energy that marine plants, like phytoplankton, need to be the source of food and oxygen for not only ocean creatures, but for the entire planet. Another problem that is linked to the lack of sunlight is the scarcity of oxygen. Without the sunlight, algae cannot produce the oxygen they need to survive, leading them to die and decompose. When they decompose, they consume all of the oxygen in the area which then creates “dead zones”, or areas in the ocean with limited or no oxygen, causing other plants and animals around them to die.
Harmful algal blooms (HABs) occur when those colonies of uncontrolled algae produce toxins, called cyanotoxins. Cyanotoxins have harmful effects on people, fish, birds, and other marine mammals. According to the EPA, excessive algal growth in Lake Erie threatens the human health of nearby inhabitants.
Toxic algae can affect humans through ingestion, inhalation, and contact. Symptoms of exposure to toxic algae include irritation of the eyes, skin, and throat. Toxic algae’s health impacts can even be as severe as causing neurological damage. BMAA, a neurotoxin found in blue-green algae, has been linked with early-onset Alzheimer’s, ALS, and Parkinson’s Disease.
Image source www.cleanwateraction.org
In 2014, the people living in the city of Toledo, Ohio experienced a catastrophe that is still impacting their lives. The city urgently informed the people of Toledo to not drink or come into contact with their tap water in any way due to the City’s water system becoming contaminated with toxins from a harmful algal bloom growing in Lake Erie. This left people unable to brush their teeth, take showers, cook dinner, do laundry, and drink the water. People frantically traveled all around the state to nearby cities because the water supply became scarce. Restaurants and other businesses that depended on the water were forced to close until the city could fix the issue. As people started to leave the city and seek refuge wherever they could, the governor declared a state of emergency and brought supplies, including jugs of clean water, to Toledo. This crisis lasted for three days before officials were able to declare the water safe to consume again. The water crisis left the people of Toledo afraid for their safety and wondering if it would ever occur to that degree again.
Photo of Lake Erie’s Western Basin During a HAB www.greatlakes.org
The algal bloom located in the western parts of the Lake Erie basin that affected Toledo continues to reappear in the summer months. Although the recurrence of the bloom leaves people wondering what the level of toxicity will be that particular year, Toledo has made an effort to control their exposure. Filters are often used in households as a preventative measure to eliminate any negative components in the water. Additionally, the city conducts daily tests on the tap water and waterways to ensure the levels of toxicity never reach the level of what they were during the crisis in 2014.
Scientists and environmental agencies are working with coastal states and states bordering the Great Lakes to prevent harmful algal blooms and their impacts, including limiting the amount of nutrient runoff into nearby bodies of water. One initiative is the H2Ohio Initiative - created to protect the water quality in Ohio from the challenges resulting from failed septic tanks and nutrient runoff. The mission of H2Ohio is to keep all Ohio water safe for its residents by funding proper land-based practices and water-based restoration programs.
Other organizations, including Farmers Alliance and researchers at the Ohio State University Stone Laboratory, have taken initiatives to limit fertilizer runoff by utilizing the “four R’s”. The four R’s consist of using the right fertilizer source at the right rate, at the right time and the right place. Farmers who use this system can test their soil and find out the precise amount of phosphorus needed for their soil type to prevent excess amounts of phosphorus from becoming pollution. Other management practices used to limit the amount of nutrients traveling to water bodies include planting cover crops and buffer zones. Cover crops prevent bare grounds containing excess nutrients from being washed away by rain or snow. Buffer zones are trees, shrubs, and grasses planted between a crop field and waterway, where excess nutrients are absorbed before washing into the water.
The public can even take preventative measures at home! This includes choosing phosphate-free detergent, soaps, cleaners, and other household products and also cleaning up after pets to prevent animal waste that contains nutrients from traveling to water bodies. Improving Lake Erie’s overall health is key to ensuring that the quality of water stays clean and pollution free!
Resources:
https://www.agriculture.com/news/crops/farmers-rethink-practices-to-solve-algae-blooms
https://www.cleanwateraction.org/features/harmful-algal-outbreaks-and-drinking-water
https://www.epa.gov/greatlakes/lake-erie
https://www.epa.gov/nutrientpollution/sources-and-solutions-agriculture
https://greatlakes.org/campaigns/lake-erie-algae-blooms/
http://h2.ohio.gov/ohios-need/
https://governor.ohio.gov/wps/portal/gov/governor/media/news-and-media/031419
https://www.noaa.gov/what-is-harmful-algal-bloom
https://odh.ohio.gov/wps/portal/gov/odh/know-our-programs/harmful-algal-blooms/welcome/
https://greatlakes.org/2019/08/five-years-later-lessons-from-the-toledo-water-crisis/