Great Lakes Water

Lake Erie Algae Crisis

Published: May 1st, 2017

Authors: Andrew Montry & Christopher Fox-Strauss

Topic Editor: Andy Jorgensen

Topics: Water, Algae

"Sediment and Algae Color the Great Lakes" Photo by NASA's Earth Observatory/ CC BY

Introduction to Algal Blooms

Algae are a highly diverse group of autotrophic protists that are found on land, marine ecosystems, and freshwater. There are around 37,000 algal species on the planet, and most are harmless, even beneficial. However, a little under 1% of these algal species produce toxins. One class of harmful algae is the aquatic class of species known as Cyanobacteria. Cyanobacteria produce cyanotoxins which negatively impact other species and wildlife.

When certain conditions are met, these Cyanobacteria form colonies and multiply to rapidly increase in size. These large, toxic colonies are known as harmful algal blooms (HABs). HABs are caused by different sets of ideal conditions for the Cyanobacteria, depending on the species and region. Typically, however, increased light availability, warm waters, and increased nutrient levels (such as phosphorous) lead to increased reproduction and growth. This growth leads to population swelling, and eventually triggers the release of cyanotoxins. HABs can strangle ecosystems to the point of collapse through the excretion of these toxins. Marine or freshwater fish and aquatic plants can become sick and/or die from these chemicals, and the toxins become more concentrated as they work up a food chain.

Causes of Algae Blooms in the Great Lakes

In freshwater, such as the Great Lakes, phosphorus runoff into the lakes paired with warm temperatures is the leading cause of algal blooms. There are two types of phosphorus pollution that exists in water: dissolved phosphorus primarily coming from point sources such as sewer and industrial waste, and from particulate phosphorus arriving in the lake from nonpoint sources such as agricultural and residential fertilizer runoff.

Dissolved phosphorus is a more dangerous pollutant for inciting algal blooms as it is bioavailable, meaning it is more easily absorbed by the protists cell membranes. This absorption causes rapid reproduction and growth in the Cyanobacterial colonies. The levels of dissolved phosphorus in Lake Erie have over doubled since 1990. From 1998-2002, 1,464 metric tons (16.3% of the lake’s total phosphorus) of dissolved phosphorus entered the lake, and as of 2017, it has almost doubled that measurement. Although dissolved phosphorus is a larger issue than particulate, it is can be more easily stopped due to the source of the phosphorus being more easily found and rerouted. Half or more of all of the dissolved phosphorus entering Lake Erie originates from Michigan’s Southeastern shore and region. Particulate phosphorus is not as bioavailable as dissolved, but high levels of particulate runoff from fertilizer fluctuate at a higher rate than dissolved levels. Heavy rain or excess fertilizer use can cause large amounts of fertilizer to rapidly enter the waterways through a system of tile drains in the Southern Michigan and Northern Ohio installed in the early 1900s to remove water from swampland in order to increase farm land. These waterways then drain into more major rivers that feed Lake Erie. The top phosphorus aiding river into Lake Erie is the Cuyahoga river (feeding 58.5% of the particulate phosphorus). Altogether,  512 metric tons of particulate phosphorus (5.6% of total phosphorus in Lake Erie) entered the lake from 1998-2002 (B-1). Particulate phosphorus is a much more complex issue to solve than dissolved, as the exact source and timing of the runoffs is very difficult to predict and solve.

Phosphorus Contribution by River

Name of River	% of phosphorus contributed to Lake Erie
Maumee River	7.5%
Sandusky River	4.2%
Honey Creek	3.0%
Rock Creek	<1%
Cuyahoga River	58.5%
Grand River	1.6%

Brief History

Algal blooms have persisted throughout history in both freshwater and marine environments. Cyanobacteria, the main contributor to HABs, were the first form of photosynthetic life on Earth showing a significant amount of evidence that they have been able to adapt adequately over time. Major HABs have occurred in the Gulf of Mexico, on both the coast of Texas and Florida. Through HABs occurring in the Gulf of Mexico they have been given the common name “red tides.” This is due to the red pigment of the algae which ultimately gives the illusion the water is red. HABs continue to be a growing issue in the United States due to a number of aforementioned factors, in fact, since the 90s algal blooms have continued to increase in frequency and magnitude.

"Toxic Bacteria" Photo by Oregon State University/ CC BY-SA

Lake Erie Crisis

In the summer of 2011, Lake Erie experienced a record setting algal bloom. Three years later in the summer of 2014, harmful algal blooms gained national attention in the United States after a state of emergency was declared due to a large HAB in Lake Erie. This HAB affected the drinking water of nearly 400,000 people in the city of Toledo, leaving citizens without drinkable water for three days. Because of this state of emergency, researchers were determined to find the causes of this bloom and to prevent future HABs. It was found that climate change was a significant contributor. The previous spring was abnormally warm, giving the algae ideal conditions to grow and reproduce. On top of the warmer climate, it was also found that the agricultural practices of the surrounding area was also a large factor. Due to the increase in phosphorous deposits from fertilizer into the lake and the surrounding rivers the algae were given an increase in nutrients, also contributing to the growth.

Effects of HABs

Harmful algal blooms have a number of adverse effects to the environment and the organisms within that environment, including humans. Microcystin is a toxin that is commonly prevalent during HABs. It is released from a type of cyanobacteria typically common in freshwater environments. Microcystin along with Cylindrospermopsin, also released from a certain type of algae, can lead to hepatotoxicity. The symptoms include "paresthesia and numbness of lips and mouth within 1⁄2 to 3 hours after exposure, extending to face, neck, extremities; motor weakness; incoordination; respiratory and muscular paralysis". In rare cases these toxins can lead to liver failure and death. Although cylindrospermopsin leads to hepatotoxicity, there are different symptoms such as an enlarged liver, feelings of discomfort, vomiting, and headaches. Other toxins released from HABs include anatoxin which is a neurotoxin. As of today the symptoms of anatoxin and its neurotoxicity has not been documented.

These aforementioned toxins can end up in drinking water thus affecting the surrounding population. Along with affecting drinking water, algal blooms can also affect the ecosystem in which they originate. Due to the extensive reproduction and growth of algae during algal blooms, the water is deprived of many nutrients other organisms use for survival, primarily oxygen. Extreme HABs can cause complete destruction of a biome if left untreated. It is not uncommon for many organisms to die during a HAB. HABs can also affect local economies. The spike in algae growth inhibits the ability to fish in the surrounding waters due to the increased toxins and deaths of fish in the area. Public recreation is another victim of HABs. When a HAB is occurring the surrounding water is unsafe for any human to interact with it. This can deter people from fishing, boating, swimming, or even visiting the bodies of water which also plays a part in harming the local economy.

Steps Towards Sustainability

Due to the extreme nature of recent harmful algal blooms, teams such as the Lake Erie Lakewide Action and Management Plan (LAMP) have been formed to ensure these HABs do not recur. Teams like lamp have set goals that will help prevent HABs in the future and will hopefully lead to the full sustainability of our water systems. An example of these goals would be the phosphorous levels being gradually decreased by at least 40%. This is due to the critical role phosphorus plays in algae growth and reproduction. LAMP has also proposed certain initiatives to increase the prevention of HABs. While it cannot be set in stone that meeting these initiatives would rid our water systems of HABs, they were proposed by LAMP and are believed to at least help the issue. They are as follows; “we must harness market forces to help farmers reduce nutrient runoff, we must build water smart cities and cultivate water smart citizens, we must improve scientific understanding of algal blooms and their implications, and we must create a policy framework that drives action."

Further Reading:

1. A blog by Karen Chapman highlighting possible solutions to HABs
   • https://www.edf.org/blog/2014/08/19/lake-erie-toxic-algae-bloom-time-scale-solutions-we-know-work

1. An in depth analysis of the HAB that occurred in Toledo, Ohio in 2013 on EcoWatch website by Stefanie Spear
   • http://www.ecowatch.com/toxic-algae-bloom-leaves-500-000-without-drinking-water-in-ohio-1881940537.html
2. A National Geographic article by Jane Lee that examines the local Ohio algae crisis
   • http://news.nationalgeographic.com/news/2014/08/140804-harmful-algal-bloom-lake-erie-climate-change-science/
3. The Environmental Protection Agency's summary of the Lake Erie watersheds and surrounding areas
   • https://www.epa.gov/greatlakes/lake-erie
4. An introductory pamphlet on the effects and causes of HABs
   • https://www.glerl.noaa.gov/pubs/brochures/bluegreenalgae_factsheet.pdf

Citation

Fox-Strauss, C. M., & Montry, A. (2017, May 1). Lake Erie Algae Crisis. Retrieved from: Great Lakes Water