To celebrate an upcoming holiday, cities have their own tradition that they carry out. Some places turn their rivers green, like Chicago, for St. Patrick’s Day. Some places go all out for Christmas and decorate from top to bottom, like New York. But for some places, nature decides to decorate for a nefarious reason.
The residents of Lake Erie are currently dealing with a lake that has turned green. WIth Halloween so close, it would be quick to assume that they are paying homage to Chicago for their celebrations, but the truth is a bit more toxic. The lake has turned green because of a toxic algae bloom.
Algae is the informal term used to describe photosynthetic organisms and includes a diverse list of organisms that range from single cells to multicellular that includes things like kelp or seaweed. A consensus has not been reached as to what a proper term would be for these organisms if they should even have one. Even now, things that were once considered algae are still referred to as algae despite not being actual algae.
An algae bloom is simply the large concentration of algae in a certain area. Because algae is an informal term that encompasses organisms with different growth rates, size, and nutrient requirements, algae bloom also have different considerations for what is considered a bloom event. It might be millions of cells per milliliter or thousands of cells, depending on the size of the organism in question. Since algae are photosynthetic, their pigments vary in color. This variable determines the color of the bloom as some can be green, red, or even blue among many other colors. There are even algae blooms that are not caused by algae, due to incorrect classification. Cyanobacteria, a photosynthetic bacteria, was considered algae in the past and, as a result, had blooming events that were called blue-green algae. Even now, it is sometimes still referred to as algae.
Among the algae blooms, are harmful algal blooms (HAB) that result in the concentration of toxic or harmful algae in an area. This HAB can cause harm to humans, animals, and the environment they bloom in. According to the Center for Disease Control and Prevention, HAB has occurred in all parts of the United States. The problems that HAB cause to humans include skin, breathing, neurological, and stomach irritations. They can also shut down water facilities. When they bloom, they block a lot of sunlight and absorb oxygen from the body of water they are in. This results in plants and animals dying off because of lack of oxygen and water.
Lake Erie Algae Blooms
The current algae bloom started last week and cover over 700 square miles of Lake Erie. This is an ongoing problem for this area as scientists estimated that algae blooms have been growing since 2000. It is the result of a freshwater algae bloom, which results from excessive nutrients in the water. The nutrient in question is phosphorus, which has leaked out from agricultural and industrial areas and caused eutrophication, an over-enrichment, of Microcystis, which is a cyanobacterium. This enrichment process resulted in a quick and massive growth of the cyanobacteria, covering a large area of the lake.
This is not the first time that this has happened. In the 1960’s and 1970’s, there were also algae blooms that were caused by excessive phosphorus in the lake. To deal with this, they attempted to extract the phosphorus from the lake, which did help for some time. But ultimately, as scientists have noted, the algae blooms are continuously growing despite the recovery efforts. In 2011 and 2015, Lake Erie saw some of its biggest algae bloom in its record. In 2014, over 500,000 residence near the lake could not use tap water sources for 3 days because of the danger posed by the toxic algae bloom. Fortunately, this current algae bloom is not as toxic as previous ones, but it is still considerable in size and it is expected that this will be a continued situation in Lake Erie.
Researchers, lead by Jeff Ho, found that this increased occurrence of algae bloom was the direct result of historic levels of phosphorus in the lake sediments and phosphorus entering the lake during springtime from the surround areas. These contributing factors continue to feed algae and cause the bloom.
To begin cleaning up Lake Erie, the researchers suggest that the phosphorus being introduced to the lake every spring needs to be drastically reduced or removed. That means compliance from agricultural and industrial areas that leak phosphorous into the lake. This compliance could come in the form of regulations, incentives, and more strict fines or penalties to act as a deterrence. Since the spring phosphorus is only one part of this situation, there also needs to be renewed efforts to clean the lake sediments of the lingering phosphorous. Once both of these are done, the lake will recover but that will take many years after the final cleanups so patience will be required. This is especially important because there are many people who depend on Lake Erie for their water source.
According to the CDC, there is mounting evidence that HABs are increasing in frequency and severity across the world because of climate change, farm practices, waste overflow, and water runoff. These factors affect many bodies of water, including Lake Erie. This means that the initial recovery efforts above may not be enough to help the lake and drastic measures might need to be considered. The increased occurrence of algae blooms threatens to contaminate drinking water across the globe, including areas being hit by dangerous hurricanes and storms as well as developing countries with insufficient water systems.
Hopefully, as we continue to build global initiatives againsts the causes of algae blooms, like climate change, we can slow down this increase in algae bloom and prevent further damage.