There is a problem plaguing agriculture America—a problem not of oil or smog, but of a chemical pollution that has led to overgrowth of harmful algae blooms. These blooms make the waters toxic, making it impossible for people to best enjoy these lakes.
Harmful algae blooms often aided in growth by farm runoff, where rain washes fertilizers and pesticides into water systems, creating an environment in which algae blooms can thrive.
The U.S. National Office for Harmful Algal Blooms says, “Harmful algal blooms (HABs) are proliferations of microscopic algae that harm the environment by producing toxins that accumulate in shellfish or fish, or through the accumulation of biomass that in turn affects cooccurring organisms and alters food webs in negative ways.”
However, not all algae blooms are directly connected to industrial agriculture in anyway—some are the product of ocean warming, where coastal environments are becoming more habitable for toxic algae to grow. A massive toxic algae bloom broke out on the Pacific West Coast in the United States in 2015, a product of warmer ocean temperatures, brought to shore by storms. The resulting toxic bloom, according to a report by Ryan McCabe, et al. titled “An unprecedented coastwide toxic algal bloom linked to anomalous ocean conditions,” the bloom led to prolonged closures razor clam, rock crab, and Dungeness crab fisheries. These closures resulted in economic impacts to the area.
According to the Environmental Protection Agency (EPA), there are several parts to environmental change that are leading to more algae blooms, which include warming water temperature, changes in salinity, higher carbon dioxide levels, changes in rainfall, sea level rise, and coastal upwelling. Algae blooms tend to prefer warmer water temperatures, creating environments that promote algae growth. Algae also depend on carbon dioxide, where the rising level of carbon dioxide levels come into play. According to the National Oceanic and Atmospheric Administration (NOAA), carbon dioxide levels went from 9.4 billion metric tons of carbon in 2011 to 9.6 billion metric tons in 2012. Lastly, a coastal upwelling is when winds push surface water offshore and deep water moves towards the coast, bringing nutrients from the ocean floor to the surface (EPA). These extra nutrients help promote the growth of algae blooms, especially on the West Coast.
There is no single agency that has been working on the study of HABs. Instead, multiple agencies are studying different aspects of HABs, may it be toxicology, ecology, HAB monitoring, and human impact.
Not only are oceans being affected by HABs; freshwater bodies are being affected as well. This is especially seen in the Midwest, where farm runoff is a common issue. Farms often use fertilizers that contain a high amount of phosphorous that help promote plant growth. Whenever it rains, this phosphorous makes its way to bodies of water, where algae blooms can then thrive.
According to the Harmful Algal Research & Response National Environmental Science Strategy, impacts of HABs include human illness or death following consumption of to toxic shellfish or toxicity in the environment, economic issues on economies dependent on tourism and local seafood, and increased fish, bird, and mammal mortalities. These factors have a direct impact on society; may it be due to reduced tourism, impacted health, and economic hardship. They are all things that can affect people directly. Pollution is often not on the forefront of people’s minds until it becomes something that impacts them directly. A similar mindset was taken up with the COVID-19 crisis, where people paid little mind to the situation until it began to affect them or someone they know directly.
The article “Marine harmful algal blooms, human health and wellbeing: challenges and opportunities in the 21st century,” says that algae blooms are a naturally occurring event, but are becoming more and more toxic for humans and other animals. The article later says that “some microalgal blooms can cause harm to humans and other organisms. These harmful algal blooms (HABs) have direct impacts on human health and negative influences on human wellbeing, mainly through their consequences to coastal ecosystem services (fisheries, tourism and recreation) and other marine organisms and environments.”
Many people think that these blooms only affect coastal states, where red algae make ocean beaches in Florida unusable by beachgoers, or fish dying in hordes in California waters.
However, like mentioned before, algae blooms do have an effect on freshwater bodies. These algae blooms do have a local impact on Ohio, most notably seen at Grand Lake St. Marys, where harmful algae blooms have become more common over the past few years. According to the Lima News, the summer of 2010 was particularly impactful, where blue-green algae blooms make the lake unsafe for boating or swimming.
Lake Erie has also been impacted by algae blooms, with severe blooms in 2011, 2015 and 2017. According to the Dayton Daily News, “In 2014, some 500,000 Toledo area residents were told not to drink or even touch their tap water for four days because of high levels of toxins attributed to a bloom near the municipal water intakes.”
Dr. Bryan Boulanger, a civil engineering professor at Ohio Northern University, specializes in environmental engineering.
“I’ve witnessed the impacts of HABs in ecosystems before, but have not studied them directly. Overall, the impacts can be devastating. Water quality decreases. As the algae bloom grows, bacteria feeding on the algal matter create a drop in oxygen levels in the system. The lower oxygen levels harm fish populations. Additionally, if the freshwater system with HAB contamination is used as a source for drinking water, the process of cleaning up the water can release toxins from the algae into the treated water,” Boulanger said.
Boulanger explains how phosphorus runoff, along with the combination of water temperature and depth impact the extent of potential algal bloom contamination. Programs aimed at limiting farm field runoff are a mitigation measure. Along with this, changing how fields are maintained (tilling soil versus not tilling soil, soil nutrient measurements, and different fertilizer application methods) all have an impact on how much nutrient-rich runoff eventually reaches a system where algae may grow.
Boulanger goes on to say, “For drinking water treatment, implementing treatment technologies aimed at removing the algae before toxins can be generated during treatment is important. Many drinking water plants where this is a concern have accomplished this task using activated carbon within their treatment plant.”