Algal Blooms a Growing Threat to Local Economies and the Environment

Summer is a time for lemonade, fishing and taking a dip in a local lake. Unfortunately, many communities are also experiencing the effects of harmful algal blooms (also called algae blooms) in lakes, rivers and coastlines this summer. These algal blooms can form mats, films, clumps and foams and often have hues of white, green, red, yellow and brown. In addition to hindering recreational activities including swimming and fishing, these algal blooms can increase water costs, hurt local businesses, contaminate drinking water and cause harmful health effects in many areas across the globe.

What causes harmful algal blooms?

Although colonies of algae are naturally occurring, excess nutrients can cause them to grow out of control. In particular, nitrogen and phosphorus-rich runoff from commercial agriculture, wastewater and lawn fertilizers cause explosive growth.

Nutrient loads in runoff, rising temperatures and intense rainfall events that carry soil and nutrients into lakes are all contributing to harmful algal blooms. In some cases like in Utah, drought can exacerbate algal blooms when water becomes stagnant and in high-heat conditions. Likewise, diverting fresh water upstream can also exacerbate this problem.

Once optimum conditions are reached, the algae multiply, and populations frequently grow out of control. This means that some years can be worse than others, yet the harmful effects of algal blooms are steadily becoming worse across the globe over time. California, for example, reports that harmful algal blooms have increased by 464 percent in the last five years.

The exact culprit of these blooms varies a bit by the waterway. In part, it depends on the cyanobacteria at play because the exact conditions in which they thrive varies by the species. As heat waves, droughts, and extreme rainfall become increasingly common, harmful algal blooms will become more severe in many areas. Unfortunately, harmful algal species can be transported by ships in ballast water. This means that new species can be introduced, leading to new environmental problems if such algae grow unchecked into new blooms.

Why are algal blooms so concerning?

People can come in contact with algae by eating seafood, swimming, drinking water or even breathing contaminated air. Not all algal blooms are harmful, but certain species can lead to environmental and health risks. Some produce highly potent toxins, which are harmful to aquatic life and humans. Coming in direct contact with such blooms or ingesting food that contains harmful algae can lead to such extreme human health risks as liver failure, cancer and respiratory problems.

Other types of algal blooms create biomass that blocks sunlight or decreases oxygen levels in the water. Sadly, they can create dead zones or mass mortality of aquatic life. This is especially concerning in regions that are dependent on fisheries or rely on tourism. Although commercial fisheries are monitored and typically closed when unsafe conditions are reached, recreational fishing can lead to the unsafe consumption of seafood. Likewise, the closure of fisheries can have significant financial impacts on surrounding communities.

Unfortunately, toxic algae are causing beaches to close and are even contributing to water wars along the California and Oregon border. Some communities aren’t able to ensure safe drinking water supplies for their residents because they lack adequate water treatment infrastructure to respond to this threat. Unfortunately, boiling water doesn’t remove the toxins – and any necessary infrastructure improvements could cause the cost of sourcing local water supplies to increase.

Long-term economic and public health risks

In Toledo, Ohio, the cost of water is expected to double between 2019 and 2025, boosting living expenses for residents. The expenses of ensuring a safe drinking water supply are being passed on to residents through water rate hikes. Unfortunately, that burden can fall the hardest on low to moderate-income residents. 

Algal blooms are also covering Lake Okeechobee, Florida’s largest freshwater lake. Its once clear waters are now opaque. This green carpet is hurting the local tourism industry and human health, but political issues are hindering any positive action and progress. There is also disagreement within the surrounding region on the best way to mitigate algal blooms without hindering commercial agriculture.

“None of this is cheap,” said conservation biologist and ecologist Hilary Swain, director of Archbold Research Station, located near Lake Okeechobee. “None of it is easy, and all of it’s going to, unfortunately, take quite a long time. But all of it is worth doing and all of it’s worth doing now because our problems are only going to get worse. We’re only digging ourselves a deeper hole down the road if we don’t address this.”

Image credit: Koushik Chowdavarapu/Unsplash