How Are Algal Blooms Harmful to Humans and the Planet?

Algae are part of an ecosystem, helping habitats thrive and grow. They are also visually pleasing, adding texture and color to water bodies. However, parameter disruptions can cause overgrowth or algal blooms, which can be dangerous and even fatal at times. 

What Are Algae?

Algae are a diverse group of aquatic organisms, although some species are also found on land. These species do not have complex structures like plants — algae are nucleic-bearing and do not have stems, roots or leaves — but can still photosynthesize. Some algae contain only one cell, while many have up to millions of cell counts. 

Algae live in bodies of water, including oceans, rivers, ponds, lakes, and wet soil. In many countries, the types of algae found change through the seasons. They are commonly categorized by color, which results from the chlorophyll and other pigments in their cells. 

How Does Algal Bloom Happen?

Algae blooms happen when cyanobacteria, also known as blue-green bacteria, have excess nitrogen and phosphorus, especially in dead zones. This growth takes up all the oxygen in the water and also blocks sunlight from reaching the river bed. This could cause the underwater plants to have less sunlight for their photosynthesis, causing stunted growth or death.

When the algae die, they take up oxygen, causing the aquatic habitat to struggle to thrive. In the long run, these ecosystems can die. Some algal blooms create toxins, a phenomenon called harmful algal blooms. These can cause contamination in drinking water, which can be dangerous to animals and people. 

The biggest dead zone in the country is located in the Gulf of Mexico. It is 6,500 square miles and recurs every summer due to nutrient imbalance. 

How Does Algal Bloom Hurt People?

Many people flock to places with algae because of its attractiveness. Algae blooms, such as the bioluminescent beaches in La Parguera, Puerto Rico, U.S., provide some iInsta-worthy shots. Algae blooms are harmful to humans and can cause adverse effects if left untreated. Here is how:

Ingesting Contaminated Water

Humans can accidentally consume the water while swimming. The toxins in algal blooms can cause various health problems, such as gastrointestinal conditions, liver damage and neurological issues. These are not always fatal, but they could be, depending on the type of toxin and intensity of exposure. 13 states in the U.S. reported 227 cases of algae bloom poisoning in 2020, including 95 human cases and 1,170 cases. 

Skin Contact

Conducting recreational activities in water affected by algae blooms can expose people to deadly toxins through skin contact. People with existing skin conditions can find their issues worsening. In addition, people can also experience skin irritation, eye issues, and rashes. If these are left untreated, algae bloom poisoning can be fatal.

Seafood Poisoning

Besides ingesting and having contact with algal bloom, eating contaminated seafood can also cause adverse consequences. Aquatic organisms are exposed to the toxins these blooms release and can impact humans who eat them. Consuming contaminated seafood can cause serious health consequences, including paralytic, diarrhetic and neurotoxic shellfish poisoning. For some, it could be mild gastrointestinal issues. In some cases, this could turn deadly. 

In 2020, one algae bloom-associated death due to paralytic shellfish poisoning was reported due to a noncommercial shellfish harvest. 

How Does Algal Bloom Impact the Environment?

Besides humans, harmful algae bloom also impacts the environment in many ways. Among these are:

Acid Rain

When algae decompose, they release nutrients like nitrogen and phosphorus into the atmosphere. These nutrients mix with the air and react with other chemicals to form acidic compounds that become acid rain. Acid rain can rip the soil off essential nutrients, making it harder for plants to grow. This causes a lack of food for wildlife. In addition, it can also weaken trees and cause more diseases, pests and structural integrity issues. 

Hypoxia

As algae decompose, they consume significant amounts of oxygen from the water. This causes oxygen depletion, also known as hypoxia. This condition can suffocate fish, shellfish, crabs and other aquatic organisms, further causing mass deaths, disruptions to the food chain, and catastrophic harm to marine ecosystems.

Air Pollution

Harmful algae blooms can contribute to air pollution by emitting volatile organic compounds (VOCs) into the air. These VOCs can react with other compounds to create ground-level ozone, which is a significant part of smog. It also releases foul odors and particulate matter, which can jeopardize the air quality. 

Water Pollution 

Algae blooms can produce toxins that would contaminate water sources. These can pose risks to other plants, humans, livestock and wildlife. In addition, the decomposing algae has an unpleasant smell and looks unsanitary. This causes the water to be unsuitable for recreational or commercial activities. 

Ecosystem Disruption

Algae blooms can block sunlight from reaching underwater plants, causing a lack of photosynthesis and an imbalance in the aquatic ecosystem. They can also disrupt the nutrient cycles in the water, affecting the growth and survival of various underwater organisms.

How Can It Be Prevented?

Recent advancements in prediction technology are transforming the monitoring of these blooms. Remote sensing techs, such as satellites and drones, measure parameters like water temperature, nutrient level and chlorophyll concentration to refine predictions on potential blooms.

In addition, modeling innovations have simulations to forecast algae overgrowth based on environmental factors. These advancements can help scientists identify areas with high risks and activate preventive measures.

People who visit water bodies must be alert to the latest advisories and stay away from areas known for frequent algae blooms. They should also wear protective clothing and safety gear when swimming or diving to avoid skin contact and ingesting harmful chemicals. 

If there are suspicions of coming in contact with harmful algae or symptoms persist, they should wash themselves and their clothing with soap and water and seek medical attention as promptly as possible. 

Algae Blooms Can Cause Harmful Impacts on People and the Ecosystem

Algae overgrowth could be dangerous. Therefore, reducing contact with this phenomenon is vital to ensure safety. People must seek quick medical help if they suspect being poisoned by an algae bloom.