Have you ever wondered why algae blooms often get worse during the summer months? You’ve probably seen at least one article about toxic or harmful algal blooms (HABs) during the heat of summer, recommending residents to take caution near water bodies. It’s getting more common to see increased algal blooms throughout the world. The Environmental Protection Agency (EPA) of the United States links this to climate change and warming temperatures in their article about Climate Change and Harmful Algal Blooms.
The increase of algal blooms in summer is because of several factors related to temperature, light, and nutrient availability.
In the summer months, temperatures are generally warmer, which can increase the growth rate of algae. Warmer water temperatures can also increase the stratification of the water column, leading to reduced mixing of nutrients and oxygen between the surface and deeper waters, which can favor the growth of certain types of algae.
In addition to temperature, sunlight levels tend to be higher in the summer months, which can promote the growth of algae. Algae need sunlight to photosynthesize and produce energy, and longer days with more intense sunlight can increase the growth rate of algae in the water column.
Finally, nutrient availability can play a role in the growth of algae. In many lakes and water bodies, nutrients such as nitrogen and phosphorus are limiting factors for the growth of algae. During the summer months, nutrient runoff from agricultural and urban areas, as well as from increased recreational use of water bodies, can lead to higher nutrient concentrations in the water, providing more resources for algae to grow.
Taken together, these factors create optimal conditions for algae growth in the summer months, leading to increased algal blooms, and potentially harmful effects on the ecosystem and water quality of lakes and other bodies of water.
Excessive algae blooms in lakes can have a range of consequences for the ecosystem and water quality, including:
Oxygen depletion: As algae blooms grow and die, they consume large amounts of dissolved oxygen from the water. This can lead to low dissolved oxygen levels, which can stress or kill fish and other aquatic organisms. Extreme oxygen depletion from algae can cause hypoxic dead zones that can persist and lead to large fish kills.
Water quality degradation: Algae blooms can release toxins and other organic compounds into the water, making it unsafe for swimming, fishing, or other recreational activities. Blooms can also cause taste and odor problems in drinking water supplies.
Ecological impacts: Algae blooms can alter the food web and nutrient cycling in lakes, which can have long-term impacts on the health of the ecosystem. For example, some types of algae can outcompete other types of plankton for nutrients, leading to a shift in the types of organisms present in the water.
Economic impacts: Algae blooms can have significant economic impacts on communities that rely on tourism or recreational activities associated with lakes. Homes and other properties located near lakes affected by algae blooms may see a decline in value due to the unattractive appearance of the water and concerns about potential health risks. Algae blooms can make lakes and beaches unattractive for swimming and other recreational activities, leading to lost revenue for local businesses that rely on tourism.
Public health risks: Some types of algae can produce toxins that can harm human and animal health. Exposure to these toxins through drinking water or recreational activities can cause skin irritation, respiratory problems, or other health effects. These health effects can result in increased healthcare costs for affected individuals and communities. Algae blooms can make drinking water supplies more difficult and expensive to treat, due to the presence of taste and odor compounds, toxins, and other organic materials. In severe cases, the effects of summer algae blooms on the ecosystem and water quality may require costly remediation efforts, such as dredging, shoreline stabilization, or installation of treatment systems.
Nanobubbles help prevent and reduce algae blooms in summer by targeting the root causes of excessive blooms through efficient oxygenation and chemical-free oxidation.
Indirectly, nanobubbles create conditions that make it harder for algae to thrive by increasing dissolved oxygen throughout the water column, leading to better water quality and improved oxidation-reduction potential (ORP or Redox), a measure of water’s oxidizing capacity to break down contaminants.
Introducing high concentrations of nanobubbles into the water increases the oxygen levels in the water, particularly in the deeper layers where oxygen is often limited. This efficient oxygenation of the entire water column can limit the growth of algae and promote the growth of beneficial bacteria. More beneficial bacteria help convert excess nutrients such as nitrogen and phosphorus into less harmful forms, which reduces algae proliferation.
Furthermore, nanobubbles help break up and disperse existing algae blooms by causing cell lysis or degradation through natural oxidation. This prevents the formation of dense mats of algae on the water’s surface, which can block sunlight from reaching deeper layers of the water and create oxygen-depleted zones. Nanobubbles also oxidize other contaminants to improve water quality overall, making lakes more resilient to algae blooms.
By promoting oxygenation, reducing nutrient levels and oxidizing existing blooms and contaminants, nanobubble technology helps prevent and reduce the severity of summer algae blooms in lakes and other bodies of water.
Moleaer offers nanobubble generators specifically designed for lakes and ponds, in flow rates from 40-150 GPM and even higher for larger water remediation projects. The Kingfisher, for instance, is a smaller unit with simple controls, a robust design and only three moving parts. It is the lowest cost nanobubble generators for lakes and ponds on the market today. Installation is simple and it only requires regular preventative maintenance. Moleaer’s Clear nanobubble generator has optional remote monitoring, which is essential for lake managers on the go. Learn more about Moleaer’s products.
Controlling summer algal blooms may require a multi-pronged approach depending on the severity of the blooms. Nanobubble technology can be paired with other control methods depending on the needs of the water body. Lake managers should apply an integrated pest management (IPM) strategy for the most effective and long-term control. This includes implementing the “right tool, at the right time, in the right place,” a fundamental part of IPM.
Reducing summer algal blooms in lakes and other bodies of water can involve a combination of approaches.
1 - Prevention is always first in IPM, starting with cultural changes (practices that reduce pest establishment, spread and survival) that can reduce the start of algae in the first place. Some techniques include:
Watershed management: Managing the surrounding land and waterways that feed into the lake or body of water can help reduce the levels of nutrients and other pollutants entering the water. This can involve practices such as implementing vegetative buffers along streams and reducing stormwater runoff.
Nutrient management: Reducing the levels of nutrients such as nitrogen and phosphorus in the water can help limit the growth of algae. This can be accomplished through practices such as reducing fertilizer use in agricultural areas, upgrading wastewater treatment facilities, and promoting the use of low-phosphorus detergents. Nanobubbles are a chemical-free way to manage nutrient levels as well.
2 - Next, physical controls can be implemented as they are generally the least invasive and with the lowest risk:
Aeration and mixing: Providing oxygen and mixing the water column can help increase oxygen levels and disrupt the growth of algae. Though traditional aeration systems help with mixing, nanobubble technology is superior at adding oxygen to water, preventing the formation of stagnant, low-oxygen zones. Nanobubbles also oxygenate the entire water column and penetrate the sediment layer, supporting healthy muck digestion.
3 - Biological means of control, such as predators can be used next:
Biological control: Introducing natural predators or competitors of algae, such as certain types of fish or beneficial bacteria, can help limit their growth and control their spread.
4 - Lastly, IPM suggests chemical controls as a last resort solution to pest issues. These should be used sparingly as handling and applying chemical pesticides has their own risks:
Algaecide treatment: Chemical treatments can be used to kill or control algal blooms, although care must be taken to avoid negative impacts on other aquatic organisms and to minimize the release of harmful chemicals into the environment.
Reducing summer algal blooms requires a holistic approach that addresses the underlying causes of nutrient enrichment and promotes healthy ecosystem functioning. Combining IPM strategies such as nutrient management, nanobubble generators, aeration and mixing, algaecide treatment, biological control, and watershed management can help promote long-term water quality and reduce the severity of algal blooms.