The Cause and Effect of Harmful Algal Blooms

Management of Cyanobacteria Harmful Algal Blooms

The California Lake Management Society (CALMS) is a non-profit organization that works to manage lakes and reservoirs throughout California. In April of 2023, Precision Measurement Engineering (PME) had the privilege of attending a webinar hosted by CALMS. Guest presenter Rick Almalfi, Vice President at Aquatic Consulting & Testing Inc, discussed the management of Harmful Algal Blooms (HABs), which is a rising global issue. HABs are colonies of cyanobacteria, also referred to as blue-green algae, which cannot control its growth. There has been a noticeable increase in the amount of lakes being dominated by cyanobacteria in recent years causing harmful effects to the environment and surrounding life forms. At Precision Measurement Engineering, multiple products have been specifically designed to help combat situations like this by monitoring and logging various aspects of water quality. In this article, we will discuss blue-green algae and how it can be monitored by PME products.

How are HABs Formed?

Sunlight, slow-moving water and nutrients such as nitrogen and phosphorus all contribute to the creation of harmful algal blooms. Nutrient pollution causes algae to overgrow which lowers the levels of dissolved oxygen in waters. Significantly low dissolved oxygen levels in water can create a deadly environment for plants and aquatic life through anoxic conditions. The main sources to cause occurrences of nutrient pollution are products of agricultural runoff such as fertilizer, animal manure and wastes from human activities such as cars, power plants and detergents. The increase in these sources has caused a rise in cyanobacteria in lakes which results in HABs.

Most Common Cyanobacteria in Lakes

Cyanobacteria are microorganisms that structurally resemble bacteria but lack nucleus and membrane-bound organelles. Unlike other bacteria, cyanobacteria can conduct oxygenic photosynthesis and contain Chlorophyll A, the predominant type of chlorophyll found in algae that absorbs light from the orange-red and violet-blue areas of the electromagnetic spectrum. The most common cyanobacteria found in Southwestern lakes include Oscillatoria, Lyngbya, Microcystis, Anabaena, Anabaenopsis, Nodularia, Aphanizomenon, Gloeotrichia, Shizothrix and Planktothrix. There are different forms of cyanobacteria, such as colonial, filamentous, spiral, spherical and ovoid unicellular, unsheathed trichome, sheathed trichome, false branching and true branching. Anabaena, Anabaenopsis and Nodularis all contain heterocyst which is a differentiated cyanobacterial cell that allows for nitrogen fixation. Nitrogen fixation is dissolved nitrogen in water that can be taken in and converted into nutrients for the algae.

Impacts of HABs

With summer approaching, it is important to understand not only the environmental impact, but the effect HABs have on recreation, property values and human/animal health. Rick Amalfi and Joshua K. Abbott published an article which stated “water in community lakes [have] substantial value to homeowners over and above the everyday costs of maintenance” (Abbott). When community lakes are contaminated with HABs, the value of properties and neighborhoods becomes negatively impacted. When swimming or boating in a lake contaminated with cyanobacteria, humans and pets run the risk of being exposed to the toxins released. Cyanotoxins are released from the cyanobacterial cell during cell death and lysis. The toxins released that can affect human and animal health include hepatotoxins (liver), neurotoxins (brain), dermatoxins (skin) and endotoxins (gastrointestinal tract). These toxins have been linked to multiple dog fatalities, exceeding 14 deaths in the year 2019 alone. Toxins and oxygen depletion in the water can result in death of fish and other aquatic lifeforms as well. The Centers for Disease Control monitors HAB-related illnesses and offers advice on symptoms and treatment.

How can HABs be Managed?

HABs can be managed by nutrient reduction, light inhibition, algaecides and biologicals. The most common cause of HABs is a surplus of nutrients in the water. Nitrogen is difficult to eliminate due to cyanobacteria’s ability to absorb it from the water and atmosphere and fix it into nitrites, nitrates and ammonia. To reduce those nutrients, phosphorus is targeted and removed by introducing aluminum sulfate or aluminum substitutes to the water. The use of aquatic dyes allows for wavelengths of light used during photosynthesis to reduce by 30%. Algaecides, such as copper surfactants, work to kill cyanobacteria by interfering with the phospholipid layer of the cell and allowing the copper to penetrate and break down the cell. The growth of cyanobacteria can be monitored by PME instruments before it becomes more difficult to treat and causes further harm to the environment.

PME Products Measure Blue-Green Algae

PME’s miniDOT logger can help researchers identify HAB threats, present and future, by measuring amounts of dissolved oxygen in the water column. The miniPAR Logger is a portable, submersible instrument for measuring diffused sunlight through water, or PAR (Photosynthetically Active Radiation). PAR is a key indicator for understanding nutrient loading, photosynthesis, algae blooms, or other biological, chemical, or physical processes. PAR loggers can monitor the light penetration at various depths, providing data as to how quickly algal blooms can occur based on the amount of light received. The Cyclops-7 Logger is able to collect Chlorophyll A measurements, which helps to track the number of cyanobacteria in a body of water.

To learn more about these products, visit our Blue Green Algae page.

To learn more about HABs, watch the CALMS webinar here.