What is Algae and How do Algal Blooms Form?

What is algae?

Algae grows in ponds and dams and can form a green scum across slow-moving waters, coating rocks and other surfaces. Algae growth reduces flow rates, block pipes and pumps, reducing the availability of water for livestock, agricultural, mining, industrial applications and potable water supplies.

The term algae is a multiple of the word alga. Algae is a general term covering a wide variety of microscopic organisms. Distinguishing features separating them from plants is the lack of a root system, stems, leaves and vascular system.

The number of individual species of algae ranges between 35,000 and 1 million.

Like plants, algae produce oxygen through the process of photosynthesis. This production of oxygen is one of the defining characteristics of algae, despite the broad variety of physical characteristics that algae exhibit. The giant kelp in our oceans is actually a type of algae, not a plant, as are the microscopic plankton.

It is estimated that algae produces between 50 – 85% of the world’s oxygen. The vast majority is produced in our oceans.

Algae in agriculture and industry

Algae can cause problems in potable water, livestock, industrial, agricultural and mining water supplies.

These problems can include extra friction, mechanical blocking, aesthetic concerns and even toxicity.

Toxic blue-green algae (also known as “cyanobacteria”) in potable water, have the potential to cause serious health problems for both humans and animals.

Blue-green algae health risks range from simple skin irritations through to potentially life-threatening toxicity. Farm animals consuming water contaminated with blue-green algae may ingest toxins that cause immunosuppression, photosensitivity, spontaneous abortion and even death.

Many species of algae are microscopic and free-floating in water, potentially resulting in blockages of pipes and machinery. Examples of the effects of non-toxic algal blooms are:

  • Clogging of agricultural pumps and filters, thereby requiring constant cleaning.
  • Blocking of horticultural irrigation nozzles, resulting in water stress and uneven growth for plants.
  • Reducing flow in irrigation channels and raceways and the subsequent impact on crops.
  • Restricting direct access to water for livestock, causing animal stress, especially in hot conditions.
  • Impact on production output for mining due to clogged pumps, filters and supply lines and the required equipment maintenance.
  • Unattractive or foul smelling algal scum for ornamental water features such as parks and golf courses.

Using Coptrol as an effective algaecide can minimise all these effects.

How do algal blooms form?

Algal growth occurs as a result of:

  • Sunlight. As a photosynthesising organism, algae must have sunlight. This is where it derives its energy from.
  • Nutrients. Algae require nutrients, specifically phosphorus and nitrogen. This can be derived from decomposing fertiliser runoff, wastewater or effluent, vegetation or simply high nutrient content in soil.
  • Warmth. Algae typically propagate successfully in warmer water.

Algae can grow in a variety of environments with a different absolute temperature, variable salinity and pH and access to sunlight. A variety of environmental factors may lead to algal blooms.

Identifying algae

Generally algae can be categorised as either green or blue-green varieties. Green varieties can be single cell or filamentous. These species of alga generally cause physical problems. Blue-green algae can be toxic and should be treated with caution. In the event you suspect a blue-green algae problem, please call RCI for further advice.

There are a number of species of aquatic weed commonly mistaken for algae. Although they can cause physical problems, algaecides are not an effective form of treatment.

Aquatic weeds commonly mistaken for algae are:

  • Azolla
  • Duckweed
  • Liverwort

It is important to identify whether your “pond scum” is normal aquatic weeds or algae, in order to apply the appropriate treatment.

Coptrol Algaecide

Coptrol is a chelated copper algaecide. Algae seeks out the chelate as a nutrient and in doing so, ingests copper into the cell. Over time, the cell accumulates copper to a level that is toxic to the algal cell. Learn more about Coptrol algaecide