Blue-green algae are among the planet’s earliest organisms. True, they look like algae and can be identified by their dark blue-green color, but they are not—they are rather cyanobacteria. They form a kind of ‘skin’ or ‘oval tiny balls’ approximately the size of a small marble and have a foul odor.

They survive by consuming ammonium. Their presence in a pond implies an excess of ammonium (a hazardous chemical), implying that the filter does not perform biologically. It is not recommended that you swim in ponds that have a high concentration of blue-green algae.

What to Know About Cyanobacteria—the Blue-Green Algae

A lot of cyanobacteria blooms, such as those making headlines in Florida, can create toxins (cyanotoxins) which will lead to acute and, in some cases, long-term harm to wildlife and humans. A category of cyanobacteria are particularly dangerous to pets and children.

According to the EPA, recreational exposure to cyanobacteria can result in “fever, headaches, joint and muscular pain, stomach cramps, blisters, diarrhea, mouth ulcers, vomiting, as well as other allergic reactions.” Although the study on the health dangers of blue-green algae is still underway, disorders such as Alzheimer’s, Parkinson’s disease, and cancer may be linked to exposure.

Cyanobacteria is especially dangerous to dogs who are exposed to it by swimming or wading in algae-infested water. Even though blue-green algae bloom usually dies as quickly as it appears, hazardous conditions can remain after the bloom has faded.

Among other environmental pressures, the bloom’s dying process consumes significant amounts of oxygen within the waterbody, which can be toxic or dangerous to birds, fish, and other aquatic species. The disintegration of the bloom can also cause water discoloration, contamination of drinking water, and diminished invertebrate reproduction.

Toxins trapped within some cells can be released during a breakdown, further endangering wildlife, as witnessed throughout Florida’s, the Great Lakes’, and other significant waterbodies’ waterways.

All cyanobacteria do not produce toxins, but harmless blooms can negatively influence the environment and local economies. Unmanaged or recurring algal blooms can lower property values and increase HOA and community maintenance expenditures.

What Causes Blue-Green Algae?

The presence of algae may be caused by the number of fish and excessive feeding of fish. The phosphate concentration will skyrocket; the maximum is 0.5 milligrams per liter. It is also possible that the nitrate level is too low; a value of 5 to 10 mg per liter is ideal.

What are the Warning Signs of Blue-Green Algae?

Dead fish and/or waterfowl, inexplicable illness or death of a cat or dog, unappealing smelling water, and skin rashes after human contact with water. Furthermore, if you are concerned about the toxicity of an algal bloom, you should be vigilant when observing pet behavior.

What are the Side Effects of Cyanobacteria Poisoning?

Vomiting, jaundice, diarrhea, convulsions, disorientation, excessive salivation, coma, shock, shortness of breath, and death are all possible outcomes. With these repercussions on the horizon, it is critical to be informed and proactive in the fight against blue-green algae.

How Do Cyanobacteria Affect Your Pond?

Blue-green algae, unlike other varieties of algae or string algae growth, produces a slimy blanket on the surface of a body of water. If this layer of bacteria develops thick enough, it will be able to entirely block out sunlight from the depths of the water. In this way, it can prevent competing algae from growing and completely dominate a body of water.

Blue-green algae blooms have been observed to appear seemingly overnight in some circumstances. This is due to blue-green algae’s capacity to develop at nearly any depth in a body of water. These blooms growing at a greater depth can be difficult to spot, posing a difficulty for unskilled pond keepers.

How to Prevent Cyanobacteria in Ponds

Fish fatalities, surface discoloration, and “mat-like accumulations on the surface and shoreline,” according to the EPA, signal the blue green algae bloom is underway. Therefore, you have to check the water to see if cyanobacteria are growing in it.

Proactive water quality monitoring can predict the formation of a bloom, and subsequent testing (by a certified laboratory) can identify whether there are toxins being created. Finally, it is preferable to prevent an algae bloom than to treat one that has already occurred.

To prevent and reduce the risk of a harmful algae bloom, associate boards and community managers can adopt the following measures:

1. Add water movement and pond aeration by using fountains or aerators.

2. Collect and get rid of pet waste, which is a typical source of extra bacteria.

3. Place rain barrels throughout the neighborhood to decrease pollution runoff.

4. Use landscaping techniques such as xeriscaping to boost groundwater filtration. This filters the water before it enters the lake or pond.

5. Use wild flora around pond and lake borders instead of manicured lawns or cement banking. Allow for the growth of natural plants around the water or pond’s edge.

6. Request that your lawn care business remove grass clippings and leaves from ponds and lakes to prevent decomposition.

7. To reduce nutrient-filled runoff, use phosphorus-free fertilizers and detergents.

8. A pond management expert can use phosphorus-binding chemicals in nutrient-rich ponds and lakes to prevent nutrients from encouraging algae growth.

9. Exercise relative understanding of climate change and research updated support.

10. Consult a skilled water-management expert who can frequently test the pond or lake quality and provide necessary solutions.

Conclusion—Precautions When Combating Cyanobacteria

One risk of any chemical control strategy is the possibility of post-treatment oxygen shortage induced by the breakdown of dead plant material. Oxygen deficiency can kill pond fish.

If the pond is extensively weeded, it may be possible (depending on the herbicide used) to treat the pond in portions and let each section degrade for about two weeks before treating the next area. Aeration, particularly at night, following therapy, may aid in the control of oxygen deprivation.

When utilizing aquatic herbicides, the area and/or volume of the pond or area to be treated is a common issue. To be on the safe side, check SRAC #103 Calculating Volume and Area of Tanks and Ponds. Also, some aquatic herbicides come with water use restrictions, so check to be certain.

Finally, always follow label directions and water use restrictions before using any herbicide to combat the notorious cyanobacteria, aka blue-green algae.