You may have seen the viral story about three dogs who passed away after drinking and swimming in water that had blue-green algae. It is a scary thought for any pet owner. Humans can also be affected by the toxins. Let's discuss below what blue-green algae is, how to spot an algae bloom and how to protect yourself and family (fur-family included). 

What is a harmful algae bloom?

HAB stands for Harmful Algal Bloom. There are many species of single-celled organisms living in the oceans, including algae and dinoflagellates. When certain conditions are present, such as high nutrient or light levels, these organisms can reproduce rapidly. This dense population of algae is called a bloom. Some of these blooms are harmless, but when the blooming organisms contain toxins, other noxious chemicals, or pathogens it is known as a harmful algal bloom, or HAB. HABs can cause the death of nearby fish and foul up nearby coastlines, and produce harmful conditions to marine life as well as humans.

What is Blue-Green Algae

Blue-green algae is the common name for several different types of algae. They are actually bacteria (Cyanobacteria) which are able to photosynthesize, hence the green color. Cyanobacteria are bacteria that grow in water and are photosynthetic (use sunlight to create food and support life). Cyanobacteria live in terrestrial, fresh, brackish, or marine water. They usually are too small to be seen, but sometimes can form visible colonies. Cyanobacteria have been found among the oldest fossils on earth and are one of the largest groups of bacteria. Cyanobacteria have been linked to human and animal illnesses around the world, including North and South America, Africa, Australia, Europe, Scandinavia, and China. Cyanobacteria are the most common, but not the only, group of algae to come from HABs.

HABs have been reported in every U.S. coastal state, and their occurrence may be on the rise. HABs are a national concern because they affect not only the health of people and marine ecosystems, but also the 'health' of local and regional economies. 

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How are HABs formed? 

Harmful algal blooms (HABs) occur when colonies of algae—simple plants that live in the sea and freshwater—grow out of control while producing toxic or harmful effects on people, fish, shellfish, marine mammals, and birds.

Factors promoting algal growth include sunlight, warm weather, low turbulence, and nutrient sources, such as phosphorus and nitrogen. While we know of many factors that may contribute to HABs, how these factors come together to create a 'bloom' of algae is not well understood. Some HABs have also been reported in the aftermath of natural phenomena like sluggish water circulation, unusually high water temperatures, and extreme weather events such as hurricanes, floods, and drought. It can also happen in nearly every state that has standing water and gets warm enough to produce blue green algae.

How do I know if water contains blue-green algae?

If you detect an earthy or musty smell, taste or see surface scums of green, yellow or blue-green the water may contain blue-green algae.  Some cyanobacterial blooms can look like foam, scum, or mats on the surface of fresh water lakes and ponds. The blooms can be blue, bright green, brown, or red and may look like paint floating on the water. Some blooms may not affect the appearance of the water. Only examination of a water sample under the microscope will confirm the presence of blue-green algae.

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How can you protect yourself, your family, and your pets from exposure to HABs?

  • Don't swim, water ski, or boat in areas where the water is discolored or where you see foam, scum, or mats of algae on the water.
  • If you do swim in water that might have a HAB, rinse off with fresh water as soon as possible.
  • Don't let pets or livestock swim in or drink from areas where the water is discolored or where you can see foam, scum, or mats of algae in the water.
  • If pets (especially dogs) swim in scummy water, rinse them off immediately - do not let them lick the algae (and toxins) off their fur.
  • Don't irrigate lawns or golf courses with pond water that looks scummy or smells bad.
  • Report any musty smell or taste in your drinking water to your local water utility.
  • Respect any water body closures announced by local public health authorities.

What to do if you or your pet have been exposed? 

Get medical treatment right away if you think you, your pet, or your livestock might have been poisoned by cyanobacterial toxins. Remove people from exposure and give them supportive treatment. 


Preventing Algae Blooms: 

Algae need three things for optimal growth: light, nutrients and high temperatures. Lowering the nutrients, light and temperature available to the blue-green algae in the water supply will help reduce algal growth. The speed at which water is flowing and mixing is important in controlling light and nutrient availability to algal cells. Keeping livestock away from the farm dam or water supply; avoiding run-off into water supply from fertilizers and pesticides; taking some water treatment measures BEFORE bloom starts; and if practical - changing mixing patterns or covering the dam or water supply to screen out light may help.

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