Toxic Algae Blooms

Algal blooms are a major environmental problem that often occur in Florida’s waterways during late summer or early fall. Our waterways are often affected by red tides and blue-green algae. These harmful algal blooms can have severe impacts on human health, aquatic ecosystems and the economy. It is important to learn about harmful algal blooms therefore you can keep you and your family safe.

Algal blooms can be toxic. People and pets should stay away from water that is green, scummy or smells bad.

What are harmful algal blooms?

Harmful algal blooms, or HABs, need three key ingredients: sunlight, slow-moving water, and nutrients (nitrogen and phosphorous). While nitrogen and phosphorus are naturally occurring nutrients in an aquatic system an abundance of these nutrients in the water can cause algae to grow faster than the ecosystems can handle. These large growths are called algal blooms. This abundance of nutrients is usually caused by a wide variety of human activities.

What are the effects of harmful algal blooms?

Harm water quality, food resources and habitats, severely reduce the oxygen levels in the water which can cause illnesses in fish and the death of large numbers of aquatic species. Some algal blooms produce elevated toxins and bacterial growth that can make people sick if they come into contact with the water, consume the contaminated fish or shellfish, or drink the water. Algal blooms can also cause economic effects such as increases in the treatment of drinking water, losses in tourism, commercial fishing, and real estate losses.

Whats the different between red tide and blue-green algae?
Red Tide

In Florida and the Gulf of Mexico, the algae species that causes most red tides is Karenia brevis. This bloom of algae often turns the water red thus the name “red tide”.



Blue-green Algae

Blue-green algae, Cyanobacteria (blue-green algae) are common in Florida lakes, rivers, streams, and ponds. There are approximately 20 cyanobacteria species in Florida’s waters that are capable of producing toxins! As with other harmful HABs cyanobacteria and their toxins can disrupt and damage sensitive ecosystems, and threaten public and natural resources, health and the environment.


What can you do to help prevent algal blooms?
  • Use phosphate-free detergents, soaps, and household cleaners.
  • Be smart with your laundry and dishwashers – select the proper load size and only wash when you have a full load and use the proper amount of detergent.
  • Always pick up after your pet and avoid walking them near bodies of water.
  • Inspect your septic systems annually.
  • Don’t use toilets as trash cans.
  • Use water and energy efficiently.
  • When washing your car wash on your lawn or use a commercial car wash; commercial car washes are required to properly dispose of water waste.
  • Drive Smart! Plan out your trips. carpool or use public transportation.

For more tips visit this link


What do you do if you see sick, injured, stranded or dead wildlife during a algal bloom?

Call 1-877-WHALE HELP (1-877-942-5343) to report injures, hooked, entangled or stranded sea turtles or marine mammals. You can also report via the Dolphin and Whale 911 Phone App. To report other sick or injured wildlife and large fish kills contact FWC Wildlife Alert or call 1-888-404-FWCC (888-404-3922).


Posted: July 13, 2020

Category: Coasts & Marine, Conservation, Recreation, Water
Tags: Algal Blooms, Blue-green Algae, Red Tide, Water Quality

Subscribe For More Great Content

IFAS Blogs Categories