What is Green-Blue Algae? Is It Dangerous?

Green-blue algae may not be an algae, but it does lead to algal blooms and a lot of health risks for you and your pets. It’s best to avoid it whenever you can. However, to do that, you first have to understand more about green-blue algae, how to identify it, and the dangers it poses.

What Is Green-Blue Algae?

Green-blue algae isn’t an algae at all. Instead, it’s a type of bacteria called cyanobacteria. This bacteria is aquatic and prefers water that is fairly warm and full of nutrients.

Most of the time, the bacteria exists in the water without anyone ever knowing about it. However, there are times when the bacteria grows quickly.

These growths are known as algal blooms. They cause quite a problem, not only for people but for local wildlife and ecosystems as well. While most algal blooms cause problems on some level, green-blue algal blooms are some of the worst.

Where Does Green-Blue Algal Blooms Occur?

Green-blue algae is most often found in lakes and streams. Their most favorable conditions are shallow, warm, and nutrient-rich waters, but they can be found in some other bodies of water as well.

This algae isn’t contained only in fresh water. It’s also found in oceans and estuaries. It does tend to stay near the shore, such as in bays.

Because cyanobacteria do best in warm water, most green-blue algal blooms occur around summer. However, the bacteria is present all year, and blooms may occur at other times of the year, as long as conditions are met.

Signs of Green-Blue Algae

It’s usually very apparent when blue-green algae is present as an algal bloom in water. Usually, in all or part of the body of water, there will be some sign of green sitting on the water. It tends to look like a thick green streak of paint or even pea soup. Other times, it may look like an oil spill on the surface of the water, intermingled with green scum.

While the water is usually green, that’s not the only color it can be. Sometimes, the water can also change to be red blue, brown, or orange.

Of course, it’s not always obvious. There are times when only a very small portion of the water is showing signs of an algal bloom, or the green color might not be as apparent. Some species of green-blue algae stay near the bottom of the water and attach to plants. Some just grow on the bottom of the water just on top of the soil and don’t come up unless they are disturbed.

As the algae starts to decay, the presence of the algae is even more apparent. Decomposed alga has a strong smell that smells very swampy.

What Causes Green-Blue Algal Blooms?

While green-blue algae blooms have occurred naturally in moderation throughout history, the current abundance of these blooms comes from humans and the waste that runs off into the ocean. They enjoy having a lot of nutrients, such as phosphorus and nitrogen.

These happen to be two of the nutrients people are dumping into the water in excess. Fertilizers, animal waste, human waste, insecticides, pesticides, and fungicides all contain nutrients that green-blue algae love.

To slow down algal blooms, the reduction of these nutrients from farming and sewage systems has to be implemented. Unfortunately, it’s not an easy process. Many groups are working on solutions, but haven’t had much luck as of yet.

Most of it is due to industrial farming and old sewer systems. But it’s possible to do your part to help local water systems and the ocean as well. Avoiding using synthetic fertilizers and those rich in phosphorus can make quite a difference. You also want to work on reducing your insecticides, pesticides, and fungicides, if you use any, or go for more natural solutions to your pest problems.

Other steps you can do to help reduce algal blooms is to try and prevent grass clippings, soil, or an abundance of leaves from washing off of your yard and into the sewer system, especially when making major changes to your yard that involve a lot of digging.

Is Green-Blue Algae Dangerous?

The short answer is yes, green-blue algae is dangerous. It has the potential to create toxins known as cyanotoxins. They can be deadly to people, pets, and local wildlife.

Green-blue bacteria doesn’t create toxins every time it turns into an algal bloom. However, because it’s impossible to tell whether the algal bloom is toxic or not, and the fact that green-blue algae can be dangerous even when the toxins aren’t present, it’s best to avoid these blooms all the time.

Dangers to People and Pets

The toxins produced by green-blue algae, known as cyanotoxin, aren’t a joke. While humans rarely die from the toxin, the symptoms aren’t pleasant by any means. Many who go through the experience compare it to food poisoning. The symptoms can start up to two days after exposure to cyanobacteria.

Even if you aren’t in the water, being on or near the water can cause health problems. You risk breathing in some or accidentally coming into contact with some of the water. Though activities like boating, kayaking, and fishing offer low to moderate risks, there’s still a chance. Swimming and accidentally ingesting water offer the highest risks, however.

Some symptoms include dizziness, fever, cramps, headaches, vomiting, and diarrhea. Children also face an increased danger and may have to go to a hospital after encountering toxic cyanobacteria.

While the toxin is usually not life-threatening for people, it is often deadly for pets like dogs. Some of the first signs of cyanotoxins in pets are diarrhea, breathing problems, loss of appetite, and difficulty standing.

Even small quantities of this toxin can make dogs deathly ill. For this reason, if you believe your dog ingested some, it’s best to go to a vet immediately. Unlike with people, most animals experience symptoms within minutes of coming into contact with the water.

Even if the algal blooms aren’t toxic, it’s best to avoid them. For some people, cyanobacteria can cause skin irritations and rashes.

It’s important to note that it isn’t easy to remove cyanobacteria from the water. If you see a green-blue algal bloom, it’s best to avoid the water entirely. Even the best filters and boiling of the water will not remove the toxins from the algal bloom. So it’s not recommended you cook with it or drink the water. Even eating plants and animals from the areas infected with cyanobacteria isn’t advised.

Using the water for things like dishes or washing your hands may cause skin irritations like rashes.

Dangers to the Environment

Green-blue alga poses dangers to the environment in several ways. For one, it outcompetes other, more beneficial algae in the area. Green-blue algae are large and slimy, which means most animals avoid eating them.

Then, because no animal is eating the algae, they end up dying and decomposing. This decomposition process uses up a lot of oxygen in the water. Sometimes, it takes up so much oxygen that it can kill fish, plants, and other aquatic animals due to suffocation.

In oceans, some animals are simply able to move away from the area without oxygen, but certain plants and animals can’t do that. Then, in lakes, where there is little space for animals to leave, there’s a high risk of all the life in the lake dying off.

These areas are known as dead zones because no life can exist in the area while oxygen isn’t present. Sometimes, these zones are temporary, but in some areas, the algae blooms and dies off so often that the algal bloom is permanent.

Many of the algal blooms are large, as well. Some are so big that they are visible from space. This provides scientists with a unique opportunity to get a bigger picture of how algal blooms move, and grow, though the sizes are alarming for local flora and fauna.

The toxins that blue-green algae produce aren’t only dangerous to people and pets. Local wildlife may also get sick or die if they drink the water. Birds, especially waterfowl, have been known to stagger around, appearing almost drunk, if they take in too many cyanotoxins. Livestock and larger animals may also experience negative effects on some level, though it may not be as life-threatening.

How to Tell if Green-Blue Algae Is Toxic?

There’s no way to tell by looking at green-blue algae whether it’s toxic or not. Algal blooms from cyanobacteria look the same whether they produce toxins or not.

There’s also no way to tell if a green-blue algal bloom is likely to be toxic or not based on the situation or environmental factors. Scientists have been searching for warning signs on whether or not an algal bloom will be toxic, with no success.

Some big blooms will not produce any toxins, while other blooms will produce an abundance of toxins, and the location, time of year, and external factors can all be the same. It’s a clear sign that there are large gaps in the knowledge scientists have about these bacteria and the algal blooms they form.

How to Keep Yourself Safe When Green-Blue Algae Is Present

The best way to keep yourself safe is to avoid any water where green-blue algae is sighted. You don’t want to walk through, or take your pets or children into the water. If your dog does end up in the water, you want to make sure they don’t lick their fur or drink any of the water.

If you did get some of the water, you want to scrub yourself down well with soap and clean water as soon as you can afterward. You also want to avoid eating any fish that come from that water.

What to Do When You See Algal Blooms

The best thing to do when you see toxic algal blooms is to call it in right away. Even if you aren’t positive that it’s an algal bloom, it’s a good idea to call and let someone confirm it. Since algal blooms can be so dangerous, local governments want to be able to check right away if there are toxins present in the water. If the results come back positive, they will send out a warning so that people avoid the area.

Several different plants look like green-blue algae, including duckweed, water meal, green algae, and even an abundance of tree pollen. There are ways to tell them apart from green-blue algae, but if you’re ever in doubt, don’t be afraid to call your local fish and wildlife department to ask them to check. Even if they don’t handle the checks themselves, they may be able to guide you to the right group to call.