Blue-green algaeBlue-green algae are bacteria which grow in warm, shallow, slow moving or still freshwater. There are known as cyanobacteria too, but they are more commonly known as pond scum. They need light for life. That is why they are photosynthetic bacteria. The first known species were blue-green. Now we know of algae from olive-green to red in color.
When the conditions are good (hot, calm weather), algae populations can increase dramatically. This can create large blooms which are big numbers of blue-green algae. These blooms can cover the whole surface. Blue-green algae mostly do not live long. Some of these blue-green algal blooms can be toxic or can be poisonous if they are swallowed by wildlife, livestock, pets or people. You should not even swim in these waters, because you can get itchy. And if you drink water with these toxic blue-green alga, you may have symptoms such as sore throat, stomach cramps, diarrhoea , vomiting or fever. The toxins are very dangerous, so if you have any of these symptoms, visit your doctor immediately. Do not even cook with such water, because boiling will not remove the toxins. One sign that the water is contaminated is that you see dead or distressed animals along the coast. If you see this, contact your regional office immediately. In blue-green algae you can find these two types of toxins:
- Neurotoxins which influence the nervous and respiratory systems. This toxin can cause death within 30 minutes. You may have problems with breathing, stupor and problems with moving.
- Hepato-toxins which toxins influence the liver and after about 36 hours or longer, after drinking water with this toxin, you can die. Even if the water is safe again in few days because the blue-green algae is short-lived, do not take the risk. Do not drink any untreated water. Even if it looks clean. If you want to be sure about the safety of your water, ask your local Ministry of Environment. They will test your water and they will tell you if the water is safe.