During the hot season, harmful blue-green algae may appear in our lakes and rivers. Over the holiday season, there is less monitoring for these algae blooms, so it’s crucial to know the signs to avoid getting sick.
Blue-green algae, also known as algal blooms, can grow quickly and unpredictably. They can produce toxins that are harmful to both people and animals, warns Dr Gregory Evans from Toi Te Ora Public Health.
Dr Evans advises avoiding water that looks discoloured, smells unusual, has green or brown particles floating in it, or has a scum or algae mat on the surface or bottom. These algae blooms can release toxins that can cause skin rashes, stomach problems, and vision issues. They can also affect the nervous system, leading to numbness, breathing difficulties, and asthma attacks.
Algal blooms can float freely in lakes, but in rivers, they usually attach to rocks at the bottom. They can also accumulate along the shoreline. Dr Evans warns that these algae mats and scum can be toxic, so it’s important to keep children away from them.
If you think you’ve come into contact with an algal bloom, shower and change your clothes as soon as possible, even if you don’t have any symptoms. If you feel unwell after being in contact with water, seek medical advice from your doctor.
Dogs are also at risk of becoming seriously ill if they consume or come into contact with toxic algae or algae mats. Keep them away from water if you suspect an algal bloom.
Currently, there are health warnings due to algal blooms for Lake Ōkaro, Lake Maraetai, and Lake Ohakuri. For information on local health warnings, check the following channels:
