Some people may have noticed the green algae growing at Te Kukuwai o Toa/the Elsdon wetland, and we want to assure everyone that it's naturally occurring and harmless.
The algae is actually a good thing - it purifies the water by gobbling up nutrients from the soil, plant and root materials that were dug up and moved to create the wetland, and it absorbs heavy metals from streams and rivers.
It's a very normal occurrence for the algae to bloom during the first summer when nutrients are high, and temperatures get warm enough.
Once the algae has absorbed all the nutrients and the plant growth creates shade across the wetland, it'll stop growing and is not likely to bloom next summer.
Is it harmful?
No, it is not harmful or toxic. In fact, the algae are important in the freshwater environment helping to 'purify' the water by absorbing nutrients and heavy metals from streams and rivers.
Algae are the basis of most aquatic food webs. They are food for many small aquatic invertebrates, and in turn, these small creatures are food for larger animals such as fish and birds.
13 Dec 2022
