What is Red Tide?

Red tide is an aquatic phenomenon that is sometimes witnessed in the Whitsundays. Contrary to popular belief, it does not signify the presence of poisonous algae and the water is still safe for swimming, fishing and snorkelling!

In other parts of the world, red tide highlights the presence of dinoflagellate algae that will render some fish and shellfish temporarily poisonous, so it's easy to understand why it has such a reputation!

However, red tide in the Whitsundays is caused by the phytoplankton trichodesmium erythraeum, which is a little hairy bundle of an organism. When this plankton blooms, it forms long streaks of rust coloured or yellow-green streaks of algae that form long chains in the water. The wind blows it into rows along the surface of the water, which can be seen from cruising boats of aerial flights and can end up being quite an impressive side! While not harmful, unfortunately the red tide does have an unpleasant smell so it's good to steer clear and now swim around the blooming plankton.

When you look at the bundles closely, you will see that they are made up of bundles of tiny threads, rather than of oil or coral spawning - two other types of slicks you might see in the Whitsundays. Oil slicks are caused by human beings and human errors, while slicks caused by coral spewing are a natural occurrence that takes place each year between October and December.

The red tide is a natural part of life here in the Whitsundays and is usually witnessed between August and October of each year.