BACKGROUND
Where did the urchins come from, and where are they going?
Ocean water is always moving. Winds and differences in water temperature and salinity help move the water around Earth in large patterns called currents. These currents are like giant rivers in the ocean. Currents can be warm or cold, some flow near the surface, and others move deep down.
The East Australian Current is like an underwater river that flows from Queensland down past New South Wales and all the way to Tasmania, carrying water, nutrients, and key species along the coast.
Credit: The Harbour School SydneyThe East Australian Current is getting warmer.
That’s bad news for kelp, because kelp like being cold. When the water gets too warm, kelp can become stressed and more likely to get sick.
Because the water has become warmer, Centros are moving from New South Wales into new areas. These spiky creatures are multiplying and munching away on the kelp.
Where are the longspined sea urchins going?
We’ve found a video in the case files - it could hold an important clue to help solve the mystery.
Detective! From the video, can you find out which Australian states the Centros are spreading to because of warmer ocean temperatures?
The map has two colours on it.
Use the key below to figure out what each colour shows, and match each colour on the map to the correct description:
The natural habitat of the longspined sea urchin (where the species is originally found)
The new areas where the longspined sea urchin has spread and is now causing damage
Clue File
🔍 What did you discover?
Write down one important thing you learned in this lesson that will help you solve the mystery of why the kelp forest is disappearing.