The threat

What's Happening?

Longspined sea urchin, also known as 'Centro' which is short for their scientific name Centrostephanus rodgersii, are a large urchin living in the Great Southern Reef.  

Centro are native to NSW. But because Tasmania's waters are warming at over twice the rate of the global average, Centro have expanded southwards along the eastern coastline, where they don't have many natural predators.

There are now estimated to be over 20 million individual centro urchin in Tasmania, and they are now reproducing in Tasmanian waters.​

Rabbits of the Sea

As rabbits are on land (eating everything down to the roots), Centro are an underwater equivalent.

Centro eat seaweed, kelp and even microscopic algae down to the bare rock. They can quickly create sparse, empty barrens which can extend for many kilometers. 

Adult Centro do not travel far. Once a barren has formed, they stay put in close proximity and survive in a state of semi-starvation for years, eating any kelp that tries to regrow there.

In 2002, urchin barrens covered 3.4% of Tasmania's East Coast Rocky Reefs. This increased to 15% in 2017. Research has predicted that without a meaningful response, almost half of all reefs in eastern Tasmania could become urchin barrens by the mid-2030s.​

Urchin barrens displace over 120 Tasmanian endemic species.​

Habitat Loss for Abalone and Rock Lobster

The Great Southern Reef is Australia's extensive and interconnected system of temperate reefs, characterised by kelp forests, shallow rocky reefs and deep sponge gardens. It spans over 8,000 km of coastline across southern Australia and Tasmania.

These reefs are critical habitat for thousands of species, which in turn produce enormous value for recreational, tourism and commercial sectors.

Abalone and Rock Lobster are two of Tasmania's most valuable wild fisheries, producing 1,000 tonnes of each annually, and up to $150 million per year into our economy. They are also highly valued recreationally, and are a traditional food sourced from Sea Country by Tasmanian Aboriginal people. 

Without healthy rocky reef ecosystems, there is no habitat or food for abalone and rock lobster. This is just one concern of Centro expanding into Tasmanian waters. ​​