This year, the tragic die-off of large volumes of coral at the treasured Great Barrier Reef has provided a climate change shock like few others. The cause was too much warm water — which seems to have pushed the corals past a thermal survival threshold. And that warm water, in turn, is tied to climate change.

Now, however, a team of researchers has revealed that another Australian coastal ecosystem that gets less attention — Australia’s kelp-dominated Great Southern Reef, which covers a huge expanse along its more temperate southern and southwestern coasts — saw an equally dramatic ecosystem upheaval five years ago.