Advanced Australia
Tasmania
What's left of the giant kelp forests, and fish that walk on their fins
Until just a few decades ago, these coasts were covered by giant kelp forests with canopies reaching the surface. Today only a tiny fraction remains. And on the sandy seabed lives a fish that, instead of swimming, walks on its fins, and is on the verge of disappearing.
In this profile you'll find out what Tasmania's giant kelp forests were and why they've almost entirely disappeared, what handfish are and why their situation is so critical, what temperate diving in southern Australia is like, how cold it gets, and what training it requires.
This is the destination in this encyclopedia where ocean change is most visible and most measured: it isn't a forecast but an ecosystem that has largely already been lost, and species counted individual by individual.
Geography and access
Tasmania is an island south of the Australian mainland, in cold temperate waters, with an east coast of bays and dolerite peninsulas and a south coast open to the Southern Ocean.
Its waters were once dominated by giant kelp forests, an alga that forms floating canopies at the surface and three-dimensional structure through the water column, comparable in complexity to a terrestrial forest.
The warming of the current running down the east coast has pushed the conditions that kelp needs further south, and the forests have disappeared from more than ninety percent of their historical extent. Patches remain, some in experimental restoration zones.
The warm water also brought mainland sea urchins, which graze the kelp and create barren grounds: a documented process that is difficult to reverse.
On the sandy and sediment seabeds of some estuaries lives a group of benthic fish that move by propping themselves on their fins, with tiny, highly localized populations.
Access is by domestic flight to the island and road transfers. Much of the diving is done from shore or with short boat trips.
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