Science //

Cast away

Australian kelp forests are struggling to withstand the forces of nature, writes Richard Withers

Reaching to the stars, a shot from the seabed. Source: Brett Seymour Photography
Source: Scuba Tutor

The imposing swagger of lush, fern-green underwater forests is a breathtaking site to behold; but these great wonders of the Australian seas are now endangered and at risk of literally being swept away.

Australia is home to kelp forests across western Victoria, south-east Tasmania and south-east South Australia. Recent concern over the welfare of Australia’s remaining kelp forests, however, has led to Environment Minister Tony Burke’s listing of the regions as ‘endangered’. It’s the first time a marine ecological community has been given a degree of protection that is governed by federal environmental law.

“Giant kelp forests are being progressively lost due to a warming of the sea surface temperature caused by climate change, invasive species and changing land use and coastal activities that contribute to increased sedimentation and runoff and biodiversity loss,’’ Burke told The Saturday Age.

Kelp is a type of brown algae that is rooted to rocky seabeds, from which long streamers of kelp grow, held upright by unique gas bladders contained in adjoining leaves. Kelp can grow up to a staggering 30 metres above the seabed, and within this mossy maze a community of dependant marine life flourishes.

Reaching to the stars, a shot from the seabed. Source: Brett Seymour Photography

Yet marine species are being driven south in the search for colder water after scientists confirmed the effects of the strengthening East Australian Current on local marine ecology. Off the east coast of Tasmania, CSIRO experts have reported that kelp forests have shrunk by more than 95 per cent. It’s alarming figures like these that have brought kelp forest preservation onto the federal government’s agenda.

Overfishing in these near-shore ecosystems has released herbivores from their usual population regulation and the subsequent overgrazing has left the regions barren. The diverse ecosystems fostered by kelp forests have provided a habitat to important species, including black lip abalone and southern rock lobster as well as a range of species that are endemic to Australia.

The severity of the decline in one of the world’s most fascinating ecosystems is sure to propel preservation efforts into effect.