Restoring Tasmania’s underwater giants

Giant kelp is the largest species of marine algae and one of the fastest-growing organisms on Earth. 

They can grow more than 40 metres tall, at a rate of up to 50 cm per day. These towering plants used to form vast underwater forests along Tasmania’s southern and eastern coasts, providing important habitat and shelter for numerous marine species, and generating crucial organic matter that feed the coastal food web. 

– Karen Gowlett-Holmes, in Reviving Giants (2024)

Since the 70s more than 95% of these Giant kelp forests have disappeared along Tasmania’s coast due to climate change, warming waters and Long-spined sea urchins overgrazing the ocean floor. 

Despite this gloomy trajectory, hope is on the horizon. Mick Baron and Karen Gowlett-Holmes, owners of the Eaglehawk Dive Centre, have seen first-hand how the kelp forests have disappeared, but they are also part of bringing it back.

In the short film “Reviving Giants” from 2024, Mick and Karen are working with scientists to develop methods to restore Giant kelp forests. In late 2022, they initiated the project by planting out an area of 7000m2 juvenile giant kelp, grown in a lab and planted in the ocean. 

Six months later, those tiny kelp had grown over 5 metres tall.

This winter, the Eaglehawk dive centre set up its first live-in internship programme, with interns coming from all over the world to continue helping in the restoration of the Giant kelp forests.