Giant kelp forests off Tasmania once grew so thick that fishers struggled to navigate through them. Today, divers are regrowing that ecosystem one hand-planted spore spool at a time.

  • 95% of Tasmania's giant kelp forests lost since the 1940s
  • 6 live-in diver interns trained in the program's first 2026 intake
  • 1 year — how fast a forest can regrow under the right conditions
  • ~$3,000 AUD covers a month of board, food, and restoration diving

The Tasmanian Giant Kelp Restoration Project, run through the University of Tasmania's Institute of Marine and Antarctic Science (IMAS), is now recruiting ordinary people — not just marine biologists — to do the physical work of rebuilding a lost forest.

How you plant a forest underwater

The restoration technique, developed by IMAS professor Scott Ling, starts on land: kelp spores are grown in a laboratory and wound onto spools. Divers then carry those spools underwater and wrap them around the base of existing seaweed at protected sites around the Tasman Peninsula.

The newest recruits come through a live-in internship at the Eaglehawk Dive Centre, an hour south of Hobart. Six interns completed the program's first two intakes this winter, including a Masters student from California, a diver from Sweden, and one from Perth. Part of their job is "underwater gardening" — clearing competing seaweed from around the juvenile kelp so it has room to grow.

"When conditions are right, you can regrow a forest within a year." — Dr. Scott Bennett, marine ecologist, IMAS

A 95% collapse — and a comeback plan

The scale of the loss is what makes the project urgent. Warming waters and overgrazing by invading sea urchins have driven Tasmania's giant kelp into collapse since the 1940s, and dive instructor Pauline Nuttens has watched it happen in real time: she guided groups through a thriving forest in 2015, and when she returned the following summer, it was simply gone.

That collapse matters well beyond the loss of scenery. Kelp forests are nursery habitat, shelter, and a food source for a huge range of marine species — losing one is closer to losing a forest on land than it might sound.

Results so far have been what Dr. Bennett calls "a mixed bag," since warm snaps, herbivorous fish, and storms can undo a season's planting. The project's current focus is picking restoration sites with conditions that actually favor long-term kelp survival, rather than planting everywhere at once.

Why the interns matter

Training outside divers to a professional restoration standard — rather than relying solely on marine biologists and paid commercial divers — multiplies how much reef the project can replant each season. Each intern pays roughly $3,000 AUD to cover a month of board, food, and dive gear, turning what used to be pure research labor into a program the public can join directly.

For Nuttens, the goal is straightforward: more hands in the water, and more people who leave Tasmania having actually helped regrow a forest instead of just reading about one disappearing.

Sources: ABC News and the Tasmanian Giant Kelp Restoration Project.