Kelp restoration in NSW: bringing back the golden crayweed

What crayweed means for kelp restoration NSW

New South Wales' standout story is crayweed (Phyllospora comosa), a large golden-brown seaweed that, like kelp, forms canopy forests over shallow rocky reefs. Those canopies underpin temperate reef life along the coast, sheltering fish, abalone, rock lobster and a tangle of smaller seaweeds. When people talk about the kelp forest New South Wales once had off its biggest city, crayweed is usually the forest they mean.

By around the 1980s, crayweed had vanished from roughly 70 km of the Sydney metropolitan coastline — gone from the reefs between the northern and southern beaches where it had been common. The loss is widely linked to the poor coastal water quality and sewage outfalls of that era. Water quality later improved as outfalls were upgraded and moved offshore, but crayweed did not naturally return. The reefs stayed bare of their golden canopy, a gap in the kelp forest New South Wales had taken for granted.

The science: crayweed can be replanted

Here is the hopeful part, and it is important to be precise about whose work it is. Scientific, research-led restoration — driven by the university and research community in Sydney — has shown that crayweed can be replanted and re-establish on reefs where it had been lost. By transplanting healthy crayweed from surviving populations to the north and south onto bare Sydney reefs, researchers have shown that the transplants can survive, reproduce and seed new patches that persist on their own.

That body of work, often described under the banner of "crayweed Sydney" restoration, is the research community's achievement — not Ocean Greens' own. We point to it because it changes what is possible: it demonstrates that a lost canopy forest on a metropolitan coastline can, with care, be put back. It is one of the more encouraging results anywhere in temperate reef restoration.

A coast under pressure on two fronts

Crayweed's disappearance is only part of the picture. The broader NSW coast also faces ocean warming and the southward spread of sea urchins, which graze reefs down to urchin barrens. As warmer water pushes further south, the long-spined urchin extends its range and clears canopy faster than it can recover — a different mechanism of loss to the historic water-quality decline behind crayweed, but one that threatens the same temperate reefs.

That combination matters in New South Wales because these reefs sit along one of Australia's most populated coastlines. Temperate reefs here support fisheries and biodiversity that millions of people live beside — abalone and rock lobster, the fish that anglers chase, and the quiet nursery habitat that a healthy canopy provides. NSW forms a key northern stretch of the wider Great Southern Reef, the temperate reef system that wraps Australia's southern coast.

What Ocean Greens is planning in New South Wales

Ocean Greens sees NSW as a planned expansion. Our aim is to scale proven restoration approaches — the kind the research community has demonstrated for crayweed, and the kelp methods we describe in our kelp forest restoration in Australia work — into a continuous "rewilded corridor" down the New South Wales coast. Rather than a handful of isolated patches, the goal is connected stretches of restored canopy that can support one another.

To be clear, this is planning and surveying language, not completed work. We are mapping candidate reefs, building partnerships and modelling where a rewilded corridor could take hold first. Any impact figures we publish — areas restored, canopy re-established, timelines — are targets and projections for 2030 and beyond, not results we have already achieved. Kelp restoration New South Wales is, for Ocean Greens, an ambition we are preparing to deliver, alongside our sibling efforts in Victoria and Tasmania and our broader programme of rewilding Australia.