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Crayweed, a large, golden brown seafar, found on the Australia’s southeast coast, plays a crucial role in the health of the ocean. His underwater forests catch carbon, create protection for types of sea and serve as a kindergarten for creatures such as abalones and rock strolls.
Once widespread on the Sydney coast, it disappeared from a 70-kilometer route in the 1980s, at a time when the waste water was released into the sea according to Operation Crayweed. The nature conservation initiative, which is mainly conducted by scientists from universities and research institutes, aims to restore 60 hectares of forest in flat rocky reef life.
“We not only bring back a kind, we also build an entire ecosystem, ”says Dr. Adriana Vergés, professor of marine ecology at the University of New South Wales Sydney and co -founder of Operation Crayweed.
Crayweed is attached to biodegradable mats to grow new forests. – Tom Burd
Improvements in wastewater disposal mean that the water around Sydney has become clean enough, according to the group, to support Crayweed. However, so that it can return, it must first be planted and then successfully reproduced.
Scientists and voluntary healthy male and female crayweed are attached to designated restoration sites, which were collected by wild populations on biodegradable mats that are defined on reefs.
Crayweed reproduces when male plants pour sperm into the water, fertilized the eggs from the female plant. These fertilized eggs grow to young crayweed, which is known as “craybies”, which anchor itself on the sea floor and grow into new forests.
As soon as the mats have established themselves, the mats are removed and the forest continues to grow and spreads by itself.
Since Operation Crayweed began over a decade ago, they have sought 16 locations along the Sydney reefs, seven of which have now created self-wearing crayweed populations. According to Vergés, the restored forests already cover two hectares and microscopic animals are already returning.
Three new locations, Lurline Bay, Dee Wann and South Maroubra, were added in 2024. Dee, why in a single year alone from only 10 crayweed plants jumped to 466 youth festivals, and in early 2025 more than 1,500 craybies had established themselves in South Maroubra after Operation Craywed.
“I get a real kick to see it. And now it is expanded so much that you can see it without getting into the water,” says Vergés. “When the flood is low, you can see how the colored pencil fluctuates while the water pulls off the coast.”
Mat hole in South Maroubra. – Claudia Santori
The team plans to restore 10 more websites in the next two and a half years.
Dr. Prue Francis, a senior lecturer for Marine Science at Deakin University, who is not part of Operation Crayweed, says that the project can have a greater impact on the region.
“People often concentrate on the dramatic bleaching of coral reefs, but the decline is calmer until it is too late with seaweed forests. These underwater forests support an entire ecosystem. If they are gone, as in parts of Sydney, in which colorful pouring has disappeared, nothing grows back,” she told CNN.
“Restoration efforts such as Operation Crayweed are not only about bringing algae back, but also about saving an entire network of life that depends on it,” she added.
The new limit of science
The team not only planted crayweed, but also uses advanced techniques to survive in a world in which climate change makes the oceans warmer and environmental conditions more extreme.
It has successfully mixed genetic populations from the north and south of Sydney, which enables the restored populations to reflect the natural genetic diversity and structure of healthy existing populations – “an important innovation”, says Vergés – and tests whether crayweed genetics or microbes (tiny living organisms live on its surface).
The team also wants to build a “BioBank” of Crayweed populations as a contingency if they are wiped out by a heat wave.
“In Western Australia, such a marine Heatwave deleted entire populations of the crayweed. To prevent similar losses, we turn to cryocke -ess reservation,” says Vergés. “We collect the sperm and eggs from different populations and freeze them at ultra-low temperatures.”
Crayweed harvested and ready for plants. – Chanelle webster
While other KELP species were crying in research laboratories all over the world, nobody had successfully applied the method on Crayweed, says Catalina López-Bermúdez, who works on freezer efforts as part of her doctorate at the University of Sydney.
“We have no genotypes or organic covers for these species,” she said. “So if we lose a population, it has disappeared forever.”
In addition to the technical challenge, the work has a deeper meaning for López-Bermúdez: “Sometimes it is difficult as a young scientist not to feel hopeless. But that feels like something real that can do something,” she says. “It gives you hope.”
The efforts of Operation Crayweed are part of the global efforts to regain lost seabird. The Kelp Forest Challenge aims to restore four million hectares of Kelp worldwide by 2040.
For Vergés, the success of the project is both scientifically and personally. “I swim in the ocean at the weekend and wherever I go now, I see crayweed again,” she says. “It was gone and would never have come back by itself.
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