{"id":218806,"date":"2025-06-27T14:23:13","date_gmt":"2025-06-27T14:23:13","guid":{"rendered":"https:\/\/www.europesays.com\/uk\/218806\/"},"modified":"2025-06-27T14:23:13","modified_gmt":"2025-06-27T14:23:13","slug":"crayweed-forests-are-returning-to-sydneys-coastline","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/uk\/218806\/","title":{"rendered":"Crayweed forests are returning to Sydney\u2019s coastline"},"content":{"rendered":"

\n Editor\u2019s Note: Call to Earth is a CNN editorial series committed to reporting on the environmental challenges facing our planet, together with the solutions. Rolex\u2019s Perpetual Planet Initiative<\/a> has partnered with CNN to drive awareness and education around key sustainability issues and to inspire positive action.\n<\/p>\n

Sydney, Australia
\n CNN
\n \u00a0\u2014\u00a0<\/p>\n

\n Crayweed, a large, golden-brown seaweed, found along Australia\u2019s southeastern coast, plays a crucial role in ocean health. Its underwater forests capture carbon, create shelter for marine species and serve as a nursery for creatures like abalone and rock lobsters.\n <\/p>\n

\n Once widespread along Sydney\u2019s coastline, it disappeared from a 70-kilometer stretch<\/a> around the 1980s, at a time when sewage was being discharged into the sea, according to Operation Crayweed. The conservation initiative, primarily run by scientists from universities and research institutes, aims to restore 60 hectares of forest in shallow rocky reef habitats.\n <\/p>\n

\n \u201c<\/strong>We\u2019re not just bringing back one species, we\u2019re building an entire ecosystem,\u201d says Dr. Adriana Verg\u00e9s, a professor of marine ecology at the University of New South Wales Sydney, and co-founder of Operation Crayweed.\n <\/p>\n

\"Crayweed<\/p>\n

\n Improvements in sewage disposal mean the water around Sydney has become clean enough to support crayweed, according to the group, but for it to make a return, it must first be planted and then successfully reproduce.\n <\/p>\n

\n At designated restoration sites, scientists and volunteers attach healthy male and female crayweed collected from wild populations onto biodegradable mats fixed to reefs.\n <\/p>\n

\n Crayweed reproduces when male plants release sperm into the water, which fertilizes eggs from the female plant. These fertilized eggs grow into young crayweed, known as \u201ccraybies,\u201d which anchor to the seafloor and grow into new forests.\n <\/p>\n

\n Once established, the mats are removed, and the forest continues to grow and spread on its own.\n <\/p>\n

\n Since Operation Crayweed began over a decade ago, it has targeted 16 sites along Sydney\u2019s reefs, seven of which now have established self-sustaining crayweed populations. The restored forests cover over two hectares, and microscopic animals are already returning, according to Verg\u00e9s.\n <\/p>\n

\n Three new sites, Lurline Bay, Dee Why, and South Maroubra, were added in 2024. Dee Why alone jumped from just 10 crayweed plants to 466 juvenile crayweed in a single year and by early 2025, more than 1,500 craybies had established themselves at South Maroubra, according to Operation Crayweed.\n <\/p>\n

\n \u201cI get a real kick out of seeing it. And now it\u2019s expanded so much that you can see it even without getting in the water,\u201d says Verg\u00e9s. \u201cWhen the tide is low, you can see the crayweed swaying as the water pulls away from the coast.\u201d\n <\/p>\n

\"Mat<\/p>\n

\n The team plans to restore 10 more sites in the next two and a half years.\n <\/p>\n

\n Dr. Prue Francis, a senior lecturer in marine science at Deakin University, who isn\u2019t part of Operation Crayweed, says the project can have a wider impact in the area.\n <\/p>\n

\n \u201cPeople often focus on the dramatic bleaching of coral reefs, but with kelp forests, the decline is quieter, until it\u2019s too late. These underwater forests are supporting a whole ecosystem. When they\u2019re gone, like in parts of Sydney where crayweed has vanished, nothing grows back,\u201d she told CNN.\n <\/p>\n

\n \u201cRestoration efforts like Operation Crayweed aren\u2019t just about bringing back seaweed, they\u2019re about saving an entire web of life that depends on it,\u201d she added.\n <\/p>\n

\n As well as planting crayweed, the team is using advanced techniques to help it survive in a world where climate change is making oceans warmer, and environmental conditions more extreme.\n <\/p>\n

\n It <\/strong>has successfully mixed genetic populations sourced from north and south of Sydney, which enables the restored populations to reflect the natural genetic diversity and structure of healthy existing populations \u2014 \u201can important innovation,\u201d says Verg\u00e9s \u2014 and is testing whether crayweed genetics or its microbes (tiny living organisms that live on its surface) play a greater role in helping it survive rising ocean temperatures.\n <\/p>\n

\n The team is also looking to build up a \u201cbiobank\u201d of crayweed populations as a contingency in case they are wiped out by a heatwave.\n <\/p>\n

\n \u201cIn Western Australia, such a marine heatwave<\/a> erased entire crayweed populations. To prevent similar losses, we are turning to cryopreservation,\u201d says Verg\u00e9s. \u201cWe collect the sperm and eggs from different populations and freeze them at ultra-low temperatures.\u201d\n <\/p>\n

\"Crayweed<\/p>\n

\n While other kelp species<\/a> have been cryopreserved in research labs around the world, no one had successfully applied the method to crayweed, says Catalina Musrri Fuenzalida, who is working on freezing efforts as part of her PhD at the University of Sydney.\n <\/p>\n

\n \u201cWe don\u2019t have any genotypes or biobanks for these species,\u201d she explained. \u201cSo, if we lose a population, it\u2019s gone forever.\u201d\n <\/p>\n

\n Beyond the technical <\/strong>challenge, the work has a deeper meaning for Musrri Fuenzalida: \u201cSometimes, as a young scientist, it\u2019s hard not to feel hopeless. But this feels like something real, something that can make a difference,\u201d she says. \u201cIt gives you hope.\u201d\n <\/p>\n

\n The efforts of <\/strong>Operation Crayweed are part of wider global efforts to recover lost kelp habitat. The Kelp Forest Challenge<\/a> aims to restore four <\/strong>million hectares of kelp globally by 2040.\n <\/p>\n

\n For Verg\u00e9s, the success of the project is both scientific and personal. \u201cI swim in the ocean on weekends, and everywhere I go now, I see crayweed again,\u201d she says. \u201cIt was gone, and it never would\u2019ve come back by itself.\u201d\n <\/p>\n

\n Correction: This story has been updated to correct the name of Catalina Musrri Fuenzalida.<\/p>\n","protected":false},"excerpt":{"rendered":"Editor\u2019s Note: Call to Earth is a CNN editorial series committed to reporting on the environmental challenges facing…\n","protected":false},"author":2,"featured_media":218807,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3843],"tags":[728,70,16,15],"class_list":{"0":"post-218806","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-environment","8":"tag-environment","9":"tag-science","10":"tag-uk","11":"tag-united-kingdom"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@uk\/114755784521805694","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/218806","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/comments?post=218806"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/218806\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media\/218807"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media?parent=218806"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/categories?post=218806"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/tags?post=218806"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}