A thick cloud of coral spawn has blanketed parts of the Great Barrier Reef, signalling a key window for restoration work.<\/p>\n
Each year corals release trillions of eggs and sperm simultaneously to improve their chances of survival.<\/p>\n
But research indicates only about one in a million grow to become coral.<\/p>\n
Many are lost as larvae expend energy, face predators, and struggle to settle on the sea floor.<\/p>\n
<\/p>\n
Coral spawning on the Great Barrier Reef this year. (Supplied: Jennifer Matthews)<\/p>\n
On Lizard Island CSIRO and Southern Cross University researchers have seen success in their attempts to increase the resettlement of coral spawn across wider areas by deploying “larval seed boxes”.<\/p>\n
The method involves filling clear perspex boxes with millions of larvae, then releasing them gradually over degraded habitat to increase natural settlement.<\/p>\n
CSIRO senior research scientist Christopher Doropoulos said last year’s work showed an increase in settlement of up to a 56 per cent across thousands of square metres of reef.<\/p>\n
<\/p>\n
Researchers have been placing boxes filled with coral larvae onto the sea floor in order to improve the health of the reef. (Supplied: CSIRO)<\/p>\n
“We got some really positive results showing larval dispersal and settlement onto the reef at scales that haven’t been demonstrated before,” he said.<\/p>\n
During spawning, crews collect spawn from night slicks and grow the larvae for three to five days in floating culture pools before loading about 2 million into each box.<\/p>\n
Divers then secure the boxes on the seabed and remove a base slider with graded holes so larvae can leave gradually and settle in a way that mirrors natural behaviour.<\/p>\n
<\/p>\n
Scientists filling perspex boxes with coral larvae. (Supplied: CSIRO)<\/p>\n
“The beauty of this is that we can deploy many of these units across the reef,” Dr Doropoulos said.<\/p>\n
“They can do it in their own time when they’re ready to leave the box and then find somewhere on the reef to metamorphose.<\/p>\n
“It kind of encapsulates more natural processes and so that’s why I think in the first study it was such an effective tool.”<\/p>\n
Researchers also use a pink rhodamine tracer in surrounding water and a blue dye on larvae to verify settlement, creating a colourful spectacle in the water.<\/p>\n
<\/p>\n
Christopher Doropolous says the larval seed boxes returned good results in a first trial at Lizard Island. (Supplied: CSIRO)<\/p>\n
“The ultimate goal is to produce something that can be used by local communities,” Dr Doropoulos said.<\/p>\n
“To really see effective restoration \u2026 will be up to about four to five years.”<\/p>\n
This year the project is taking place in the Whitsundays.<\/p>\n
Feeding baby corals<\/p>\n
On Moore Reef, 40 kilometres off Cairns, University of Technology Sydney researchers are testing a custom “coral baby food” to lift survival rates during the most vulnerable phase.<\/p>\n
<\/p>\n
Jennifer Matthews feeds baby coral. (Supplied: Jennifer Matthews)<\/p>\n
Researcher Jennifer Matthews and her team collected millions of larvae during the big spawning event this week.<\/p>\n
“It was so dense, you could barely see your hand in front of your face,” she said.<\/p>\n
Despite the abundance, most will not survive without support, so the team is trialling targeted nutrition.<\/p>\n
“In the lab we found that we could double their life, double their survival rate,” Dr Matthews said.<\/p>\n
The project first trialled feeding the baby coral two years ago, but Cyclone Jasper wiped out the opportunity to see any possible results.<\/p>\n
<\/p>\n
Baby corals are fed before being placed back onto the reef. (Supplied: Jennifer Matthews)<\/p>\n
This year the team is back to feed and settle the coral on small tiles that are then placed on marked plots for monitoring.<\/p>\n
“[The food is] essentially little balls of tasty fats,” Dr Matthews said.<\/p>\n
“This is the first time that hopefully \u2026 it’s gonna be seen all the way through to the six-month survival rate.”<\/p>\n
‘Every marine scientist’s Christmas’<\/p>\n
Great Barrier Reef Foundation managing director Anna Marsden said this year’s spawning event was especially important for restoration after a few major events damaged the reef.<\/p>\n
She said there was plenty of work to do after Cyclone Jasper, heatwaves, floods, poor water quality, and attacks by crown-of-thorns starfish.<\/p>\n
<\/p>\n
Coral larvae is collected from the surface of the ocean. (Supplied: CSIRO)<\/p>\n
“You would absolutely say that this time of year is every marine scientist’s Christmas,” Ms Marsden said.<\/p>\n
She said the combination of targeting survival at different stages or using seed boxes to increase their spread was the best way to ensure survival.<\/p>\n","protected":false},"excerpt":{"rendered":"A thick cloud of coral spawn has blanketed parts of the Great Barrier Reef, signalling a key window…\n","protected":false},"author":2,"featured_media":278415,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22],"tags":[64,63,22214,161399,144528,161398,161400,6076,98773,75,161397,161396,128],"class_list":["post-278414","post","type-post","status-publish","format-standard","has-post-thumbnail","category-environment","tag-au","tag-australia","tag-coral-bleaching","tag-coral-rehabilitation","tag-coral-spawning","tag-coral-spawning-great-barrier-reef","tag-crown-of-thorns","tag-csiro","tag-cyclone-jasper","tag-environment","tag-great-barrier-reef-health","tag-reef-restoration","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/278414","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/comments?post=278414"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/278414\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media\/278415"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media?parent=278414"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/categories?post=278414"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/tags?post=278414"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}