When kelp disappears, the people who rely on it suffer. Around the world, coastal communities are being mustered into action. Is it enough?
John Minehan is an environmentalist, he says, but only out of necessity.
He makes a living diving for abalone off the coast of Mallacoota in Eastern Victoria, a dangerous and highly skilled job he鈥檚 been doing for decades now. A job he loves.
鈥淪ometimes I close my eyes on the way down and I wait till I hit the bottom and I bury myself in amongst the kelp forest and I feel safe,鈥 he says.
Abalone used to thrive in the cold grey waters of the Bass Strait, fused to the reefs and hidden among the kelp.
But something changed a few decades ago and divers started noticing increasing numbers of Centrostephanus rodgersii, a sea-urchin that will eat a kelp forest down to bald rock if you let it.
Many of the underwater forests John had visited for years disappeared, replaced by thousands upon thousands of sea-urchins.
鈥淚t was quite daunting to lift your head and see these urchin barrens seeming to extend forever,鈥 he says.
鈥淵ou鈥檇 think 鈥榦h my god, how are we ever going to get on top of this?鈥欌
Then the abalone catch plummeted and communities along the coast began to wonder whether they were going to lose their livelihoods.
鈥淟ike the surface of the moon鈥
Apart from a narrow band in the tropics, kelp grow well right around the world, hugging coastlines from the Arctic to the Antarctic.
There are more than 100 species 鈥 some which reach up to sixty metres tall and can grow two feet a day, while others cling to the shallows.
Kelp forests pull carbon from the atmosphere, protect the shore from erosion and improve water quality - and they provide habitat to countless marine animals, and livelihoods and food to the nearly billion of us who live within 50 kilometres of one.
鈥淚n a healthy kelp forest you have the diversity of fish and invertebrates, big and small, some the size of your thumbnail, some the size of you, living, feeding, breeding, being part of the ecosystem,鈥 says 91色情片 kelp researcher Dr Aaron Eger.
But they are also under threat.
鈥淲e estimate that 65% of kelp coastlines are threatened and likely declining around the world.鈥
Alongside more than 200 researchers from 35 regions with kelp forests, Dr Eger has helped compile a first of its kind map of kelp conservation efforts worldwide.
Together, they are trying to show who is doing what and where, and what is working and why.
The details, published in the , show a mixed bag.
鈥淜elp forests are declining in most regions, but there are a few regions that are stable, and then there are even a few that are increasing,鈥 Dr Eger says.
But the study hints at some common threats, like rising ocean temperatures pushing some species past their limits, which the data shows can magnify other threats.
Booming sea-urchin populations are another key driver of decline, but the paper shows that an outbreak in one region might have different causes and different solutions to an outbreak in another.
鈥淵ou might get new populations of sea urchins establishing when the water gets warmer,鈥 says Dr Eger.
Or, as happened in the Pacific North-West of the United States, humans hunted otters nearly to extinction, and with nothing to eat them, urchin populations exploded.
鈥淲hen we overexploit the big fish and predators that eat sea urchins, they end up really running rampant through a kelp forest.
鈥淲hen the kelp goes it can feel like the surface of the moon down there,鈥 Dr Eger says.
Bringing the kelp back
That鈥檚 certainly how John Minehan remembers urchin barrens, and it was a sight that compelled him to act.
In the early 2000s, the abalone industry in eastern Victoria determined that to save their livelihoods they would have to restore the kelp.
To do that, they would have to get rid of the urchins.
鈥淲e thought 鈥榯his is the answer, this is all we have to do, and abalone production will stabilize and potentially grow,鈥 John says.
Clearing the urchins was relatively straightforward.
An army of commercial divers headed out to the reefs and plucked the spiky purple-black invaders off the rocks one by one and tossed them into sacks.
Thousands of them, tens of thousands.
John says each diver could remove around 1800 urchins an hour, or around 5000 in a typical three-hour shift.
鈥淭hat鈥檚 about two a second,鈥 he says.
鈥淲e became quite efficient at it.鈥
At first, there were just so many urchins it didn鈥檛 feel like they were making much of a dent, but that soon changed.
鈥淰ery quickly when you go to swim around the reef, you realize 鈥榯hat area's been cleared, and that area's been done, and those divers have done over there鈥.
鈥淎s a team we were able to clear quite large areas quite quickly.鈥
And within about 18 months after they first started, the kelp was back.
From the seabed on up
Dr Eger鈥檚 paper shows that around the world different groups are tackling the decline of kelp in different ways.
Attempts to build community grassroots stewardship are common, and Dr Eger says that nearly everywhere you find kelp, you find researchers mapping and monitoring it.
鈥淚鈥檓 reassured that everyone's on it and working on it and is willing to participate in this,鈥 he says.
But active restoration 鈥 planting kelp seedlings on areas of barren reef or removing urchins so kelp can return naturally 鈥 is taking place in less than half of regions.
That鈥檚 concerning to Dr Eger because while it means we have increasing data on the scale of the problem, we鈥檙e not always doing much to solve it.
鈥淭here鈥檚 sometimes this mentality of 鈥榗ollect more data, collect more data, collect more data鈥,鈥 he says.
鈥淲e just need to start making conservation decisions before time runs out.鈥
The study notes that while ocean warming, marine heatwaves, and climate-driven ecosystem change are huge drivers of kelp decline, adaptation measures are not common.
Scientists in California are furthest ahead - they鈥檙e studying kelp genomes to identify heat-resistant species, information that could one day be used to restore forests.
But that鈥檚 a long way off being rolled out at scale and is anyway hamstrung by a lack of funding 鈥 a problem, the study notes, facing restoration efforts globally.
聽鈥淢uch of the world doesn鈥檛 really think about kelp decline,鈥 Dr Eger says.
鈥淎nd that鈥檚 cool because it's led to these more grassroots, underdog type organisations working on the problem just because they love it, not because it's the most attractive thing to do.
鈥淚f we can just get these groups the support they need, there is an incredible potential to unlock some truly positive change for our oceans.鈥
Dr Eger hopes that the Kelp Forest Alliance can unify the disparate groups working to save kelp 鈥 scientists, commercial fishers, Indigenous Groups and volunteers 鈥 in a global network that shares data and expertise and drives conservation forward.
鈥淭he fact that we got this group together is really empowering to me,鈥 he says.
Where did the abalone go?
It鈥檚 been nearly a decade since kelp restoration wrapped up off eastern Vic and John says the kelp forests are still healthy, as are the communities that rely on them.
They managed to restore about 100 hectares of kelp in all, and when juvenile abalone were spotted re-colonising the reefs, locals began to celebrate.
鈥淚n every instance there's an initial response,鈥 John says.
鈥淭hey grow and move around and migrate onto the areas that have new kelp on them.
鈥淚 guess maybe the fresh kelp is sweeter tasting? Who knows.鈥
聽It felt promising, like their plan had worked and that all the money the community had tipped into the largely self-funded restoration program had been worth it.
But that initial response soon fizzled.
No one knows why, but the thick and healthy kelp cover hasn鈥檛 meant an increased abalone catch, and populations aren鈥檛 recovering.
鈥淚t's deeply disheartening,鈥 John says.
鈥淭he size of our harvests continues to drop, and the economics of our industry has suffered as a result.鈥
But John and the abalone divers have adapted.
When they first started clearing the sea urchins they saw them as nothing more than an invasive pest that needed to go.
In the years since though, a whole new industry has popped up along the coast, an industry that might ensure the future of the kelp after all.
You can eat sea urchins - the Japanese call it 鈥渦ni鈥, the Italians 鈥渞icci di mare鈥, and the Chileans simply say 鈥渆rizo鈥.
The delicate, salty-sweet flesh hidden behind those brittle spines has the texture of custard and is prized for its richness.
There are now multiple businesses in the Mallacoota area processing sea urchins for export, something that never existed before.
John credits the new industry to the durability of the kelp鈥檚 return, saying that because they鈥檙e out there collecting them, sea urchins aren鈥檛 getting to plague proportions.
鈥淚t's employing more people in these small regional towns, and the urchin harvest alone improves the kelp forest.
鈥淭he urchins at one point felt like the enemy, but it turned out that they had real value and ultimately became a much larger industry.鈥
He鈥檚 backed up by Dr Eger鈥檚 study, which points to an emerging model of restoration that is making a huge difference.
From British Columbia to Mexico, all the way over to Japan and down to Mallacoota, kelp is thriving where it鈥檚 linked to people who have a long-term economic stake in its health.
It鈥檚 not the whole solution, but it shows a way forward.
鈥淲e have the capacity. It's just a matter now of redirecting that knowledge and putting it into action,鈥 Dr Eger says.
鈥淣ow that conservationists have a sense of what can work, they need to get on with it.鈥
