If you want to grow a forest, a good place to start is with some seedlings — but when one Wellington group decided they wanted to replant a forest underwater, things were a little more complicated.
On the coastline of Wellington Harbour, towering forests sit just out of sight. These giant kelp soar skyward from their rocky root systems that in turn create a place for sea life to call home.
“They’re extremely ecologically important. They’re probably the most important group of species in the marine environment,” said Chris Cornwall, a senior lecturer in Marine Biology at Victoria University.
But the once abundant seaweed forests of Wellington are in a slow decline.
“The major two problems are sedimentation, so from the different river sources, it smothers the seaweed,” Cornwall said.
“The second problem is overgrazing by kina. So if we take out big snapper, crayfish, blue cod from the ecosystem, we remove all the predators of the kina and the kina numbers go up and the sea seaweed numbers go down.”
Zoe Studd from Mountains to Sea Wellington knew it was a problem linked to public perception. People needed to understand how important seaweed forests were before they were willing to do anything about it.
So three years ago, she started Love Rimurimu which quite simply translates to Love Seaweed.
“It’s quite slimy stuff, right? So we weren’t entirely sure that the kids would be into it, but they really were.”
Studd and her team gathered together scientists, community leaders and local Iwi to educate people about seaweed forests. But it was the youngest members of the community that dove into the deep end and began to study their decline.
“The ocean’s my second home, so I see it as kind of like a grass area but it’s a playground. Honestly, it’s just quite beautiful to see it grow,” said Ngawaierua Campbell.
She’s one of the Kura Kelpers — a group of young Wellingtonians who was conducting research with Love Rimurimu and asked why nobody was replanting seaweed forests.
“We rather foolishly said, ‘Yeah, that sounds like a piece of cake. Let’s do that’,” Studd said.
“But we knew we didn’t know a lot and that that knowledge was sitting in institutions like Victoria and NIWA, but it wasn’t out in the wider community.”
Love Rimurimu connected with NIWA to develop their seaweed nursery. Using an old car engine, tipping buckets and a few crates, the team developed a place for tomorrow’s forest to take hold.
Last September, the first seedlings were lovingly placed in restoration zones along the coast by the Kura Kelpers.
Each little strand is connected to a rock and lowered into its hopeful new home.
“We’ve never been a part of anything this amazing. As students, too. I thought scientists were like the ones that would probably do this. But no, it’s Kura kids,” said Mihirangi Kohatu.
It’s been a complicated process that, like the tiny seaweed strands, is still in its infancy.
Up to 70% of the seedlings that were planted out last year were quickly eaten by marine grazers, but the other 30% were thriving.
‘Ramp up our efforts’
They’re low numbers but according to Studd, this is just the beginning.
“This year we will ramp up our efforts, so the amount going out and the breadth of time that we’re planting out as well — because that’s part of the learning.”
She hopes that one day local communities will be able to grow infant seaweed themselves.
“The really exciting next step I think for this project is that we are looking to develop a community agriculture facility, which would mean that the students would be learning about being the agriculturalists in the future for those plant outs.”
And maybe one day locals will look to our underwater forests as they do our native giants — with love and understanding of how important they really are.