Courteney Beven is a scientific diver and chef who in recent years has become an "underwater weeder" on the side.
So far, Beven has racked up over 1,000 hours in Fiordland seas, gently collecting the invasive seaweed Undaria.
Courtney Bevan out on a dive. Photo: Supplied
Undaria - known as the 'gorse of the sea' - first arrived in New Zealand on the hull of an international vessel and has taken over native species with rapid speed, Beven tells Nine to Noon.
Back in 2010, there was a "small outbreak" in Fiordland's remote Breaksea Sound, she says, but not enough funding for divers to really get on top of it.
"Unfortunately, last year [Undaria] has spread down to another isolated area in Dusky Sound.”
The seaweed species soon took hold taking a liking to its new environs, she says.
"It has these tiny, microscopic spores that will attach to anything, the hull of the vessel, anywhere, and it will remain dormant until the environment is right for it to flourish.
“It [only] took one spore on the hull of the vessel to come into Fiordland and unfortunately, took hold and rallied in the environment that was there.”
It was daunting to witness the scale of Undaria's spread, Beven says.
“The first few dives when we actually got in there and started surveying the extent of it, it was pretty depressing to be fair. You'd look at your colleagues underwater and just sort of shake your head because we talk about it and I've heard a lot about it, but to actually see it was pretty sad.
“Because Fiordland has such a unique marine life to have such an invasive seaweed spread over quite an extensive range was a real shame to see.”
Undaria can attach itself to anything, she says.
“It's a real pig of a thing because it can grow on top of other plants. It can grow on rocks, it can grow on marine life that's actually in the water. I've seen it growing on a paua before.”
Removing it by hand is a delicate job too, she says, lest you inadvertently spread the spores further.
“We've just got to be very cautious with our handling, and obviously not shaking it too much and try and get it up to the surface as quickly as possible so that it's not in the water column for too long.”
Scientific divers bring the seaweed to the surface in catch bags, she says.
“We generally dive in a group of 3 and we probably bring up 24 catch bags, in a single dive, which is a few hundred kilos of wet-weight seaweed.”
Their mission now is to contain its spread.
“I believe will be a constant battle, it is a very hard thing to attempt to eradicate, containment is the main goal at the moment, just to try and reduce the spread of it. But it will take years of consistent diving in that area to even get close to eradication.”
As well as diving, Beven works as a chef on the charter boat and educates clients about conservation through food.
“I was very lucky to get an opportunity to work on Pure Salt, which is a charter vessel down there, as a chef. They're an incredible company and the owners are amazing and have a lot of conservation-minded projects. It was through them that I developed a bit of a passion towards looking after my own backyard and especially Fiordland.”
