Weeding with a wonderful view

Published Sep 14, 2014

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Cape Town - So why would a small group of twenty-somethings forsake the delights of the city and their social circles for a full 13 months, opting to spend their time dangling at the end of ropes off scary sea cliffs on a tiny island that is one of the more remote places on Earth?

Well, for a sense of adventure, obviously, as well as the feel-good response that comes with helping remove a serious threat to one of the world’s most pristine and ecologically important natural environments.

Oh yes: and while some might consider them to be rolling stones, they’re going to be gathering plenty of moss.

Actually, what’s involved is the alien invasive moss-like plant Sagina procumbens – technically it’s a procumbent pearlwort – and the three young people who left Cape Town aboard the SA Agulhas 2, bound for the British territory of Gough Island deep in the southern Atlantic Ocean, will be making its very intimate acquaintance.

When Michelle Risi, Chris Jones and Werner Kuntz arrive, they will play a key role in the conservation programme aimed at containing and eventually eliminating Sagina before it runs wild as it has done on South Africa’s Marion and Prince Edward Islands.

Gough is one of four islands in the Tristan da Cunha archipelago that is part of the United Kingdom Overseas Territory of St Helena, Ascension and Tristan da Cunha. Gough and another of the Tristan four, Inaccessible Island, are proclaimed natural category World Heritage Sites, while Gough has also been designated as a Ramsar Wetland Site of International Importance and is operated strictly as a nature reserve and site of special scientific interest – the only full-time human habitation there is at a South African meteorological station.

Gough and Inaccessible are globally recognised for their immense natural value, with the islands holding many unique species of plants, birds, and invertebrates, as well as being rich in history.

So there was real shock when in 1998 a sharp-eyed conservation officer discovered Sagina, a native European plant, growing on Gough, and eradication efforts have been under way since 2000.

Ironically, the invader almost certainly didn’t make its way south from Europe but instead – embarrassingly – is believed to have arrived from Marion Island via Cape Town, with its seeds having hitched a ride aboard a container used by the South African National Antarctic Programme at a time when containers were not designated for use solely to one destination (Marion, Gough or Antarctica).

Peter Ryan, director of UCT’s Percy FitzPatrick Institute of African Ornithology, who has a long association with research and conservation efforts at both the Tristan and Prince Edward Island groups and who is also on the current Gough 60 relief voyage, explains that Sagina has unfortunately spread “all over” Marion and Prince Edward Islands already.

“Areas invaded by Sagina at Marion have reduced abundance of invertebrates and obviously it pushes out native plants... It’s got a whole knock-on effect and it makes it harder for birds to burrow as well. So it’s not something we want to get away on Gough.”

The first place it was found at Gough was at the cement slab at the crane point.

“Presumably there were containers that had been sitting on the mire (wet, soggy) vegetation at Marion Island and that had not been cleaned properly (before being used for Gough),” says Ryan.

“For the first couple of years we tried to deal with it during the annual takeover, in spring, which wasn’t the best time – you really want to be there in late summer. So Sagina got away and is spread now along about 250m of natural cliff. The big concern is that if it spreads up into the highlands – then we’ll never get it back.”

The plant has proved really difficult to deal with, in spite of extra people having been sent to the island since the early 2000s, funded by the UK’s Overseas Territory environment programme. Efforts included the use of a big boiler, because heat treatment in the form of boiling water is one way of dealing with the seed, while growing plants were removed, bagged, put into boxes and dumped at sea when the supply ship was returning to Cape Town.

“We’ve also been spraying it with herbicides and we use pre-emergent treatment to stop the seeds germinating, but still it’s managed to creep a little... so in the past few years we’ve been trying really hard,” Ryan says.

Risi, a 24-year-old from Durban who recently completed her marine biology master’s degree at the University of KwaZulu-Natal, will be primarily responsible for the eradication programme for the next 13 months. She is being funded by the Royal Society for the Protection of Birds, and she’ll be assisted by Jones and Kuntz who have been working as interns at South Africa’s Environmental Affairs department.

“The thing about Sagina is that it’s this tiny little plant, you really wouldn’t think it can do much,” says Ryan.

“When we get to Gough now, we’re going to struggle to really see anything. But as spring warms up, seedlings start popping up and within six to eight weeks they can mature and start setting seeds, and the seeds can last 100 years if you don’t do anything about it. So it’s really scary, you’ve really got to be on the ball.

“We know more or less where it occurs – it’s not solidly along that 250 metres (of cliffs) but it’s in little pockets here and there, and you must be very dedicated and conscientious and keep checking. Every five to 10 days you’re going to go back and you’re going to treat whatever you find. It requires attention to detail – it’s not macho alien clearing.”

Two highly experienced rope-access instructors are also going to Gough to help – the senior instructor, Jan Bradley, has worked there during the past four takeover expeditions – and they will oversee the cliff access work.

“Because you know what those sea cliffs are like – they’re scary! So they will make sure the others know what they’re doing. Jan knows the whole deal, he’s very passionate about it,” says Ryan.

Speaking at the Waterfront quayside on Thursday just before sailing, Risi said she and her colleagues – already dubbed the “Sagina Ninjas” – trained in rope-access work in Pretoria in a warehouse.

“I was a bit concerned about upper body strength, but it’s easy to get yourself rope prepared.”

It would be her first trip to Gough Island and she was really looking forward to it.

“I’m quite an adventurer so, ja, I’m very excited, it looks beautiful.

“I’m a bit worried about sea-sickness but it’s a very larney boat!

“My parents are very supportive, they think it’s an awesome opportunity, and one of my uncles worked with the navy and went to both Gough and Antarctica, so my mom thinks it’s cool to have family who’ve been to Gough.”

Sunday Argus

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