Seeking a profit in pest seaweed
A Dunedin seafood company wants to expand into seaweed harvesting, even though authorities have spent millions trying to eradicate what is regarded as a pest. The ‘‘weed’’ is still here and Southern Clams owner Roger Belton tells business reporter Jacob
ROGER Belton wants New Zealand to think differently about a certain type of seaweed.
His business, Southern Clams, has been harvesting Undaria pinnatifida — in Japanese, ‘‘wakame’’ — from Otago Harbour since getting a permit in 2016.
But the business is restricted to taking the seaweed, also known as ‘‘undaria’’, from artificial surfaces such as ropes, buoys and wharves despite it being widespread in Otago and Southland.
‘‘Now, there’s virtually no harbours in the country that don’t have it,’’ Mr Belton said of the exotic species, which was introduced to this country about 35 years ago.
‘‘All the attempts to eradicate it have been resoundingly unsuccessful. The policy is now around control.’’
That is significant for Southern Clams, which argues it has started turning the problem into a product.
And Mr Belton reckons he has a better means of controlling the ‘‘weed’’.
Harvesting involves cutting off the reproductive organ, known as the sporophyte, and taking it as well as the blade (the long leafy parts).
The holdfast — the part that clings to whatever surface the seaweed is hanging off — is left.
‘‘The reason for that and the reason why that’s effective as a control means is because basically [undaria] is an annual . . . so it will not regrow from the holdfast.
‘‘And you’ve removed the reproductive body, so you’ve helped manage the problem.’’
Harvesting happens between the end of winter and the beginning of summer — usually all the salvageable product decomposes over summer.
The business pulled in nearly five tonnes of the seaweed last year, Southern Clams representative Miao Zhang said.
Mr Belton described the foray into seaweed as being at a research and development stage, despite the company having two customers in New Zealand that process the seaweed into food and health products.
Those customers wanted more than Southern Clams had been able to get them, and he was frustrated harvesting was restricted to artificial surfaces, Mr Belton said.
‘‘That is very unfortunate because this socalled problem is propagating throughout the coast and those areas we cannot remove it from because our permit has got a condition on it.’’
The Ministry for Primary Industries says it only allows undaria farming from selected heavily infested areas.
An MPI spokesman said undaria remained an ‘‘unwanted organism’’ under the Biosecurity Act.
‘‘The rules around harvesting or farming it came about after extensive consultation and they are there to stop the potential risk of it to spread further.
‘‘These include prohibiting undaria from being harvested from organic surfaces.’’
In 2012, the MPI opened up Wellington, Marlborough and Banks Peninsula for undaria farming.
Environment Southland, MPI unit Biosecurity New Zealand and the Department of Conservation have together tried to eliminate undaria from Sunday Cove in Fiordland.
Their response led to seven years without mature plants being found, until April 2017, when plants were found in Beach Harbour about 2km from Sunday Cove.
There are now rules for clean vessels, gear and residual seawater and all boats entering the area.
Mr Belton said Doc’s removal of undaria was wasteful.
‘‘Good taxpayer money goes into the rubbish tip, whereas we could be using our time and our resources to develop a really valuable product for New Zealand.’’
If Southern Clams was given a wider consent to harvest more — something it asks the Ministry for Primary Industries every year — that could lead to an industry supplying seaweed and more employment, Mr Belton said.
‘‘It could become a significant part of our business.’’
Mr Belton and Mr Zhang have made trips to China to learn about commercially harvesting and processing the product.
From that, they were able to set up their processing centre, which they now have at their offices in Bombay St.
The seaweed comes in from the harvest in large wool fadges, which are sorted by workers, the blades and the sporophytes being separated and sent for processing.
The blades are hung and dried before being sent to the customer.
Mr Belton said he aspired to develop undaria as a form of aquaculture — something they saw plenty of in China.
A farm here would take the shape of a marine farm space with lines down for the undaria to grow off.
With more access to undaria, he was confident he would be able to find more demand for the seaweed, which his customers said was the best, Mr Belton said.
‘‘What we’ve established is they like the quality of what we’re doing.’’
His customers said it was ‘‘the best they’ve ever received from New Zealand and that’s why they want more of it’’, Mr Belton said.