Can green-lipped mussels be the next heavy lifter?

[This post first appeared in the Fairfax NZ Sunday Star Times, and on Stuff, on 22 March 2015 under the title ‘Green-lipped bounty all ours’.]

If New Zealand is to double agri-food exports by 2025 in line with Government targets, then we are going to need some lateral thinking. We won’t get there just by doing more of what we have been doing.

Related to this, in recent weeks I have been giving thought as to whether the green-lipped mussel can be one of the heavy lifters that can get the job done for New Zealand.
The green-lipped mussel is indigenous to New Zealand. The species is found nowhere outside our coastal waters. It is easily identified in the shell by its distinctive emerald green colour. The flesh is also distinctive from other mussels.

Maori would no doubt have harvested green-lipped mussels for many hundreds of years, but most of nature’s mussels are well hidden. In most years there are huge amounts of microscopic mussel spat washed up attached to seaweed on the Northland Coast, particularly on the so-called Ninety Mile Beach. Exactly where it comes from no-one knows.

The farming of green-lipped mussels began in a small way more than thirty years ago. In recent years, the industry has greatly expanded, such that mussel exports were worth $181 million in 2013. However, production volumes vary considerably between years and the returns in some earlier years were higher.

The main farmed area is in the Marlborough Sounds. Commercial mussel farming needs weather-protected waters, and the Marlborough Sounds are ideal. Other areas include Coromandel, Nelson and Banks Peninsula.

Part of the production issue is that the farms rely on wild-harvested spat to seed the farms, much of which is transported from the beaches of North Auckland. The harvested volumes of spat vary with La Nina/ El Nino climate cycles.

If the industry is to grow to be an export heavy lifter, then first there have to be spat nurseries where baby mussels can be harvested from adult mussels. Development of the reproductive technologies is the thrust of a Primary Growth Partnership between the Government and Sanford, which is the largest of the industry players. This program is costing about $24 million, with equal contributions from Government and industry. Much of the scientific work that underpins the project is being carried out by the Cawthron Institute.

The term ‘farming’ can be misleading. There is no required husbandry. Nor are the mussels supplied with any artificial feed. Visually, the farms comprise surface ropes and buoys with no other infrastructure. The farms are visited by boat and the mussels harvested from the ropes that they attach to.

To get the system started, ropes are dunked in a slurry of spat and then suspended from buoys. Each mussel filters about 360 litres of sea water per day through its gills and from this the mussel extracts the nutrients it needs for growth.

The mussel meat is predominantly protein and water, with low carbohydrate and fat. Under good conditions, it takes 12-18 months to produce a marketable mussel from spat.
Mussel processing is quite simple. The mussels are split open and left in a half shell and then blast frozen. Their shelf life in this form is two years.

The largest market is the USA followed by Thailand. However, other Asian markets are developing rapidly. The muscles are trademarked as GreenshellTM mussels with all major companies using this shared brand. Currently, the constraint is production, including year-to-year variability, and not the market.

The mussels are best cooked lightly. They are reputed to have anti-inflammatory properties and are used in a range of health products.

A key advantage of the green-lipped mussel industry is that this species of mussels is indigenous to New Zealand and nowhere else. Also, the new nursery technologies which should underpin the industry will have 20 years patent protection. In any case, any industry competitor would need to have weather-protected waters at the same temperatures as coastal New Zealand. There are not many parts of the world that can meet those criteria.

Once the nursery issues are solved, I can only see one constraint that will hold this industry back. It will be environmental concerns and associated regulations.

Pollution is unlikely to be a major issue given that the nutrients are all coming from the ocean. However, New Zealanders will have to decide whether they like the sight of buoys and suspended ropes in their coastal waters and bays.

Currently, I have no doubt that regulatory issues are holding the industry back. I also have no doubt the ongoing debates as to how we should manage this industry will be heated. As well as the environmental issues, more work is needed on appropriate lease conditions and associated rentals for farming access to the waters. We all have a stake in those waters.

Personally, I have no plans to be actively involved in the debate that must occur. I simply say that this is an industry with very big potential.