New Zealand green lipped mussels are bivalves belonging to the phylum mollusca which include shellfish (clams, oysters), snails, octopodes, and squid. They are also known as the New Zealand mussel as well as greenshell mussel, greenlip mussel, and green-lipped mussel. It's scientific name is perna canaliculus.
Being invertebrates, they don't have an internal skeleton made of bone. And amazingly enough, invertebrates include 98% of all animal species. Molluscs have bilateral symmetry (and are some of the most complex invertebrates including octopodes. Molluscs have gills to help them exchange gasses under water. The phylum Mollusca is one the most diverse groups of invertebrates.
Where in the world are green lipped mussels found?
As the name suggests, the New Zealand Green-lipped mussel is native to New Zealand and is generally found below the low tide line as well as intertidally, which is the area of the shoreline between low and high tide.
Greenlip mussels are unique to New Zealand although they are considered an introduced pest in Australia. On the map below you can see the main aquaculture areas for green lipped mussel cultivation.
New Zealand green lipped mussels aquaculture sites.
The mussels prefer moderately exposed coasts and the warmer North although there are many aquaculture farms around the North of South Island.
Just look at the beautiful place they call home.
South Island, New Zealand, home of many aquaculture mussel farms.
It's Important What They Eat
These bivalves filter the water that passes into their shells and absorb the phytoplankton, which are the "plant drifters" of the oceans. The name comes from the Greek words phyton, or "plant", and πλαγκτος ("planktos"), meaning "wanderer" or "drifter".
Phytoplankton are autotrophic, that is, an organism that produces complex organic compounds from simple inorganic molecules using energy from sun light. These simple one-celled plants are the original producers in the food chain, and are fundamental to not only the ocean ecosystem, but to all life on the planet. Phytoplankton combine energy from sunlight and inorganic chemicals and use it to create energy-rich molecules such as carbohydrates as well as fatty acids. Very complex little fellows.
There is another interesting thing that has a great effect on the physical properties of the phytoplankton and therefore on the fatty acids found in the mussels and that is the fact that there is a big hole in the ozone layer over New Zealand. This hole allows more radiation from the sun to enter the earths atmosphere right over New Zealand.
The phytoplankton depend on sunlight for their survival and in order to survive the ravages of these powerful rays, they produce higher quantities of anti-oxidants than phytoplankton in other areas of the world. The mussels that feed on these drifting plants concentrate these anti-oxidant rich molecules and fatty acids.
Greenlip mussels were harvested manually from the shorelines of New Zealand until the 1960s, when greater demand motivated the industry to use a dredging method to be able to supply local demand. The mussel beds in the Nelson region and the Coromandel region were quickly dredged out and some visionaries turned to aquaculture in order to grow enough mussels to fill the demand.
Among those early pioneers were Noel and John Turner. These and others at the time, participated in experimenting with innovative cultivation techniques in which young mussels called mussel spat, were grown on ropes suspended from rafts.
In the fiords and sheltered areas on the northern coast of South Island, with its phytoplankton rich and pristine waters, the first trials were carried out by these early pioneers. Using this method, the green lipped mussels are ready for harvest in 12 to 18 months and in 1971 the first aquaculture mussels went on sale. This first harvest was a record 7 tons.
Modified longline aquaculture
The growers began switching from the raft method of cultivating mussels in favor of a modified Japanese longline system. The current process uses this modified longline system even out in open waters. Spat, the seeds or eggs from the female mussels, are seeded on the ropes where they attach themselves with threads formed by a special secretion.
The mussels grow on the ropes, filtering phytoplankton from the water and mature reaching between 9-12cm (3.5-5 inches). The mussels require no food or feeding which means that their entire process leaves no impact on the environment. The do not eat something that is needed by other sea creatures and there is always an abundance of these phytoplankton.
From 1970 to 1980 mussels were being exported to the United States in the form of powdered health supplements to help alleviate arthritis symptom. In 1981, when strict US drug legislation was placed into affect, this market collapsed overnight. This change in US legislation moved the mussel supplement industry to develop extracts from mussels which were then able to be exported.
Special one ton bags of mussels
Frozen mussels became the prime export, using the trade name NZ Greenshell Mussels. New Zealand's second most important seafood export by the year 2000 was mussels with over $170 million in sales to over 60 countries.
The harvesting of the green lipped mussels follow a careful plan so that they are harvested only when they are mature and not right after spawning. Mussels can live out of water for several days, but the harvesting is very carefully controlled and coordinated with the processing plants so that the mussels are only out of the water for a few hours before they are processed.
One ton bags of freshly harvested
Aboard the harvesting boats, the green lipped mussels are loaded into special bags designed to hold one ton. These bags are taken off the ships and loaded into waiting trucks and are taken to the processing plants.
Top of page>>