Some of Mahurangi Technical Institute’s work highlights include:
NZ Short Fin Eel Breeding Project
One of the major research projects being conducted in MTI’s Warkworth facility is the breeding of NZ Short Fin Eels. Eel farming worldwide is a multibillion dollar business but currently relies on juvenile eels (called ‘glass eels’) caught from the wild for growing-on to marketable size on eel farms. Due to water pollution, migration barriers (e.g. dams), changing land use, over fishing, and predators, the natural, wild glass eel population is in serious decline.
In 2006 the world wide take of wild glass eels was about 300 tonnes but the demand was 1200 tonnes. 1 tonne equals about 5 million glass eels and at the average price (2006) of NZ$1600 per kilogram the value of 300 tonnes was almost half a billion dollars.
The MTI research team is working towards developing a process that will produce glass eels for supply to aquaculture farms which in turn will relieve the pressure on the wild stocks of eel. Soon after the opening of the new facility, MTI researchers successfully bred NZ Short Fin Eels for the first time in captivity; a great achievement considering that up until recently very little was known about the breeding habits of the NZ Short Fin Eel. The challenge now is keeping the larval fish alive for 100 days by which time they will have matured into baby or “glass eels” and can be transferred to aquaculture farms to be grown to market size.
There is very little demand for perch as a food fish in New Zealand because other species are traditionally favoured, but in Europe it is highly regarded. Switzerland, for example, imports about 4000 tonnes of perch fillets annually from other EU countries and demand exceeds supply.
Redfin perch was introduced into New Zealand in the 1860s and is now widespread throughout the country. It has firm, white flesh and tastes somewhat like gurnard.
The growth of the farmed perch industry in Europe is limited by the availability of sufficient fingerlings (young fish) for farmers to raise, and by redfin perch being seasonal spawners. As New Zealand’s breeding season is about six months later than Europe’s, there is an opportunity to export “out of season” fertilised eggs from this country to a major perch hatchery in Ireland which supplies young fry to other European countries. It is expected that this supply could raise the Irish hatchery’s annual production by about 25%.
MTI’s research team exported the first shipment of live eggs in 2006 to a hatchery in Ireland. About a million eggs contained in 5 separate boxes were successfully air freighted and a second consignment of the same size was dispatched a week later.
Creating the ideal conditions for successful transport of millions of live eggs to the other side of the world and completing the considerable volume of paperwork to meet legal compliance for export from New Zealand and import into Europe were major exercises. They are aspects of a successful aquaculture operation that are frequently under estimated.
NZ Native Freshwater Fish Export Project
Giant kokopu is the largest New Zealand native freshwater fish, apart from eels, and currently some of them are being studied in Canada for their potential as a new ornamental fish for the North American and Japanese aquarium markets.
A trial export to Canada of captive bred giant kokopu was made in November 2007 and if these fish acclimatise well, it is hoped that significant quantities will be shipped in the future. This may also open up a market for other species of New Zealand native freshwater fish.
Currently MTI is successfully raising koura (freshwater crayfish), banded kokopu, and inanga and is experimenting with culture of several other native freshwater fish for production and sale, including red-finned bully, common bully, Crans Bully, and torrent fish.