Tuna aquaculture - New Zealand
New Zealand's first eel farm was established in 1971. Despite other farms opening in later years, no eel farms remained by the start of the 1980s.
The failure of the farms was attributed to a variety of reasons which included poor economic conditions, escalation in food costs, depressed export prices, problems with culturing New Zealand eel species and some instances of disease. The irregular supply of glass eels was one of the greatest constraints to production.
With funding from the Ministry of Science & Innovation (MSI) NIWA's Bream Bay Aquaculture Park has established protocols for the weaning and on-growing of eels in fresh and brackish water recirculation units, and growth and survival rates under intensive culture. It has also conducted product evaluation which has demonstrated that intensively-farmed New Zealand shortfin eel is acceptable in Japanese cuisine.
When glass eels are captured, longfin and shortfin eels are frequently found together, and it has been established that longfin eels do not perform well in culture. Any plan to commercially harvest glass eels will need to consider the sustainability of both species.
The major bottleneck in eel aquaculture in New Zealand, as in other countries worldwide, is the availability of wild glass eels. It is currently illegal to possess eels weighing less than 220 g except under a special permit. Any commercial access to glass eels will require legislative change, and any future regulatory change which is likely to enable glass eel collection will require the fishery to be demonstrably sustainable and socially acceptable.
References and further reading
Chisnall, B., Martin, M. (2002). Short-term fattening of wild-caught shortfinned eels. Fisheries & Aquaculture Update 1: 4.
Chisnall, B.L., Martin, M (2002). Growth of female shortfinned eels stocked into dairy farm and factory wastewater ponds: a preliminary study. NIWA Technical Report 118. NIWA Wellington. 22 p.
Dobson G. (2011). Prospects for eel aquaculture. Coast & Country 133: 4-5.
Jeffs, A.G., Watene, E. (2003). The eel aquaculture opportunity. Seafood New Zealand 11: 36.
Jellyman, D., Lokman, M. (2003). Encouraging results from freshwater eel culture. Aquaculture & Biotechnology Update No. 6. http://www.niwa.co.nz/fisheries/fau/no06-2003/encouraging-results-from-freshwater-eel-culture
Kayes, P. (2010). National Eel Workshop. May 2010. Conference Proceedings. National Eel Workshop, Whakatane, Te Whare Wānanga o Awanuiārangi. http://www.wananga.ac.nz/Research/Documents/National%20Eel%20Workshop%20Proceedings%202010.pdf
Kearney, M. (2009). Aquaculture potential of the New Zealand shortfin (Anguilla australis) and longfin eel (A. dieffenbachii). Unpublished PhD Thesis, University of Auckland, 2009.
Kearney, M., Jeffs, A., Lee, P. (2008). Effects of salinity and temperature on the growth and survival of New Zealand shortfin, Anguilla australis, and longfin, A. dieffenbachii, glass eels. Aquaculture Research 39(16): 1769-1777. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2109.2008.02053.x/abstract
Kearney, M., Jeffs, A., Lee, P (2011). Development and early differentiation of male gonads in farmed New Zealand shortfin eel, Anguilla australis. New Zealand Natural Sciences 36: 33-44. http://www.science.canterbury.ac.nz/nzns/issues/vol36-2011/kearney_a.pdf
Kearney, M., Jeffs, A., Lee, P (2011). Seasonal differences in the quality of shortfin glass eel, Anguilla australis, and subsequent effects on growth and survival in captivity. New Zealand Natural Sciences 36: 45-55. http://www.science.canterbury.ac.nz/nzns/issues/vol36-2011/kearney_b.pdf
Lokman, P.M., Young, G. (2000). Induced spawning and early ontogeny of New Zealand freshwater eels (Anguilla dieffenbachii and A. australis). New Zealand Journal of Marine and Freshwater Research 34: 135-145. http://www.royalsociety.org.nz/publications/journals/nzjm/2000/010/
Te Wai Māori. (2009). Opportunities for Customary and Commercial Freshwater Aquaculture. Te Wai Māori Trust, Wellington. 60 p. http://waimaori.maori.nz/publications/Customary and Commercial Opportunities for Freshwater Aquaculture 2010.pdf
Todd, P. (1974). Studies on the reproductive biology of New Zealand freshwater eels. Unpublished PhD thesis, Victoria University of Wellington. 328 p. http://researcharchive.vuw.ac.nz/handle/10063/663
Todd, P. (1979). Hormone-induced maturation of New Zealand freshwater eels. Rapport et Procés-verbaux Réunions. Conseil Permanent International pour l'Exploration de la Mer 174: 91-97.
Todd, P.R. (1981). Hormone-Induced Maturation in Male New Zealand Freshwater Eels (Anguilla spp.). New Zealand Journal of Marine and Freshwater Research 15(3): 237-246. http://www.royalsociety.org.nz/publications/journals/nzjm/1981/026/
Watene, E. (2003). Potential for Commercial Eel Aquaculture in Northland. NIWA Client Report AKL2003-032. NIWA, Auckland. 36 p.
- Mahurangi Technical Institute: http://www.mti.net.nz/
- Ministry of Fisheries: www.fish.govt.nz/
- NIWA's National Centre of Aquaculture & Biotechnology: http://www.niwa.co.nz/our-science/aquaculture-and-biotechnology/aquaculture-species/eel
- Te Ara: http://www.teara.govt.nz/en/eels/4
- Te Ohu Kaimoana: http://teohu.maori.nz/
- Te Wai Māori Trust: http://waimaori.maori.nz/