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Breeding the NZ Short Fin Eel, Anguilla australis

by David Cooper
Aquarticles

In a major scientific and technological breakthrough that is likely to have major economic and conservation benefits the aquaculture research team at Mahurangi Technical Institute (MTI) have succeeded in breeding the NZ Shortfin Eel, Anguilla australis.

The MTI aquaculture research team

After five years of trying and a considerable investment in money the team, led by Dr. Tagried Kurwie, finally achieved their goal of reliably and repeatedly producing viable ova and hatching them in commercial quantities.

Dr. Kurwie holding the NZ Shortfin Eel, Anguilla australis

Dr. Kurwie, who emigrated to NZ with her family in 1997 after fleeing Saddam Hussein's regime in Iraq and is now based in England ( flying out for extended periods each eel season), says 'we were at the point of giving up. If we had not succeeded this season we would have ended the project as we were running out of ideas."

The eel breeding project is the brain child of Mr. Paul Decker, director of MTI and self confessed "aquaculture crazy". (Seems to be prerequisite for working within the industry in NZ!) Paul has been behind and/or involved in many aquaculture ventures in NZ, most notably the breeding of Grass Carp and Silver Carp under contract, an activity that is also carried out at the MTI campus in Warkworth.

Mr. Decker started MTI in 1990 and the privately owned tertiary provider runs mostly marine based courses and qualifications. The Diploma in Marine Technology, which is MTI's leading qualification, has a strong focus on training people for the aquaculture industry and the students have undoubtedly benefited greatly from the opportunities offered by being in such a "hands on" aquaculture environment and from such close proximity to ground breaking research.

The major breakthrough came on 30 June this year. Up this point the team had been able to successfully mature the adult eels, fertilize the eggs and take them through to nearly hatching stage and had been able to achieve this more or less to order for some time. However on this occasion not only did they hatch but they hatched in the thousands, nay tens of thousands. In fact it was an "embarrassment of riches" and the logistical problem then became what to do with them all. This feat was repeated later that same week and Dr. Kurwie is now confident that the procedure can be repeated reliably.

One unforeseen challenge that arose at this point was the fact that the newly hatched larvae, at less than 2mm and totally transparent, are almost impossible to see. So much so that we are certain that there was an earlier hatching that went unnoticed as an empty egg was found at one stage during microscopic examination of the embryos in a batch preceding the spectacularly successful ones. The visibility issue was eventually overcome by the use of a black light of the type often employed in teenagers bedrooms for the viewing of fluorescent posters! Incidentally it is amazing how silicone air tubing glows in this light. At one point the hatchery looked more like a 60's disco than a research laboratory!.

Eel hatching out

Eel hatchling - 3 days old



Eel hatchlings

As of this writing the larvae have been taken through to 5 days old from hatching. This far exceeds any expectations for this year's research project. The focus now is to raise the larvae through the marine leptocephalus stage and on to the glass eel stage which is when eel farmers take them for rearing. Dr. Kurwie, whose PhD is in the area of fish nutrition, is quietly confident that she can achieve this over the next two tears and this of course becomes the focus of the research for the near future.

To this end MTI will be seeking interest from potential investment partners to fund the required research and development of the process through to full commercialisation. "This has now got too big and too important to plod along on our limited budget and we now need to get serious" said Mr. Decker. "It is our preference to try and keep the benefits of this research in New Zealand as much as possible. However we have had serious interest already from overseas especially Japan," comments Paul, "and we need to keep up momentum as you can bet that others are also working in the same area somewhere in the world and the need to stay one step ahead is paramount'"

The work so far has been carried out in the lab at MTI and in a "mini lab' specifically constructed within a fibreglass shipping container. The plan now is to secure commercial premises nearby and construct a whole new facility with the best in containment and filtration equipment. The feeding trials alone will require 20 different populations (at least) and therefore 20 different holding systems alone. Then of course there are holding facilities for the brood stock, of which there will of course be greater numbers than previously, lab facilities, temperature control equipment and a never ending list of bits and bobs . All this will need to be in place by January 2006 so the team has a busy time ahead.

EelCo Broodstock facility

EelCo larval fish room

One luxury that the research team is anticipating is having enough room to move. As you can imagine with so much going on in such a small space there have been considerable logistical nightmares to contend with.

The responsibility of building and maintaining the new facility falls to Adrian Paarman and Kim Pierce the technicians on this project. Adrian, the head techie' is also the tutor of the Diploma in Marine Technology. Before joining MTI Adrian was involved for many years in the construction and installation of live seafood holding systems. As well as having a firm understanding of the biological and engineering requirements Adrian has that rare and valuable ability to make anything, often from not much. (In fact at present he is working on our own nuclear reactor made entirely from string!!)

In addition to caring for the livestock on a day to day basis and assisting Dr. Kurwie, Kim Pierce has been documenting the entire project photographically. All the photos that you will see of various adult eels, eggs, embryos and larval eels are his.

The final member of the team is myself, David Cooper. Despite the rather grand title of "Project Manager" my role is really to do the paperwork and procure the needed supplies. Not nearly as much fun as playing with the eels but I guess somebody has to do it.

As with all projects of any kind the support of suppliers and other organisations has been instrumental in bringing this exercise this far. In particular we would like to credit Gould Aquahaven from Canterbury. Gould's have been the suppliers of migrating eels to the project from day one and have never failed to supply good quality, well packaged eels on time. As a large commercial eel processor and shipper Gould's must surely rank MTI as their smallest customer. Yet they have never failed to supply anything other than a quality service and we are grateful to them for this.

Although this project has been largely funded to this stage by Paul Decker it has received some timely financial support from the Foundation for Science Research and Technology (FRST) via a Technology for Business Growth grant (TBG) over the last two years. These funds have made the achievement of this milestone possible and their investment has secured for New Zealand a significant scientific and economic achievement.

The TBG grant was made possible by the professional services of Ian Gray of Ibis Group who acted as an investment consultant. His enthusiasm for the project, interest in the whole field of aquaculture and knowledge of the funding application and reporting procedures (not to mention his patience) have been greatly appreciated.

As always there have been many challenges along the way and some of these have been quite humorous. The adult eel holding facility is equipped with an electric fence system to keep them in. This equipment has provided much amusement in the form of visitors who have been "shocked" to discover that we really did mean it when we said that there was an electric fence around the inside edge of the tanks!

There was also the time in 2004 that the electric fence failed due to a power cut (it now has a battery back up system). Of course the eels noticed this unexpected path to liberty and decided that a mass migration to the floor was in order. As some were already a little on the "stiff' side by the time the situation was discovered it was decided that we needed to get some back up eels just in case. However the original eels all recovered well from their adventure (although it did set progress back a bit) and by the time that the back ups arrived they were surplus to requirements. Also the backups were all quite large as this was all that was available at the time and so would have soaked up a positive fortune in hormones if they had been used in the research. So it was off to the smoke house for the new eels and the staff at MTI were all treated to a sample of the end product so to speak!

Internationally the farming of Anguillid eels is a significant industry. Unfortunately, due to the complez nature of the eels biology, the entire industry relies on wild caught stocks of glass eels and elvers to provide animals for raising.

Fillet of Eel

Of course this resource is under pressure from a degrading environment and pressure of fishing, not to mention increasing regulation. Therefore the weak point in this industry is the reliable supply of juveniles to grow on. Currently, according to a recent Australian government report on the international eel industry, glass eels (wild harvested) are fetching between US$750 per kilogram to US$10,000 per kilogram. The world wide take per annum is between 350 and 1150 tonnes!

You can see from the above figures that even using the most conservative estimates there is considerable scope for a commercial venture supplying glass eels.