By Rob McCormack
There are 4 different species of eels you can find in Coastal NSW. Only 2 of them are of interest to us and
these are the most common types. Basically we have two types of eels, Long Finned (Anguilla reinhardtii
) and Short Finned (Anguilla australis). The main type we do is the Long Finned as this is the
one that receives the highest price and demand in this region.
Long Finned eels can be identified by the (top) dorsal fin which is longer than the short finned eel. The
long finned eel's dorsal fin starts well before the anal fin (bottom) which starts just after the anus (vent).
On the short finned eel the dorsal fin (top) starts just a little before the anal fin (bottom). Short finned
do not grow as large as the long finned. Under 10kgs.
Long Finned eels are fascinating animals. They start their lives as eggs in the Coral Sea off New Caledonia
and or New Guinea in deep water 300 to 3000 meters down. It's not exactly known as eels are still a mystery to
most researchers as their life cycle has not been repeated in the laboratory as yet. From there they drift
with the currents, then hatch into larva drifting and swimming with the currents till they hit the East Coast
of Australia. When these baby eels drift down the coastline of Australia they enter the river systems and
migrate upstream. When they first enter the rivers they are called glass eels as they are very small and clear
(see through). Once they enter fresh water and start feeding they become pigmented and darken in colour and
are called elvers. These glass eels and elvers migrate upstream in enormous numbers at the right time of
It seems unknown why they enter some river systems rather than others but it is supposed that there is some
sort of genetic imprinting in the eels from their parents to return to the area their parents came from. Also
rainfall is an important factor. Elvers have an instinct to migrate upstream and need flowing water for this
to occur. Drought conditions see a dramatic drop in recruitment of elvers into drought affected river drainage
As a general rule it is the male eels that stay in the salt/brackish water and usually the female eels which
migrate well upstream from the salt water and are the ones that enter your freshwater rivers, creeks and dams.
Eels are a major problem for people who want to use farm dams for aquaculture. When your farm dam fills and
then overflows the overflow water may only be a small trickle through the paddock but eventually that water
hits a creek or steam with eels in it and they can scent/feel/smell that dam water which is different to the
general paddock runoff water and follow that scent back to your dam. Generally they will stick to the water
course but if an obstacle is in their path they will go overland around the weir/waterfall etc. They can
survive quite well out of water in moist conditions. They may be only small elvers only 100mm long but over
time they will grow into massive eels. Generally these eels will stay from 10 – 30 years in your dam and then
in flood conditions migrate back to sea to breed and then die. Long finned eels have been known to grow to
over 80 kgs in size and live for 60 years. When these adult eels migrate back to the sea they actually change
shape. The head flattens and the eyes broaden around the head.
Eels are extremely tough; 10 years ago we did an experiment on a 2 kg eel to see how long it could survive
without food. We kept this eel in a 1000 litre tank in good quality water with aeration for 18 months without
food before it started getting ulcers and we took pity on it and gave it a feed, cleaned it up and then let her
In a normal farm dam type situation it usually takes the small elvers at 100mm long approximately 3 years to
become a major predator in your dam. The 3 year olds are in the 250 – 350 gram range and rapidly grow in size
from then on and if it's a yabby dam can completely eliminate all yabbies from the dam as there is nowhere a
yabby can go that an eel can not. The yabby of the Cherax variety with a thin smooth shell has no
defense against eels and are easy prey. The Eustacus type with a thick, strong and spiny shell can
cohabitat with eels. It's not as critical with native fish as most Australian native fish are fast and smart
so most can mostly avoid eel predation. However, the eels will eat the same food as the fish so the more eels
the less food available for your fish.
In a yabby dam eels are not a problem until they are over 200 gram in size. That is at that size that they
start making a noticeable impact on your yabby population. Most people on the Eastern Drainage who put in a
new farm dam and stock with yabbies will usually have a great yabby dam for the first 3 years them year 4
notice a major decline of numbers and by year 5 have no yabbies at all. The dams at most risk to eel
infestation are those with a large catchment which quickly fill and overflow regularly. Those dams with small
catchments and intermittent overflows are less likely to be heavily infested with eels.
Eels can be captured quite easily from farm dams. Set lines are a traditional way. Just 3 – 4 metres of
strong fishing line tied to a tree or stump on the bank with a heavy duty long shank hook (Number 2 or 4) and a
piece of fresh meat or fish for bait. Eels are a predator which hunts in the shallows of your dams at night.
Just bait the lines (6 or 8) up in the afternoon and leave out overnight. Check in the morning and usually you
will find the eels have caught themselves. Eels are very strong and smart, they will tangle themselves under
rocks and snags etc so make sure your set lines are only short. They also tend to twist and roll which can but
extreme pressure on your system so use heavy duty hooks and line.
Traps are also good eel catchers. At Port Stephens we use a large black opera house type trap which we bait
with pilchards. This works very well as pilchards are excellent bait as their strong oily smell attracts eels
from a long distance. These type eel traps are on sale at RBM Aquaculture. We also use fike nets from time to time and these also work very well.
For our commercial harvest of eels we use a home made eel trap approx 600mm square and up to 3mtrs long. These
traps catch around 60kgs/trap/night if the eels are present.
We grow mostly long finned eels here as in NSW this is the one with the ready market and high demand. In
Victoria and Tasmania they tend to produce more short finned eels. Caution should be taken if you are
purchasing glass eels as you may well be purchasing the wrong type. Don't get short finned or you may find
there is not a ready market for the final product in NSW.
Long finned eels sold by us are sold to an exporter who then sells them to Asia. We just have a 10,000
litre tank here with our eels in it ready for pick up. The exporters have their own transport trucks and come
out to our farm. We load the eels up into fine net bags at 30 – 50 kgs per bag, these bags are then weighed
and the eels then emptied into the live transport tanks on the back of the truck. We usually do loads of about
100 kgs per go. Only long finned eels are taken and need to be over 650 gram in size. The bigger the better.
The exporters pay you at time of pick up at a rate dependent on time of year of $11 up to $15/kg. Small eels
and short finned eels they will take off your hands but at $3 - $4/kg.
Both these 2 species of eels have excellent aquaculture potential and many farmers are starting to farm
eels. Because of the difficulty of breeding eels in captivity (has not been done commercially as yet despite millions of
dollars spent in research in the Northern Hemisphere - some experimental work is showing its possible) all glass eels for culture are captured from the wild.
In NSW the NSW Fisheries department is unsure of the glass eel stocks available so has capped the collection of
glass eels at 300 kgs/year. To date this supply has been unreliable. Another source of glass eels is to get
them from interstate where more are available regularly. There are from 3000 to 6000 glass eels per
Eels can be grown intensively in recirculation systems at up to 100kgs/m³ but generally at around 60kgs/m³.
They can be grown intensively in ponds at 7,000kgs/ha or just extensively at 500kgs/ha. Eels are cannibalistic
and grading to separate the large from the small is wise. In the wild we work on a catch rate of 300kgs/ha of
larger over 650gram eels. So if you have farm dams this is what you can expect to harvest from natural stocks
in this region.
Many people are looking at eel farming these days due to the relatively high prices paid per kilogram. You
can purchase small eels from professional fisherman at around 200 – 300 gram in size and from $2 - $4/kg.
These eels can then be trained onto pellet feed and fed daily in special earthen eel ponds can reach a weight
of 1kg in 12 months. This is the easiest method of growing eels as using glass eels is a very labour intensive
method. 200gram eels can be easily trained onto Silver Perch or Barra Pellets without any great effort. Keep
them well fed in good quality water and cannibalism will be greatly reduced.
We do most of our eel fishing over winter at Port Stephens. This is not the best time to do it as eels are
cold blooded animals so as the water temperature drops their metabolism slows so they don't need as much food
or feed as much. However if the water is over 15 C then eels can be captured in our traps. We usually fish
over winter as we usually receive a better price then and we usually have a bit more time available. We sell
the larger eels we capture and keep the smaller ones and grow them up in a pond. We just capture eels as we
get spare time and store them in a tank until we have enough for either stocking a pond or for sale.
The only problem with holding eels in winter is that their metabolism is going slow so they are more
susceptible to infections. In the traps when captured they run their head along the trap looking for a way out
and can loose their slim covering which can let infections attack the eel. We have had big trouble with eels
in winter in our holding tanks in the past with fungal infections. We have overcome the problems by holding
them in tanks with a prophylactic treatment of hydrogen peroxide and colloidal silver ions in the water. This
has been 100% effective and no fungal outbreaks occur now.