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Eels ~ Shortfinned - Anguilla australis ~ Longfinned - Anguilla reinhardtii General Information Biology Husbandry Information Land and Water Requirement Capital and Operating elements and costs Financial Information Licensing Information Best practice environment guidelines Papers

General Information (Longfin Eels)

Most longfin eels are found in Queensland and New South Wales and on Lord Howe Island.

Longfin Eels are diadromous, that is, they move from marine to fresh waters as juveniles and return to the sea as adults.  These eels live in a variety of freshwater and estuarine environments including coastal lagoons, rivers, creeks, swamps, lakes and farm dams.  Longfin eels prefer riverine habitats.

Longfin eels probably spawn in the Coral Sea waters deeper than 300m, although the exact location of spawning grounds remains unknown.  Females produce between 5 and 10 million pelagic eggs.  Within 2-10 days the eggs hatch into pelagic larvae called "Leptocephali"  The leptocephali are carried by ocean currents to the continental shelf where they develop into "glass eels" - toothless, unpigmented forms which move into estuaries with the assistance of currents and tides.  Longfin eels enter estuaries mainly in summer and autumn.

The Glass Eel stage lasts approximately 12 to 18 months, after which they develop pigmentation and functional teeth - they are then called "Elvers"  They then move from the estuaries into lakes, swamps and the freshwater reaches of rivers and creeks.  This migration takes place during spring and summer, and mainly at night.   Following this second migration the eels enter a sedentary feeding stage when they are known as "brown eels" or "yellow eels"

As Longfin eels reach maturity they move downstream to the entrances of rivers and creeks prior to commencing their spawning migration. 

A number of changes occur as they mature.  The dorsal surface becomes grey-green and the belly silvery white.  The pectoral fins and eyes enlarge, the lateral line becomes prominent and the skin thickens.  Internally, the gonads enlarge, the stomach degenerates and the anus constricts to reduce water loss.  Mature eels are referred to as "Silver Eels"

They leave the estuaries from late summer to autumn.  Some eels swim distances further than 3000 kilometres.

The main Australian commercial fishery for eels is in Victoria.  Restrictions apply.  Longfin eels are not cultured on a commercial basis at present, but a number of pilot projects are underway.

Colour of raw fillet:  White to pink.
Texture:                 Firm to medium.
Fat Content:           variable, can be very oily.
Flavour:                  Delicate fishy flavour. 

Eels have an amazing life history. Wild eels spend part of their life cycle in both fresh and salt water and spend most of their adult lives (up to 14 years) in fresh water, then migrate downstream to spawn at sea when sexually mature from 6 to 24 years of age. Victorian short-finned eels spawn in the ocean somewhere off the coast of northern Queensland.

The juvenile glass eels or elvers then swim all the way down the eastern coast of Australia back to rivers and streams in Victoria, New South Wales and Tasmania.

The adult short finned eel is common and widespread in Victoria south of the Great Dividing Range and can be found in both running water and low-lying adjacent wetlands.

Eels are primarily carnivorous, eating small fish of various types, worms, insects, small crusteceans and molluscs.

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Source: http://www.dpi.qld.gov.au/

Eel culture is an entension of the commercial eel fishery and involves the ongrowing of elvers taken from Victorian coastal streams by the Department of Natural Resources and Environment (NRE), and either stocked in public waters under special permits or grown out in private ponds or tanks. As there is yet no known method of breeding eels in captivity, the supply of glass eels can be a limiting factor in eel farming. Collection methods and abundance of glass eels from Victorian estuarine waters is still being assessed by Fisheries Victoria however of the limited trials to date more than 100 kg. of glass eels were collected from one river system. Glass eels number between 5,000-8,000 head for each kilogram taken. Each kilogram of glass eels has the potential to achieve 750 kilograms of final product within 12 months. Fisheries Victoria requires 10% of ongrown pigmented elvers to be returned to the wild to ensure sustainability of the wild stock.

Eel culture has considerable scope for further growth through research and development of intensive farming techniques and improved utilisation of south-eastern Australian glass eel and elver resources.

To date Victoria has provided the most ready supply of glass eels for aquaculture purposes. Tasmania provides a ready supply of elvers captured on manmade obstructions as they migrate upstream. However, elvers grown in Tasmania face additional shipping costs. Early growth rates have also indicated that glass eels are more readily grown in intensive aquaculture than older elvers.

Through a public expression of interst process, NRE has already allocated most of the glass eels it has collected for grow-out by the private sector, and a further allocation is expected in the near future.

Eels require medium quality freshwater with an optimum temperature of 26^o C. Grown in closed tank systems in Gippsland.

Investment opportunities for eels lie in establishing closed systems to more efficiently grow out glass eels or elvers for both export and domestic markets. New ventures may develop as more glass eels or elver are collected by Fisheries Victoria. 

The approximate price of the small farmed eels are between $5.00 and $8.00 per kg at the farm gate. You would then need to add the freight and export charges to the above price.

Applicants for a new aquaculture licence should read through the following information. Licence application forms can be obtained from the Fisheries Victoria Aquaculture Unit head office or from regional NRE offices.

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Source: http://www.nre.vic.gov.au/

Glass Elver for grow-out are available from the Department of Natural Resources and Environment.

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