Scientific Name: Anguilla anguilla
Maximum Weight: 11 lb 2 oz (5.03kg)
Average Weight: 1 – 3 lb (0.5kg – 1.5kg)
Average Length: 16 - 28inches (40cm – 70 cm)
Life Span: 15 – 70+ Years
Eels have a long, tapering body with only one pair of fins, the pelvic fins, with both the dorsal fin and the ventral fins running almost the entire length of its body in a continuous ribbon to merge together at its tail end.
The European Eels tend to be referred to as Brown or Yellow Eels when in freshwater as they take on colouration to best suit their habitat at the bottom of rivers and ponds, having a dark grey back and head, with a pale brown/brass or yellow/green sheen to their flanks giving way to a white belly.
Whilst the Eel appears scaleless, they do in fact have microscopic scales that are embedded in the skin, and they allow the exchange of respiratory gases whilst travelling across land: famously well known for having a very slimy body. Eels grow quite slowly in the wild, and usually take many years grow to any real size from an angling perspective.
As Eels find their home, rather than being confined to a Stillwater or river system, they can and will live in the smallest of streams to the largest of rivers and from the smallest ponds to the largest lakes and man made gravel pits, and are able to deal with quite polluted water as well as the crystal clear waters of a chalk stream. They will find their niche within the ecology of their home and often remain unseen for years whilst living the freshwater stage of their life. Eels inhabit most waters with large female specimens sometimes making ‘surprise’ appearances on waters where the species is rarely caught.
Eels have an acute sense of smell, and use this to find dead flesh on which they can feed, whilst also feeding on invertebrates, insect larvae, worms and small molluscs, turning to predation in addition to scavenging as they become larger, eating small fish and frogs. Eels feed little in cold temperatures and may not eat at all over the course of a winter, remaining inactive in holes. Some believe that Eels may feed as snakes do, slowly digesting a meal until their stomachs are completely empty, before resuming the search for food with their feeding patterns reflecting this pattern.
Eels themselves are predated on by Herons, Goosander and Otters and of course Man.
There is no need for fine tackle and line should be of at least 10lb breaking strain as eels can easily bite through thin line, but use supple strong mono as their sensitive lips will detect hard line and result in a dropped run.
Thread deadbaits onto the hooklink using a bait needle and then tie on your hook: sizes 4-6 are ideal.
Soft, supple coated wire ?
Eels are scavengers and as such the best baits are small deadbaits or a bunch of lobworms on the bottom, often close in the margins or around weed beds where the fish like to hunt at night. Small deadbaits such as Roach, Rudd or Gudgeon, sometimes obtainable by scooping with a landing net in margins with overhanging reeds, can be knocked out and then scored with a sharp knife across their body so that blood and body juices are released, allowing the eel to use their highly developed sense of smell to locate them.
Care should be taken when handling as their vital organs lay behind the head at the top of the body and exerting a hard grip will damage them, you will end up with more slime on your hands than usual as they will wriggle even more than normal in an attempt to get away from the pressure. Laying a lively Eel down on a wet unhooking mat and stroking its belly continuously whilst slowly turning it on its back as it relaxes will usually make it quite complaint and provide the photograph opportunity if desired.
Deeply hooked Eels should have the line cut close to their mouth as they can usually shed the hook within a few days, that said, strike early to avoid damage to the fish in the first instance.
None of FAS’s fisheries appear to contain ‘bootlace’ Eels, between 8” and 12” in length and with the innate ability to tie them into a knot as soon as they leave the water, as few if any have been reported during catch reports. With the drastic reduction in the number of elvers that are able to pass the elver nets and eventually make their way upstream, travelling through all manner of waterways and even crossing land, to eventually find their way into stillwaters of all types, their numbers of young and ultimately specimen Eels are not likely to increase in the near future.
In the last 10-years, Eels of 5lb+ have been reported as being caught from Tarn Pond, Mill Lane, Frensham Great Pond and Stillwater Back Lake, with unconfirmed reports of a large fish from River Valley. With other venues likely to have Eels residing within them, plus the various river sections all offering the potential for large specimens, the opportunity remains to land a truly ‘wild’ specimen fish with an incredible life story, but the challenge of specifically fishing for, let alone catching larger Eels remains a challenge that few FAS Members rise to.
|11:02:00||4.989||1978||Simon Terry||Kingfisher Lake, Ringwood|
Farnham Angling Society Record
|6:11:00||2.721||July 2009||Duncan Charman||Tarn Pond|
All freshwater Eels throughout the world are catadromous species, meaning that they breeds in the ocean, but lives their lives in freshwater. The European Eel has a truly fascinating life cycle and one that is a true wonder of nature, and indeed, many details of which remains an enigma, as the full facts are still a mystery to this very day. The life cycle was not worked out until early 20th Century, and to this day, no one has yet seen a European Eel spawn in the wild. The same goes for the other 14-species of freshwater living Eels, with the details of the spawning sites for every species not being known as yet.
European Eels spawn somewhere in the Sargasso Sea, in the Atlantic Ocean: east of The Bahamas and south west of Bermuda, after hatching the tiny young eels known as larvae. It is unknown precisely where the Eels spawn, but the smallest eel larvae have been found in the Sargasso Sea, and with no other strong ocean currents to bring them there, and without the ability to travel any real distance themselves, it is believed that the adult eels must spawn close to where they have been found. It is believed that females may discharge between 5-10 million eggs, a truly enormous number: but given the journey the offspring have to complete, such high numbers are required for successful re-population.
A theory based upon information from studies of newly hatched larvae, temperature preference tests on adult eel injected with hormone treatments and the tracking of larger eel species using implanted transmitters indicates that eels may collectively spawn in the upper 200m of the Sargasso Sea.
Once hatched, the eel larvae are known as ‘leptocephalus’ (latin for narrow head), start their lives as clear, gelatinous and leaf shaped. At just a few mm in length they simply float around as plankton in the weedy seas of the Sargasso for up to 2-years or may be quickly swept away in a north-easterly direction in the upper layers of the Gulf Stream that crosses the Atlantic Ocean. After a journey that appears to last between 6-10 months and having fed on phytoplankton, they are eventually carried over the continental shelf between the ages of 7-months to 2.5 years old.
Once over the Continental Shelf, their bodies then metamorphose from their flattened willow leaf shape into the classic form of a small eel, at which point they become known as Glass eels because of their transparent appearance.
The Glass eels arrive in early winter off the coasts of southern European countries such as Portugal and Spain and in spring to early summer off Britain and northern Europe. Their keen sense of chemical detection in water allows them to follow the rich scent of organic molecules that discharge into the seas from the river systems along the coast of Western Europe.
The Glass eels, transparent and between 6cm to 12 cm long, gather and live in estuaries where they feed on zooplankton. With water temperatures rising to between 6 and 12°C, they first rise in the water column and get swept in on flood tides and then drop down to the bottom of the estuary or river to await the next flood tide: thus ratcheting their way up the tidal route at quite a pace. They travel in increased numbers at night, especially those with low levels of moonlight, and maintain their course upstream through increasingly less saline water toward completely freshwater.
It is just as they start to make this journey through the estuaries and into the rivers basins that they become the target of fisherman in the UK using hand held dip net, nets strung out across the current to catch them having been banned in the UK. Only a small percentage of the Glass eels that arrive at the coasts ever make it upstream. Through the combined changes of birth habitat and diet, the Glass eels gradually develop pigmentation and at this point would begin to be classified as Elvers.
The Elvers will begin to ‘run’ up rivers at speed at night, and as they do so will often encounter obstacles in their path, but are often able to breach them, whether natural or man made. Those such as weirs and sluices, simply being by-passed by crawling from the water and slithering across land to a different water body or by actually ‘climbing’ over small tumbling waterfalls by wriggling up surrounding rocks, moss and vegetation by clinging to whatever they can use as leverage to aid their ascent. Unfortunately, the increasing use of weirs and dams on river systems. create increasingly difficult barriers to the Elvers whilst returning to their period of development in freshwater. The use of passes for them are likely to be built in increasing numbers to overcome this problem.
Having traveled across the Atlantic and through estuaries and brackish water the Elvers reach freshwater where they will spend the next phase of their life, taking up residence in freshwater streams, ditches, rivers and all manner of stillwaters throughout the UK and Europe. Although elvers are sexless, it is possible that the population densities of developing eels and competition can cause hormonal changes that then determine their sex, with higher densities in the lower levels of a river system giving rise to more males and with lower densities giving rise to more females. If this theory is correct, it is unlikely that the small male eels would be found in any numbers away from the main river systems.
Sexual maturity and Yellow & Brown Eels
It is thought that sexual differentiation begins at about the age of 5, with maturity in the European Eels being reached by males between the ages of 6-12 years old and 35-40cm in length, with females being 9-19 years old and some 45-60cm in length.
As the Eels develop and begin to mature, increasing in size and reaching between 35cm –50cm in length, their bodies gain a more yellow brown colouration as they develop sexually, and may continue to move further upstream or simply relocate for up to 30-years. The females can grow considerably larger if they do not leave their homes to spawn and it is these large fish that become the fish that are so highly sought after by specimen Eel anglers with a 4lb fish considered a specimen and of considerable age, often in excess of 40 years. The largest recorded Eel is reported as being 133cm long, whilst the oldest fish was proven to be 84 years old.
Those eels that remain in or closer to the estuarine environment appear to progress their life-cycle far quicker than those that travel into freshwater where the eels generally grow larger as they are older.
The Final Metamorphosis
Whilst the Eel may not spawn within this country, when sexually mature, the eels once again change: both before and during their journey. They increase their body to give them strength and reserves for their enormous journey to the Sargasso Sea, the increase in both muscle and fat preclude their stomachs degenerating to provide space for reproductive organs. They develop darker backs, silver flanks and white bellies for camouflage in the sea; their skin thickens for insulation; eyes increase in size to enhance sight; fins becoming enlarged to assist swimming; the anus constricts to reduce water loss: all of these adjustments take place to assist in their ability to deal with their future environment and the call to spawn.
Most Eels return to the sea at some point, but it is not known what triggers their migration, the hours of August sunshine, temperature and rainfall are all considered important: but migration does occur in significant numbers over a few days and the so called ‘runs’ downstream only occur at night.
When swimming downstream toward the sea, the Silver Eels will once again be actively fished for with traps, but once this final obstacle is overcome, they head back out to sea, back over the continental shelf and into the depths of the Atlantic Ocean.
Silver Eels have an increased fat content of more than 30%, a 400% increase from that of the eel in freshwater residence, therefore providing the much needed energy to make their migration back across the seas and oceans during which they do not feed, being solely reliant upon the reserves that have been built up during their freshwater life.
Silver Eels have been tagged in the sea and data from these have shown that they can swim steadily at a speed of 12km/hr for sustained periods. Indeed, scientific studies in laboratory swim-tunnels show that Eels can swim four to six times more efficiently than salmonoid fish, and in trials where they swam more than 5,000km, their body composition did not change. Fat, protein and carbohydrates were all used in the same proportion, therefore demonstrating that the European eel is physiologically able of reaching the Sargasso Sea without feeding.
The Silver Eels head out over the Continental Shelf and into the Atlantic Ocean, somehow navigating the ocean whilst enduring an arduous journey, toward the Sargasso Sea over a period believed to be about 6-months. It is possible that they may use the Canaries Current that runs past Spain and northwest of Africa before being deflected west toward the Sargasso Sea, although no Silver Eels have ever been reported as caught by commercial fisherman.
The use of long life microscopic trackers on silver eels returning to the sea, may in the future provide biologists with the answers as to whether the eels die after spawning, but also the true location of their spawning site: or sites as the case may yet be.
Whilst there has been a broadly accepted and long held hypothesis, since the start of the 20th Century, that all European Eels migrate to the Sargasso Sea for reproduction, and comprise a single, randomly mating population (known as Panmixia theory), more recent scientific observations appear to indicate that this theory may be an overstatement and that more than one site may exist.
The Panmixia theory refers to a breeding population coming together to breed randomly without preference of a particular mate, therefore meaning that the gene pool and subsequently the species stays true to form without developing modification as would happen if choice were to play a part in breeding. This means that European Eels share all characteristics with no genetic difference at all to address the climates of northern or southern Europe. If specific mating preference did take place, in light of their future being completely beyond the control of the larvae themselves whilst ‘surfing’ the Gulf Stream to Europe, the choice of when to depart for Portugal or Scotland simply does not arise, so selective breeding would have been a waste of the eels resources which instead revolve solely around mating.
However, if the Eel spawning were to take place in slightly different areas of the Sargasso Sea, with larvae joining the Gulf Stream at slightly different times, destination choice may be fractionally improved. Ultimately of course, until the precise spawning site location is known, theories will remain just that.
None of the 15 recorded species Eel that spend a part of their life living in freshwater, have ever reproduced naturally in captivity, although hormonally injected adults have been seen to spawn in laboratory controlled conditions in Japan.
Eels in crisis & “Fish for the Future”
The Environment Agency have indicated that studies have revealed that the numbers of European Eels in Britain and across Continental Europe have declined by as much as 95% in the last 25 years, with recruitment at les than 1% of levels in the late 1970’s, with numbers seemingly still reducing each year.
As a result of very serious concern being expressed about the natural population of the European Eel being near to collapse, in 2004 the European Commission proposed the development of a ‘Community Action Plan’ for the management of European Eels. The aims being for at least 40% of Silver Eel biomass being allowed to return to sea and with 60% of Glass Eels (less than 4” or 100mm long), being used for restocking purposes within each country each year. Although agreement has been made about adoption of the plan, progress remains slow, as each member state has to arrange their own individual plan for each river basin, with the threat of reduced eel fishing being imposed as a penalty upon them if they do meet the target dates.
It is little known that the European Eel as a fish stock is the most widespread and highest employing single fish stock in Europe, with a great many peoples livelihoods are affected by the Action Plan that is starting to be implemented.
As a result, urgent measures are being adopted within the UK to address the requirements of the EC Action Plan and hopefully this will be successful, leading to the likely return of the ‘bootlace’ in future years. The success of the plan will be reviewed every 3-5 years with reports on: Eel mortality through non-fishing (such as habitat loss) and reduction measures; silver eel biomass returning to sea; glass eel capture including % used for restocking, aquaculture & consumption. The plan is set to continue for 3 generations of Eel, so could well last for 60-years based on north European growth rates.
There is considerable debate as to the cause of the population crash that has occurred, with it likely that a mixture of contributing factors are the true cause:
- Some fisherman believe it is simply a natural cycle, suggesting that there was a surge in elver numbers in the 1980s and that stocks are now returning to natural levels. But historical date on elver fishing does not appear to back this claim.
- Others believe it is the result of too much commercial fishing.The entry to the rivers from the estuaries is when Elvers are at their most vulnerable as they fall foul of fisherman’s nets, with many being exported to satisfy the markets of Continental Europe with Spain being major consumer of elvers as food, with France and Belgium being noted exponents of aquaculture in northern Europe. This includes the rearing of the eels on fish farms for food and increasingly for the restocking of natural freshwaters to aid natural repopulation. In the 1990s, the total annual European catch of elvers amounted to 500T, that contained an estimated 1,500,000,000 elvers.
As a result of over fishing in the 1990s, the price of Japanese eel soared and led to importers turning to the cheaper European Eel to meet demand in the Asian markets, thus increasing the demand for the elver population and increasing the price steadily from £60/kg in 1995 through the late 1990s to a record high of £525/kg in 2005, with prices reducing to £300/kg in 2006, but still at £200+/kg in 2009. Owing to Chinese success in their own control of eel fishing and improvements to aquaculture and higher survival rates of Japanese elvers, the demand has gradually declined.
A potential factor in this aspect is the time that it takes female eels to sexually mature. Following the period of greatly increased elver fishing, the impact is being felt. Baring in mind the considerable time that it takes females to mature, being a minimum of 9-years in freshwater, a 6-month sea journey to spawn, the entire life cycle appears to be a minimum of 10-years, so following a 12-year increase in demand from 1995 to 2006, the decrease of returning glass eels to the European coastline appears to be a symptom of the over fishing of elvers that occurred during that period of time.
- Another factor may be the shifting and slowing of the Gulf Stream, meaning that not as many larvae are swept from the Sargasso Sea to Western Europe.
- Others believe that disease is the answer as it is believed that the European Eels may be being affected by a nematode worm accidentally introduced from Asia, whilst simply a parasite in swim bladders of Japanese Eels that originate in the Pacific Ocean and live in China and Japanese freshwaters. Unfortunately, these have a more damaging effect on their new host, as is often the case with new parasites, attacking the swim bladder with serious consequences for the Eel as it is essential in completing its 4,500 mile, 5-year journey across the Atlantic Ocean to the Sargasso Sea.
Environment Agency (EA) and “Fish for the Future”
Whatever the real reason for the decline in elver numbers, it is hoped that the reform to fisheries legislation outlined by the EA in their guidance “Fish for the Future”, will enforce a reduction of glass eel fishing, combined this with an extensive restocking programme and ensure a reduction in the number of silver eels being taken. In time, this will help increase our Eel stocks for the future throughout the UK and hopefully, across Europe.