Trout
The Brown Trout
(Salmo Trutta)
or
Sea Trout
(Salmo Trutta Trutta)
The brown trout (Salmo trutta) or Breac Donn (meaning dappled) is a native Irish species and the most widely distributed freshwater fish in Ireland. It thrives in waters of all types, from small mountain streams to broad limestone rivers and loughs. It’s main requirements are clean water and gravel in which to spawn.
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They breed and spend their early life in freshwater, before some migrate to the sea. They return as adults to freshwater to breed. It is mainly female fish that go to sea, the better feeding giving them a reproductive advantage as the larger the hen the more eggs she will produce.
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Brown Trout (Salmo Trutta) have a brown back with reddish or black spots at times and they have a pale belly, brown coloured sides and reddish brown fins, non migratory trout are in our rivers and streams of Ireland's west coast. Some trout will form colony type behavior and interbreed, they can often be born at the top of a catchment and not even frequent the lower areas of the river.
Sea trout (Salmo Trutta Trutta) that choose to migrate to sea as smolts usually they move at nighttime from our streams and rivers, feeding from the sea in abundance the returning sea trout will now be silver in colour and will spawn in late autumn, if they stay they will lose their silver colour but are larger and take back their brown colour.
This is a brown trout returning from sea and now her spots are changed.
TROUT STOCKS ARE WORRYINGLY LOW AND ANGLERS ARE REMINDED TO CATCH AND RELEASE AND CONSERVE THE FUTURE OF
SUCH A GREAT SPORTING FISH SPECIES.
Life Cycle of Trout
Spawning
Between November and February a female brown trout digs a nest or redd in gravel shallows. As she releases her eggs, they are fertilised by the male and then covered with gravel. The gravels must be 10-40mm in size, loose and free of silt with plenty of oxygen rich water flowing through them
Eggs
The Trout spawn eggs, 2-5mm in diameter, hatch into alevins in a few months, depending on temperature
Alevins
Alevins stay in the gravel, living off the yolk sac. They then emerge as fry, set up territories and grow into parr.
Parr
Fry and parr are territorial and solitary. They need plenty of cover in the river from stones, weed and trailing bankside plants, and shallow water that is not too fast flowing. Only around 5% of young trout survive their first year of life.
Adults
Adult trout have a territory that gives them a good supply of food and a place to hide from predators, preferring deeper pools. In winter, they migrate, perhaps miles upriver, to spawn. Brown trout live up to 5-20 years.
The Song of
Wandering Aengus
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BY WILLIAM BUTLER YEATS
THE WIND AMONG THE REEDSÂ (1899)
I went out to the hazel wood,
Because a fire was in my head,
And cut and peeled a hazel wand,
And hooked a berry to a thread;
And when white moths were on the wing,
And moth-like stars were flickering out,
I dropped the berry in a stream
And caught a little silver trout.
When I had laid it on the floor
I went to blow the fire a-flame,
But something rustled on the floor,
And someone called me by my name:
It had become a glimmering girl
With apple blossom in her hair
Who called me by my name and ran
And faded through the brightening air.
Though I am old with wandering
Through hollow lands and hilly lands,
I will find out where she has gone,
And kiss her lips and take her hands;
And walk among long dappled grass,
And pluck till time and times are done,
The silver apples of the moon,
The golden apples of the sun.
European Eel
European Eel
European eels live long, complex lives, travelling thousands of miles and repeatedly transforming their appearance.
It all begins near the island of Bermuda in the deep, blue waters of the Sargasso Sea. Eggs hatch into transparent, leaf-shaped larvae that join the salty river of the Gulf Stream as it sweeps North-East across the Atlantic. Their 4,000-mile drifting journey lasts a year or two before they reach the shores of Ireland, Europe and North Africa. Here, they metamorphose into finger-length, see-through miniature eels – called glass eels – to continue their journey inland.
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It’s this stage of the eels’ lives that has caused alarm over the species’ risk of extinction. In the past 40 years, the number of glass eels arriving in Europe has fallen by around 95%. A suite of threats is implicated in the eels’ demise – weirs and dams, hydropower and water-pumping stations could be blocking their migration pathways from the sea into the freshwater catchments where they grow and mature; overfishing, pesticides and parasites are believed to be part of the problem; and climate change may be shifting the track of the
Gulf Stream so that fewer glass eels are hitching a trans-Atlantic ride.
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Life Cycle of Eels
Eggs/ Larve
5MM - 80MM
After spawning in the Sargasso Sea, the eel’s eggs are assumed to drift eastwards towards Europe with the Gulf Stream. During this time, the eggs hatch into leaf-shaped young larvae, called leptocephalus.
Glass Eel
APPROXIMATELY 8CM
It’s only on reaching the European continental shelf that they metamorphose into the cylindrical shape we associate with eels. These virtually transparent fish are known as glass eels.
Elver
<12CM
On entering freshwater, glass eels darken in colour as pigmentation takes place. Now known as elvers, they migrate upstream to a wide variety of freshwater and estuarine habitats. Eels may even move over wetland to reach some bodies of water.
Yellow Eels
UP TO APPROXIMATELY 1M +
Known as yellow eels while freshwater-resident, they can remain in these habitats for more than 20 years, feeding on invertebrates and fish.
Silver Eel
FEMALES >45CM LONG,
UP TO 1M+.
WEIGH 250G - 6KG
MALES <45CM LONG.
WEIGH AROUND 150G
Once ready to reproduce, they turn into silver eels and migrate to the Sargasso Sea.
Starting their lives of in the larval form in the Sargasso Sea and drifting to the continental shelf Anguilla Anguilla the European Eel makes an amazing journey to start out its life.
Eels can live for a very long time, up to 85 years that we know for sure. But usually when they are 7 to 20 years old, they suddenly leave the freshwater and swim to sea again, returning to the Sargasso Sea were it all began.
When Eels make this journey here , they transform and become what we call the silver eel leaving our freshwaters ,Silver Eels stop eating completely for the total duration of their trip back to the Sargasso Sea, which can take anything up to and over a year.
Instead of eating, they develop sexual organs with their eyes changing operating in water levels of epipelagic, mesopelagic and bathypelagic depths.
Many studies have been carried out in eels with contentions being put forward by Aristotle and Freud that the eels on examination have no sexual organs but this is historical studies and advances in scientific research teaches how and where sexuality comes into play with Eels in our rivers .
At what point these observations were made in the cycle of three changes the eels undergo in its lifetime plays a lot into those historical assumptions .
Rather than mating procreation the Female lays her eggs in the water columns of the Sargasso Sea and then the Male almost similar to spawning fertilizes the eggs by releasing sperm into the water columns areas of the eggs.
So while in the earliest growth stage in our rivers sexuality of eels is in the last phase of their lives the Silver Eel phase , with so many metamorphisms it is no wonder reproduction is very much hidden until the third and final stage of their lives ,yes that is right regardless of the duration of time spent in our rivers once eels turn silver and migrate they are on the final journey of their life.
A catadromous species they have one life cycle growing in our fresh waters leaving to their home in the Sargasso ,spawning and then dying.
Eels are impacted by a number of issues that has cause the stock levels of European Eels to be classified as critically listed endangered and protected under fishery law under the Eu Eel management programme.
Anguilla herps virus ,European EVX and Anguilla Collides Carrasus all have a devastating impact upon the eel population combined with illegal fishing and the black-market trade on young elver eels as a deliciously food well documented over many years .
Despite all of what the Eel goes through it still makes that journey lives amongst us in our streams and estuary lakes until it must return home to die.
We need to do more to protect this species before its to late.
A truly amazing Creature
Gallery
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More information about European Eels
Eels in Inishowen
FUNDED BY A SEEDS OF CHANGE GRANT SCHEME FROM DONEGAL CHANGEMAKERS
by Thomas Lawrence APRIL 2021