The Ice Age Brown Trout

If you have looked into fishing in Iceland you have probably heard the term “ice age brown trout” and seen people rave about their size and strength. But what exactly is an ice age brown trout, how do they differ from a regular brown trout and why are they so highly praised and sought after?

The short answer; ice age browns is the name given to the strain of brown trout inhabiting Lake Þingvallavatn, Iceland’s largest natural lake. The reason people get obsessed with these beasts is quite frankly their incredible size, as well as fighting strength, not to mention the beauty of this creature. Fish over 30 lbs are caught each year.

Ice Age

For the long answer, we need to go back 11 thousand years when the ancestors of the ice age trout moved in from the ocean and colonized the area. Those ancestors were anadromous brown trout that moved back and forth between Lake Þingvallavatn and the open ocean. Roughly 9 thousand years ago receding glaciers and volcanic activity made passage between Lake Þingvallavatn and the ocean impossible, in effect trapping these previously sea-run fish in the lake. In the time that has passed since then, the trout have made some remarkable adaptations to their new surroundings, one of which is the fact that the ice age trout only reach sexual maturity between the ages of 5-8 years old. In a research done by biologist Jóhannes Sturlaugsson, an ice age brown trout that had reached over 20 lbs in size but was not yet sexually mature was found. Another remarkable adaptation that the strain shows is the fact that unlike most other brown trout in Iceland, the strain does not spawn every year once reaching sexual maturity, but in fact, each fish only spawns every 2-3 years. Those years that the fish do not expand their energy at spawning, they pack on weight and size fast. With remarkable growth rate up to 5 lbs a year has been documented in tagged fish. 

Food Sources

The main food sources for these fish are threefold, the 3-spined stickleback which is a small fish inhabiting the shallows of the lake, any of the 4 sub-species of Arctic char that inhabit the lake but mainly the Murta sub-species (Salvelinus Alpinus Murta) as well as insect life mainly in the form of midges, Chironomidae and caddis in all life cycles. These feeding patterns make them perfect to target with a fly rod as they will take streamers, nymphs and dry flies when presented to them.

The fishing season for them lasts from 15 April until September, with primetime usually being 15 April-15 June.

For more information on research done on the ice age brown trout, we recommend checking out http://www.laxfiskar.is/index.php?lang=en

FishPartner beats on Lake Þingvallvatn

Kárastaðir beat 1

Villingavatnsárós beat 3A

Villingavatnsárós beat 3B

Villingavatn beat 3D(The lake)

Kaldárhöfði beat 4

By Sindri Hlíðar Jónsson, Partner and Head Guide at Fish Partner

Spencer higha holding giant ice age brown trout
phil tuttle holding large brown trout
ice age brown trout half submerged in water
derek olthius and spencer higa holding 2 very large brown trout
3 men holding 3 large brown trout
a giant brown trout
man holding large ice age brown trout half submerged
head and front side of half submerged brown trout
man standing in water holding a fly fishing rod
a fly fishing man casting into a lake standing on a rocky island at þingvallvatn
man holding large ice age brown trout
view of kárastaðir coast line
man in black hoodie holding large brown trout
a fly fishing man with beard holding large ice age brown trout
blue gill plats of large brown trout
bearded man in white beanie holding large brown trout
large female brown trout
bearded man with hat holding large brown trout with streamer in mouth he caught fly fishing in lake þingvallvatn
fly fishing rod and large brown trout half submerged
half submerged large brown trout

Popular Fishing

A Hidden Gem in the Highlands – The river Kaldakvísl is truly a hidden gem. Fished only by a select few, Kaldakvísl has now been made exclusively available only to the customers of Fish Partner. Words are unequal to the task of describing the landscape’s beauty. Diversity and contrasts are the river’s main characteristics.
One of the best brown trout beats in the world – Villingavatnsárós (means the mouth of river Villingavatnsá) is one of the greatest brown trout beats in the world. The beat offers the opportunity to catch the giant ice age brown trout on small nymphs and dry flies. Streamers can also be strong. The beat is only fished with two rods and all brown trout shall be released. It is fly-fishing only.
A Hidden Gem in the Highlands – The river Kaldakvísl is truly a hidden gem. Fished only by a select few, Kaldakvísl has now been made exclusively available only to the customers of Fish Partner. Words are unequal to the task of describing the landscape’s beauty. Diversity and contrasts are the river’s main characteristics.
One of the best brown trout beats in the world – Villingavatnsárós (means the mouth of river Villingavatnsá) is one of the greatest brown trout beats in the world. The beat offers the opportunity to catch the giant ice age brown trout on small nymphs and dry flies. Streamers can also be strong. The beat is only fished with two rods and all brown trout shall be released. It is fly-fishing only.
Tungufljót river in Skaftafell is one of the best known Sea trout rivers in Iceland and is most famous for the high average weight of fish caught, every year multiple Sea-Run Brown trout in the 20lbs range are caught with the average weight of the fish being between 5-10 pounds.

Accessability

  • Easy – Very little hiking required, easy for every one.
  • Modrate – Some hiking required.
  • Hard – Strenuous hiking require, good physical conditions required.
  • Mixed – Some easy access areas and others that require hiking.