A Fishing Phenomenon

…the giant, but catchable, trout of Lake Thingvallavatn

There is an old Icelandic proverb “Fertile is water that runs under lava” that perhaps has its roots in the fertile waters of Lake Thingvallavatn. I have now had two extraordinary fishing experiences on this beautiful lake an hour from Iceland’s capital city Reykjavik and the easiest way to communicate them to you is simply to describe them.

I fished the lake for the first time in 2014. The first evening was cold and windy and tough to catch fish but our guide and host Kristjan managed to catch a 9lbs fish and that was enough to get our attention and made us want to persevere with the fishing the next day. On the second day, we fished the ION Hotel water, the warm bay in the morning where we caught fish but we did not get to grips with it properly only having a few hours there and then in the evening we went to the other beat where the river comes in to the lake. That evening was one of the most memorable fishing nights of my life. We caught something like 25 trout up to around 8 or 9lbs, most on small buzzers drifting with the flow of the river coming in to the lake. The fish were extraordinarily strong, the weather beautiful and the fishing beyond our imagination. We did one final night at the legendary Blackrocks bay where the big fish cruise and we got lucky there too with a 15lbs fish and some other visible takes that made the mind boggle! Although I now realise that I understood far less than I thought, I had seen enough to know that the fishing could be something very special.

Lake Thingvallavatn (pronounced ‘Think – valla – vatn’) is Iceland’s largest lake covering 84 km2. It is 14.5 metres long and 9.5 km wide. Its deepest point is 114 metres, with an average depth of 34 metres. One third of its bottom is covered in vegetation with 150 types of plants and invertebrates even though it is at a constant temperature of 2 – 4 degrees. The reason for this is that 90% of its catchment is from underground. The lake is 12,000 years old and also famous for Þingvellir, the location of the first Icelandic Parliament, which is located at the northern end of Thingvallavatn.   It was formed in 930 and stayed there until 1798.   The area was turned into a National Park in 1930 before being declared a world heritage site in 2004. Nearby is Silfra, a rift that is part of the divergent tectonic boundary between the North American and Eurasian plates. This is a famous freshwater diving area with the most famous being “Silfra Cathedral” which is 100 meters long. The water is so clear you can see from end to end. Lake Thingvallavatn’s biggest brown trout is 36lbs caught in 2014 from the bank on a fly rod.

The brown trout, which originate from Britain genetically, became isolated after the last Ice Age when access to the sea was closed through volcanic activity. As has so often been the case, the trout population was decimated by the building of a dam and, in this case, its failure which wiped out the best spawning area for the trout on the Upper Sog. With the number of spawning pairs almost down to single figures, the eggs of just a few fish were taken from the Öxara river, near Þingvellir, and nurtured about 25 years ago and now the wild stock is bouncing back to the point of a conservation and fly fishing phenomena.

There were four of us; we all arrived as Lake Thingvallavatn virgins except myself. Our guides were the new leaseholders of the ION Hotel water, Johann or Joey Hafnfjörð of Vididalsa fame. Joey has been a guide and more recently Head Guide, and now part owner of the company that runs the Vididalsa, for over 20 years. He and the Vididalsa are synonymous and he is a bit of a legend in Iceland, everyone knows him and everyone likes him. Our other guide was Bjarni Jónsson. Bjarni was quiet and considered and great fun, a really lovely man and a pleasure to spend time with. I later learned that he was a dental technician for another Icelandic fishing legend ‘Toti the Dentist’ who is closing in or, more likely, has now caught over 20,000 salmon. What I enjoyed most about them both was their enjoyment of being out with us despite some often appalling weather. They were both great company throughout our time.

The first evening was spent looking round the lake and understanding how it worked and how the dam system was now set up. We did a little fishing and caught a couple of fish. The wind was getting up and it was beginning to rain. We retired to our base for the three days, the Ion Hotel tucked away in the south of the lake under the James Bond-esque setting of the steaming Nesjavallavirkjun Power Station which takes advantage of natural elements to supply Reykjavik with hot water. The next morning, with the weather turned from unpleasant to horrendous rain and gales, we set off to fish what is known as Beat 2 of the Ion Hotel ‘beats’, without question the best beats on the lake. The reason for Beat 2’s extraordinary success is the small Olfusvatnsá river which brings warm water in to the lake which attracts the trout. It is not that it is a source of food, no amount of insect life could make these fish as big as they are or sustain them. What is actually taking place is that the trout are using the warm water to increase their metabolism to digest what they do eat which is copious and seemingly endless amounts of 6 to 8 inch char as we were to witness with many fish caught regurgitating semi-digested char. The char often looked like skinned fish with perfect pinky-orange flesh. We did take one or two for the kitchen and with the exception of char and a few black stones, nothing else at all was found in their stomachs.

Of course, as we began fishing we did not know this so our approach to these fish was as if we were fishing to potentially feeding trout. Gales and rain are hardly the best conditions for this. We would see the fish breaching off the river mouth and assumed this was some kind of feeding activity but again, with time, we realised that this was more the activity of a salmon frolicking than feeding trout. We fished mostly streamers and large nymphs for the morning and did OK catching about 10 fish up to about 5 or 6 lbs but it was not until the end of the morning session that the penny began to drop. We started fishing the outflow as one would a river, presenting nymphs as one does river fishing and streamers or lures as one would salmon fishing. The last fish of the morning was caught closer to the bank than any others. It was certainly 8lbs but possibly 10lbs. I say possibly because we insisted that our wonderful guides Joey and Bjarni get weigh nets from Reykjavik the next morning and we soon concluded that our estimates were likely all under rather than over reality.

That afternoon, our understanding of how to fish increased substantially. We were able to fish both Ion Hotel beats and this gave us more time and space to work together to understand the fish and the fishing. At Beat 2, the river had begun to colour and rise with the ever-present wind and rain and rather than spoil our fishing, we realised it was improving it because there was more warm water coming in to the lake. It was coloured and therefore the fish felt more secure in coming in closer and were less spooked by our presence. We spent a great deal of the afternoon session upstream nymphing with great success. At Beat 1, the learning curve was just beginning. Beat 1’s key feature was a hot spring coming into the lake, and we later realised part of it was seeping into the bay in other spots along the volcanic beach which was also drawing the fish in close – by close I mean two feet from the bank. That afternoon however, our greatest lesson was that when one hooks a bigger fish, the impressive fight which we were getting from the 5lbs to 8lbs fish turned into the sternest test our trout tackle would likely ever see. The Icelanders will use 10kg leaders but we felt that a balance needed to be struck between strength of leader and presentation and fish sensitivity to seeing the leaders especially in the very clear water using nymphs. We realised we needed to sharpen up on our tackle set up when we were broken by our first monster that afternoon.

Still the rain poured and the wind blew harder but the following morning we were now truly gripped by the potential for extraordinary fishing and headed out again. We were still in ‘trout-fishing mode’ trying to get an angle on the fishing for a downstream presentation where possible and this served us well. At Beat 1 or ‘the bay’ as we called it, we discovered hot spots for where the fish would be (later realizing the reason for them) and we were able to catch some beautiful fish including our first two double-figure fish at 12lbs and 10lbs but when we returned to the hotel, it was clear that things had ramped up a notch at ‘ the river’ too with four double-figure fish landed two of 12lbs and two of 11lbs. One monster had been lost at the net on a nymph but over 20 fish had been landed. Suddenly we had caught 30 fish for the morning. The wind and the rain continued that afternoon making the bay tricky, but the river went from strength to strength with another 20+ fish caught with a 17lbs fish and a 13lbs fat beauty landed. By the end of the evening, the wind was too strong, the waves too big and we finally had to retire.

The morning brought calm and the lake was like glass especially at the bay. The river was clearing quickly but continued to produce fish with streamers from time to time, but we found that a hung nymph or pair of nymphs was very effective and interesting fishing. At the bay there was a hatch of caddis and although we still believed the fish are not feeding for survival, they were taking the caddis off the top and thus we are able to catch wild 8lbs brown trout on dry flies. That day, with the calm we also learned that stealth at the bay was paramount. We sat right on the edge of the water to remove any chance of breaking the skyline and waited for the fish to settle and come close and rise. The same happened in the afternoon and the hanging nymph was also very effective.

On our last morning, the bay continued to produce dry-fly opportunities and a 12 – 14lbs fish on a caddis was hooked but a 4lbs fish took the hanging nymph and of course both fish were lost. At the river, more big fish were landed up to 14lbs and more lost on the nymph with tackle just not strong enough to cope. Reels with 300 metres of backing were almost spooled but a fish dragging all this line can break strong leaders.

When the dust had settled and we headed home, the magnitude of what we had experienced began to sink in. We had caught 165 of probably the most beautiful, strong brown trout in the world, certainly that we had ever seen. Most were over 5lbs, 16 were over 10lbs and the biggest was 17lbs. We had used 5, 7 and 8 weight rods, floating lines almost exclusively and flies ranging from 4 inches ‘snakes’ to size 18 tiny bead-head nymphs and dry flies. We had employed almost every tactic we knew and evolved our technique and tackle set up as we learned. Although we fished the same water, the fishing seemed to be ever-changing. If we were to return, we would be much better prepared, especially in the backing and leader department, which might have saved numerous disappointments.

So, the lake has produced two extraordinary fishing experiences and my understanding has increased threefold since I first wet a line on Thingvallavatn. What are my reflections? There will be the extreme purists for whom this may not appeal. The flyfishers who only want to fish for feeding trout, trying to match the hatch. For them, I can see that fishing for these trout may just take the edge of it for them. There will also be the devoted river fishers (trout or salmon fishers) that have to have the moving water for the fishing to be perfect for them so again, what we did for the three days may not be perfect for them either. The greatest weakness is that the spots we were fishing are so unique and draw the fish so effectively, they are far and away the best places on the lake and therefore offer not as much variety of circumstance as changing beats on a river every day or each lunchtime. But the weather almost does that for you and, as they say in Iceland “if you don’t like the weather, wait a minute” the chances of having the same conditions for three days are slim. I suppose the fishing could be most likened to Rio Grande sea trout fishing with the fish comparable in size and probably prettier and certainly stronger. The weather did change constantly for us and thus each time to went to the water, the challenge was different, made more so by switching beats. We learned something every time we went to the water and we marveled at the strength and beauty of the fish each time we returned. Three days is probably the right amount of time and in that time, while I can understand the purists point, I defy the majority not to love it and be entirely enthralled by their time at this magical, beautiful place.

The last word must go to the trout themselves. These fish were on the point of extinction and are now thriving and huge credit must go to those that made the effort to campaign with the Icelandic Government to restore them. They are quite simply stunning. All of us took time with each fish to simply look at it and admire its perfection. In all reality, they are likely a ferox trout (Salmo ferox); a lake brown trout, feeding at night on char, using the best conditions to digest, living for up to16 years compared to an average brown trout (Salmo trutta) living up to six years. On the last day a 14lbs or 84cms hen fish was caught with two tags in her; one from 2009 and one from 2014. In both cases she was caught by net in the little Olfusvatnsá river in October when the fish are spawning by the scientist Jóhannes Sturlaugsson, who works on the lake. In 2009 she weighed 3kg or 6.6lbs and was 71cms long. She has been seen spawning in the Olfusvatnsá river every year since thus making a huge contribution to the return of this unique strain of Lake Thingvallavatn trout. It was the first time she had been caught on rod. This was an extraordinary experience and great thanks to the Ion Hotel and the guide team for looking after us so well.

Comments 6

  1. edward dudnyk

    I ‘m interested in the iceland lake trip and or the best sea run browns fishing in a river. thankn you. Ed Dudnyk- 561-776-8118

  2. Bob G

    I am also interested in seeing the Northern Lights. Is this a good time of year? From the above blog it seems to be cloudy and rainy a lot mid April

    1. Post

      To see the northern lights you need to go to Iceland November to Feb or go to Alta, northern Norway October – early March, both times there is not alot of fishing to be done. Where are you located and I can have someone make contact to help make a plan.

  3. Dylan Amis

    Hi Tarquin,

    I’m soon to be travelling to Iceland to fish this most awesome lake. Could you perhaps recommend the leaders i should be looking for.

    Kind regards,

    1. Post

      Hi Dylan, where are you headed? Do you know which part of the lake? I ask because that will determine what flies you are using etc. Choice of leader is one of the big challenges – it starts with what weight rod you use and its action (soft etc), then what size hook you have, getting the balance between all these is the challenge mixed with the cocktail of large, fast running fish towing many metres of backing behind them. If using streamers, I would not worry, 12 or 15lbs Maxima or flourocarbon would be fine, the challenge comes when fishing nymphs, we tried to go as light as we could for presentation but we still needed some beef so we ended up with 8 to 10lbs Froghair. Hope this helps.

  4. Art Marks

    Thanks for sharing a very interesting fishing experience. I admire how you adjusted your technique.

    My wife and I attempted some fly fishing in Iceland a few years ago, but with much more limited success.

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