The fish ladder

The Dammå fish ladder is a mere five-minute drive upstream from the camp. The fish ladder is emptied twice a day in the summertime and provides a great way to observe the trout up close. The fish handler picks out each fish and weighs, measures, determines its gender, before it is released on the other side of the ladder. This takes place at 8am and 4pm every day, starting June 10th.

The fish ladder started operating in 1950, around the same time it was decided that a powerplant should be built in the area. The ladder has been emptied manually ever since and all the statistics has been recorded, which means that there are records of every single fish that has passed through there for the past 70+ years. This makes Dammån quite unique.

Come visit the fish ladder today and perhaps combine it with lunch or dinner in our restaurant!

Fishladder statistics 2021

Here you will find all the statistics over the years.

Watch a clip of the ladder being emptied

 

History

In the late 1930’s, a decision was made to start controlling the water levels of Lake Storsjön. This rose the question of the potential damage it might cause the Dammå trout population. Data was already recorded whenever fish was caught, but the scientists needed more data and decided to study the large trout’s migration patterns, gender distribution, growth etc. This data could only be collected by examining each fish. Therefore, barriers were built in river Dammån to be able to map out the Storsjö trout’s migration. The barrier spanned across the entire river and had a cage placed in the middle. The cage was emptied four times per day and is still being manually emptied to this day. The number of barriers along the river and the streams branching off it, was gradually increased to six, to gain even more knowledge of the migration patterns. The study included other aspects too, for example, to assess the size of the Northern pike population, which could pose a potential threat to the trout. However, the Northern pike is predominantly a cannibal. Of the 17 pikes that were caught as part of the project, none of them contained trout, however, there were traces of pike smolt and roach. The pike tends to inhabit areas where the trout normally does not thrive, although it is still not a guarantee that the pike is harmless to the trout population.

The study also showed signs of other fish in the waters, such as whitefish, perch, and grayling, albeit in small numbers. As for predators, the merganser is quite common and preys on smolt. At one point, one of the birds was shot and in its belly they found as many as 20 ID tags from young trout. Additional birds have been shot since, with similar stomach content. (The ID tags were used during the 1950’s but were discontinued later, since they were prone to injure the fish and cause inflammation in their dorsal fin.)

Another predator is the mink, an invasive species. Around the time of World War II, the mink was introduced to Sweden for farming, but a large number escaped the farms and into the wild. The population has thrived and poses a serious threat to the fish population. Many small streams have been completely emptied of fish by the minks. They make the most damage in the wintertime, when the

water levels are low, and they can more easily get to the smolt. There is now an annual hunt for mink in place during August and September, to manage the population.