fish can be 50-60 years old and well over 10 pounds. Only in the Grenland area in Telemark is detected 23 water with carp. The fish are spread by anglers who want fish stocks only.
problem is that the fish carrying a variety of parasites and viral diseases. Although it is not yet proven in Norway, the carp help to eradicate a number of amphibians.
Recent figures from the Norwegian Institute for Nature Research NINA shows that in 2013 has 11 new fish species have become established – and remanufactured ones – in freshwater throughout Norway.
– This can have a very negative effect on both naturally occurring fish species and biodiversity, says scientist at NINA, Odd Terje Sand Lund.
Goldfish on the run
The reddish-yellow aquarium fish goldfish – “silver crucian carp” – which is only found naturally in the area from Eastern Europe to China, has been detected in water in Aust-Agder, Rogaland and Akershus. Although the fish struggling hard in cold winters, it has in some cases survived and multiplied in both Aust-Agder and Rogaland. Colder temperatures can cause the gold fish distribution in lower Eastern District.
Norwegian salmon browsing the global sushi wave
When the fish landed in Stamnes Tjernet in Akershus following implantation of an aquarium, it turned out that it carried with it a whole new parasite – larvae of a tapeworm – in the gall bladder. Now this tapeworm, which has not previously existed in the country, spread in Norwegian fauna.
Sand Crawls, regnlaue and carp
The small fish species such as sand creeps and regnlaue are both likely to spread to Norwegian rivers because sport fishermen from Europe brought with them as live bait.
Sand Crawls, with thick lips, overbite and a comfy line on each side of the mouth, are found along the river in Vestfold and Nesheim river in West Agder. This species comes from the south, and is found in Denmark and Sweden, as well as from Spain in Europe to northern Asia. It spreads very quickly, and the greatest danger is that it competes for food with trout.
5-7 cm long rainy Lauenstein has spread in Langangselva watercourse in Aust-Agder.
species can quickly spread to other waterways in large populations, and researchers fear that it can outcompete native fish species.
High risk of the bearded Suteren
researchers also warns against Suter a fish of the carp family from Southern and Central Europe. The biggest Suteren reported caught in Norway is 3.9 kg.
The dark brown carp fish with two recognizable barbels of the mouth are now 100 locations in southern Norway, 40 places in Telemark, and various places in Buskerud, Akershus, Hedmark and Oslo. In Østfold fish established in Flesjøvannet and Vansjø. Also this species is spread because it is an attractive sport fish.
Suteren in itself is not a tough fish, but NINA researchers believe it can form large populations that can compete with other natural species. The fish dig in sediments at the bottom of the waters, and cast up mud and nutrients that can reduce water quality. The fish can also cross with bream and spread bacteria and viruses that eradicates various amfibiedyr.
Spreading parasites
One of the poteniselt dangerous alien species is rødgjellet sunfish, which was first discovered in Eine dam in Asker. The fish is probably after released from an aquarium. Sunfish are found in a variety of water in eastern Norway.
fish is heavily infected by parasites of the type monogeneans, which has been fatal to the populations of salamanders, fish and snails in waters where it is exposed.
– It may be that people will be kind to the fish when they are on vacation, so they empty the tank. It is of course unfortunate. We will of course not be spread by rødgjellet sunfish. They multiply rapidly. But I do not think it is able to outperform the Norwegian perch, for it is very robust, says Ingierd.
Another strange fish – which poses no danger – is dvergmallen. The fish came as aquarium fish from America in 1890, and has spread to six lakes and rivers in Asker. The risk of spread is low, and it is not kejnt to be the bearer of troublesome parasites. It’s taken dvergmaller of up to 2 kilos in Nuremburg.
Several species on the doorstep
The 11 new species is only the start.
researchers warn ange several alien fish species are on the doorstep of the Norwegian fauna, including Vimm, saber carp, damkaruss, catfish, small dog fish, sand lightweight and sterling.
These fish have already established themselves in Finland, Sweden or Denmark.
The new species comes on top of another major challenge in the Norwegian fauna, namely that fish species such as minnows and pike are propagated to new waterways. The pike has destroyed trout and trout populations in all known cases where pike have been deployed, including Krøderen.
Need better monitoring
– The most important thing now is to get people to understand how dangerous this is. What we can do is try to prevent the spread of fish species, including by getting people to stop putting out new fish species such as angling. This was banned by Inland Act in 1992, and the new nature and diversity law states yet clearly states that this is illegal, says Sandy Lund.
– When an alien species first has managed to establish itself, then it is usually too late to do anything. It is best to ensure that the spread stops. And in most cases performed exposing the fish of people who do not understand how damaging this can be for biodiversity or for the attractive species already in the river, said Sandy Lund.
Carp has been put into the water in Norway since the 1600s. Many of the waters that are currently used for carp is water that is otherwise not interesting to fish in.
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