It was the summer of 2013 when the migratory mussel was discovered in the East Gothic lakes Roxen and Glan. An inventory showed that the mussel spread to Roxen via the Göta Canal. In August 2019, a re-inventory of the canal system against Vättern and Vänern was carried out with the aim of documenting.

According to the inventory, only mussel larvae were found on the same premises as in 2013. This is about the canal furrow downstream of the lock in Norsholm, in Motala Ström at Kimstad and in Motala Ström in Norrköping. According to the Vätternvårdsförbundet, the results indicate that no new large stocks have been established west of Roxen, but at the same time larval inventory is not a completely safe method for documenting mussel occurrence.

According to the inventory, the density was highest in August at the premises in Norrköping. There, 80 larvae per liter were measured. Adult migratory mussels can be spread by humans within and between water systems on objects such as boats and aquatic plants. Live larvae are spread mainly in water that is being moved.

According to the report, boats, fishing gear and other equipment should be cleaned, emptied and dried before moving to a new water. It to reduce the spread of the water mussel.

If you find a mussel you should report it in the species portal or notify your county administrative board or water conservation association.

In the clip below you will find out more about the mussels when they were first found in 2013:

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