The mysterious freshwater pearl mussel

The Dokka Delta Wetland Centre focused on the freshwater pearl mussel, and the species’ importance as an environmental indicator, for some time. As nature guides at the Wetland Centre, we often experience that visitors find this species especially interesting. At the Wetland Centre, we aim to highlight this species as an example of a threatened species, and how we can achieve a sustainable balance so that we can utilise nature, now and in the future, whilst avoiding species loss.


The freshwater pearl mussel is a fascinating and exciting species. Just the fact that it can live to over 250 years old means that it is unique in Norwegian fauna. It also has a remarkable, and sometimes secretive, lifecycle – with many life stages that make it especially suited to act as an indicator of excellent water quality. The mussel’s dependence on specific conditions, for example access to suitable fish hosts, paints an important picture of the relationships and dependencies that exist in nature, and how important it is that we do not eradicate any of the species that are present.


Sustainability is an important principle in the appropriate conservation of natural resources and species. The freshwater pearl mussel, and its sensitivity to adverse changes in its environment, is a species that is often used when considering examples of insufficient and inappropriate sustainable conservation. Our field days in the nature around Fallselva river in Søndre Land educate the students about this red-listed species and the principle of sustainability.


Course delivery:

The course is mostly focused on the freshwater pearl mussel, but also considers the wider aquatic environment - including other small aquatic animals, and the important factors that affect the water quality. The mussel’s biology is highlighted such that the students see the relationship between human disturbance and the dramatic effects that this can have for a specific species in one or several stages of its life cycle. During this course that takes place next to the Fallsevla river, the idea is emphasized that we can still utilise and enjoy the great outdoors, without negatively affecting the freshwater pearl mussel.


The teaching involves the use of practical exercises and activities where the students get to experience close contact with the mussels and the river environment. The students will be able to get close to this species in its home environment – with the chance to see the mussels in the river substrate using aqua scopes, as well as at the wetland centre where we have special permission to remove and display examples of these mussels. The students will get the chance to share their own stories and questions, and hopefully develop a sense of wonder for this species as well as a desire to learn more. The students will also receive a task in preparation for the field-day - to speak to their parents, grandparents and other family members to learn any of any experiences they might have had with this species, that was previously harvested in large numbers to find pearls.


In addition, we investigate other indicators that the river is a healthy ecosystem by: netting for aquatic insects and determine the species caught, observing the birds and birdlife around the river, fishing for small fish with homemade fishing rods etc.

We welcome the teachers to engage with the design of the course, to create the best possible field-session that suits the needs of individual classes.