After having almost disappeared from their former distribution areas for many years, the blue mussels have now returned to Bohuslän.
The researchers have found exceptionally large quantities along the west coast.
– It’s millions upon millions, says Mats Lindegarth, professor of Marine Sciences.
The findings have prompted researchers from the Tjärnö marine laboratory to examine around 80 locations along the coast from Kungsbacka up to Strömstad. Here, mussels are collected so that the team can later compile how many mussels there are in different environments, how they survive – and hopefully provide answers to what led to this year’s large growth.
– We have made an estimate regarding the adult mussels before and concluded that there are 500 million or something like that, says Mats Lindegarth. When there are new recruits, it is 10, 100, maybe 1000 times more.
“Important role in the sea”
There are several theories as to why there are now so many mussels. Mart Lindegarth thinks it may have something to do with the weather situation, which has been special this year.
– It could be currents that have been on at the right time just when the larvae were ready to settle down. I would think the answer is in there somewhere, he says.
Purifies many liters of water per day
Mussels have an important role to play in the sea – not least because each mussel can clean several liters of water per day.
According to the researchers from the Tjärnö marine laboratory, it is very positive news that they can recover after several years of decline.
– It is positive for both mussel farming and nature that they can perform their ecosystem services again, filter and provide food for both birds and starfish, says Mats Lindegarth.