That, and also aggressive overfishing.

A large part of traditional Swedish food is based on herring: Sill, pickled herring, is present on all the major holiday meals - Midsummer, Christmas and Easter.

There’s also the infamous Surströmming, fermented herring, of which there has been a shortage for several years now. While a small minority of the population, mostly older northerners, eat Surströmming, the loss of this tradition would be quite sad.