Surströmming is a lightly salted, fermented Baltic Sea herring traditional to Swedish cuisine since at least the 16th century. It is distinct from fried or pickled herring.
Opened can of surströmming in brine
A can of Surströmming, with the top noticeably bulging due to fermented gases being released
Surströmming served on tunnbröd (a Swedish flatbread) with boiled potatoes and vegetables
Oxford Symposium on Food & Cookery, 2010. Held at St Catherine's college, Oxfordshire, UK
Kusaya is a salted, dried and fermented fish that is produced in the Izu Islands, Japan. It has a pungent smell and is similar to the fermented Swedish herring surströmming.
Surströmming
…has one of the most putrid food smells in the world, even stronger than similarly fermented fish dishes such as the Korean hongeo-hoe, the Japanese kusaya or the Icelandic hákarl, making surströmming an acquired taste. At the end of the 1940s, surströmming producers in Sweden lobbied for a royal ordinance…
Freshly grilled kusaya on Hachijō-jima island
Bottled kusaya from Niijima island