Fermented fish is a traditional food preservation method that involves the anaerobic fermentation of fish. This process enhances the fish's flavor and extends its shelf life by using salt and beneficial bacteria. Common examples include surströmming from Sweden and feskekörka from Norway. The fermentation process breaks down proteins into amino acids, creating a unique taste and aroma. Fermented fish is rich in nutrients, including omega-3 fatty acids, and is often used in various cuisines around the world. It can be enjoyed on its own or as an ingredient in dishes, contributing to both flavor and nutrition.