청어, or herring, is a small, oily fish commonly found in the North Atlantic and North Pacific oceans. It is known for its silver skin and distinctive flavor, making it a popular choice in various cuisines. 청어 is often consumed pickled, smoked, or fried, and is rich in omega-3 fatty acids, which are beneficial for heart health. In addition to its culinary uses, 청어 plays a significant role in the ecosystem as a forage fish, serving as a food source for larger predators like seabirds and marine mammals. Its population dynamics are closely monitored due to its importance in both commercial fishing and marine biodiversity.