The primary source of food for blue whales is krill, small crustaceans that are found in abundance in the ocean's surface waters. These tiny organisms form massive swarms, and blue whales use their specialized feeding technique called "lunge-feeding" to capture them. During lunge-feeding, a blue whale opens its mouth exceptionally wide and quickly lunges forward, engulfing a large amount of water along with the krill. The water is then expelled through baleen plates, which are specialized structures in the whale's mouth that act as filters. The baleen plates trap the krill while allowing the water to pass through.
The incredible size and feeding habits of blue whales highlight the significance of their role in maintaining the balance of marine ecosystems. As they consume vast quantities of krill, they contribute to nutrient cycling and play a crucial role in supporting the entire food web. However, these remarkable creatures are highly susceptible to human activities such as hunting, climate change, and pollution, making their conservation a critical priority.