What would happen to the fish swimming in lakes below freezing.?

Fish swimming in lakes below freezing can survive due to a combination of physiological adaptations and the unique properties of water. As the surface water cools and freezes, it forms ice while the denser, warmer water remains beneath, creating a habitat where fish can thrive. Many species produce antifreeze proteins to prevent ice formation in their bodies, allowing them to continue swimming and feeding in cold temperatures. Additionally, their metabolic rates decrease, reducing their need for oxygen and food during the winter months.