Food scarcity: The food that whales eat, such as krill and plankton, is not always evenly distributed throughout the ocean. In the summer, when the water is warmer, food is more abundant in the polar regions. However, as the water cools in the fall and winter, food becomes scarce in these regions. This forces whales to migrate to warmer waters where food is more plentiful.
Mating and breeding: Many species of whales migrate to specific breeding grounds to mate and give birth. These breeding grounds are often located in warmer waters, which provide a safe and comfortable environment for the calves.
Water temperature: Some species of whales are very sensitive to water temperature. They prefer to live in water that is within a certain temperature range. When the water temperature in their summer feeding grounds becomes too cold, they will migrate to warmer waters.
Hunting: Some species of whales, such as the humpback whale, have been hunted nearly to extinction. This has led to a decrease in the number of whales in the summer feeding grounds.
Pollution: Pollution can also have a negative impact on the health of whales. When whales ingest pollutants, it can cause a variety of health problems, including reproductive problems, cancer, and immune system disorders. Pollution can also damage the environment that whales live in, making it more difficult for them to find food and survive.