For thousands of years, some of the largest whales on Earth, like humpbacks, blue whales, and fin whales, have traveled long distances each year. They move from warm breeding areas in the tropics to cooler, nutrient-rich waters near the poles. These migrations are crucial for their survival and are guided by environmental signals they’ve relied on for generations. But now, climate change is throwing these signals off course, causing big problems for these marine mammals.

Climate Change Scrambling Nature’s Signals

Scientists say that rising temperatures and changing weather patterns are disrupting the natural cues whales and other migratory species depend on. Trisha Atwood, an ecologist from Utah State University, explains that these animals have finely tuned routines based on memories and environmental clues. But climate change is causing shifts in ocean temperatures, currents, and ecosystems, making it harder for whales to find their usual feeding and breeding spots.

In a recent workshop organized by the United Nations Convention on the Conservation of Migratory Species of Wild Animals, over 70 scientists discussed how climate change is impacting species that cross borders in search of food, mates, and suitable habitats. Their findings are alarming: almost no migratory species are unaffected. From whales and dolphins to Arctic shorebirds and elephants, all are feeling the effects of warming and unpredictable weather. These changes threaten their survival by altering habitats, food sources, and migration timings.

Changing Habitats and Food Sources

Climate change is causing habitats to shift or disappear. Asian elephants, for example, are moving to higher ground and closer to human settlements, leading to more conflicts. Shorebirds that breed in the Arctic are arriving too late or too early for insect blooms that their chicks depend on. Marine ecosystems are also suffering. Seagrass beds, vital for many marine animals including sea turtles and dugongs, have shrunk by about 30 percent. These ecosystems store a significant portion of the world’s oceanic carbon and support fisheries and coastlines.

In the oceans, warming waters are forcing marine species into new areas. For instance, juvenile great white sharks are moving north along the U.S. West Coast, which has led to an increase in shark bites on sea otters in Monterey Bay. Whales and dolphins are also at risk. In the Mediterranean, heatwaves could reduce suitable habitat for endangered fin whales by up to 70 percent by mid-century. In the Amazon River, record-high temperatures in 2023 caused the deaths of over 200 river dolphins, as their shallow habitats dried up and temperatures soared above 100 degrees Fahrenheit.

Impacts on Prey and Migration Routes

Many marine mammals rely heavily on specific prey that is shifting due to climate change. The North Atlantic Right whales, critically endangered with fewer than 400 left, are struggling as their prey, tiny copepods, move toward cooler waters. This makes the whales more vulnerable to ship strikes and entanglement in fishing gear while they chase their food. Similarly, North Pacific humpback whales have altered their routes, often entangling in fishing gear as they follow prey shifts caused by changing ocean conditions.

In polar regions, the story is similar. Krill, a key food source for many whales, depend on sea ice for their lifecycle. Rising temperatures and melting ice are disrupting krill blooms, which usually peak in sync with whale migrations. When krill are scarce or arrive earlier, whales face longer, more arduous journeys to find enough food. Some whales are forced to travel greater distances, but sometimes they find little to no food at all. As sea ice melts, krill move to colder waters or disappear, further complicating the whales’ feeding cycles.

All these changes highlight how climate change is upsetting the delicate balance that marine species have relied on for generations. The impact on whales and dolphins isn’t just about individual animals; it affects entire ecosystems and the health of our oceans. Protecting these species requires understanding these shifting patterns and addressing the root causes of climate change to help restore some stability to their migratory routes and habitats.

Inspired by

• https://arstechnica.com/science/2025/10/whale-and-dolphin-migrations-are-being-disrupted-by-climate-change/

Sources

• insideclimatenews.org
• conde.digital
• cnevids.com
• insideclimatenews.org
• cms.int