Cetacean Migration

A look at the paths of whale travel with Yacquie Montecinos, Yacquie Montecinos, Marine Biodiversity Conservation Manager at WWF-Chile

Whale Migration Routes in the Eastern Pacific

Climate change, maritime traffic, underwater noise, and fishing activities are affecting whales at many points along their migratory routes — routes that are critical to their survival.

1. BERING STRAIT

A major migratory corridor between the Pacific and Arctic for gray whales, bowhead whales, and belugas. These whales migrate across thousands of kilometers to reach rich feeding areas in the north. The increase in industrial and military activity in this region, combined with climate change, significantly threatens whale populations and the resilience of this corridor.

2. FROM HAWAIʻI TO ALASKA

The Hawaiian Islands are the only breeding ground for North Pacific humpback whales. Each year, they travel over 4,800 km to feed in the nutrient-rich waters of Southeast Alaska. They depend on acoustic communication to navigate and coordinate behaviors. Disruption of this communication due to marine noise can increase stress levels and reduce survival rates.

3. WEST COAST OF NORTH AMERICA

This corridor is used by a diversity of whale species, including gray, blue, and fin whales. Marine protected areas and sanctuaries along this corridor safeguard feeding and nursing grounds. However, threats such as ship strikes and entanglement in fishing gear continue to pose significant risks to these whales.

4. EASTERN TROPICAL PACIFIC

Whale populations from both hemispheres use this area as a migratory transition zone. Conservation strategies have been coordinated through the Eastern Tropical Pacific Marine Corridor (CMAR), a regional cooperation initiative between Costa Rica, Ecuador, Colombia, and Panama, to protect marine biodiversity.

5. PERU

The waters of northern Peru form a critical migratory area for humpback whales. These whales come from Antarctica to breed and give birth along the coasts of Peru and Ecuador. Coastal development, pollution, and industrial fishing pressure are growing threats to their habitat.

6. SOUTHERN CHILE

Blue whales and southern right whales travel along Chile's Pacific coast, between Patagonia and Antarctica. These areas are vital for feeding and reproduction, especially the Corcovado Gulf and adjacent fjords, which host one of the most important feeding grounds for blue whales in the Southern Hemisphere.

7. ANTARCTIC PENINSULA

This is a crucial feeding zone for several whale species such as humpback, minke, and fin whales. The impacts of climate change, including melting ice and changing prey availability, threaten whale foraging efficiency. Coordinated action is essential to manage Antarctic marine ecosystems and reduce human impact.

What have we learned about whales from their migration patterns? 

We have learned a lot. We have not only managed to understand their migratory patterns, but also understand that, for example, humpback whales migrate closer to the coastline than blue whales, even more so when it’s a mother-calf pair. On a smaller scale, we now understand how they use their feeding ground and that they move in different ways depending on what area they are going to, and in terms of looking for food, feeding directly, or even transiting within the feeding ground.

How is this information beneficial from a conservation perspective? 

This information is key in order to promote effective conservation actions, because with it, we have now been able to identify high-risk areas of collisions with shipping routes, and therefore areas that need the implementation of mitigation measures. We’ve also been able to identify critical habitats (like feeding grounds) that need designated conservation measures such as marine protected areas. For a few species, we’ve also learned that they are resident in specific regions and that their migrations are just from one side of an island to another, like blue whales in Sri Lanka.

How do whales know how to navigate the big blue? How can we apply these techniques to human life?  

This is one of the fascinating whale mysteries. There are a few theories about this, related to their capacity to follow magnetic lines as they have magnetite in their brains. Another is related to the capacity to follow sunlight and the stars. There’s also speculation that they follow the level of salinity and water temperature, meaning they follow currents. For humpback whales specifically, some scientists think that they use other whales' singing as a signal that they are getting closer to critical habitats, like reproductive grounds, of other whales. And the last one, which makes total sense, is that whales learn to navigate from their mothers and elders, or more experienced travelers. I really like the idea that this is a capacity they develop during their early ages, thanks to the knowledge transferred from the adults in their population.

Where Did You Come From, Where Did You Go: The Journeys of endangered whale populations that call the Pacific Ocean home

1. Blue Whale

The largest animal on Earth. In the southern tropical Pacific, there’s a fascinating population that does not take the traditional migratory route, which is usually from the poles to more central areas. This particular blue whale population found its feeding ground in southern Chile, specifically in the Gulf of Corcovado. Scientific evidence has shown that they do not go all the way down to Antarctica's water to feed. So they spend their time in the Gulf of Corcovado between December and June, feeding, then migrate all the way up to the warm waters around the Galápagos Islands. 

But this population is also very unique because of its vocalization, or song, which is heard only in the Gulf of Corcovado with no similar records of it anywhere else in the world. So if you want to hear this song, you have to come down to Chile. During their feeding season, this population moves through the Fiordland system since the Gulf of Corcovado is located in the north of the Patagonia region and surrounded by channels and fiords with fresh water entering the system. And of course, we don't know where they go to give birth to their calves. 

2. Humpback Whale

This is the species that takes the longest migration within the Southern Tropical Pacific, from Antarctica up to Central America, navigating around 4,900 miles just one way. Humpbacks are one of the few whale species that are managing the recovery of their population size. And because more individuals are using the Eastern Pacific blue corridor, we now understand that interaction with human activities is still a massive threat to them.

3. Southern Right Whale 

This is the most endangered species in the Southeast Pacific blue corridor, categorized as critically endangered, with no more than 33 individuals along the coast of Peru and Chile, according to the last census. But good news: Last year a scientific paper reported a couple of southern right whales sighted in Ecuador.

4. Fin Whale

These are all a mystery — nobody knows where they breed, and it was just a few years ago that it was possible to identify a feeding ground in Chile. There is a nursery ground that has been identified in the Gulf of California… but that is all the information that we have.