Yves here. While I’m retaining the Yale Climate Connections title, it’s worth noting that many outlets misuse and diminish the term “hero.” A true hero takes significant risks, even facing death, to assist others without any desire for personal gain. Nonetheless, whales are far more impactful environmental stewards than most realize.
By Daisy Simmons, an assistant editor with Yale Climate Connections. Originally published at Yale Climate Connections
Who hasn’t experienced awe at the sight of a whale bursting through the ocean’s surface, bridging the sea and sky in a breathtaking, mammalian, and altogether alien display? It offers a fleeting glimpse into an entirely different realm of existence.
Whales, among the largest and most magnificent beings on our planet, are recognized by scientists and environmental advocates as climate heroes. Throughout their lives, they release copious amounts of waste into the ocean, rich in nitrogen, phosphorus, and other nutrients essential for phytoplankton growth. This microscopic life not only produces significant oxygen for our atmosphere but also absorbs climate-warming carbon dioxide through the process of photosynthesis.
Moreover, the massive amounts of carbon stored in their bodies remain out of the atmosphere for their entire lifespan, along with centuries after their death. However, as climate change warms the oceans, these vital creatures increasingly require protection from habitat alterations that threaten their food sources and overall survival.
Chris Johnson, a marine scientist and conservation strategist leading the World Wildlife Fund Protecting Whales & Dolphins Initiative based in Melbourne, Australia, shared insights about his work with whales, their climate-protecting roles, and strategies to ensure their safety in a comprehensive interview with Yale Climate Connections.
This interview has been lightly edited and condensed.
Yale Climate Connections: What drew you to whales and this line of work? Did a specific moment or realization inspire your focus on them?
Chris Johnson: I consider myself somewhat of an “accidental scientist.” Growing up in New England, the sea was deeply rooted in the culture, yet I never aspired to be a marine biologist. My interests were more creative, leading me to study music in college before moving into technology in the late 1990s.
The pivotal moment came in 1998 when I met Dr. Roger Payne. Roger played a significant role in helping the world recognize that whales are intelligent, social beings with intricate lives, and their conservation is critical. He was a visionary, seeking innovative solutions to address the major threats facing our oceans. That encounter redirected my life and career.
YCC: Your organization describes whales as “wildlife climate heroes.” What are the primary ways they combat climate change?
Johnson: Whales contribute significantly to ocean health and productivity in several key ways.
First, there’s nutrient recycling, often referred to as the “whale pump.” Whales feed at depth or in productive areas, releasing nutrient-rich urine and fecal plumes nearer the surface. These plumes, rich in nitrogen, phosphorus, iron, and other elements, support phytoplankton growth—the microscopic organisms that form the foundation of marine food webs, produce a large part of our atmosphere’s oxygen, and sequester carbon dioxide through photosynthesis.
Whales also transport nutrients across the ocean during their extensive migrations. Many species travel between high-latitude feeding grounds and breeding areas in lower latitudes, linking ecosystems that may be thousands of kilometers apart. This is often described as the “great whale conveyor belt.”
Additionally, whales accumulate carbon within their bodies throughout their lives. Upon death, when their carcasses sink to the deep seafloor—known as a whale fall—some of that carbon stays sequestered from the atmosphere for centuries. Furthermore, the carcass serves as a food source and habitat for various deep-sea organisms and microbes. While whale falls are ecologically important, their contribution to global carbon storage remains modest and uncertain.
YCC: Are there specific whale species you would highlight due to their critical ecological roles?
Johnson: I want to focus on the great whales, though the science is still evolving. Blue and fin whales are noteworthy because of their immense size: blue whales are the largest animals to have ever lived, with fin whales close behind. Their feeding habits and nutrient recycling can significantly affect productivity across expansive regions.
Sperm whales, the largest of the toothed whales, are remarkable deep divers. They spend much of their lives foraging offshore for deep-water squid, thus transferring nutrients from the deep ocean to the surface. Their world is also defined by sound, making them particularly vulnerable to underwater noise pollution. Their intricate social structures are reshaping our understanding of culture in marine environments.
Humpback whales represent a conservation success story. Certain populations have significantly rebounded since the end of commercial whaling. However, in the Southern Hemisphere, climate modeling indicates that climate-induced changes to Antarctic krill may impose renewed pressure on humpback populations and potentially reverse some recovery gains by 2050.
A cautionary tale is the critically endangered North Atlantic right whale. As ocean warming alters the distribution of its prey in the Gulf of Maine, these whales have moved into riskier areas, facing increased dangers from ship strikes and fishing gear entanglements in the St. Lawrence River. Climate change is intensifying their exposure to pre-existing threats.
YCC: What are the primary challenges whales currently face?
Johnson: Climate change is reshaping ocean conditions, affecting whale behavior and movement patterns.
For many species, the most pressing concerns involve their prey. As waters warm, currents shift, sea ice diminishes, and marine heatwaves intensify, prey availability may become erratic. Whales may find themselves traveling longer distances, spending more time searching for food, or altering migration timings. This is crucial for baleen whales, which must accumulate substantial energy reserves during limited feeding seasons. A female’s ability to reproduce is closely linked to her feeding success.
One of the most significant global threats to whales, dolphins, and porpoises is entanglement in fishing gear. An estimated 300,000 cetaceans are killed each year due to fisheries bycatch, but this figure is over 20 years old. Assessing the true scale of this issue is challenging due to limited monitoring and reporting in many fisheries.
Other ongoing pressures persist. Ship strikes, underwater noise, chemical and plastic pollution, poorly conceived offshore development, and, in certain regions, commercial whaling continue to impact whale populations.
I am particularly worried about the cumulative impact of these pressures. A whale might cope with a single stressor, but the combination of reduced prey, increased noise, rising entanglement risks, and vessel traffic can slowly diminish its overall health and resilience.
YCC: What conservation efforts or solutions are most critical right now, and how can individuals contribute?
Johnson: Effective whale conservation must operate at the scale of their lives and migration patterns. We need to approach ocean management as a cohesive system and work to enhance its ecological connectivity.
Whales traverse thousands of kilometers across vital habitats. We refer to these interconnected habitats and migratory routes as “blue corridors.” These pathways often span national waters and international seas, frequently intersecting with escalating impacts from shipping, fishing, pollution, and climate change.
Much of our effort involves mapping these essential habitats and migration routes so that governments, policymakers, and industries can prioritize them for improved ocean management and protection. We established BlueCorridors.org to facilitate easier access to this information and inspire action.
Several potential solutions are already available. Reducing ship speeds in high-risk areas can mitigate the chances and severity of vessel strikes. Modifying fishing gear and practices—like “on-demand” or ropeless systems—can help lessen entanglement risks. Creating well-designed protected areas can safeguard critical habitats, while noise reduction measures in shipping can aid whales in communicating, navigating, and foraging. Robust climate action is indispensable; transitioning to a low-carbon future is crucial for preserving the prey and habitats on which whales rely.
We know that whale populations can recover if we prioritize this on a global scale. The worldwide moratorium on commercial whaling has allowed some populations, including humpback whales, to bounce back, but much remains to be accomplished.
On a personal level, individuals can support effective ocean and climate policies, opt for sustainable seafood, minimize plastic usage, and inquire about fishing practices’ impacts on marine wildlife. They can also back communities and organizations focused on whale-safe solutions, work to reduce pollution, and adhere to responsible whale-watching practices. These actions become especially powerful when they help build broader political and market support for change.
YCC: After all your time studying and working to safeguard whales, what do you hope people will come to understand about them?
Johnson: I hope people recognize that whales serve as vital indicators of ocean health and are inspiring symbols of the marvels of life on Earth.
Do whales need us? They have existed long before us and thrived well prior to the onset of commercial whaling and other human challenges that have transformed their oceanic environment into a complex obstacle course. Today, they require our stewardship to manage our impact effectively.
Do we need whales? Undoubtedly. We rely on a healthy, resilient ocean fostered by whales and other marine organisms and ecological processes. A world with flourishing whales is not only more vibrant but also healthier for future generations. By protecting whales and their blue corridors, we safeguard something fundamental—something beyond ourselves.
