Climate & Sustainability
Q&A with Malin Pinsky: On ocean warming, moving fish, and why it all matters
Marine ecologist Malin Pinsky explains how record-breaking ocean warming is driving unprecedented shifts in marine life, disrupting ecosystems and economies, and challenging both science and policy to keep pace with rapid environmental change.
Associate Professor of Ecology and Evolutionary Biology Malin Pinsky. (Photo by Nick Romanenko)
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Key takeaways
- Climate-driven ocean warming is triggering mass marine migrations, with fish and marine mammals shifting poleward or deeper in response to rising temperatures and oxygen loss.
- These shifts are upending global fisheries and ecosystems, increasing extinction risks, driving economic disruptions, and sparking geopolitical tensions over access to marine resources.
- Pinsky urges action across disciplines and communities, emphasizing sustainable seafood choices, civic engagement, and a recognition that ocean health is fundamental to life on Earth.
Malin Pinsky is an associate professor of ecology and evolutionary biology at the University of California, Santa Cruz, where he leads the Global Change Research Group. A world-renowned marine ecologist, Pinsky studies how climate change is reshaping ocean ecosystems, from the movement of fish populations to the growing risk of marine extinctions.
His research combines fieldwork, large-scale data analysis, and policy-relevant modeling to understand how marine life is adapting—or failing to adapt—to a rapidly warming planet. Pinsky’s work has informed fisheries management and climate adaptation strategies in the U.S. and globally, and he collaborates with scientists across disciplines and continents to track the shifting rhythms of life beneath the waves.
In this conversation, Pinsky unpacks what recent ocean heat records mean for marine life and human societies, why fish are on the move, and how climate change is redrawing the map of global fisheries. He also reflects on the political obstacles to scientific progress, the cascading effects of oxygen loss in the ocean, and what individuals can do to help protect the planet’s largest—and most underappreciated—climate buffer.
You can hear more from Pinsky on this topic on this episode of The Great Simplification podcast.
Q: 2024 was a record-breaking year for ocean temperatures. Just how unprecedented are these changes?
Malin Pinsky: 2024 wasn’t just the warmest year on record for the ocean—it may have been the warmest in the last 100,000 years. That’s going back before behaviorally modern humans had fully spread across the planet. We’re seeing ocean temperatures that resemble the Eemian period 120,000 years ago, or even the mid-Pliocene 4 million years ago—when giant armadillos roamed North America and beech trees grew in Antarctica. We’ve also recorded 104 countries hitting their highest-ever temperatures this year. CO₂ levels are now at 420 parts per million, the highest in at least 2 million years.
Q: Why is the ocean warming so fast, and what’s the significance of that?
Pinsky: About 90 percent of the excess heat from global warming ends up in the ocean. That heat is measured in zettajoules—a thousand million million million joules. To give you a sense of scale, imagine lifting a trillion apples three feet into the air, then multiply that by a billion. Without the ocean absorbing all that heat, we’d be very crispy toast. But this warming comes at a cost, particularly to marine life and the humans who depend on it.
Q: How is marine life responding to these changes?
Pinsky: Fish are on the move—northward, southward, and deeper into the water column. This is the largest movement of animal life in recorded history, and almost certainly the largest in the last 10,000 years. Since the 1970s in the U.S. Northeast alone, blueback herring have shifted 260 miles north, black sea bass 190 miles, and American lobster 150 miles. These shifts affect everything: food webs, international supply chains, even geopolitics.
Q: Why are these shifts happening? Is it just about temperature?
Pinsky: It’s not just heat. Oxygen plays a major role. Warmer water holds less oxygen, and ocean layers are becoming more stratified, like a lid trapping warmer, less oxygenated water near the surface. Fish need to balance oxygen, food, and temperature to survive and reproduce. We’ve found that low-oxygen conditions help explain why black sea bass are moving north. Cold-water fish are also struggling to pump oxygen through their bodies at their range edges.
Q: What are the broader consequences for ecosystems and people?
Pinsky: Species are “walking the plank” toward the ends of the Earth. At the poles, where species have nowhere else to go, extinction risks are highest—up to half of all polar marine species could be lost. In the tropics, we could see 25 percent of species disappear locally. This reshuffling scrambles ecosystems like a snow globe, disrupts fisheries, and drives conflict over who gets to catch what. We’ve even seen a clam processing plant move from Virginia to Massachusetts. The American lobster market tanked after a marine heatwave shifted the season. Conflict is already emerging between states and nations over fish.
Q: What about marine mammals and coral reefs?
Pinsky: Corals are in serious trouble. Australia is investing billions to save the Great Barrier Reef, but it’s not nearly enough. Marine mammals like the North Atlantic right whale—already critically endangered—are also shifting north because their prey, like copepods, are moving. Dolphins are showing up further north on both coasts of North America and in Europe. These shifts aren’t random—they’re tracking food, not just temperature.
Q: Has the scientific community been able to track these changes well?
Pinsky: We’re getting better, but there’s still a lot we don’t know. Much of the ocean remains poorly observed. That’s why we collaborate with institutions like the Smithsonian, doing “genomic time travel” by comparing fish collected a century ago with those today. In the Philippines, we’re re-collecting coral reef fish in the same spots to understand how they’ve adapted—perhaps to tolerate more sediment in the water.
Q: What do we know about the long-term prospects for marine life? Can species adapt?
Pinsky: Some can move or acclimate—like building muscles through exercise—but that only goes so far with rising temperatures. Evolution is slower, but we’re finding that it may play a bigger role than we thought. The problem is, we’re pushing species to move, adapt, or die faster than ever before.
Q: For people who care, what can they actually do?
Pinsky: Speak up—at the ballot box, in your communities, through art and culture. Make sustainable choices: buy American seafood, especially if it’s frozen. Avoid imported salmon and shrimp, which often come with a heavy environmental cost. Use tools like the Monterey Bay Aquarium’s Seafood Watch. Sustainable fishing helps species survive climate change.
Q: Any personal advice to listeners in this time of climate anxiety and polycrisis?
Pinsky: This is the time for all hands on deck. Whether your skillset is art, biology, organizing, finance, or construction—everyone has something to contribute. Don’t wait for someone else to fix it.
Q: What about advice for young people just becoming aware of the crisis?
Pinsky: Find what you care most about, and make that your passion. For me, it’s my two kids. I want them to have the same sense of wonder I had growing up, whether it’s exploring tidepools or hiking in the mountains.
Q: If you could wave a magic wand, what’s the one thing you’d do?
Pinsky: Capture the past and future greenhouse gases we’ve emitted. That alone would buy us crucial time.
Q: Any final thoughts?
Pinsky: We’re all connected to the ocean, whether we realize it or not. It’s a place of wonder and beauty—but it’s also the canary in the coalmine for the Earth.