The Forest We Forgot to Save: David Helvarg’s Forest of the Sea

There is a moment in David Helvarg’s new book where Julie Packard, on her retirement as CEO of the Monterey Bay Aquarium, is asked by a New York Times reporter to opine on SpongeBob SquarePants. The reporter helpfully prompts her that the cartoon lives in a pineapple under the sea. Packard’s response, delivered coolly, is that scientifically this does not happen. It is a small exchange, two sentences in a book of many, but it tells you a great deal about what Helvarg is doing in Forest of the Sea: The Remarkable Life and Imperiled Future of Kelp (Island Press, out May 5). He is taking an ecosystem that the reading public has mostly filed under “smelly tangles on the beach” and rebuilding it, paragraph by paragraph, into something worth a serious adult’s attention. He is doing it without lecturing. And he is doing it with the kind of dry, observational eye that recognises a SpongeBob question for what it is and lets the source’s own deadpan do the work.

I have spent twenty years in ocean conservation and a fair amount of that time in places where coral takes up almost all the oxygen in the room. Coral is photogenic and warm-water and people will pay to visit it on holiday. Kelp is none of those things. It lives in cold green water along coastlines that do not, as a rule, feature in honeymoon brochures. The great underwater forests of California, Alaska, Patagonia, Norway, South Korea, the Falklands and a dozen other coasts have spent the last half century quietly disappearing, while almost no one outside the field has noticed. This is the gap Forest of the Sea steps into, and the excerpt that follows this review will give you the scale of the problem in Helvarg’s own words.

What a review can do that an excerpt cannot is tell you why this book, and why now. There is no shortage of conservation writing about the ocean. Most of it falls into one of two registers: the activist’s, which arrives with a clenched fist and a long list of villains, and the science writer’s, which arrives with footnotes and very little imagination for the reader. Helvarg’s engaging writing style provides the reader a narrative that is easy and often fun to follow even as it addresses complex and often troubling issues. He has the credentials to make this work and the writerly instincts to keep them out of the way. He is the founder and executive director of Blue Frontier, the producer of the Rising Tide ocean podcast, the co-founder of the Peter Benchley Ocean Awards, and the author of seven books including Blue Frontier and Saved by the Sea. He has been a war correspondent. He dives. None of this is on the page in any heavy-handed way.

What is on the page is a journalist’s restraint: the willingness to let an interview subject finish a sentence, the discipline to follow a fact where it goes rather than where it ought to go, and an ear for the moments when a quiet detail does more than a statistic. The opening dive in a Monterey kelp forest, with leopard sharks circling at a distance and three wolf eels staring out of a cave with what Helvarg calls “snaggle-toothed disinterest,” is the kind of scene most ocean writers would either gush over or skip. He does neither. He just shows you the eels. By the time he gets to Doug Jung, the California abalone diver who tells him the loss of his local kelp forests is worse than the Tubbs Fire that took his house, the reader has already learned to trust the writer’s eye, which is the only reason a comparison that strong lands.

I will say what Forest of the Sea is not , because that is sometimes the most useful thing a review can do. It is not a comprehensive scientific reference. It is not a policy white paper. It is not an activist’s handbook with a call to action at the end of every chapter. It is a piece of long-form ocean journalism in the tradition of Susan Casey and Carl Safina, written by someone who has been on this beat for a very long time and who trusts his reader to absorb the science through the story rather than the other way around. Which is, in my experience, the only kind of conservation writing that actually moves anyone.

If you have ever stood on a Californian beach looking at a wrack line of brown stalks and not thought much of it, this is the book that will rearrange your sense of what is just offshore. If you already work in the field, it is the book you will want to put in the hands of the friend who keeps asking, politely, what exactly it is you do all day.

Forest of the Sea: The Remarkable Life and Imperiled Future of Kelp is published by Island Press on May 5, 2026. More about the book and David Helvarg’s other work at forestoftheseabook.org. Available in hardcover and ebook through Amazon, Barnes & Noble, and Island Press directly. Helvarg will be in conversation about the book at Busboys and Poets, 14th and V, Washington DC, on Monday, June 2 at 6 pm ET. RSVP is required.

An excerpt from chapter one of Forest of the Sea

Kelp is generally not thought of in the same way as coral reefs, sharks, or dancing dolphins. Actually, it’s rarely thought of at all. So don’t worry if you haven’t heard of the Great African Sea Forest, where My Octopus Teacher was filmed, or Australia’s Great Southern Reef, which is more than three times longer than the Great Barrier Reef, or the Kelp Highway, which stretches from Russia across the Bering Sea and down the west coast of North America to Mexico, or the Sea Forests at the End of the World, whose brown canopy covers the waters of Patagonia and the southern tip of Latin America. You can find similar marine forests in the colder waters of Norway, New Zealand, England, Scotland, Ireland, Iceland, Greenland, Canada, Japan, Spain, Portugal, Korea, Peru, the Galápagos Islands, and the sub-Antarctic Falklands (aka Malvinas).

Although this book is set predominantly in the United States, the challenges that kelp forests face are global. Unlike the burning of the Amazon rainforest or the unprecedented wildfires scorching the planet from Siberia to Los Angeles, the other great forest disaster now taking place on our blue planet, the decline of living kelp forests beneath our seas, has gone largely unreported. And yet at 2.8 million square miles, kelp forests cover an area larger than the Amazon, bordering and enriching the waters of many of the world’s coastlines.

At the same time, kelp forests have declined by as much as 60 percent over the past half century as they’ve repeatedly been affected by pollution, overfishing, mechanical harvesting, and, increasingly, marine heatwaves that have seen places such as Prince William Sound, Alaska, recording 76-degree water temperatures, as deadly to kelp as the 100-degree water temperatures in the Florida Keys were to reef-forming corals several years ago.

Although many people know the world’s coral reefs are in trouble, fewer know that giant marine algae such as bull kelp are facing the biggest threat to their existence since they first evolved more than 32 million years ago. What happens to the seahorses, salmon, lobster, whales, and more than 1,000 other creatures dependent on kelp forests if they disappear? What happens to us? Neither science nor society has figured that one out.

Kelp forests and other large algae (which come in red, green, and brown) are also essential to the regulation of our atmosphere. Along with mangroves, salt marshes, and seagrasses, they absorb vast amounts of carbon dioxide through photosynthesis while generating 20 percent of the oxygen we need to live, about the same amount as all of the world’s rainforests. Microalgae, mainly phytoplankton, produce another 50 percent of our oxygen. It only makes sense that algae and marine plants should generate 70 percent of the oxygen we breathe, because the ocean covers 71 percent of the earth’s solar-absorbing surface area, almost all of which is rich in photosynthesizing life.

Kelp forests, like coral reefs and salt marshes, are also good for storm protection, grooming waves (we’ll get a surfer to explain later), damping down sea surges, and reducing coastal erosion. And yet, along with the deep ocean, the forests of the sea are a largely unknown realm, even though you can often spot their canopies bobbing just offshore. Other than the piles of pungent kelp wrack that decay on our beaches, attracting seaweed flies, kelp flies, beach hoppers (sand fleas), and the shorebirds who feast on them, they remain as mysterious to most people as the depths of the Marianas Trench 7 miles below the surface of the ocean. Unfortunately, out of sight and out of mind is not a useful way to address one of the great conservation challenges of our time.

Some coastal communities such as Fort Bragg, California, are being hammered by the loss of wild kelp forests. “The destruction that’s occurring is worse than the fire that burned down my house and 10,000 other homes in Sonoma County” (during the 2017 Tubbs Fire, which actually destroyed 5,643 structures), says Doug Jung, a longtime California abalone diver who used to free dive for red abalone outside Fort Bragg and would then join dozens of friends and family for long evenings of cookouts on the beach. Still, today there is far more global interest in farming kelp than in saving it, even though wild kelp is the “mother seed” for the expanding seaweed aquaculture industry.

That’s not to say there isn’t good news in the focus on seaweed and kelp for regenerative and climate-friendly food production (more than 40 million tons a year at present), for use as an emulsifier and bonding agent in a wide range of everyday products (e.g., toothpaste, shampoo, and beer), or as a potential source of new products such as clothing, anti-inflammatory drugs, bioplastics, and wound healing gels. But this emerging market sector and the commercial fishing industry, which also depends on kelp, are failing to make the investments needed to save the wild marine forests that are essential to their livelihoods and whose environmental services are estimated to be worth $500 billion a year according to a 2023 study published in the prestigious scientific journal Nature.

Also, we’re constantly learning of new uses for kelp. If you’ve ever considered an exfoliant treatment, for example, some orcas have as well. A summer 2025 report in Current Biology identified how the southern resident orcas of the Pacific’s Salish Sea use loose bull kelp stipes, or cut off 2-foot lengths with their teeth, and place them next to a partner’s skin. They then roll the kelp pieces between their bodies. Based on drone observations, this kelp “loofah” treatment suggests that, as crows have already demonstrated, you don’t need hands to be an effective tool user. In this case, however, you do need a healthy kelp forest.

The idea that you save what you love is appealing when it comes to koalas, whales, and coral reefs, but too few of us have immersed ourselves in the ethereal beauty and unique live action you encounter diving in a kelp forest. Why? “It’s that cold water. People like to be comfortable. Get in that warm water with the coral,” National Geographic explorer in residence Sylvia Earle notes sagely.

And so, other than some Indigenous ones, too few stories tell of the wonders, the creatures, and the people whose lives depend on and are defined by these forests of the sea. And again, what happens if they go away? That’s one of the questions we’ll try to answer in this book while also introducing you to some engaging people, places, and animals that thrive on this wet and salty frontline of life, profiling its first responders and restoration scientists, artisans and fishing folk, divers and tribal stewards working to save another of our great foundational wonders of the world.

After all, kelp is one of the most resilient and fastest-growing organisms on Earth—capable of growing up to 2 feet a day—even as it faces rapid decline. I’ve swum through a kelp forest that ten years earlier had been a moonscape-like urchin barren. One California cove full of kelp was wiped out by a landslide but fully recovered within two years. In South Africa, climate change, which generates winners and losers, has had the counterintuitive effect of expanding the range of its kelp forests. In Norway, warming waters have allowed the expansion of urchin-eating crab populations that are helping restore the kelp. In Argentina citizen action has led to the creation of marine parks that protect their healthy wild kelp, and in South Korea thousands of acres a year are being restored by a government fishery agency collaborating with local communities in the largest global effort to date to grow a solution faster than the problem being confronted.

And yet, short of a rapid transition off fossil fuels, which is not happening at this time, you can’t really talk about hope for the future of kelp forests that are being pummeled by marine heatwaves but instead may have to focus on saving what’s left, with the understanding that kelp forests, although resilient, are now in need of active human intervention. This could mean establishing fully protected marine parks, investing in essential research, and restoring damaged habitat to ensure that healthy kelp forests continue to exist, expand where possible, and perhaps someday thrive again, as they have for millions of years across the temperate seas of our blue marble planet.

But this will require a commitment to the multigenerational task of ecosystem restoration that also needs to become a major human enterprise and job generator during the remainder of this century and into the next (and the one after) if there’s to be any chance of saving the countless species of flora and fauna, both wet and dry, that make up the web of life in which we too are entangled.

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David Helvarg is the founder and executive director of Blue Frontier and the author of seven books on the ocean and conservation. He produces the Rising Tide podcast and co-founded the Peter Benchley Ocean Awards. He lives in California.