S1: Welcome in San Diego , it's Jade Hindman. On today's show , we often hear about the importance of forced on the planet. But what about the ones under the sea ? Well , kelp forests grow more than 100ft tall in our oceans and have a profound impact on the climate. David Hallvard wrote all about it in his new book. This is KPBS Midday Edition. Connecting our communities through conversation. You know , this week is NPR Climate Solutions Week , and we feature stories about how communities are tackling the challenges of climate change during this time. And when we talk about our oceans specifically , we often hear about how climate change is harming ocean animals , depleting coral reefs , and rising seas. All are very real concerns. But less well known , though , are the kelp forests that live in our seas across the globe , and they are seeing big impacts from climate change as well. Kelp forests have declined by as much as 60% in the past half century , and a new book is looking to call more attention to the plight of kelp and how it's changing our oceans. It's called forest of the sea , the remarkable life and imperiled future of kelp. I'm joined now by the book's author and ocean advocate , David Hallvard. David , welcome to Midday Edition.
S2: Jade , pleasure to be with you.
S1: Glad to have you here. So you've written several books about the oceans and the need to preserve them.
S2: The idea that the only resource not fully exploded in the ocean is good investigative stories. And I realized that. So I wrote a book about the Coast Guard , the only armed service that's not really fully resourced or acknowledged. And I wrote one about the Golden Shore , California's love affair with the sea. Because I see California as a model of you're trying to grow solutions faster than the problems , but we're the fourth largest economy. We have 40 million people , almost. We do really well by our coast and ocean. But right when that book came out in 2013 , California , the whole western coast of North America was hit by what was called the blob , a marine heat wave that really damaged particularly California's kelp. The. And even a decade later , 95% of the bull kelp forests north of the Golden Gate are gone. Here we have the giant kelp south from Monterey , the central and southern part of the state. And they're recovering but damaged. And now we have another marine heat wave headed our way. This is NOAA reported last year that 2025 marked the hottest the oceans ever been in recorded history , which goes back to the 1880s. Which makes sense because 90% of our greenhouse gas heat is absorbed by the ocean. And and what that does to kelp helps kelp. Like our other global forest. It's this forgotten , literally larger , you know , space than the Amazon basin. And it's this cold water realm. It's this marine habitat that , like coral reefs , is incredibly abundant. It's got over a thousand species it protects and including a lot of the wildlife that we consume , like salmon and cod and herring require this incredible macroalgae. It you know , we.
S1: Have a system in there.
S2: Right ? And we're looking at forest on land and I've , you know , gone out with Cal Fire and covered the fires in California. But California has this other forest crisis which few people understand , which is , you know , kelp forests like cold water. And maybe that's why we know less about them. I mean , I love diving and coral on coral reefs.
S1: That water is chilly. But , David , like , for somebody who who doesn't , who can't quite even imagine what a kelp forest is , can you describe it ? Um , for our listeners , um , for anyone who might not know exactly what a kelp forest is.
S2: Well , and you can go right here , Point Loma , and see a kelp forest from the shore. I mean , the amazing thing. They're macroalgae. They're actually algae , but they look , it's called evolutionary convergence. They look like forest. I mean , they have hold fast that look like roots , but they don't provide nutrients. They provide habitats. They're anchors. And then the stipes , you know , they come together. It looks like the redwoods of the sea when you're in them. Um , it's often it's cold. It's hard to get in there. But when you're in there and the light filters down , it's cathedral light. You see , you know , three dimensional life , the the stipes and the blades. They have floats. And the canopy on the surface sometimes is so thick that that seabirds will walk across it. Oh , wow. And and it's very , you know , people say , well , it's pretty , but I'm not a diver. I'm not going to put on the , you know , the semi-dry suit and the hood and the booties and get in there.
S1:
S2: But like off San Diego , it's about 30ft deep. Off the California coast. We have shallow coastal waters , and so 30 , 60ft and swaying , it's like you can't walk. It is just one of the most beautiful forests you've been in. But instead of birds , they're official around you and , uh , eels on the bottom and bat rays and leopard sharks. I just , uh , last time I was down here , my friend Charlie , he used to work at KFWB. We went out and we did some free diving. He came up. He said there was just a big four foot shark. It was gray on the top , and I figured it's not a leopard or , you know , some of the other , uh , sharks that are common there. But it could be a seven gill. It could be a baby white. It's. It's always exciting to be there in the kelp.
S1: Well , you touched on this. San Diego has been an important place for kelp.
S2: I mean , first , it has an indigenous history. Humans actually settled the Americas , coming down the kelp highway. The kelp provided coverage for , you know , for generations we thought it was the land bridge. But humans migrate along the kelp , and they were able to eat herring , grow on on kelp and the kelp itself. Um , so it provided nutrients and food. People settled here. So for thousands of years , people were living well with the kelp and Point Loma. It was in World War One. It was used. It was a source for gunpowder. And so there was a huge factory complex after the Second World War. Alginate uses expanded alginate. It you know , the cells of the kelp are like 60% cellulite , like in a tree cellulose , but the other 40% is called algae. And it turns out it's a great stabilizer and is now used in almost all processed food as well as most cosmetics. Your lipstick , your toothpaste. It's used medicinally. So this is an essential element. And for generations it was harvested. So Chalco was the big one. I moved here in the 1970s. There were these big barge like ships with blades on the front , and they would cut the top 3 to 4ft of the giant kelp here and processed. I mean , each boat could collect 500 tons a day. Um , and it was all processed for the algae. And today 97% of that algae is is farmed mostly in China , Japan , the Koreas. And so the market so telcos moved on to other products. They left San Diego in the 80s. But while they were there , they were also working with top scientists at Scripps Oceanographic and starting with the. In World War Two , when it was also being used for fireproofing and for explosives , um , it became Scripps became a center of experimentation , and one of the first divers there was C.K. Chang was a Chinese national , and he left Scripps , and he went home after the war and became the father of Chinese aquaculture , which today produces half of the 40 million tons a year that's produced both for the algae but also as a food crop. The UN thinks that we'll be eating seaweeds will be a bigger crop than potatoes by the end of the century.
S1: It's so fascinating.
S2: Um , when Chalco was operating , it was measured in thousands of acres. Uh , coral and kelp. When I started working on full time on ocean issues. 20 years ago , it was still. Overfishing and pollution that were the main problems. Now that's being overwhelmed by these marine heat waves. It just makes it harder for the kelp to survive and it takes out predators. Um , what happened in Northern California ? The only predator left was this giant , fast moving sea star called the sunflower sea star. It was predating on these urchins. And when it when it died in the heat wave , then these urchins came out of the hidey holes. They reproduced 10,000%. And now you have these diverse kelp forests. You now have urchin barrens. And so people like me , recreational divers come out of work. Commercial urchin divers , um , are trying to restore the , uh , the kelp.
S1:
S2: It's been estimated to produce half $1 trillion of value for us , not only in terms of of the stabilizers of algae and the food itself for food security , but also like corals , it prevents extreme waves and storms from damaging it , prevents erosion , protects the coastline , it generates oxygen , it's photosynthesizing. So kelp , along with seagrasses and mangroves produce 20% of our oxygen. And when you go down to the microalgae , the the plankton in the ocean produces another 30 to 50%. So people think of the environment , but they kind of stop thinking of it at the water's edge. You know , most of the oxygen generated on this planet is from the ocean , which is the source of life. And and , you know , the pleasures of it's hard to love something that you don't understand. People sort of get. And that's why chapter two in my book is otter things because people get charismatic cute. I mean , 6 million years ago , two species evolve that have had huge impact on the kelp , the humanoids and the fish eating otters. And one developed into a charismatic , intelligent tool using creature and the other became us people. So the otters play a keystone role in the kelp. Interesting.
S1: Interesting.
S2: They're the guys who eat all the herbivores , the the urchins and the abalone.
S1: Well , and you said you.
S2: Eat healthy , balanced.
S1: Well , you participate in efforts to to maintain kelp forests. Talk a bit more about some of the the efforts that are going on , because some of those efforts are happening in Los Angeles. I mean , tell me a bit more.
S2: Well , I've basically been reporting on those efforts in places like , um , I mean , there's three things that people are doing. They're doing the research , which I'll be speaking at scripts about with a lot of the leading researchers. Um , they're doing establishing marine parks where there's healthy kelp and , like Latin America and around Argentina and the Falklands , they're creating a big marine protected areas to keep healthy kelp healthy. That's still operative. And where it's been depleted , like off our coast. Um , many volunteer groups like the Bay Foundation and I went diving with the Bay Foundation off Palos Verdes , where over the last decade , they've restored over 80 acres of wild kelp. And the great thing is , like my friends who do coral restoration , they're like , take a fragment and cement it to a dead reef. And they get all excited if it's grown a foot in a year. But you you get the conditions right for the kelp to come back to the bamboo of the seal grow 100ft one. One of the areas that that the Bay Foundation's restored up in off la , um , it got hit by a mudslide. Destroyed it. Two years later , it was back. So it's scaling up. It's recognizing the value of it. The Koreans Korean Fishery Agency does that. They've restored 50,000 acres. Amazing.
S1: Amazing. Well , you know , in the last minute and a half , we've got here in a previous book of yours , 50 Ways to Save the Ocean. You give readers ideas for actions that they can take to help.
S2: I mean , our energy choices , because the scientists in Tasmania said we can restore the kelp , we can bring it back. It's expensive. But if we're not all fossil fuels by the end of the century , we're not going to have kelp forest or coral reefs. And then we'll find out how hard it is to live without our life support systems. Um , you can vote the ocean. I mean , you know , there's a congressman from Northern California , Jared Huffman , who's introduced to help the kelp bill 5 million a year for restoration and and study. And this is essential. And because we got blindsided by this , this last heat wave , the ocean is changing so rapidly that getting involved as a citizen , if you're a diver , there are lots of volunteer opportunities to smash urchins and bring kelp back , but also just get educated like , oh , I know , read a good book. Forest of the sea is I mean , I wrote it really because people don't make the connection between kelp climate and the future of the ocean , and we need all the living parts we can have. And if we can do that , I'm not pessimistic , optimistic. I believe in triage. We save what we can while we can. And what else is there to do ? I mean , we don't know what the future brings. All we know is if we don't try , we lose. It's all too precious and sacred to lose. Indeed.
S1: Indeed. I've been speaking with David Helwig. He is the author of the new book forest of the Sea The Remarkable Life and Imperiled Future of Kelp. He'll be appearing at Scripps Institution of Oceanography this evening at 6 p.m. , and we'll have a link to that on our website at KPBS. David , thank you so much.
S2: Oh , thank you Jade.
S1: That's our show for today. I'm your host , Jade Hindman. Thanks for tuning in to Midday Edition. Be sure to have a great day on purpose , everyone.
