IRA FLATOW: This is Science Friday. I’m Ira Flatow. For the rest of the hour, we’re diving into seafood– squid, salmon, tuna– because the seafood options on restaurant menus are not the same as they were 30 years ago. And what we love now may not stay on menus thanks to– you guessed it– climate change. Warming waters means changes to fish stocks. And that means a different catch is getting to your plate.

Researchers from the University of British Columbia looked at more than 360 menus dating back as far as 1880. And they found a connection between climate change and which seafood types rose to fame on restaurant menus over the years and which ones flopped off. Get it?

On our menu is Dr. William Cheung of the University of British Columbia’s Changing Ocean Research Unit based in Vancouver, British Columbia. Welcome to Science Friday.

WILLIAM CHEUNG: Thank you for having me.

IRA FLATOW: Looking at menus is a very clever way to track the impact of climate change. How did you come up with that idea?

WILLIAM CHEUNG: Yes, so for me and my team, we have been studying climate change effects on the oceans and fish stocks and fisheries for the last decade. We find connections between the changing ocean conditions, particularly ocean warming, with the fish stocks and the fish that our fisheries are catching. And we want to, then, know how that affects people who may be less connected to the oceans. I mean, people who live in a city, that do not go out fishing or do not even visit the coasts very often. And one thing that I think they can connect to the ocean is through the food that they eat. So we think about, OK, let’s start with restaurants.

IRA FLATOW: Yeah, so you looked at more than 360 menus going back to the 1880s. How do you do that? I mean, how do you even find menus that go back to the 1880s?

WILLIAM CHEUNG: Yes, so one thing that we thought of is to know what the restaurants offer. This menu is a very good starting point. And one of the reasons is that there is a physical or digital record of menus, and that we can also easily access these records as well. So for present-day menus, a menu of the restaurants particularly in big cities like Vancouver, the menu online, especially during the pandemic time. And there are also records, particularly for the older menus, that are kept in museums. We also find archives of restaurant menus or banquet menus in the city of Vancouver archives.

IRA FLATOW: And these menus told you a story, didn’t they?

WILLIAM CHEUNG: Exactly. So we were really surprised that our analysis actually shows what we were expecting, that the climatic conditions affects the kind of seafood that the restaurants would serve in these different cities. But we originally thought that there were so many factors that would be affecting what a restaurant would serve in their menu– demand from the customers, the price of the seafood, or just the trend of food culture at that time. But even with all these factors, we find that there’s a relationship between the kind of seafood that the restaurants serve and the environmental conditions of the ocean adjacent to the city where many of these seafood are sourced.

IRA FLATOW: And I know one standout species from your paper was the Humboldt squid. What did you learn about them?

WILLIAM CHEUNG: The Humboldt squid is a really good example to illustrate why we are seeing that the seafood menu is actually getting warmer, in the sense that it is containing now more warmer-water species compared to the past in Vancouver. Humboldt squid is a species, a squid that prefers warm water. And we know that in recent years, as the ocean warms up, and particularly in the years where the oceans off British Columbia was particularly warm, the Humboldt squid distribution expanded to our coast, and often in large numbers.

And we find that Humboldt squid, before those time periods, are actually– we couldn’t find that in the seafood menus that we looked at. But then it only occurred in recent years. And it’s actually getting more common. And so one of the reasons that we suggest is that because of the expansions of the Humboldt squid as the oceans warms up, it actually increased the availability of Humboldt squid to the restaurant, and thus the chef is more likely to select this species in the menu.

IRA FLATOW: Wow. So when did the Humboldt squid just start showing up on the menu? About what year?

WILLIAM CHEUNG: It’s in the last decade.

IRA FLATOW: Really?

WILLIAM CHEUNG: Yes.

IRA FLATOW: Wow. You found them on many menus?

WILLIAM CHEUNG: Yes. We did. And the contrast is that before that, we couldn’t find that in any menu that we looked at.

IRA FLATOW: That is amazing. And on the flip side, are there any fish that aren’t as popular on menus anymore?

WILLIAM CHEUNG: One of the big contrasts is Pacific sardine. Pacific sardine was very common in seafood menus in Vancouver before the 1950s because, at that time, British Columbia had big sardine fisheries. But then the sardine fisheries collapsed. It was because of various reasons, overfishing, because of environmental change. So since then, sardine become rare in the seafood menus.

But one thing is that, based on our previous research as well as some research from other colleagues, we know that Pacific sardine is a warm-water-preferring species. And when we use our computer simulation models to make projections of future change in sardine populations and fisheries, we project that British Columbia will have more sardine. That may likely stimulate more fisheries, catches of sardines, as well. So we expect that in the near future, sardine will become more common in seafood menus.

IRA FLATOW: And what fish would the sardines be replacing? Could it be salmon? I’m thinking of salmon as a cold-water fish. And it’s a staple on the West Coast, right? Are salmon disappearing?

WILLIAM CHEUNG: That’s what we are worrying, too, particularly sockeye salmon. We know that sockeye salmon have not been doing really well in the wild populations in British Columbia in the last decade. And even with really strong conservation efforts, the salmon populations are still not in a good situation.

And part of the reason is because of the changing climate and that, as you said, sockeye salmon prefer colder waters. And so the warmer waters actually becomes a threat to them. We project, actually, sockeye salmon population will decline further if our climate continues to change without mitigation. So what it means is that it’s likely that local seafood menus will become less likely to serve salmon, sockeye salmon. It’s likely to become more expensive and less accessible to consumers as well.

IRA FLATOW: Yeah. There are lots of factors, I think, to consider here, like people’s tastes changing and other problems in the ocean that affect seafood. How do you know these changes are from climate change and not just a fad that we’re no longer eating this kind of fish, or we are eating this kind of fish?

WILLIAM CHEUNG: That’s a good point, and we admit that many of those other factors besides climate are affecting the restaurants’ choice of seafood in their menu and that it is very difficult for us to just isolate the climate effects when we analyze the seafood menus. And we did some analysis to try to reduce the influence.

So for example, we know that the recent years, there are more aquaculture, farm-based seafood that are available to local restaurants. We identified those species that are not native to British Columbian waters. And so we assumed those species to be either imported or farmed by fish farms.

So a good example is Atlantic salmon. Naturally, Atlantic salmon does not occur in British Columbia. So we exclude those from our analysis. This helped us to focus on species that are caught from local waters. So that would help us to build stronger links between the changing ocean environment in the waters outside of British Columbia and the changing seafood menu.

IRA FLATOW: My last question to you– I need you to look into your crystal ball. So I walk into a seafood restaurant 20 years from now. What seafood am I going to find on the menu? And what’s going to be gone?

WILLIAM CHEUNG: In this case, we will be seeing much more squid in our menu, those Humboldt squid as well as other squid species. And so we will be having a menu that is full of squid as well as sardine as well. In contrast, our signature species like sockeye salmon is likely to become rarer and less common.

IRA FLATOW: Any chance we get some anchovies in there with the sardines? Anchovies are warm water, are they not?

WILLIAM CHEUNG: Actually, in this case, the sardine will be a more likely species to see than the anchovy.

IRA FLATOW: Oh. Thinking of my caesar salad.

WILLIAM CHEUNG: I like anchovy, too, yes.

IRA FLATOW: Well, that’s about it. It’s fascinating, using menus to figure out what our food is going to be like in the future. Thank you for taking time to be with us today.

WILLIAM CHEUNG: You’re welcome. Thank you very much.

IRA FLATOW: Dr. William Cheung of the University of British Columbia’s Changing Ocean Research Unit based in Vancouver. You’re listening to Science Friday from WNYC Studios.

OK, so seafood selections on restaurant menus are changing along with our climate. But before a fish turns into a dish, it has to go through a chef. Here to tell us how chefs are adjusting to a changing basket of ingredients is Chef Ned Bell, the owner and chef at the Naramata Inn in Naramata, British Columbia. Welcome to Science Friday.

NED BELL: Thank you so much. Thrilled to be here.

IRA FLATOW: Nice to have you. Now, I understand that you’ve been a chef for, what, 30 years?

NED BELL: Yes.

IRA FLATOW: Has the menu looked different from when you started versus now?

NED BELL: When I started cooking, dinner looked like beef tenderloin, overcooked asparagus, and mashed potatoes. And you know, that was maybe the European influence of meat and potatoes. Nutrient-dense, plant-based ingredients are becoming more and more and more important and relevant to a healthy diet. And the way I like to describe my food is I garnish with sustainability. So high-quality protein, often from the ocean, ingredients that are harvested, grown, or caught ethically, in the most sustainable manner possible. And of course, maybe a slightly smaller portion size.

IRA FLATOW: Chef, we just heard that Humboldt squid are a fairly new addition to Vancouver’s menus. Years ago, you wouldn’t have found them anywhere. What do you make of that? Do you use Humboldt squid?

NED BELL: Well, absolutely, I have. Humboldt squid became more and more relevant and prevalent on our menus because fishers would offer them to us because the ocean was warming and species were moving. And for me, I really want to eat and cook with the ecosystem.

IRA FLATOW: So as new fish and seafood appear on the scene, this is not a terrifying fact. This is a nice challenge for you to cook up new dishes.

NED BELL: Oh gosh, yeah. I mean, it forces us to be creative, of course. But at the end of the day, I’m a chef. I live every day in creativity. I’m not a consumer, although of course I am, but seafood can be daunting. It can be confusing.

It can be scary. It’s hard to cook. It’s smelly. It could look funny. It could have heads and tails and fish and skins and eyes and all the things.

We like square chunks of flavorless protein in the middle of our plate. We have always liked that in North America. We’re not very adventurous. And so I really want people to, as I said before, eat with the ecosystem and maybe just be willing to be a little flexible, adapt a touch to what your fisher or your fishmonger may suggest you should be cooking that day.

IRA FLATOW: That brings me to this question, just right in that wheelhouse. I mean, is there any seafood that you’d love to put on your menu, but you’re worried people won’t eat it?

NED BELL: I mean, it’s hard to answer that question because it would change every season. It would change every month. Right now is the BC spot prawn season. It’s about a seven to nine week season here up where I live. And as a bycatch of that fishery is octopus, giant Pacific octopus.

Well, there’s no targeted fishery for giant Pacific octopus, so all of that is what we call a bycatch of the spot prawn fishery. And so what I would love is if we maybe were a little bit more adventurous when we went out to restaurants and said, you know what? I’m going to order that octopus feature that the chef put on his or her menu tonight.

IRA FLATOW: Speaking of the ocean and the fish and the seafood that are in it, and we can see that that is changing as climate change heats up the ocean, if I were to walk, hopefully, into your restaurant in 20 years, what seafood do you think I’d find on your menu?

NED BELL: Shellfish, for sure– Mother Nature’s real fast food– if we are lucky to still have healthy oceans. And that is a big if depending on climate change and acidification and warming oceans and all of that. Shellfish– A, it’s delicious. B, it’s available year round. C, it’s relatively inexpensive in comparison to some higher-priced proteins.

I would say smaller fish. Not big fin fish, but, as we were talking about earlier, anchovies and sardines and some of these fisheries that, if the ocean is thriving, these fisheries thrive.

IRA FLATOW: Might we see more seaweed salad on your restaurant in the future, from kelp or whatever other kind of algae is growing there?

NED BELL: Oh, gosh, yeah. I mean, seaweed– superfood, high in vitamins and nutrient density and all the delicious things. It adds umami and briny, salty tastiness to all kinds of different recipes. And it really, I hope, finds its way onto our dinner tables, not only in restaurants, but maybe also into our homes.

IRA FLATOW: Chef, that’s about all the time we have. I want to thank you for taking time to be with us today.

NED BELL: Oh, my pleasure. Thanks very much for having us.

IRA FLATOW: Chef Ned Bell, the owner and chef of the Naramata Inn in Naramata, British Columbia.

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