Stranded astronauts return, and the whale pee funnel

In recent times, smartwatches have been shown to be able to detect the onset of viral infections some considerable time before obvious symptoms of illness appear, even to the victim. This is reflected in subtle changes to the way that heart rhythm varies, for instance. But now new research suggests that beyond just alerting the individual about the impending problem, these devices might be able to help stop a pandemic. I’ve been speaking with Märt Vesinurm from Aalto University in Finland…

Märt - We already knew from research that wearable devices and specifically smartwatches are able to detect infection before any sort of symptoms, so sneezing or coughing, start. We sort of asked ourselves how much of an impact can it have if we were to use these devices in pandemic management and people were to sort of change their behaviour given a smartwatch alert.

Chris - And what are the smartwatches that are responding to? When we look at them and we can say, ah yes, this person is infected with something, what's the giveaway that the watch is able to pick up on?

Märt - Yeah, so I guess the most common ones, of course, are the body temperature, heartbeat, heart rate variation, and then blood oxygen level. So those are like the most common ones, I would say.

Chris - And that, crucially, changes before a person may even be aware that they've got something.

Märt - Yeah, so likely even with the most basic devices, you would see an increase in your heart rate, for example, just before you start showing symptoms.

Chris - Because one of the things that caught us out with the pandemic was, initially we assumed that if you weren't symptomatic, you weren't infectious. Obviously, if we get prior warning that someone might be infected with something before they realise, you could take action sooner. Is that where you're coming from with this?

Märt - Yeah, exactly. And actually, we also know that a significant amount of the sort of infections to other people come from before you actually show any symptoms. So that was especially problematic with COVID, for example, because the incubation all of the time between you getting infected and actually showing symptoms was so long that you had quite a while to infect other people before you actually realised that you yourself were infected. So if we can really hit that mark, we could have a huge impact on how pandemics develop.

Chris - So take us through what your parameters were. What fraction of the population would have to be using a smartwatch, did you assume? And what sort of a difference, if they did, would it make to the trajectory of a problem like COVID?

Märt - The proportion of people using the smartwatch was actually sort of merged together with a parameter we called reduction in social contact. So if you get the prompt, how much would you reduce your social contacts? And that's essentially very similar to saying if you don't get the prompt because you don't have a smartwatch, you just wouldn't reduce contacts at all with the smartwatch. You know, there's some other parameters that we used for the development of the viral load. So the amount of the virus in the human body for these different diseases. We also looked at previous research on how early wearable devices can detect certain diseases. One very important part of the study was also that these smartwatches can catch people who are also asymptomatic completely. So there's 20 something percent plus or minus something in many diseases where people infect other people but show no symptoms at all. And those are also something that is possible to catch with wearable devices.

Chris - Taking all that into account then, if we did have COVID Mark 2 tomorrow and smartwatches in the population, what sort of a difference could this sort of intervention make, do you think, based on your simulations?

Märt - I think it would be a really big, big difference, but it of course depends. For example, we looked at three different variants of COVID. The very first one, for example, we could have almost eliminated in sort of a very realistic context. If we were very optimistic, we could eliminate almost everything, but, you know, keeping realism in mind. But on the other hand, then we looked at Omicron, which was really infectious. And so for that case, the most likely, likely outcome would be sort of flattening the curve, as to say.

Chris - It's going to make a difference, though, on the demographic of the country and also the living conditions, isn't it? Because one of the arguments made was that in countries like Sweden, where the approach was a bit different to countries like the UK, people said, well, hang on a minute, the density at which people live in Sweden is very different than, say, the density at which people live in London. And so if you're wearing a smartwatch, it makes no difference whatsoever if you go home and infect all your housemates.

Märt - That's of course true. But then again, assuming that if you get the alert even one day before, you know, you could make the decision to stay at home and not, you know, follow up with a visit to your grandma, for example, or the store, or if that's an option to you, you could work from home. So there's a lot of these decisions that you yourself could make given that extra information. You could still reduce the amount of extra infections by making, you know, more better decisions, or at least more well informed decisions.

Chris - So do you think policymakers should be listening to you and saying, well, this should be part of our pandemic planning for the future?

Märt - I definitely think that policymakers should consider it part of their toolbox, because that could have a huge impact on how we manage pandemics. I think that there are, of course, ethical considerations always when any kind of government or also centralised data collection even crosses someone's mind. But even say, you know, in a situation where I voluntarily go out and buy myself some sensors or a smartwatch, have that go to my phone, and based on that infect less people, I think that policymakers should be at least aware of this possibility.

A study has found that whales play a massive and previously unrecognised role in moving thousands of tonnes of nutrients - foremost among them nitrogen and phosphorus, which are essential in sparking plankton blooms - over thousands of miles of ocean. This creates a nutrient cycle on an epic scale as they feed in one place and later relieve themselves - as well as reproduce and die - in another. The University of Vermont’s Joe Roman has made the discovery by studying the habits of humpback, right, and grey whales. And don’t be under any illusion about how much urine we’re talking about…

Joe - So a typical human, we make about two litres of urine a day. Fin whales are much larger. So that's the only species that's actually been studied. And this is from whaling data in Iceland. Estimates are maybe a thousand litres or 250 gallons per day and similar amounts for other large whale species. And that is rich in nitrogen. It's also rich in other nutrients like phosphorus. And then it also has chlorine and sodium. And for your listeners to realise, that's pretty common, right? In the ocean. So we really looked at the nutrients that are limiting, that are going to spark growth in those areas.

Chris - And so to what extent might they therefore be moving nitrogen around rather than just pick up nitrogen in their food from a local area and then they just pee in that local area. So they just cycle what's already around. Have you got evidence they're actually actively moving the nitrogen from A to B?

Joe - Whales are what's known as capital breeders. What does that mean? It means they feed for part of the year and they breed at a different part of a year, unlike humans, which have to feed while they're having offspring. So they're travelling a thousand, two thousand kilometres to places like the Caribbean or Hawaii. And the females, in order to give birth and in order to lactate and to gestate, they need enormous amounts of energy. Where do they get that from? They're breaking down the fats and the proteins that they stored in the summer. And in the process, they have to release excess nitrogen, excess phosphorus. Other pathways include placentas. So whale placentas can be hundreds of pounds. Infant mortality in whales can be fairly high. So when a calf dies, that brings a lot of nutrients. And then the whales themselves can also, you know, they can die on the breeding grounds as well. So those four pathways are how they bring nutrients. But because whales are peeing all the time, that's the main source by far, is the urine, is the main source for nitrogen and other nutrients.

Chris - So how much nitrogen are they moving and other nutrients around the planet when they go from A to B in this way?

Joe - About 4,000 tonnes of nitrogen per year. So what we did is we looked at one particular system, whales that feed in Alaska and breed in Hawaii because that system is well studied. There, they bring as much nitrogen from Alaska to Hawaii as the local processes of wind and upwelling transport into these systems. So this is a biotic or a biological form of bringing these new nutrients, these external nutrients, into the system. And then we start to get an idea of what the impact might be on phytoplankton. Hawaii, about 4,000 tonnes of biomass or just body are transported there every year. And that's comparable to like 10 million Big Macs. I mean, they're bringing a lot of food into the system. So it's not just the nutrients, but sharks feed on the carcasses or the placentas, fish feed on it. These nutrients can get into the coral reef systems. So it's two processes, one sort of daily in the urine and the other in, you know, at the end of an animal's life is the other big pulse of nutrients or biomass food.

Chris - Did we see an impact then when there were fewer whales? Luckily, numbers are climbing across many species because of international bans on whaling. Wasn't always like that. And some animals were close to the point of jeopardy. They have rebounded. So are we now seeing a change in that nitrogen flux and what impact is having?

Joe - That's exactly right. So historically, whales were, it depends on the species. We haven't talked about blue whales and fin whales, but blue whales, for example, were reduced to about 1%. Largest animals ever existed on the planet, down to 1% of their population in the Southern Hemisphere. So basically they had no ecological role. And that still sadly remains for some species like the North Atlantic right whale, only 350, 400 whales on the planet. Their ecological role is pretty small. Let's look at some better news though. Right whales in the Southern Ocean, as well as humpback whales in the North Pacific and gray whale populations have all increased. They're rarely up to historical numbers, but that has allowed us to really examine what the impact of these whales could be. I think 50 years ago, 60 years ago, oceanographers overlooked the role of whales. They were so rare. Of course they weren't important. We had basically eradicated them. But keep in mind, Chris, that we still have a long way to go here. One study that we mentioned is that 4% of the biomass of mammals on the planet is wild biomass. The vast majority are humans and cows and sheep. That 4% includes all the whales, all the great whales. So it's not surprising that we haven't considered animals as being an important part of what I describe as the circulatory system of the planet because we really sort of clogged up those arteries. And now we're just starting to see in places like Hawaii and the Caribbean what the restoration of these species can mean for local ecosystems and for global nutrient transport.