Flying into the Future

A global study of sharks has found that they’re in danger of being fished over a quarter of their entire habitat. This comes from an international collaboration of marine biologists, who have tracked ocean sharks to produce the first ever world map of their hotspots. By comparing the hotspots to fishing routes, they have shown that the most valuable species are in danger over almost three-quarters of their entire range. Phil Sansom spoke to David Sims, one of the study’s authors, who is a senior research fellow at the Marine Biological Association Laboratory in Plymouth.

David - Pelagic means "of the open ocean," and so pelagic sharks are sharks which roam the open ocean. By using satellite tracking to identify shark hotspots across the global ocean and also tracking longline fishing vessels, we found that the overlap of the shark hotspots where they prefer to be and hangout, overlaps at least 24% of the time with these longline fishing vessels.

Phil - So that's like a quarter of the entire area that sharks live in is an area that they’re in danger of being fished?
David - We couldn't track every shark, but for the just under 2000 sharks that we did track yeah, 24% of the places they prefer to gather and to be, were entirely overlapped by longline fishing vessels. And these longline fishing vessels, each of those vessels deploys a line that's a hundred kilometres long with over a thousand baited hooks.

Phil - So that's a serious deal for sharks, right?

David - It is, yeah. Obviously, they're attracted to the baits on these lines, and because the lines are so long and there are thousands of these vessels across the global oceans which are trying to catch sharks, because, as opposed to 20 odd years ago sharks have a real value now.

Phil - Now let me ask you; it can't be easy to figure out where sharks gather or where they like to live, how did you actually do it?

David - A project at a global scale requires a global scale research group. There's 150 scientists across 100 institutes in 26 countries. We tagged just over 1800 different pelagic sharks and we gathered all the satellite tracking data of all sorts of different species of pelagic sharks. We gathered it all together in a giant database and then we were able to analyse, to explore, the movements of the sharks in relation to the environment.

我们发现鲨鱼更喜欢in areas where there are strong boundaries between different water masses with different characteristics, so fronts between different temperature water masses for example. And these sort of transition areas, these sort of boundaries are areas where there's usually lots of plankton and, of course, that plankton attracts in fish and squid that the sharks like to feed on.

Phil - That's so interesting that you actually had to physically tag the sharks.

David - That's it. That's the nature of this project is that it's the first one that's really worked at the global scale for pelagic sharks. We tracked about 23 different species, including the Great White shark and three species of hammerheads actually, but also the Blue shark and Shortfin Mako shark, and they're interesting because those two species make up about 90% of the pelagic sharks which are caught by high seas and shell fisheries. So those two are the most commercially important and obviously they're the ones that we are particularly concerned about as a consequence of this study, because we found that, in fact, 76% of blue shark space use and 26% of shortfin mako shark space use was entirely overlapped by these longline fishing boats.

Phil - Now let me ask you because you keep saying "overlap," but how do you know that overlap necessarily means they're in trouble?

David - Yeah, it's a really good question. We actually thought about that and in the study we actually calculated the fishing effort that was going on and related that fishing effort to actual landings, so these are tons of sharks that have been recorded on the global databases. And what we found was a positive relationship between the amount of fishing effort and the magnitude of landings of those species, so there was a direct link between the fishing effort, the overlap, and mortality.

Phil - So what do we do?

David - What we propose is that the maps we’ve produced of where the hotspots are can really start to become the foundational blueprint of shark conservation at the global scale. And so where we have these shark hotspots it could be that these are the sites that policymakers and scientists may select to protect sharks. That's not to say that that's the only tool that can come from this sort of study.

One thing that this does suggest is that the surveillance of megafauna like sharks is actually a very powerful way in which you can start to look at a new management of the oceans. If you know where the sharks are and maybe other megafauna like turtles and whales, it might be possible then to focus where the enforcement happens and for focusing where particular patrol vessels might be, for example. So I think the future holds this much more broad and satellite-based technology led conservation, which I think for sharks will be absolutely crucial.

People with haemophilia don’t produce enough of a critical factor that helps blood to clot. As a result, they have to inject themselves regularly with a replacement form of the factor to avoid suffering lethal bleeds into their joints and organs. But, within a year or two, it should be possible to offer patients with haemophilia a long-term solution using a gene therapy technique that enables cells in the liver to produce the missing blood clotting factor. Sandy Macrae is the CEO of the US-based company Sangamo therapeutics that’s developing and conducting clinical trials on the new technique. Speaking with him at the recent Biotechnology Innovation Organisation (BIO) meeting in Philadelphia, Chris Smith asked Sandy about the therapies the company are exploring...

Sandy - So I think the one that people talk about most is for haemophilia, which is the blood disorder that the Royal Family suffered from in Victorian times. And now there are two or three companies, including mine, that have medicines that will be on the market in the next 3 to 4 years and provide an option for these patients that they won't have to take factor every day or two, but will have one injection and be done for 5 to 10 years.

Chris - Are you saying then that you've got a way of genetically modifying a haemophiliac so they can make the thing they don't have?

Sandy - We need to be careful how we describe that. In gene therapy you park a version of the gene in the cell. So it's not stitched in, and it's not forever, and it may only last 5 to 10 years. But for these patients, 5 to 10 years is a long time compared to having to inject yourself every day.

Chris - What's the strategy then? What do you actually do to get that gene into them and where do you park it?

Sandy - That's a good question. We borrow a virus and the virus goes to the liver where it infects the liver cells. Once it infects the liver cells it releases the bit of DNA that then produces the factor that the patient was missing, and the liver acts like a factory releasing a little amount of factor each day.

Chris - What's the virus that you use to get the gene into the liver cells?

桑迪——它叫做腺相关病毒,所以it's related somewhat to the cold virus.

Chris - And how does the liver tolerate that? Is it quite comfortable to have this virus going in there?

Sandy - Mostly. Most patients tolerate it very well. Occasionally, patients will get a slight inflammation of their liver and that's something that we need to monitor carefully, and so for the first 3 to 6 months of the patient's treatment they'll be having their liver enzymes measured on a weekly basis. Very few have had any trouble with this course of treatment.

Chris - And how much virus do you actually have to administer to the person in order to treat them? Because you've got to presumably hit a lot of cells in order to get them making enough of the factor, and that means you're going to need a lot of virus?

Sandy - You need to hit a sufficient number of cells to produce the protein. You give a very large number of virus particles: E to the 11, E to the 12, E to the 13. These are more than grains of sand on the beach.

Chris - That’s a hundred billion plus, isn't it?

Sandy - Yes. It's a huge amount.

Chris - Can you make that much easily in the lab? Because that's been one of the problems that’s held back this field in the past is actually scaling up the amount of virus you need to do it in a way that's going to be deliverable for the numbers of patients that we need to treat.

Sandy - Absolutely right. One of the most important things in this field is having reliable manufacturing. It's possible to do this, you make large vats of virus - a bit like homebrew - and you create virus in the billions, as you describe. It needs to be done with quality because patient safety is the most important thing.

Chris - The liver cells aren't long-lived like a nerve cell though are they? They turnover, they die off, and they’re replaced. So that means, presumably, you're going to have to keep doing this to keep the levels topped up in the person?

Sandy - Our liver replaces about 1/7 of its cells every year, so over the course of 10 years you'll be replacing a lot of the cells. Gene therapy doesn't pass it on to the daughter cells, to the next generation. We need to follow these patients out for a period of time to see how long it lasts, what's the durability. But if I was a patient, if I could get 5 to 10 years of benefit from it, I think that's a good balance of benefit and risk.

Chris - So where are you in the trials process now with this?

Sandy - We're in the proof of concept trial. We've seen some really powerful results from our virus and our construct, and then we're at the stage of handing it over to our partner Pfizer, who'll take it into phase three and then to registration.

Chris - One problem that people who have to inject factor VIII for haemophilia experience from time to time is, because they're putting into their body something that their body doesn't naturally make, the immune system regards it as hostile and you get an immune response against it. And that means that actually they then don't get any therapeutic benefit through injecting it. Is there a risk - because you're putting in something that some of these haemophiliacs aren't naturally making with your virus - you're going to have the same problem?

Sandy - A great question. And there's a cohort of patients with antibodies to the factor that mean that they would be excluded from the current trials, and there's other medicines that other companies are developing for them. Nobody has yet seen that reaction from patients with gene therapy, and it's perhaps because it's given chronically in low levels and perhaps something to do with the liver that we can avoid that. But of course we need to follow these patients long-term to make sure they get continued benefit from it.

Chris - How do you actually get the virus just into the liver?

Sandy - We infuse it into a vein. It's a very unremarkable process where the patient waits for an hour or two while the drip slowly drops the virus into the vein and it manages to find its way there.

Which would you prefer: a plane flown by humans or one that is fully controlled by autonomous systems? Currently, aircrafts are controlled manually by a pilot but can also switch over to autopilot, an automatic system. In some cases, pilots can be in full control of the airplane for as little as 10 minutes throughout an entire flight. To find out exactly how safe this level of automation is for autopilot, and whether it could replace humans altogether, Matthew Hall set out to Cambridge Airport...

马修-商用飞机的自动驾驶仪come to the point where it's been implemented in almost all aspects of flight - all except the takeoff process. It's a little scary to think about just how much of our safety, while airborne, is in the hands of an automated software. We do also have the pilots that can take control at any time, in case of an emergency, but what if something were to happen to those pilots? Are we at a point now, in automation, where a novice could grab control of the plane and potentially land without incident? In a mission to discover more about present and future autopilot systems, I took off toward Virtual Aviation Airline Training which is home to a flight simulator used to train pilots for commercial aeroplanes...

本,今天,你将会看到飞机simulator - it's the Airbus A320 simulator and it's a device that is used to train pilots and it simulates the flight deck of an Airbus A320.

Matthew - That's Ben Boness, an aeroplane pilot and flight simulator instructor who is going to coach me through the landing process in his flight simulator.

本-The simulators are as close to the real aircraft as you can get. We use official system that simulates the outside environment, but all of the switches and the controls within the simulator are exactly the same in terms of look and feel as per the real aircraft. So the autopilot has to replicate what the autopilot would do on the real aircraft for us to have the aircraft or the simulator certified for what we use it for, so it is a hundred percent exactly the same as per the real aircraft. The only difference with the simulator, of course, is that there isn't motion. It's a fixed base simulator but apart from that everything is exactly the same as the real aircraft.

Matthew - But it's a simulation. What are some of the controls that you can do with this simulator that you can't do in real flight?

本-We have the ability to freeze a simulator. So if we want to cover some points of learning we can just freeze it and then talk about the particular manoeuvre, or what we’re looking at in the simulator - so we can freeze time. We are able to simulate different conditions, we can introduce failures, so that the trainees can see how the aircraft reacts. And we can change the position of the aircraft as well, so we could one minute be making an approach into a particular airfield, and then 10 minutes later we could reposition it to another airfield to look at a takeoff.

Matthew - If something were to go wrong and the pilots were unable to fly this plane and one of the customers at the back had come in and fly this thing, had to land it, is the autopilot in a condition where a novice, like myself, could take control and land a commercial sized aircraft?

本-I'm confident that we can talk you through how the autopilot flies and the different modes we can use to operate it and we'll see if you can land the aircraft yourself. I'm confident you'll be able to.

Matthew - Well no pressure then!

Ben then took me through an open hangar full of planes housing the simulator entrance. He opened the doors, and I was immediately in awe at the sight from the other side. The simulator itself is a massive metal box, easily the size of a living room, and on the inside metal box half of the interior was just dull white walls but the other half was alive - with the lights and controls of a perfect 'copy and paste' replica of a cockpit from a commercial aircraft.

Ben shut the soundproof doors, turned on the simulator, sat me down in the captain's chair and programmed the scene for an in-flight emergency situation. The pilots are down; I've been thrown into the front, I’m at 35,000 feet and I have no idea if I can land this thing.

本-So you need to come forward.

Matthew - The first step: activate the autopilot which is turned on simply by pressing a button labelled AP1.

The second step: descend to 20,000 feet which is controlled by turning a dial anticlockwise until the number 20,000 is displayed on the screen. And just like that, the plane cuts its throttle, and starts descending with no further control from me where it will eventually level off on its own.

The third step: once cleared by air traffic control is to get to 1300 feet in preparation for landing.

本-Okay. So we've now descended from 35,000 feet and we find ourselves 3 miles from the runway, 1,000 feet above the ground, currently flying at 140 knots and now it's Matt's job to get us on the ground.

We’ve been talking about the future of aviation, and that future might be electric given that batteries are overall a cleaner energy source than fuel. Fully electric cars are everywhere now and batteries are constantly improving their capacity by about 5% each year. But that being said, why is there still no Tesla equivalent for aeroplanes? To find out, Izzie spoke with Paul Robertson, a senior lecturer in electrical engineering from Cambridge University.

Paul - There are some leisure aircraft, which are just one or two seaters, which are purely electric but they're very much limited by their range and flight time. So typically up to about an hour’s flight time would be what's currently achieved in these sorts of aircraft. It's a 'hot' research topic at the moment, looking at moving up to larger aircraft from your two seater, four seater, nine seaters up to airlines sort of scale

But one of the major issues which limits electric aircraft is the power density in the batteries. By that I mean for a given weight of battery, how much energy can you store compared to burning fuel using a conventional engine? And at the current time, equivalent weight-for-weight batteries or fuel, then burning fuel gives you about 20 times the energy that you'll get from batteries.

Izzie - Wow. And what about the mechanics going on, say, with a car compared to a plane, does that impact anything at all?

Paul - In cars, when weight is an important issue in cars, for performance and to a lesser extent for range, but in an aircraft it's absolutely critical because the total weight of the aircraft determines how much power you need to fly and so if you're storing a certain amount of energy that tells you how far or how long you can fly for. By increasing the weight of batteries, for example, in an aircraft, you make the overall aircraft heavier, it therefore requires more power. So if you just double the number of batteries, the weight of batteries, that does not double your range because you’ve paid a penalty for the extra weight that you're carrying.

Izzie - If we were in a situation where we could get rid of all of the fuel, with the batteries we've got at the moment, how far could a plane go?

Paul - If you're to take out of say an airliner, you took the engines off, you take the fuel tanks out and you replace that equivalent mass, that weight with batteries and electric motors, if you could do that your flight time would probably be around half-an-hour.

Izzie - That's not very much at all!

保罗,这是相当有限的。然而,有some applications where even short flights of that sort of endurance are useful. City to city hopping is a possibility. We still though have the issue, how do we recharge the batteries or do we swap them out, what do we do in order to refuel the aircraft? Because the infrastructure to do that is very different to what we currently have which is just piping liquid fuels around. So it isn't just the technology of the batteries in the aircraft themselves, in any sort of commercial application we have to think about the infrastructure which goes around it.

Izzie - And what are some of the other major issues associated with say an all electric commercial aircraft?

Paul - Okay. So we've talked about the batteries which is the main one. There are lots of other things which concern us if we're going to commercial aviation. We need to look at legislation and certification, so that's what makes the aircraft safe, how do we prove it safe, and how do we operate it. If we change the propulsion system from our normal aviation fuel to electric then, as I say we need the ground infrastructure, we need all the testing and qualification work to be done. We need to rewrite the manuals on how the pilots are trained for these propulsion systems, we need change to simulators.

So there's a lot behind commercial aviation and, in fact, the regulations are really only just beginning to be looked at now for how do you certify these sorts of aircraft? It's not so much in issue at the very small-scale, leisure aircraft, there are experimental categories we can work in there. But when you move to passenger carrying the general public, then it's a very different regime and everything needs to change basically as we move from our current fuel burning approach to a purely electric approach.

Izzie——可能我们看到的组合燃料和蝙蝠teries? Is that something that would be possible?

Paul - Yes that is. That's what we call a hybrid electric propulsion system. What we're doing in that case is we are assisting the conventional fuel burning engine, whether it be a turbine or a piston type of engine, we're assisting that with an electrical boost, or we’re combining an electrical machine with that fuel burning engine so that we can improve the overall efficiency of the system.

Izzie - And so would it be that you'd have the batteries to get off the ground but you'd then use fuel for once you reach your correct altitude?

Paul - Yes, that's the basic idea. Burning fuel, because of the large amount of energy it stores in a given mass, then that's a good way to propel yourself a very large distance. But the addition of an electric boost means that you can optimise the size of that fuel burning engine for that long cruise condition and the extra power you need for takeoff and climb is provided by the electrical system.

Izzie - And what about going fully electric, could that be a possibility?

Paul - It's a possibility, but I think it's quite a long way off. The density of the energy storage in batteries is not high enough at the moment and it'll probably be some decades before we can store enough energy to take an aircraft to match the sort of ranges which we can get now. So going transatlantic, transcontinental, it would be very difficult for a purely electric aircraft to do that for some time yet.

While electric propulsion remains in development, liquid fuel reigns supreme which is not good news for air pollution emissions. A 747 burns on average 5 gallons of fuel per mile! Multiply that by several hundred miles a flight and then by several million flights a year, the emission toll adds up quickly. To find out how much of an impact this has on the environment and if there is a solution Adam Murphy and Izzie Clarke spoke with Hector Pollitt, director and head of modelling at Cambridge Econometrics.

赫克托耳,我们仰望天空,我们看到aeroplanes with vapour trails and we think oh, this must be causing a lot of pollution. To some extent this is true; however, at the moment the aviation sector accounts only for 2% of global emissions. The concern is that whereas most of the other sectors in the economy are starting to decrease emissions, in aviation we're very much seeing the opposite going on, and it's predicted that in the coming decades overall emissions from aviation could triple.

Adam - So where is this increase coming from? Why are we seeing it going up?

Hector - Yeah in summary we're seeing more flights overall, more aeroplanes taking off and landing, so more fuel being burnt and more emissions resulting. In the UK, there's this constant debate about the expansion of Heathrow in the southeast; and the airport capacity, of course, that is another way of enabling more flights. Even more important than that is the growing size of the middle-class in the developing world and all of these people with their newfound wealth who want to go to other countries, other continents, and see other parts of the world for themselves.

Adam - Now we heard about the issues and challenges behind electric flight, but are there any other solutions being tested or implemented right now that can help?

赫克托-是的。我认为在气候由e change we're always looking to technology for the solutions. We heard about electrification as one possibility in aeroplanes. There are also potential biofuel options that are out there in the future. Again these are still under development and we don't know how that will go, but they may be something that's a bit more realistic in the shorter term. Also there are some specific short run measures that would improve efficiency in aeroplanes. One option would be even getting the airlines to use the latest flight planes available to improve efficiency. Also reducing taxiing on runways, for example - planes could be pulled up rather than operating under their own thrust in the airports. And a more rational flight path through the air traffic control services, and that could reduce overall distance per flight which would help a bit. But these are only short run solutions.

Adam - You mentioned biofuel, what exactly is that and what state is that in?

Hector - It's an area where there is a lot of research going into at the moment. It hits some of the same issues that we heard with the electrification about the power-to-weight ratio in the planes. I suspect at some point we will start to see a blended fuel coming in, a bit like we have in petrol in our cars, so you'll start to see an increasing proportion of jet fuel kerosene being mixed with biofuels. It's still at a reasonably early stage though, we can't say anything for sure on this topic.

Izzie - What actually would they be mixing in with kerosene?

Hector - Yeah, that's a good question and I suppose it really depends on how the technology will go. We hear quite a lot about algae-based research and next-generation biofuels, so it's something that's a bit different to the corn that's grown and converted into biodiesel that we put in our cars at the moment.

Adam - What's the future here? Do we see an end to this problem?

Hector - It's going to be very difficult to stop people from flying I think, particularly in the developing world. I think when it comes to climate change though, the state we’re at now, and not least we're seeing the record temperatures last week, I think we really need to throw everything that we can at the problem, so I would propose a multi-pronged approach. Yes, let's try to reduce our own flying a bit. Putting a tax on aviation fuel which is currently pretty much tax-free at the moment would certainly help with that. Consider airport capacity, whether it’s really necessary going forward. Let's use the most efficient planes that are available. Let's put in these other efficiency measures as well and do the best that we can with that. Let's see where we can go with these new technologies as well - just throw research resources into it and maybe something will pay off in the long run.