Monica McCard: and climate change is our biggest threat right now to when we think about marine organisms, that's our biggest threat. And actually the second biggest threat is land fish.

Jenny: Hello, I'm Jenny Hickman.

Rebecca Nesbit: And I'm Rebecca Nesbit. Welcome to Cat Among the Penguins. Today we're going to be asking the question, can we stop the lionfish invasion? And Jenny, when you suggested this, it felt like a very loaded question because of that word, invasion. What is evasion? What is the problem here?

Jenny: Yeah, so lionfish are probably one of the world's most famous invasive species. So they're incredibly beautiful. They've got these really, really bold brown and white stripey patterns all over them. They've got these delicate flowing, very elegant fins and they're covered in highly venomous spines. They're really, really venomous. they're originally native to the Indian and Pacific oceans, but They've moved into the Atlantic and they can now be found along the southeastern coast of the USA. and down into the Caribbean Sea and even as far down as Brazil. It's not fully clear how this invasion started. So the most kind of highly cited reason is Hurricane Andrew, which was in 1992, really, really strong hurricane. And people believe that Hurricane Andrew blew through South Florida, broke open a public aquarium and released these fish into Biscayne Bay. but there's a lot of skepticism around it being Hurricane Andrew as the culprit. Mainly because there are sightings, that date back further than Hurricane Andrew, but also because it seems a little bit too specific for a hurricane to kind of blow everything apart, but very specifically just release these few fish. So possibly more likely the reason is releases back into the wild from home aquarists who have had them in tanks and got a bit fed up of them.

Rebecca Nesbit: Okay, let me get that right. So people at home keep these highly venomous fish in tanks.

Jenny: Yeah, they're actually really, really popular home aquarium fish. So it's actually one of the reasons that they're super economically important is people love to have them in their fish tanks.

Rebecca Nesbit: People are very, very strange.

Jenny: are kind of crazy with their fish tanks.

Rebecca Nesbit: So I'm learning and I did already know that there are some pretty crazy fish tanks out there and that it is relatively common for people to get pets that are cute, grow big, don't want them anymore and then release them into the wild and that's why for example there are so many terrapins in parks. But lionfish seems like a really bold choice to have in your tank.

Jenny: It's a super bold choice. And I think it might become a little bit clearer when you see a baby lionfish. I've got an image I took of the smallest lionfish I've ever seen on a dive in comparison to my friend, Dom, who I was diving with. And we'll put that up online because baby lionfish are super, super cute. They start off really, really tiny. And they look super innocent, but obviously you put them in a home tank. very very quickly they get very big, they eat everything in sight and they're also really venomous so it makes working on your tank really really difficult but people are crazy they'll keep all sorts of things.

Rebecca Nesbit: I see why that would spoil your hobby being dangerous to clean out your tank. Okay, so just to clear up some terminology here, we're talking about an invasive species and that's different to a non-native species or introduced species. A non-native species is simply a species outside of its known range. It's only defined as invasive when it starts to cause problems for the ecosystem for the other wildlife. So given your wording of the title, are we safe to assume that lionfish are causing a problem?

Jenny: Yeah, for sure. Unfortunately, in this case, lionfish have gone way beyond non-native and they are causing big problems for coral reef ecosystems. So they're what's known as ambush predators, which means they're incredibly good hunters. They have these big extendable jaws and they will basically eat, they can eat anything that will fit in their mouths, that in some systems where lionfish have taken hold, they actually make up 40 % of the predator biomass. and they reduce native prey fish by up to 90 % in comparison to around 30 % that you would expect from predation by native predators.

Rebecca Nesbit: 90 % that's really quite scary that one species can be that effective. So what is it about them that makes them so unstoppable?

Jenny: This is where it gets super cool. So I spoke to Dr. Monica McCard, who is a lecturer in environmental science at Liverpool John Muir University. She specialises in invasive species and has been studying lionfish for over a decade. So she knows her stuff. When I asked her what it was about lionfish that made them so successful, she had a lot to say.

Monica McCard: they have like these what we call a perfect invader. set of traits they really do. It's like an all-round invader traits that makes them so good at what they do and high fecundity rate is the first one. so they reproduce very very quickly and when they do that they produce around about 15 000 eggs every three to four days so one female can produce at least one million eggs per year they spawn year-round so it's not like they'll only spawn at certain months of year like other species will do they spawn year round they eat small reef fish and crustaceans so they'll eat at different levels in the trophic chain they're not really that picky to be perfectly honest There's been anecdotal evidence of them taking bites out of sharks and groupers and eels that would be their big predators back in the native range. So when they're in an invasive range, it's almost like they just go to town. so they've got 18 venomous spines around their body. Just think about something having an armor all the way around them so that anything comes near them, they can use that armor instead. when they reproduce, this happens when they're under a year old. So it's usually between 10 and 18 centimeters long. That's when they start to reproduce from that. And that's not that's tiny. Exactly. That's such a small fish. And from that size, that's when they start reproducing. That's when the chaos starts. like I say we call them the perfect invader they are the perfect invader because of the traits and all of those traits together you know normally in an invasive species we see maybe one or two traits like that but with the land fish with all of these traits that make them so successful

Rebecca Nesbit: Okay, that really is the perfect invader. One species with all those different traits seems pretty rare and it makes sense how they could take over just so quickly and so convincingly.

Jenny: Yeah, and to be very, very clear, I had to edit that a lot. Mon had a good 15 minutes of content about how perfect these animals are at invading. Like

Rebecca Nesbit: it's clear they are a huge problem. We need to do something about it. And the very obvious choice, which I do hear about, for people to control them, to cull them. And I do hear about this happening, including about lionfish derbies, where people organize specific events to go out and fish for lionfish. From what I understand, it's now popular with... divers in various places in the US and the Caribbean.

Jenny: Yeah, Spear fishing is a really popular thing for a lot of divers to do now. And like you say, divers will organize big derbies and even conservation organizations will organize these. And even in places like protected areas where no fishing is allowed, no take zones, even in some areas like that, lionfish removal is still allowed.

Rebecca Nesbit: it seems like there's this real community response which can bring people together. However, I do know from previous stories such as the Cane Toads in Australia that mass culling efforts don't always have the impact you would expect.

Jenny: Yeah, and this is exactly part of the problem. In one sense, it's a really, really easy community response. People can see a problem and they want to take it into their own hands. This is a great way of doing it. But plenty of people argue that culling is just not effective. So we put the question to Mon and here's what she had to say about it.

Rebecca Nesbit: Okay.

Monica McCard: Cullen is effective locally. It's like on priority reefs. or dive sites or MPAs or anything like that, but it's not eradication. It isn't. It's not effective for eradication. That's not going to happen now. We've got to the stage with the lionfish invasion that will never be able to eradicate them. But culling is effective. But I think it's more just locally, not because it needs to be frequent. It needs to be sustained because landfish reproduce so quickly and recolonize that actually those removal targets, you know, they matter. But if densities are not pushed below, ecological impact thresholds, opposed to prey fish are going to still decline. So actually those the colon effect, it actually isn't really a management tool when it comes to those sort of bigger reefs or a larger system. But if it's a small problem locally, then Collins, it can be effective. It can be. But it isn't, it's not everything.

Rebecca Nesbit: some really interesting points there. So what I'm hearing is that culling works on a small scale. You can decrease lionfish densities enough to make a difference to the fish species they feed on in a small area, but there's no way that this will lead to lionfish eradication and it won't even work across larger reefs. It's only something you can do on a very small scale.

Jenny: Yeah, and there's actually a really interesting study which supports this and kind of adds a little bit of extra complexity to it. So there was a team of scientists in the Bahamas and they decided to survey twelve reefs across two years. every time they went out and surveyed, they would count lionfish. For some of those reefs, they would cull lionfish every time they went. For some of the reefs, they would cull lionfish half of the time they went, and for some of the reefs they didn't cull lionfish at all. And they wanted to see what kind of impact this was having. and at first it looked exactly like you would expect it to look. The cold reefs were reducing in lionfish numbers, it was up to I think 79% compared to uncold reefs, reduction in lionfish densities. but then a category three hurricane came past and completely changed everything because after the hurricane, the cold reefs actually saw. a really big increase in lionfish densities in comparison to the unculled reefs. So average lionfish densities on the reefs that they culled increased by six hundred and thirty three percent.

Rebecca Nesbit: That's a really confusing statistic. The plot really thickens because not only does a hurricane cause huge increases, but the culled reefs actually end up with more lionfish on than the unculled reefs. Why is that happening?

Jenny: It's a super interesting question. So I asked Mont and she had some interesting points.

Monica McCard: it could be that the local culling has suppressed the visible population But it doesn't actually remove those wider regional source population of land fish just because culling has removed what you can see that day doesn't actually mean that's even touched the edges of the population of land fish that's there in that area because they're very clever and they're very good at hiding and Storms may actually displace lionfish from the deeper or nearby habitats onto these monitored reefs and that's why all of a sudden you see them because that's where you're monitoring anyway. be that the storm has altered the reef structure itself and creates this brand new shelter for landfish. all of a sudden landfish then move from one area to another area

Rebecca Nesbit: So essentially Monica is suggesting that although lionfish culling may appear to reduce populations on the reefs, it's likely not having an overall impact on the wider population in the surrounding areas. So I can see why that would mean culling isn't effective in the long run. The lionfish are just going to re-invade. That makes sense. We've seen it in lots of other ecosystems with other species. But what's really concerning me here is why do the populations on culled reefs end up even higher than on reefs that weren't culled? Why has culling actually made the problem worse after a hurricane?

Jenny: Yeah, that's the super interesting bit, but it's actually not fully understood So there's something known as density dependence, which is essentially the idea that lionfish will preferentially go to live on reefs that have lower lionfish populations. So the paper mentions that a lot of the lionfish seen on the cold reefs after the hurricane were smaller, which suggests that potentially these smaller lionfish have kind of picked these reefs because they had lower lionfish populations, lower lionfish numbers and therefore less competition.

Rebecca Nesbit: Yeah, that's a really interesting suggestion, and I can see why this can only be speculation. I'm not sure how you would even do a study to test what's really going on here. So I see how we're just going to have to not understand the reason but know that that's a a very concerning point, I would say, in relation to culling. So it takes me back to our initial discussion where you mentioned that Hurricane Andrew is often blamed for starting the lionfish invasion. Do you think that that perhaps wasn't necessarily the start of the invasion at all? It was just that Hurricane Andrew was disruptive enough that it made the problem more visible, and this is when people started to take notice.

Jenny: Yeah, to me that seems pretty likely because like I say, people had seen lionfish before Hurricane Andrew. They had been seen off the coast of the US. Hurricanes do a couple of things. They disrupt water currents and water currents can act as a barrier for small or larval lionfish that can't normally cross them. And actually the sort of repeated breakdown of the Florida current by various hurricanes has been cited as a reason why perhaps lionfish were able to invade the Bahamas in the first place. What hurricanes also do is they mix all of this deep water and bring it up to the surface layers and lionfish, what we know is that lionfish thrive in deep waters. One of the big untapped problems of this lionfish invasion is that they can live down really deep. I'll pop up on the website, there's some really cool footage. Well, cool, depending on how you look at it. There's some footage that a submarine filmed off the coast of Bonaire over a hundred meters down, just absolute field of lionfish. So many lionfish down at depth. and the hurricanes will bring all of these deep waters up into the surface. So it seems pretty likely, and I can say from experience that the effect is very visible. So I actually met Mon when we were leading an expedition together in Honduras and we were diving on the reefs every day. She was there researching lionfish and one day a category five hurricane was barreling past off the coast. Fortunately it didn't hit us, but we had to sit out of diving for a few days. And the first dive we did after that storm was an absolute lionfish fest. They were everywhere. So it's a visible effect.

Rebecca Nesbit: And I'm really starting to picture what this lionfish invasion is actually like. So, to summarize, we've got a complex situation where culling potentially makes things worse in the long run after hurricanes, but it can seemingly be effective at creating short-term, small-scale reductions of numbers in particular areas on the smaller reefs. So even if it isn't a long-term solution, it might be reducing local populations, so can it still be beneficial, particularly as it's likely a good community engagement strategy, thinking back to those limefish derbies.

Jenny: Yeah, possibly, but we have to be really, really careful how we approach it. And lionfish derbies are one of the things that I asked Mon about, because they are growing in popularity and you'll get loads of divers that come out. But it does seem like that in itself could be causing some problems.

Monica McCard: They a lot of areas, especially in the Caribbean and in Florida, they put notifications out that they're going to have a big land fish derby. You've got a lot of people in the water then with spear guns and with whatever to try and remove as many land fish as possible. I don't believe that land fish derbies are the way forward It's almost making light of it and making this like a game reserve and everybody's in trying to get the land fish but they're destroying maybe reefs when there's so many people in the water. But when you make light of something as damaging as this or make it exciting to be a part of, then what happens when the land fish move off to a different area and they're no longer there? It's very easy for people in that area then to start putting them back in again recolonize again because the land fish derbies are so exciting and they're bringing people to an area, maybe put money into the economy. So I don't think it's a good management strategy.

Rebecca Nesbit: Yeah, I suppose this takes us back to the whale shark episode that we've got coming up later in this series. So anyone who isn't subscribed yet, click subscribe so that you don't miss the episode where we face some of the uncomfortable realities about the incredible experience of swimming with manta rays and whale sharks. Because while this type of thing can bring in money to the local economy, it also introduces huge numbers of people who aren't necessarily conservation-minded. aren't always good divers and they're going out into very sensitive and fragile habitats.

Jenny: Exactly. And then we end up doing more damage than good. And what one said about the potential for people to start reintroducing them is actually not beyond the realms of possibility in terms of what we've seen from people before these fish are pretty easy to buy in fish shops. And this is the type of thing people have done before with game hunting and pheasants and even canned hunting where people raise animals like lions specifically for the purpose of shooting them. This is something people will do if there's an economy behind it. However, as with all of these things, I never feel like the story is this simple and I wanted to the other side of it. So I reached out to an organization called Lionfish Caribbean. So Lionfish Caribbean was started by our next guest, Lizette, as a response to the lionfish invasion that she was seeing where she lives in Curaçao. So she had started to see these invasive lionfish and she started to catch them back in about 2009 and market them as a food product and sell them to restaurants. A food product.

Rebecca Nesbit: food product. So so people eat lionfish. What does it taste like?

Jenny: I've never eaten it, but apparently it's really, really tasty. And actually she was really enthusiastic about not only how tasty it was, but how good the meat is and how clean the meat is. So apparently it's, yeah, apparently it's delicious. I have never tried it, but I suppose that just means we need a trip to the Caribbean, right? Yeah, so she started this as she just went out and started catching some lionfish, selling them to local restaurants. At one point she started a food truck.

Rebecca Nesbit: really? Okay. Interesting. I mean.

Jenny: And it all kind of grew from there. And then she started making jewelry out of the lionfish. So nothing was wasted. And it's a really cool organization. It's grown. They now have a community of about 50 divers that go out and catch lionfish for them. They're all part owners of the organization. They do outreach and education. But they also run derbies. So I wanted to talk to Lizette about her take on derbies. And she has a very different take on it.

Rebecca Nesbit: Well.

Lisette - Lionfish Caribbean: Okay, so lionfish hunting, every location is different. So for example, the Caribbean reefs are way different than the Florida reefs are way different than the Gulf. But every location has a different way of diving and hunting for lionfish because here in Kyrgyzstan, for example, we have a very nice, dense reef. So there's a lot of coral, lionfish live in and around the corals. So you need to be very aware of your buoyancy and not holding on to the reef, not missing because if you miss you could break something right? But for example in the gulf there's not a lot of reef it's just like sand with little patches or chicken cubes or bridges that broke or what people put stuff there and there you see a lot of lionfish around those spots. So basically there you can sit on your knees in the sand and just like shoot all the fish around it. about the derbies. It has this thing of course that you're pushing people to catch lionfish to go for the biggest to go for the smallest, you know, and this loosens up. this inner thing in people that they are like, I need to win this, need to win this. So that's very difficult. You don't want them to break stuff in order to win the competition, right? But also in lot of places, there's not a lot to break anyways. We organize a derby and then there's like 50 people coming up there, but they're All of them are local lionfish hunters. They are already within the community. A lot of them are dive instructors. And they know this and we emphasize it again, right? And it's for the reef safety, but it's also for the divers safety, not to go longer and deeper or to hold on to the reef to just get that one fish For example we don't give a price for the smallest fish because we don't want people to catch like the tiny fish because it's hard to aim for and if you miss it you could break a piece of the reef. And also we say like leave the smaller fish for the moray eels because Now, we do see that lionfish are eaten by moray eels. So I am definitely not against derbies, but I do think that the organization needs to emphasize a lot about reef safety.

Rebecca Nesbit: And that is a good point because not all reefs are the same. So why should we expect derbies to be treated the same? And that view very much makes sense to me that derbies are fine when they're not on sensitive reefs, if there are rules in place and if divers know what they're doing and perhaps a part of a community that's self-policing, I can really see how that could work. I just wanted to clarify something as a non-diver. What's the difference between reefs where derbies are or aren't appropriate? What makes something sensitive?

Jenny: Yeah, well, think Lizette's point here was that reefs can be really different. So where she is in Kurosawa, she said she's got a very, very dense reef, which means you'll have lots and lots of natural reef, lots of reef building corals, it will cover a lot of the floor and you do have to be really careful. Whereas there are lots of places in the world, either naturally or because of kind of large scale die off of coral, where there's a lot less coral, it kind of occurs in smaller patches and there's a lot more bare sand.

Rebecca Nesbit: Okay.

Jenny: So it is a lot easier to avoid the coral in those areas. can kneel on the sand and look at the coral and you're not touching anything, which is a lot harder in a dense reef. And in those places you will get what she's talking about there. You'll get people putting a lot of kind of artificial structures in often to kind of regrow the reefs. Some of them are sort of more deliberately made than others. You sometimes get stuff just chucked in that's broken. Like in the UK, we get a lot of tires and things like that. You will get things.

Rebecca Nesbit: you

Jenny: just kind of put there to rebuild the reefs, which have differing effects. And I'm sure that's another episode. so as she says, derbies can run differently in different reefs and you really have to be careful. how you're running them and also the types of divers that you can expect to see there. Are they confident divers who are used to managing their buoyancy around a sensitive reef or are they just hobbyist divers who are gonna be kicking things? It really does make a difference.

Rebecca Nesbit: Yeah, as with everything, it's not just what's happening, it's the details of how it's managed, who is involved. if Lionfish Caribbean has been running for a long time and organizing these derbies over the course of years, I assume that she must have seen some changes in the lionfish population.

Jenny: Yeah, so Lizette's been going out for a long time and she definitely said that some changes had been seen on the reefs. But it's really, really difficult to know that these are definitely down to culling. So here's what she said she's seen on the reefs.

Lisette - Lionfish Caribbean: Yeah, so when I started lionfish hunting in 2010, they basically were everywhere. But lionfish also just arrived on our island or in the South Caribbean, right? And they were very ignorant. They were hanging on the reef. You could even stab them just with a knife. didn't need almost didn't needed a spear, right? So when we started to catch it, we did, and I still do see on shallow reefs where people are catching lionfish a lot, you definitely see less. even also with the temperature here in Curaçao, when the water temperature rises in the summer, we see less lionfish. than when it gets cooler because what we think is that they get go deeper. know, so I do see changes in behavior and then it's always the question does this come because of the hunters because of the human activity? maybe lionfish also know how to hide better, so they go deeper and deeper in the reef. Maybe the trumpetfish and the moray eels start to eat it. Maybe the water temperature makes a difference on it. That I don't know, I've never researched it. But yes, I see differences and I also see that lionfish respond when they got... hunted before and when they got missed or when they swim of a spear because that can happen once in a while they know those fish are smart

Rebecca Nesbit: I suppose that backs up a lot of what we've already seen, and it seems like Culling potentially could be reducing the numbers, but it isn't actually very clear what the real story is and is there a real impact and what other factors are at play. It does seem promising that there seems to be some sort of evidence that predators might be starting to recognise the lionfish.

Jenny: Yeah, for sure. It's definitely possible, but it can't really be relied upon to kind of battle an invasion like this, unfortunately. So even in their native range, it's not really thought that predation on the adults is much of a limiting factor for them at all. It's thought that their big limiting factor is predation on their eggs. So what Lizette said about potentially trumpetfish starting to recognize their eggs, that would be a huge starting point because that appears to be what keeps them under control in their native range.

Rebecca Nesbit: Okay, so where does that leave us? Sounds like predators won't solve the problem and culling has serious limitations. What are we left with?

Jenny: Yeah, so I put this question to both the guests actually, because I wanted to know what other options were there, like what are we left with? And they both talked about a possibility for traps, which sounds like there is some promise to them. So specifically traps that being developed to catch fish at depth, which is one of the places we really can't reach them and they really are hiding away down there. So effective methods of catching fish at depth sound promising. And they also talked about... A robot Hoover that was being developed to potentially sweep some fish up off the reef.

Rebecca Nesbit: Wait, a robot fish hoover. What sci-fi film have I just walked into?

Jenny: Apparently so. Yeah, apparently so. I'm not, I can't say it sounds like it's going to be the most effective solution. I would quite like to see it working, but well, exactly. Especially down at depth, you know, there's some sensitive reefs down there. So yeah, I'm not sure.

Rebecca Nesbit: Mm-hmm. I'd like to see it not damaging those reefs. Does it know not to touch?

Jenny: robot hoovers are the way forward. And the problem with both traps and robot hoovers is that they are a bit indiscriminate and they can have a lot of bycatch. So, which is sucking in things that they weren't initially supposed to catch. So possibly not the solutions. But one thing Mon raised that was quite interesting was the potential for fishes to benefit from the rise of lionfish.

Rebecca Nesbit: Yeah. Yeah.

Monica McCard: especially in those sort of countries that where they're invading right now and those small communities that rely heavily on the fishermen going out and catching fish and then coming back and then there's nothing there because the land fish have eaten them all. To me that's where those fishermen should be collecting, they should be spearing the land fish, they should be collecting the land fish and they should be selling them to the restaurants. That's where it's effective when it's paying money back into the people that are losing money because of the land fish. not necessarily about making sure we remove all of them because you can't. It's about making sure that people that are losing out because of them, because of their impact in that area, it's about making sure that they get something out of it. We're utilizing derbies like this and instead we should be utilizing the fishermen and paying them

Jenny: So with this new information from Mon, I wanted to then put this question to Lizette. I knew Lionfish Caribbean involved a lot of the local community and I wanted to know how or if they involved fishers and this is what she said.

Lisette - Lionfish Caribbean: Yes, so local community, it's a mix of people of course. So you have of course the, Yudicourcao as we call that. It's like the kids of the island. They were either born and raised here there's also a few expats or people that are either Dutch or Canadian or America that moved to Curaçao. And then we of course also have the local fishermen. And what I now really try to do is to reach them and to get them more involved. But that's difficult to be honest. we reached out recently to the association of fishermen. There's like this association. It's like, hey, how can we get them more involved? Because we need the fishermen also to catch more lionfish instead of other fish, right? There's a fish out there that, bad for the reef, is bad for the local fish community and great on your plate and we want to buy it. It doesn't matter the size or the amount. But the problem with lionfish is of course they're quite small, right? So they're like 15 centimeters to maximum of like 40, 45, what we catch And only 20 % is filet on it. So everything combined I think makes it difficult for fishermen also to go for it because first of all, you need to go out free diving in order to catch it. You need to have a spear for that and a tube where you can put it in. So it's first of all, more gear than just a line. Second of all, you need to know where you can find them because they're very hidden in the reef. You need to be a good swimmer. Not every fisherman is a swimmer actually. For the restaurants it's hard because not every chef knows how to clean it. And it's not difficult. It's not dangerous for the people who eat it. It's just dangerous for the people who clean it. But I think also most importantly is like one lionfish is quite some work compared to one big snapper. So one lionfish weighs maybe like two, three hundred grams and gives you a little piece of filet. Where one good snapper easier catch maybe, quicker, more efficient with a capital F.

Jenny Hickman: Yeah.

Rebecca Nesbit: Okay, so lionfish are impossible to catch by normal fishing gear, they're smart enough to learn how to avoid humans, they can live absolutely everywhere, and they have unstoppable survival skills which don't seem to be beaten by culling. I see why they're so successful, but what did Lizette and Monica have to say about what can be done from here?

Jenny: Yeah, it starts to look a little bit doom and gloom, doesn't it, by this point? But I think between them, they seem to have like a range of approaches, which I think makes quite a cool lionfish toolbox.

Rebecca Nesbit: It does.

Lisette - Lionfish Caribbean: So I think the way lionfish Caribbean, is handling lionfish populations around the island is really really cool to be honest we control the population, we serve the fish, we do the education and awareness and then we add value to the fish, to the catch by using their fins and their skin and their meat and their spines and whatever you know. You have education and awareness You have healthy, sustainable seafood option to eat. You have a cool product, which also again, raise awareness. you can pay a fair price to the people who go out and catch it We can involve the local community and create jobs and opportunities, and what I also like, it's local. You don't have to fly your fish all over the way over North Alaska you eat local, support the local community. you help to protect the reef. So I think Life is Grieving is already doing what I believe is the way to go. I do think we have to do more, Research how we can catch lionfish at greater depths. Because we can control the lionfish population on the shallower reefs, But we know lionfish are deeper and we know that they're eating there too. So yeah, we need to find ways how to catch them at great depths. So to keep controlling the lionfish population, we need to focus on the output like a lionfish. Caribbean style. And we also need to focus on the input basically of controlling it at other depths.

Rebecca Nesbit: That input output approach is nice. Although culling alone won't have much effect on populations, perhaps it can be combined with innovative methods such as removal from deeper reefs, and together things could have an effect.

Jenny: Yeah, absolutely. And to add to this, Mon made a really nice point about the approach that she believes is important.

Monica McCard: I think we need more long term site specific monitoring that kind of links land fish abundance with habitat conditions, prey communities, culling effort, storm disturbance. depth refuges. So basically where are they going? You know we know they can go right down to 200 metres but actually why are they going there? Are we driving them there? But I think that's going to help move management from reactive removal to predictive control and I think that that's always been my research background is predictive methodologies. If we can predict what they're going to do, when they're going to do it. then we can be ready for when they do that. But management strategies are basically reactive. So it's what can we do once they invade somewhere like when they come into the Mediterranean, there was only just a few numbers there somebody was diving and they seen a land fish but nobody removed it and then a year later two more land fish were spotted again they didn't remove them and the panic once they realized actually we've got more here we need to get rid of them the damage was already done so we need to be looking at predictive controls because to me that's the only way that we're going to have catch up with them

Jenny: And to really drive home the point Mon is making, listen to what she had to say about the potential for lionfish to find their way into temperate European waters.

Monica McCard: I think it will happen. Lionfish are really good at adapting. They adapt to a lot of things very quickly. And we see that with invasive species anyway. But what's also happening is that our waters are warming up. And a lot of our cold water species are starting to move off because our waters, especially in the UK, are too warm now for them. So why would it be something that they can't come to? What I've seen in experiments and I've seen actually in situ. that their losses are round about 11, 12 degrees. That's our waters right now. So why could they not come into our waters? What is stopping them? They're already in the med. I think there was somebody off Devon last year that a fisherman found a lionfish in his catch whether that means they're closer than what we think. I don't know. But we're literally saying worldwide, is the second biggest threat because, even if they get into our waters, we're we're in big trouble. Our fisheries are in big trouble. Because one of the last papers that I published on land fish was looking at the feeding impacts on nephrop. So Dublin Bay prawns. And nobody ever assessed if they could eat them and if they would eat them and if their temperature overlaps with theirs and it does and they do so if they get into those sort of fisheries then we are definitely in

Rebecca Nesbit: That is pretty scary, but I'd say not at all surprising when you think of how many species have already become established in the UK. The likes of parakeets, muntjac deer, Canada geese, they've just made the UK their home and are breeding very happily. I really can see this happening. So based on all this, what do you think about the original question of can we stop the lionfish invasion?

Jenny: It's very, very rare you find a species that is this good at being an invader, this successful. And I think particularly in a marine ecosystem where larvae can travel hundreds of kilometers across oceans and throughout different systems, we've got a pretty tricky job on our hands.

Rebecca Nesbit: Yeah Yeah, I definitely agree. But also from some of what I've heard, I feel there is potential to reduce the impact locally with good management of things like derbies, with innovative technologies, with more research. I think there is potential to minimise some of the damage.

Jenny: Yeah, I completely agree. We do seem to have a sort of combination of methods which can on a small scale work. I think also something to bear in mind is that sometimes nature does the work for us. So for example, if the predators do start to adapt, if trumpetfish do start to eat the eggs, that's going to be a big limiting factor. If their eggs become a food source, the reproduction is the thing we have to get under control. And the other thing is that high density populations can see a lot of things like diseases as we see in all sorts of species. Exactly, including humans. there has started to, just in the last few years, there's started to be some evidence that some local populations are reduced by disease when there's really high densities. So perhaps, maybe nature will start doing some of the work for us.

Rebecca Nesbit: Including humans. Yeah, absolutely. Who knows how things will adapt. And meanwhile in Europe, this is where it does feel like the invasion could be stopped if we stop it before it starts. For example, more controls. Why are people still allowed to keep and trade lionfish that then get released? If we can stop those releases, that's when it really is feasible to stop a new invasion.

Jenny: Yeah, for sure. So I think to conclude this episode, the last thing is it's really, easy to get wrapped up in this kind of emotive language of how invasive and damaging these animals are. But I do want to end on a slight positive note because despite the damage that they do throughout the interviews with both Monica and Lizette, what was really, really clear was just how much respect they had for these animals. They both repeatedly said how smart these animals are. And what's worth remembering is that... What we have here is a really, really incredible animal that has learnt how to not only survive, but how to thrive against the odds in an environment which is under so many pressures. And while species like this are very, very often viewed as a pest, they're quite often my favourites because how can you not be impressed by something that has figured out so many strategies to beat the competition? So I wanted to end on a little clip from Mon. This is what she had to say about her feelings towards lionfish.

Monica McCard: I mean, it sounds like I'm a big fan. I am a fan. I am because I don't know any other species that does this and has all of these traits together. That's what makes them so interesting to me How does one species, how can it do all of these things? for an invader to be as effective it needs to have specific traits for that. Lionfish have that many traits. But yeah I am a fan. I am. I kind of see myself as sometimes as an invasive species I think that I think all of us do at some stage in our lives. We feel like that. And I think that that's what makes them and even how successful they are makes them so interesting to me. And I want to know more And then the thing that I found out 10 years ago or five years ago has changed drastically in those five years that that doesn't it's not even relevant anymore. Again that's genius for a species to be able to do that so yeah that's what keeps what keeps me asking more questions

Rebecca Nesbit: They really are incredible and sometimes it's just our human values that decide what should and shouldn't do well, and we start to demonize a species rather than thinking, Wow, nature is wonderful. That's all we've got time for, but we would as always love to hear from anyone. What's your view on this? What are your experiences? Have you fished for lionfish? Have you seen them? We're always very keen to hear from you. Thank you very much for listening.

Jenny: See you next time. So since recording this episode, Lizette has very, very sweetly sent me some of their lionfish products that they make. So for the purposes of Becky and people on YouTube, have a little look at this. I've got some really cool lionfish stud earrings.

Rebecca Nesbit: wow, are those sort of lionfish spines un in the studs?

Jenny: Yep, lionfish spines in the studs. And she sent me this awesome lionfish Caribbean pen.

Rebecca Nesbit: wow. That's loads of them just inside the end of the pen.

Jenny: for anyone listening on Spotify. We will put a photo online so you can have a look at this. And if you're interested in the products that they sell, you can head over to lionfishcaribbean.com to have a look at all the other cool stuff that they sell. So if you wanna get involved in the conversation, then come visit us on catamongthepenguins.com or find us on social media. We would really love to hear your thoughts. Thank you very much for listening and we'll see you next time.