How To Protect The Ocean
SUFB 069: How To Manage Tuna Stocks
Welcome to the new "Research Thursdays", where I discuss a specific research study published in a journal. This week's study looks at a study looking for insights of the Yellowfin Tuna in the Western and Central Pacific Ocean to determine whethere the populations are genetically different than the population in Papua New Guinea. Listen to the episode to find out the results.
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Show Notes:
http://www.speakupforblue.com/session69
Welcome to the Speak Up for Blue podcast session 69 today. We're going to make Thursday's research Thursdays. We're going to talk about research papers and today's paper we're going to talk about is distinct yellowfin tuna stocks that were detected in western and central Pacific Ocean. We're going to talk about what the implications of those are to tuna stocks and why that is important. So stay tuned for the Speak Up for Blue podcast. Welcome to the Speak Up for Blue podcast. Helping you get involved in ocean conservation and now here's your host. Can't get the song bad blood out of his head. Andrew Lua. Hey everybody. Welcome back to another exciting episode of the Speak Up for Blue podcast, your voice for the ocean. I am your host Andrew Luan, founder speakupforblue.com, marine ecologist and self-proclaimed ocean printer. That's right. My business has to do with protecting the ocean. Everything I do as an entrepreneur has to do with protecting the ocean and today we are going to make Thursdays a special day. I'm trying to segment everything during the week instead of just picking random topics. So Monday, Tuesdays and Thursdays are usually what I call a solo cast but Wednesdays I've been doing solo cast because I just haven't been able to get guests but hopefully that will change in the near future. However on Monday Tuesdays and Wednesdays I want to start picking segments. Thursdays I've decided are going to be research segments and Tuesdays hopefully are going to be sort of a species. We're going to pick a species and talk about it. Something special. So we'll call it species Tuesdays and then we'll have research Thursdays. So today is Thursday. It's almost the weekend. It's very, very exciting. I'm recording this on Wednesday but you're going to hear it Thursday so you're going to start to get excited about the weekend. Some people already are maybe even planning to go out on a Thursday so your weekend is already here but I plan to work on Friday. But I get excited because Thursday I get to play hockey at night and it's close to the weekend so I know it's getting closer and closer and closer. So I hope you're all excited for that but today we're going to talk about something specific. We're going to talk about yellowfin tuna. Now and we're going to talk about stock populations and yellowfin tuna stocks and why learning about population stocks and stock structure is extremely important when we manage fisheries. I chose this article because we've been talking a lot about climate change over the past couple of weeks, actually even the past couple of months. So I want to take a little break about that and just show you how there's different things that are going on in the world in terms of research and studying and this one is all about stock populations and stock assessments and you probably heard about it you know through the news and things like that and we know tuna for the most part especially in the Mediterranean they're really going downhill and the movie End of the Line that's narrated I believe by Ten Dance and talks all about how tuna is being over exploited. Now there are some species that are not over exploited as of yet but they're getting there and so what people are trying to do, researchers are trying to do is figure out how to sustainably manage them. So we're going to go into the parts of the world now tuna is found all over the world. They're found the Atlantic and the Pacific. They're found the Mediterranean. They're also found in the western and central Pacific Ocean. You know near Thailand, near Indonesia, the Philippines, Papua New Guinea, all those areas they call that the WCPO, the western and central Pacific Ocean. So if you hear me throughout the podcast talk about WCPO, that's the area that we're talking about specifically what these researchers are trying to find is looking at tuna production and a sustainable assessment or whether this, looking at research of how we can make the yellowfin tuna production sustainable in the Philippines and in that WCPO area. So what they're trying to find, there's been a hint of a stock difference in the yellowfin tuna. So what happens is you have populations, you have a species of tuna. So I can explain this how stock assessments work. You have a tuna species, yellowfin tuna. So it's a one species. It's found quite a bit all around the world. It's found in the Atlantic. It's found in the Pacific. It's found in the WCPO area. Normally the species actually mix a lot. So Atlantic and Pacific populations are not genetically different. Their DNA is essentially the same. So they consider them very similar. Okay, and it could be attributed to the fact that they actually travel long distances so they mix. So when they reproduce, they actually, and they spawn, they actually mix populations. So a lot of these species populations that are around the world actually are not very genetically different. However, in the western and central Pacific Ocean, the WCPO area, the populations between the Philippines and Papua New Guinea, and they call it Bismarck Sea, there's been rumors that these populations have been different, or there's been sort of like suggestions that these populations are genetically different. So the wonderful authors here, I believe they're from, let me just see where they're from. Let's see about the authors. Okay, they are from the Philippines, most of them are from the Philippines. Natural fisheries and research development institute, research and ecology, assessment division, national fisheries, and development institute and Manila. So a lot of them are from the actual Philippines. And so when we, so they're really concerned, they want to make sure that this population is sustainable. They want to make sure that they have all the information they can on, you know, the this population, they want to make sure they can manage it properly. And knowing whether the populations are genetically distinct, or the same between Papua New Guinea or Bismarck Sea and the Philippines is extremely, extremely important. So to do this study, to find out whether these populations were genetically different, they actually took, I'm not going to go into the complete details of, of, you know, their materials and methods, but essentially what they use, they use, I think it was 19 genetic markers, and they used a sort of like a micro saddle, a DNA micro satellite method of determining whether these 19 genetic markers, which could tell, which are, which are researched as, you know, in the past as being either the same or different to tell whether the populations are the same or different. And they, they, they took those from various sites along the Philippines. I think there were four sites in the Philippines and one site in Papua New Guinea, which is in the Bismarck Sea. And they use those markers to tell whether the populations at each of those sites are different. So along among the five sites, they, they compared them. And then they compared them among the between the four sites in the Philippines and the one site in the Bismarck Sea. Now normally, so they took a number of, of animals from a number of fish samples from each of those sites. Okay. Now, normally you would probably have a little bit more, you know, from my scientist, my scientist, specific critique, you would have more of a difference between or more of a samples, instead of just one sample from the Bismarck Sea, but they have one sample and they've done it based on that. So when they look at the genetic analysis, they compared them using this graphic. And, you know, it's, it's very interesting to see that the, the four sites in the Philippines were actually quite mixed, right? So the genetic, they were genetically the same within the Philippines, all around the islands in the Philippines. On, in the Bismarck Sea, they're actually quite different from the, the Philippines. So all the Philippine sites were pretty much the same. They're all mixed in. There was no real significant difference. But on the, on the Bismarck Sea compared, you compare the Bismarck Sea site to the sites in the Philippines and they're actually quite different. They actually separate quite a bit. So that tells us that these species, that this, this one population species has a bit of a genetic diversity between the, the popping, popping beginning and the Philippines. Why is this important? It's important because to manage these stocks, you have to know the differences in the populations and around the WCPO. When you start talking about putting in quotas, putting in fishing zones, putting in marine protected areas, you want to make sure, this is sort of a principle of conservation, that you want to make sure that you, you protect a species or you protect an area at very different scales. So the major scales you protect at a regional scale, which tends to be, you know, larger animals because they travel more and you protect the habitats in there, you protect that, then you protect sort of the individual habitats and, and try and get a diversity of say of coral, this is the Tropic area. So coral reefs, mangroves, seagrass beds, open oceans, and you try and get a good representative area there. Then you're going to protect on a community level. So how, how the structure of the habitat and species in that habitat are actually formed. So there's going to be different communities that have that are made up of different species that are characterized by different species. And then you have a genetic diversity that you want to, that you want to contain, or you want to conserve. And this is where this genetic diversity comes from. So what happens is in evolution, you know, it's survival of the fittest certain species will take on certain genetic differences so that they can increase their survival in that area. What's happened here is there's been something that is different between Papua New Guinea and the Philippines that has allowed these species to sort of diverge genetically a little bit. Okay. And it's obviously made it so that the the the Philippines genetic markers or the Philippines genetic makeup is actually done done better because you find less of the genetic markers that have that are in the that are in Papua New Guinea. So you know, you're following me this. So this is essentially this population, these genetic markers, this genetic makeup is more successful in the Philippines. Whereas the Papua New Guinea makeup is more successful for fish in Papua New Guinea in the Bismarck Sea. Now, there's there's if there were, if there weren't any, the reason why they're probably so genetically different is that there's probably some sort of barrier, whether it be a physical barrier, either by an island or a landmass, or by some sort of circulation barrier. And the authors noted in this study that there are specific ocean circulation barriers that might impede the mixing of these two populations. Now, you know, tuna can actually travel quite a bit. So there's something there's there shouldn't be any if there's a barrier or if there's no barrier, if there are no barriers, there shouldn't be a reason why they mix. However, there are barriers here. There are there's there must be some barriers because they're not mixing. So there's something that's preventing them from mixing. The authors suggest that there are some eddies and some circulation patterns that actually don't allow the larva, which is basically the babies of these fish, to penetrate these these areas. So an eddy is essentially a circular circulation of water that that you'd have to have a certain force to penetrate. And larvae may not have that force to actually get across. So they won't come into a new area and settle in a new area. So that could be one of the suggestions. There could be some island suggestions, you know, where like there's an actual landmass that actually prevents them from going through. You just never know it's it's the that area, Indonesia, Philippines, Thailand, Papua New Guinea, all those areas have archipelago's archipelago. Sorry, I can never pronounce that properly. So essentially a number of islands that can prevent animals from mixing. So the same species from mixing and spawning and reproducing. So there's a high genetic diversity just within each species. And of course, the species diversity. So there's a this is probably one of the most diverse areas in the world because of all these different islands and other these different archipelago's that are around. And you know, you just there's it prevents it from mixing. So that might be a reason. However, tunic are very mobile, they can swim very well. So they're the eddy situation and the where the larvae can't penetrate might be the best way of doing things. More research is obviously needed to try and figure out what barriers are there are in between these areas and why they're there and how that's being affected by the populations. But from a management standpoint, fisheries management standpoint, it's important now in the future to say these are two distinct populations, genetically distinct populations. We need to ensure that both of these populations survive. Why do we need to make sure both these populations survive? We need diversity within the elephant tuna. Okay, we need diversity within species, even genetic diversity. Because if everything's the same, if all the the all like if the genetics end up being similar across all populations, and something comes in the area to wipe out fish, whether it be a virus, whether it be anything, lack of food or something like that, that doesn't allow that genetic makeup of species to persist, then we could see an entire wipeout of that population. However, if we have two different populations, two genetically different populations that have different feeding strategies or different reproduction strategies or avoidance strategies or predation strategies that Mike might allow them to survive a specific event, or a specific scenario that that will wipe out another species, another genetic diverse species, or the other the other stock, then we still have yellowfin tuna. So diversity is actually important. It allows, it increases the resilience that, you know, the ability for for a species to present to persist. It increases that resilience so that we can, you know, we still have yellowfin tuna. And of course, this area is so important in the Philippines, it actually the production of tuna so important economically, it produces 10 million dollars a year in that area, with you talking about shipping and exports and things like that, and just local production. So a very important, I think this is a kind of a very important study to find out whether these populations are genetically diverse. It looks like they are, that's going to have implications on the management and how we manage these species. And it's very important, because the people in the Philippines really rely on this on these species on the yellowfin tuna as a source of food, and as a source of income. So it's important that we do this, and it's important that we do this, we manage it sustainably, and we make sure that we have all the information we can on yellowfin tuna before we make any kind of management decisions. So I really like this study, and that's why I want to share it with you. And I like doing this kind of stuff. I like reading journal articles, and I like explaining it to you guys. Sometimes I may not, I may not be as clear as I hope to be, in terms I talk a lot about the science, and I may not, I hope I don't go over the heads of a lot of people, because that's not my intention. My intention is to explain it so that you guys understand. So if you understand, and you really like it, you can go to the show notes, www.speakerforblue.com, session 69, and just let me know what you think of my interpretation, and stuff like that. I'm a big boy, I can take the critique, don't worry about it. If you don't understand it, let me know if you want it in simpler terms, I can do that as well. This is very scientific information. These are scientific journals that I want to share with you guys, because a lot of these journals are very important when we talk about conservation and management. Plus, I want to show you what these journals hold, what kind of content these journals hold, because I think it's important to not only just talk about the major issues we see on the sort of the news outlets, but what's happening behind the scenes, because some of the studies that are being produced in these magazines, in these journals, are not always covered in the mainstream magazine, because they may not be as quote unquote "sexy" or controversial. So this is really important stuff that I want to share with you guys, and of course, they're from all over the world, which is kind of nice to know what people are doing all over the world and how it can be done on your side of the world, if it's not in the same area. But yeah, and like I said, I want to do more of this kind of stuff, and I want to spend more time and go more in depth instead of just reading it, interpreting it, and then gushing it out and giving you sort of the basics. I'd love to go more in depth and spend more time on that, and that's why on Monday, we're only about four or five days away here, of launching my crowdfunding campaign on patreon.com, and it allows you to support on a monthly basis, this podcast, at whatever level you decide to support, and there's different levels of support, there's from a dollar all the way to $500, and in between, and of course, there's different incentives, you get specific access to things, or access to me, depending on what level you support as. And of course, there's different goals, there's going to be some goals on this page when I publish it, it's all going to be for you guys, you know, and for me as well to get to increase my reach, but there's different goals that I have set. For instance, if I get to a certain amount, I will start doing video more video more in depth video, I'm going to start going to on site with people like because I can spend all my time on a full time on instead of just, you know, two or three hours a night. So what I want to do is turn this podcast from a hobby into a full time gig, and I'm trying to try and do that through patreon.com. So your support will help me a great deal. And of course, as we go, as we get higher and higher goals, you know, I'm planning on doing, and once I reach a certain level, you'll see I plan on doing a digital magazine, and to get more in-depth articles and more visuals to you guys, and just different methods of reaching people. For those who like digital magazines, for those who like video, I want to hit all the different types of media, build this media company for ocean science and conservation. So if you want to see that and you want to support that, you can do so on Monday, December 14th, I will be launching this patreon.com crowdfunding campaign, and I'd really appreciate your support. And of course, you can always support just by listening. That's that's really great. And sharing all these stories with your network, your friends and your family, who you think will benefit from this. So thank you very much. You've been listening to speaker for Blue Podcast. I am your host, Andrew Lewin. Happy Thursday, and happy conservation.