How To Protect The Ocean
SUFB 088: Great White Shark Profile
Great White Sharks were vilified in the popular set of movies of "Jaws" in the 70s and they are consistently vilified in the media being described as "monsters" and "man-eaters." This tends to happen when we don't know too much about an animal, which is why the Great White Shark is this week Profiled Species on Species Tuesday.
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Show Notes:
http://www.speakupforblue.com/session88
Welcome to the Speak Up For Blue Podcast, session 88. Because the Great White Shark has been in the news so much lately, because of the death of that shark in the Okinawa, Japan Aquarium, I decided that Species Tuesday, which is today, is going to be all about the Great White Shark. 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, he just discovered periscope, and might be slightly addicted, Andrew Lewin. 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 Lewin, founder of SpeakUpForBlue.com, marine ecologist and self-proclaimed ocean printer. You can write everything I do about the ocean is to protect it. And in my business, my job, my mission is to protect the ocean, hence, ocean printer. We'll get more into that later on in the year about what I'm doing to protect them apart from this podcast. But until then, let's get into Species Tuesday, one of becoming one of my favorite days of the week to do a podcast, of course, all of them are my favorite, but Ocean Friday, Ocean Talk Friday, I think, is definitely my top one. But anyways, this is Species Tuesday, it's where I started this a few weeks back, where I profile a different species just so that you get to know the species that are in the ocean and the species that we talk about. We talk about the description of their physical appearance, we talk about their populations and their ranges because I'm a marine ecologist, ecology is all about how the species or communities or just animals interact with its habitat, so I talk a lot about populations and ranges and whatnot. And of course, we're going to go over the conservation status of the species so that you get to know where they're at, where they lie, and how they're doing. So let's get into it, but before we do, let's thank the people who are supporting this podcast through patreon.com, and that is Chris and Claire Jefford and Dr. Judith Weiss, so thank you very much for your support on patreon.com. All right, let's get into it. Here we go. So the Great White Shark, why do we love the Great White Shark? It's big. It got its height of popularity, unfortunately, during the movie Jaws, which was released in which set a movie that released in the 70s and 80s, that really petrified everybody of sharks. They made out, if you don't have, you've never seen Jaws before, which I would be very surprised if you haven't, but if you haven't seen it, essentially it's a set of stories that revolve around a Great White Shark who is pissed off, angry at humans, and decides to kill as many as possible. And then, of course, the story they try and kill Jaws all the time, and it's a massive shark. It's a bigger than what they've ever seen before, and it can sink boats, it can do all sorts of stuff, but, you know, all fictional. Unfortunately, though, that reputation has transferred into the wild. And for a while there, during the 70s, 80s, and 90s, Great White Sharks were treated as the enemy, and a lot of people were killing sharks, killing Great White Sharks because of this, because they thought they were man-eaters, and out of the 100 shark attacks on average per year, a third of them are usually because of Great White Sharks, so that really got people going. Just once a Great White Shark attacks, even though most of them were not fatal, that would make big news, and so it made it seem like shark attacks were happening more than they actually were. But in fact, when you think about how many people are on the planet over 7 billion, and only 100 people get attacked a year, it's actually not that much. However, of course, say that to the people who've been attacked, and how they feel, and if they survived, you know, it can be hard, of course, right? We're not denying that, but let's keep it in perspective and see how many people are actually attacked by sharks. Normally what they call Great White Sharks, they tend to call them sort of experimental biters, because they have been humans before and they don't really go through with eating them. They just bite, a lot of them just bite and take off, so they kind of experiment and say, "No, this isn't for me," and we're going to get into what they actually eat in just a sec. But let's just describe their physical appearance. Usually they average about 15 feet in length. They can exceed 20 feet, and they can weigh up to 5,000 pounds. They're torpedo-shaped with really powerful tails that can swim up to speeds of 24 kilometers now or 15 miles per hour from my American friends, and they have the ability to breach water when they attack its prey, which is really just, you know, people are really researchers and explorers and shark dives are really just starting to no pun intended, but breach the surface with sharks jumping to attack their prey, how fast they actually go, how they attack, which we'll get into in just a minute. Their prey are sea lions, seals, small tooth whales, and sea turtles. I would imagine that it would also include large fish if they can catch them, such as tuna and so forth, maybe even some bigger squid. Now they feed, as I said before, they attack from below, and it's interesting when they attack from below, they have a gray top side to them. Half their body is gray from the middle to the top side, so when you actually look down and say a gray white shark is below you, you may not see it initially because it's gray and it's supposed to camouflage on the bottom. Now when you're on the, if you're the prey and you're on the bottom, and I'm not asking about humans, say you're a seal, and you're on the bottom of the ocean, and you look up and there's a gray white above you, but you may not be able to tell because it has a white underbelly where it gets its name. Actually, the name of a gray white shark is actually a white shark, but people say gray white shark because they think they're so big and they're so great, and I didn't believe the movie jaws, I've heard the movie jaws kind of gave it the gray white shark name. But anyway, the white part of the white shark is actually the underbelly, it's named after the underbelly of the shark. It's white, so when you look up, you tend not to notice right away that there's a shark above you, although it probably casts a pretty big shadow if it's average of 15 feet long. But it's kind of interesting because when it kind of runs along the bottom, swims along the bottom, and it sees prey, it'll stalk it for a little bit, and then it'll attack, and it'll get up to speeds of 24 kilometers an hour, and when it breaches a surface, it's been measured. I believe, for some reason I'm thinking 30 miles an hour, or the average speed, or I think the average speed is 15 miles an hour, so let's just go with 15, let's be a little conservative in what the numbers are, but I have heard, I believe it was on a documentary that I saw was 30 miles per hour, but let's just say 15 for now, and I'll use shark researchers who are listening to this. If you can correct me, that would be great in the comments on our show notes, which is speakerforblue.com/session88. So yeah, let's move on here, so it's actually kind of interesting when you see them actually go that fast. I mean, I think about 15 miles an hour is pretty fast for an animal to move through the water, which is a pretty dense medium. Now, it can, so it also can sense movement of prey. Now, many sharks can do this through the anpuli of the Renzi, which are these kind of like holes or features on the shark, along the side of the shark, along the lateral line, and what they do is they can measure or they can detect the electrical pulses when muscles move, the small electrical pulses that happen in muscles when they move, so that's how they can detect movement in the water. If they can't see, they also have a pretty good sense of smell, but if they can't see very well, which they tend not to have the greatest of eyesight in the past, that their research has shown, but they do tend to be able to measure the electric movement of muscles or electrical movement around them and they tend to be able to detect potential prey from that. So it's quite effective and has made them a pretty efficient predator in the past. Now, let's look at the populations. There are really, from what I know, there are really five major populations around the world. There's the North American population, which one is on the Pacific and one is on the Atlantic. The Pacific is a smaller population, although it's growing, and they say it's genetically different due to isolation. It's not genetically attached to any other population around there. And then the Pacific really goes from southern California, maybe even a little south, to potentially up into Washington state, and even further, however, they tend to stay near cool coastal waters. So they might even go up as far as BC sometimes in Canada, but mostly they stick to cool coastal waters in the California area, maybe even up into Oregon and Washington at times. There's a New Zealand population, which has been featured on a lot of documentaries. They have some quite a big shark. Sorry, the Pacific one can also go down to Guatemala because there's been documentaries that have been filmed at Guatemala that have quite the large sharks. New Zealand population, there's the South African population, again, very popular in South Africa on documentaries and the way they feed. And of course, Australia, New Zealand, Australia, being close together, they would imagine that they would have quite the ranges. Now, great white sharks have been really found all over the world. I don't know if they've been found in Antarctica or the Arctic, but they have been found all the way up into England, along the Atlantic, everywhere in the Atlantic. There have been some interesting tagging results that's been by a company called Ocean Arch and they're associated researchers. Ocean Arch is a bit controversial in terms of some people who don't like to see sharks tagged the way they've been tagged. However, they do track a lot of shark movements and without going into the whole controversy, it's quite, the results are quite interesting. On the Atlantic side, they've noticed that there's been quite a loop of sharks in the summer when they go up to Cape Cod and in the winter, when they go to have to Jackson to go further and sometimes they'll go into the Bahamas area and then at other times they'll go into the Mid-Atlantic drift. But there's a bit of a loop in there where most of the sharks kind of loop around from Cape Cod in the summer down to Jacksonville, Florida in the winter and then back up again. With of course some different deviations as they go along, some of them far down as Miami and the Bahamas and so forth and of course out into the Mid-Atlantic drift in the Atlantic. So it's quite interesting to see those kind of movements and of course like I mentioned the Pacific, it can range from Guatemala all the way up to BC and I don't know how far they've gone in that respect. New Zealand and in Australia have quite the ranges in different parts of Australia, Western Australia is known for a population at a point in the year where they all congregate, usually because the seals are there and there's been some shark attacks during that time because swimmers are swimming near hollowed sites of seals and I'm sure they can get mistaken for prey at times. There's been a talk of a potential connection between the South African population and there's New Zealand population so look out for more research on that. I haven't seen any research but I'm thinking this Thursday, I might do the research Thursday on the ranges of sharks but I'll have to find the study to do that. So that's essentially their sort of ecology, population ranges and so forth. Pretty interesting how there's different populations that all have different features in those geographic areas so I would imagine it's just unique to those geographic areas. Now let's look at the conservation status, the conservation status and the IUCN Redlist which is sort of the global species at risk list is they're considered vulnerable. Now if you read a lot of websites or fact sheets on Great Whites you'll see a lot of people saying that, or a lot of those sites saying that the populations have been going down. And yes for the most part they've been going down however recently research has shown that they've kind of gone up a little bit or people are thinking that I shouldn't say research as someone because I haven't read any of those papers. I should say that some people have noticed that the populations have gone up and they might be rebounding but we still have to be very careful because they still have a bad reputation with most of the public. If you say Great Whites shark most people are saying ooh I don't want to go near one but there are a lot of ecotourism spots out there that are really trying to change that perspective. You can do cage diving if it's done properly, it's probably quite the excitement where you can actually see sharks in the wild around you, of course trying to be as safe as possible but you can actually see these bees in the wild. So it's kind of a cool thing and I think it really gives you a good perspective even if you're on a boat and you see them on a boat not underwater you get a really good perspective of what these sharks, the size of these sharks, the look and how gorgeous they really are. And of course I'm a scientist and the conservationist for the ocean. I'm a little biased but I think they're fascinating animals. Now of course there are various protections in different countries. In North America and the states where they're mostly found they have a pretty, they are protected under in California, they're protected under the California Endangered Species Act. In New Zealand they actually have a 370 kilometers of fully protected areas. They fall within that area and additionally from fishing by New Zealand flag boats outside this range. So they're protected from boats and with a maximum penalty of $250,000 and up to six months in prison. Pretty hefty fine for a fisherman who's trying to get rid of one of the best sharks in the world. In Australia a variety of different protections is protected under every different level from federal to provincial to local, I don't know if it's a municipal or county level, but they have the federally they are protected under the Environmental Protection and Biodiversity Conservation Act. Western Australia they are protecting another Wildlife Conservation Act and they are considered rare or likely to become extinct under the schedule five of that act. And in 2002 the Australian government created a white shark recovery plan which implemented government mandated conservation research and monitoring for conservation in addition to federal protection and stronger regulation of related trade and tourism activities. So essentially what the Australian government has done is they've charged their staff and scientists with knowing more about these species. The more you know about these species the more you can understand and the better you can protect them. And right now there's a lot of research on ranges where they're found, what they're eating, that kind of stuff, because they probably can't, maybe even not what they're eating, but they probably can't, you know, there are probably certain protections where they can't kill them to find out what they're eating unless they find an already dead shark. So there's probably a lot of protections around that. But as you can see it's protected quite a bit around the world but they're still being killed in, they get caught in fishing nets, people go out recreationally and try and catch them and kill them. So the enforcement is probably not always there. However, fishing nets and bycatch is a big problem not only with just the great white sharks, a lot of other different species of sharks all around the world, and of course other animals, mammals, reptiles, and fish all alike in vertebrates as well. So you know, even though there are these protections, the great white shark is still vulnerable, still considered vulnerable until further research. However, they are starting, there's rumors that they are starting to bounce back. So it'll be interesting to see how that happens and I'll try and find some research for research Thursdays on this shark to figure out what is the case in that. So, that's all for the show today, hope you enjoyed this profiling of the great white shark. This has been species Tuesday. I am your host, and you're known to be listening to this week on the podcast. Happy Tuesday and happy conservation. (upbeat music)