How 5 billion sea stars died and what we can do to save them

0:00 Since 2013, researchers have noticed a drastic decline up to 90% decline in sea stars starfish along the west coast of North America. Nobody really knew what was going on. There was this idea of a sea star wasting disease where they would just waste away and just like, kind of like tear apart underwater. And the ramifications were drastic. We saw an increase in sea urchin populations because of a decrease in the sea stars, as well as a decrease in kelp because urchins eat kelp. There are huge ramifications in finding out what has caused the decline of the sea stars and what we need to do to bring them back. Luckily, researchers have figured out what the actual cause of the sea star wasting disease and now we're hoping to be able to fix it and get that ecosystem back intact.

0:45 We're gonna talk about it all today on this episode of the How to Protect the Ocean Podcast. Let's start the show. Hey everybody. Welcome back to another exciting episode of the How to Protect the Ocean Podcast. I'm your host, Andrew Lewin, and this is the podcast where you find out what's happening with the ocean, how you can speak up for the ocean, and what you can do to live for a better ocean by taking action. On today's episode, we're gonna be talking about sea stars, including the drastic 90% decline in sea stars since 2013 because of sea star wasting disease. It's a disease that basically broke down sea stars across the west coast of North America, and it caused a lot of panic. There was people running what's going on. During that time, we saw El Nino and the blob, which was, you know, El Nino caused a lot more sea surface temperature increased.

1:31 There was the blob, which was like a blob of water that was just heating up from the North Pacific. And it was coming down towards the mid Pacific, I guess mid Eastern Pacific. And people said, well, maybe it's because of that. Maybe there's something in the water that's increasing because of this increase in temperature and it's causing like a lot of the parts of the ecosystem to kind of go out of whack. So it's not surprising that sea stars would actually have a problem and maybe they're just melting away. We didn't really know. Scientists were trying to figure out for years. And it has come to my attention that they've actually figured out what's happened. They've identified a bacterium, and I'm gonna try and pronounce this bacterium, but we'll see what happens. Vibrio pectenicida strain, FHCF-3 as the cause of the sea star wasting disease.

2:14 SSWD that has been devastating sea star populations along North America's west coast since 2013. So like I said before, the disease led to the loss of up to 90% of the Sunflower Sea Stars population equating to over 5 billion individuals leaving the species critically endangered. This is the thing, what happens when you have climate change, when you have other factors that are cumulative that can be very hospitable to other organisms. This bacteria potentially has been doing really well in higher temperatures. It's been proliferating and it's been going all over the West coast of North America, and affecting the Sunflower Sea Star population, making them critically endangered.

2:54 Like, think about taking 5 billion individuals out of a population. It's critically endangered. We're lucky that it had such a high population. It didn't go extinct. So researchers confirmed the causation by isolating the bacterium from their fluid. So it's almost like their blood fluid, their sea star blood, essentially what we call it. And fulfilling Koch's Postulates via controlled infection study. So this is just the method that they used. And the consequences have included a dramatic surge in sea urchin populations, which has in turn led to the destruction of kelp forests, a key marine habitat for, you know, supporting biodiversity, coastal protection, carbon sequestration, and local communities. Now, just to kind of take it out a little bit and, look at an overview of a kelp forest.

3:35 Kelp forest are aquatic plants that grow underneath the surface of the ocean. And they stem, like all the way from the bottom. It could be like a hundred meters, 200 meter. I don't know even know if it goes that far. But it goes pretty far up. It's secured at the bottom of the ocean, and then it goes all the way up to the top. And you know the forests are dense forests where you have a lot of cover for animals. And if you go to any aquarium, Monterey Bay Aquarium, you can go to the Toronto Aquarium here locally here in Toronto, and you can see these kelp forests and what it creates, the environment that it creates, all these fish and invertebrates are almost like made to be hidden within this kelp forest. And it's something that is extremely important to a lot of fisheries along the West coast. you know, just sustainable populations and making ecosystems, structure and security along that coastline.

4:20 There's a lot of stuff that's benefit to that and I remember in university. I'm going back to my university days 'cause my daughter's going to the same university this year that I went to, my wife went to, and I'm going back to my university days and I'm remembering population of Ecology and learning about food web systems and how when you take out a important animal within a species, within a food web, that it affects the rest of the food web and it can affect the dynamic and the balance of that ecosystem. And what I learned was, you know, urchin, sea otter and kelp forest relationship. And so when the sea Otter population dwindled, and it went to critically endangered back in the 1800s and 1900s and there weren't any protections for sea otters. The kelp forest declined because the sea urchin population increased.

5:04 Well, now we've had some success in seeing the sea otter population increase. And over time we've seen the sea urchin population decrease a little bit, but unfortunately, what we didn't really know is the amount of effect of sea stars on sea urchins. They also eat sea urchins, and the disappearance of these sea stars have shown that there's still an increase, even though the sea Otter population is doing fairly well or doing better. Maybe not at what it once was, but doing better. Even with the sea otter population there, they're not eating enough sea urchins to control the level predation of sea urchins on kelp forests. So I hope this is not too confusing 'cause I'm using a lot of things here. I should probably have a diagram maybe when I get paid to do these types of videos, we can put a diagram together.

5:46 but essentially what happens is even though you have sea otter population doing better than what it was. You don't have that sea star population, and they both predate on sea urchins. Now the sea urchin population is increasing a little bit and affecting the kelp forest population, which affects so many other species within the west coast of North America that it becomes a negative effect on the entire west coast and affects, you know, coastline security. It affects biodiversity, it affects fisheries, affects a lot of things. and having, you know, cumulative effects like climate change and maybe bad management of fisheries in certain situations and other things, and just coastal development and so forth. You have problems. So the fact that we have diagnosed the problem that's happening with the Sunflower Sea stars and other sea star populations, we can do better now.

6:30 So with the pathogen now identified. Efforts can shift towards a targeted recovery such as captive breeding, probiotic treatments, and monitoring environmental drivers like warming waters that influence disease outbreaks. So now we know when the water's warm, we can actually detect how badly this bacterium will do, and we can start looking at experiments like that. So graduate students, if you're looking for a project, this would be amazing to do because you're on the forefront, on the cutting edge of looking at how to manage this bacterium and how to manage a critically endangered population and try and bring it back, which seems to perforate quite a bit if it's healthy because there was 5 billion individuals that were killed and it's still critically endangered.

7:13 So there's a big upside in bringing these species back if we can control this bacterium. So that's the episode. I'd love to hear what you think about this is the fact that it took us so long. Why did it take us so long? I'd love to hear your questions or comments. Let me know in the comments below, if you're watching this on YouTube. If you're listening to this on the audio version, you can get in touch with me with two ways. You can go to speak up for blue.com/contact and you can email me. Just fill out the contact page or if you want to connect with me over Instagram, just DM me at how to protect the ocean. I would love to hear from you and if you want to learn more about how you can better protect the ocean, don't forget. You can join the undertow at any time. We're coming up with this app. It's an online digital app to essentially bring together people who want to do better for the ocean.

7:58 So not only do we have this community here, but it's also we have this community on this app that you can learn how and be guided to connecting to the ocean. Be with a community that wants to do better for the ocean. And essentially take part in conservation projects or learn how to fund conservation projects, identify by, you know, through vetted processes of what products to use and so forth. There's a lot of upsides, so go to speak up for blue.com/join the undertow. I wanna thank you again for joining me on today's episode of the How to Protect the Ocean Podcast. I'm your host, Andrew Lewin from the True Nord Strong and free. Have a great day. We'll talk to you next time and happy conservation.