Decoding the secret language of dolphins

Dolphins are likely the most intelligent and mysterious animals on our planet. They use complex sounds to talk to each other and to form rich social lives that we're only beginning to understand. But mass tourism is destroying their acoustic habitat. With hundreds of tourist boats chasing dolphin groups all day, the noise pollution from ship motors has forced dolphins to start yelling at each other underwater. And first studies indicate that the communication is failing. The number one thing needed right now is more research so we can quickly advocate for protection. That's why we went to one of the world's premier dolphin hotspots in Portugal to help provide the data needed to better understand the secret language of dolphins and ultimately protect these fascinating animals. We're Planet Wild. Welcome to mission eight. Dolphins might well be the most intelligent species on our planet besides humans. One way scientists try to measure this is by comparing the brain to body ratio, where dolphins come way closer to our level than any other mammal. But let's look at behavior as well. We know that dolphins have a sense of self, are capable of abstract thought, use tools, invent creative strategies to solve problems and even have a unique culture that differs between different regions and is passed on through generations. This is mind-blowingly complex behavior and there are so many examples for this, including dolphins rescuing humans at sea, which also shows their incredible friendliness and empathy towards other beings. And it's why so many people love them. But the fascination with dolphins has also made them the target of intrusive mass tourism, specifically unsustainable dolphin watching tours that have been exploding all along the Algarve coast, one of Europe's number one dolphin hotspots. Over the past decade the number of dolphin watching boats increased from 10 to 150 and some of them go out five times a day. That increases a lot the pressure on the animals. We're here with Joana Castro, the founder of AIM Portugal, an incredible organization that is studying and protecting dolphins in the region. Joana has been working with dolphins since she was a kid and has devoted her life to them. Her team has closely studied their migratory patterns over the past decade. One way to do that is through visual tagging, spotting, photographing and cataloging dolphins when they come to the surface. Together with the AIM team we're going out on the water to collect data and better understand how the increasing tourism is affecting the dolphins and how we can protect them. Dolphins can distinguish between the different types of boats that exist. If it is a fishing boat, a touristic boat, a research boat and if they feel very comfortable they can come really close. We're right in the middle of a large group now. I did not expect we would be getting so close today. Let's take a look underneath the surface. So we have a lot of newborns here and you can see them very well because you can still see the fetal marks that they have a week, two weeks old, maybe days. Oh really? Yes, they're really just absolutely newborn. Yeah. That day we were able to document the behavior of a group of over 100 common dolphins that traveled with us for about 20 kilometers. The team can identify individuals by their unique dorsal fins to compare migratory routes over the years and study group forming behavior like the interaction of mothers and calves, which is fascinating. Here are three facts that I bet you did not know. Dolphin mothers are often assisted by aunts and grandmothers when raising their young. The young dolphins can have up to 40 childhood friends that they visit regularly and dolphins are the only animals that we know that just like us use high-pitched baby talk when speaking to their little ones. I mean, how cute is that? Their social intelligence and behavior, it's in many ways similar to humans. But what makes dolphin intelligence so special, let's say compared to primates, is that they are not at all closely related to us. Our last common ancestor is literally eons ago, which makes dolphins the highest non-primate intelligence we have ever encountered in our universe. So every similarity is absolutely fascinating. But even more fascinating are all the ways in which their intelligence evolved differently from ours. Humans spend a lot of brain power on manipulating their environments based on the simple facts that we have hands. Now, without that ability, dolphins must focus their immense intelligence on other strategies like collaboration or adaptation and may have developed very specialized abilities that are way beyond our understanding. The more we understand, the more we realize how little we know yet. The key to decoding the world of dolphins lies in the intricate world of sound they inhabit. Over millions of years, they have evolved a complex system of clicks, whistles and pulses to navigate the waters, cooperate and form social bonds. Dolphins emit and perceive sound of up to 150 kilohertz. That's more than 100 kilohertz above human perception. And the auditory cortex in their brains to process that information is roughly 10 times larger than that of an adult human. And this makes them incredibly sensitive to noise pollution. Before we continue with the story, let me quickly tell you who we are. Planet Wild is a global rewilding community that anyone can join to help restore our planet through monthly missions just like this one. If you want to become part of our community, consider joining Planet Wild as a backer and help make our world a little wilder for as little as six bucks a month. And if you join today, I guarantee that you will support your first rewilding mission within the next 30 days. There's a link in the description below. Now back to the video. As human beings we tend to believe that under the sea there's this escape from the noise of the modern world. But the reality is that human noise has long invaded our oceans. Industrial shipping, offshore oil rigs, military sonar. There's virtually no place in the world's ocean where underwater noise pollution is not detectable. And for dolphins living close to shore, the dolphin watching industry has become one of the biggest stressors as they specifically target, chase and circle dolphin groups all day long. We have seen sometimes groups of eight dolphins surrounded by 15 dolphin watching boats and this is not sustainable in any way. First studies in other places have shown that the high frequency and volume from such smaller motors force dolphins not only to change their own communication frequency but also to increase their own volume. In other words, they are forced to shout at each other. But even then their communication takes longer and fails more often. Researchers even suspect that the noise pushes mothers with calves away from their preferred feeding grounds close to the shore and forces them to retreat towards deeper waters that are less suitable for raising their young. The noise is exhausting for the animals and we can see already from the surface some changes in the behavior. To enact change we need to understand what's happening underwater in the world of sounds that dolphins inhabit. And that's where we come in. The Planet Wild community is equipping AIM with two hydrophones that allow them to record dolphin communication underwater for acoustic analysis. And now let's put this thing to work. All right, so if I switch this on I'll be able to hear the hidden world of dolphins right below us? Yes, go ahead. At first everything seems like a cacophony of underwater sounds. To even start understanding what's going on we need the help of computers. And what we're trying to do with this acoustic studies is to try to have a little glimpse of what's happening and trying to make a sense out of it. Once you tune in closer you can see clear patterns emerge. These clicks are echolocation sounds. It's like dolphin sonar. They listen to the echo of these clicks to see underwater. In fact, dolphins have the most sophisticated sonar on the planet, even beating that of the U.S. military. What you see here are signature whistles. They are similar to human names. Every dolphin has a unique whistle they use to identify each other. This right here are two dolphins calling each other by name. So this individual was giving us their name? Yeah. Far from being just an academic exercise, collecting this kind of data is crucial to advocate for marine protection. Based on visual tagging alone, AIM has contributed 10 years worth of data to an incredible initiative that has just recently led to the creation of a marine protected area here at the Algarve. This is the area for the new marine protected area that we are creating now here in Algarve. It goes from Alfazina lighthouse almost until the marina of Abu Fara. Putting the reefs under protection was a huge community success and the law will go into effect next year. With a dedicated audio analysis, Joana hopes to push even further. So right now it's crucial to start a long-term study collecting data before and after to show how nature is healing. With a long-term audio analysis of the protected area, Joana's team would be able to prove the effectiveness of the new legislation and make a strong evidence-based case to further expand it. That's why our second hydrophone will be permanently installed right at the center of the protected area. This data will be the basis to advocate for even more protected areas in the future. Andrew and I are going to go down and set it up. Are you ready? Let's do this. The water was a bit murky. The exact reasons that dolphins have evolved to use echolocation to navigate. But eventually we were able to install the hydrophone as planned right at the reef. We never have a stationary hydrophone in this area so everything we learn it's going to be super exciting. Soon marine research will be the only human activity allowed in this area and we will be able to show the difference that this makes. We need to give a little bit of time to the ecosystems to recover and if we do our part and really keep it strict and limit our human presence the system will recover naturally and we will very soon see the benefits of the protected area. Being able to get such clear before and after data is the dream of any marine researcher and the excitement of the team is contagious. It's this work right here, the tedious day-to-day collection and analysis of primary data that forms the starting point and bedrock of any rewilding initiative. Because to support nature we need first to understand it and deepening our understanding of these incredible yet still mysterious animals relies on people like Joanna and her team. Being the only conservation team in the Algarve doing what we do and being such a small team it hasn't always been easy. And going out in the water facing the ocean pretty much every day can be really difficult at times. But every piece of data that we collect really helps us to understand and better protect these intelligent beings. You too can make our planet a little wilder by joining Planet Wild as a backer. Together we can bring back endangered species, clean up our oceans and rewild entire landscapes. As a member you can vote on how we spend the money, connect with me and others on our discord and see your own impact in the Planet Wild app. So make sure to sign up today there's a link in the description. And of course a big thank you goes out to all our existing Planet Wild members for making any of this happen. You've just unlocked the new dolphin badge in the Planet Wild app. Well deserved. If you want to watch some more check out our other mission videos like this one here or this one. Alright that's it from my side see you all again next month. Over and out.