Why Evolution Has Screwed Sea Turtles (And So Have We)

this video is part of the biggest collaboration ever done on youtube where creators from around the world are making videos about our planet's ocean to support the team seas campaign in order to raise 30 million dollars to clean 30 million pounds of trash from the ocean and curiosity stream has donated their sponsor time so i can tell you all about it but first let's talk about why it's so important turtles have been walking the earth and swimming in the seas for a remarkably long time around 210 million years ago the first primitive turtle with a shell emerged during the triassic period it was largely terrestrial and had a beak and armored shell just like modern turtles this was the era of the first dinosaurs and an era that gave rise to a huge explosion of diversity on the planet but it was an era that did not last forever 200 million years ago massive volcanic activity changed the earth's climate and the end triassic mass extinction event occurred killing 76 of all marine and terrestrial species however the lineage of the turtles held on 80 million years later during the cretaceous period the first turtles to live exclusively in a marine environment emerged eventually four families of sea turtles came to exist and some members of these families were incredible the giant archelon was the largest sea turtle to ever live it was three meters long and weighed almost 2 000 kilograms but these giants too did not last forever 66 million years ago the asteroid event that wiped out the dinosaurs also wiped out two of the four sea turtle families 75 of all species on earth went extinct during this time but two families of sea turtles withstood this apocalypse and continue to swim in the seas to this day one sea turtle family of soft shell sea turtles has just one remaining member the leatherback sea turtle the other six sea turtle species belong to another family of hard-shelled turtles today's turtles are a reminder of the resilience of their lineage and of their adaptability in the face of epic extinction events events the likes of which are hard to even imagine but their resilience is not infinite and today they are being put to the ultimate test numerous experts believe we are living through or on the cusp of a new mass extinction event the sixth in the history of our planet one not caused by asteroids or volcanoes but by human activity this extinction event called the holocene extinction event began around 10 000 years ago when the last ice age came to an end and humans began spreading and hunting across the earth since then there has been a steady decrease in the number of species that live on our planet however in recent years the extinction rate has skyrocketed the number of species on our planet plummeting deforestation driven by agriculture and meat consumption overfishing ocean acidification habitat loss the world over and pollution driven by increased human consumption are all forces that may prove to be worse for biodiversity than a literal apocalyptic asteroid and the resilient sea turtles who have endured so much are one of the types of animals most at risk their particular physiology making them vulnerable to our particular ways of messing with the environment the adaptations that allowed them to survive for so long are the very reasons they are in grave danger in today's world but unlike global volcanic eruptions this is an extinction event we can actually do something about yes humans are the ones doing the damage but we are also the ones who can come up with the solutions sea turtles spend nearly all of their time in the open ocean submerged in solitary for the majority of their lives however there is one exception to this entirely oceanic life when female sea turtles come ashore to lay clutches of eggs after a long migration they make their way back to their home beach the same beach where they hatched and the only beach they will ever return to they heave their bodies onto land and dig an egg chamber about 80 centimeters deep here the turtle will lay around a hundred ping-pong sized eggs then fill the hole and head back to the sea over the next two months the eggs develop and undergo temperature dependent sex determination this means that the temperature of each egg during certain periods of development determines the gender of the baby sea turtle that hatches warmer eggs produce females while cooler eggs produce males then it's time for the babies to go forth into the world they chip their way out of their eggs with their temporary egg tooth and ready themselves for the most perilous journey of their lives on their mad dash to the ocean the turtles face many dangers predators like crabs dogs seagulls or raccoons would love to make a nice snack out of a baby turtle or two the blazing hot sand can scorch their bodies and for a tiny turtle the uneven terrain must feel like navigating huge sand dunes but evolution has helped the baby turtles build impressive survival mechanisms to navigate these dangers they usually wait until nightfall to make their mad dash to minimize the risk of being seen as well as to avoid the blazing hot sun to make sure the turtles know where they need to go at night time they have evolved to be photo tactic meaning they are attracted to light hatchlings will move towards the brightest light source which is usually the moonlight reflecting off the sea for millions of years this was an effective strategy a powerful sense that pulled millions of baby turtles towards their rightful home but the clever evolution that has allowed turtles to survive this treacherous journey for so long is now unfortunately leading them to their demise if artificial light sources like street lights or lights from buildings are present near the beach this can confuse the hatchlings they may mistakenly crawl towards the brightly lit road and into highly developed areas here they can get hit by cars or snatched up by predators attacked by fire ants or simply get lost and die on some beaches disorientation can affect up to half of all hatchlings and even if they realize their mistake and turn around they might be too exhausted by then to make it to the sea evolution has not had a chance to catch up with a human invention that has been in these areas for sometimes only a few decades but with some coordination this problem could somewhat easily be reversed all that's needed is to reduce the amount of artificial light that is visible from nesting beaches lights can be given special fixtures to direct the light away from the beach or lamps can be implemented with light bulbs that only emit red light which isn't as visible to most animals windows that face the beach can be tinted and curtains can be drawn after dark to keep the light out of sight many coastal communities around the world have past ordinances that require residents to turn off beachfront lights during turtle nesting season but unfortunately these ordinances are not always enforced however even with partial compliance thousands of baby sea turtles could be saved every year and in 2014 the sea turtle conservancy was awarded a 1.5 million dollar grant to expand lighting retrofit work in the florida panhandle more grants like this and more cooperation from the public could help sea turtles of all kinds withstand some of the threat of extinction we are forcing on them this is a relatively simple example of how working to understand sea turtle's biology leads to effective conservation but not all problems facing turtles come from a single strip of land next to their nesting habitat warming seas pollution ocean plastic these are problems the entire world is contributing to what solutions are there for problems so complex what hope do sea turtles have in this onslaught of human impact when the leatherback turtle evolved around a hundred million years ago it lived along other members of the dermo kalliodi family and the other three families of sea turtles that existed at the time when the end cretaceous extinction event occurred the going got tough and competition between ocean creatures for food became more intense but leatherback turtles had a specialized diet that helped them to survive a diet that few other sea creatures find very appealing it's a menu with almost no carbohydrates no fats no proteins just a gelatinous salty package of certain fatty acids and a handful of calories each jellyfish leatherback turtles surprisingly eat almost nothing else it's an odd choice but one that gave them an edge helping them to survive a cataclysmic extinction event but just like with the turtles drawn to streetlights the leatherback's love of jellies now gets them into trouble when they mix up their favorite snack with a different clear amorphous floating item plastic bags the ocean plastic problem affects nearly all of the animals that live in the sea but turtles are one of the types of animals most susceptible to its damage an ingested plastic bag can cause internal blockages which can lead to starvation or death sharp plastics can rupture internal organs plastic straws can get caught in their nostrils or they can get entangled in discarded fishing nets which can result in serious cuts on their bodies or even drowning and plastics that build up on nesting beaches can prevent baby turtles from reaching the sea there is no area of the ocean that is not affected by the 12 million metric tons of plastic that end up in the ocean every year a plastic bag was even found at the bottom of the mariana trench 11 000 meters deep so the chances of a turtle encountering some plastic is very very high but certain organizations are poised to help if they get a call about a turtle in distress often a turtle needs surgery and months of rehabilitation this past year the new england aquarium admitted 569 sea turtles for rehabilitation some harmed because of plastic others from boat strikes or cold shock other times sea turtles just need someone paying attention to help them out just last month the new england aquarium responded to a leatherback turtle entangled in fishing gear off of cape cod the female turtle was successfully evaluated disentangled and outfitted with two electronic tags that will allow researchers to assess survivorship over the next 30 days and track her migration patterns the use of tags like this in sea turtles will prove vital for long-term monitoring they can provide up to a decade of information about animal movements and survival saving individual turtles is a necessary difficult job that is making a difference in population numbers however to truly help the turtles we need to get to the source of the problem the amount of trash we dump into the ocean is expected to triple by 2040 unless we as a species across every country do something about it there are a few key things we need to do to stop this trend the first is to simply stop producing so much plastic perhaps with taxes and incentives to get companies to knock it off another is to design packaging so that it must be recyclable or compostable and another is to expand waste collection infrastructure in middle and low-income countries plastic obviously has its place and sometimes is essential but most of what we use it for is totally not meaningful change will have to come from commitments from governments around the world but with any hope one day we'll get there until then efforts are focused around cleanup efforts like catching trash that flows from rivers before it ends up in the ocean after all eighty percent of river plastic comes from just a thousand rivers in the world if we can catch the plastic at its source so much damage to the ocean could be prevented and this is exactly what the ocean cleanup project is working to do they've invented a solar-powered trash interceptor where trash flowing down the river is guided to a conveyor belt and then loaded into a dumpster which is then taken to a waste facility currently there are only three interceptors deployed one in indonesia one in malaysia and one in the dominican republic to scale the project up to tackle a thousand rivers more government cooperation is needed and also more funding and this is the purpose of team seas team seas is a global campaign to raise 30 million dollars to remove 30 million pounds of plastic and trash from our oceans rivers and beaches where one dollar equals one pound of trash removed donations will be split between the ocean cleanup project and the ocean conservancy this is a refreshing chance to actually do something about the problems we hear so much about and that's why our team at real science and real engineering decided to donate five thousand dollars to clean up five thousand pounds of trash and if you want to donate some yourself you should head to teamsees.org as for hope for the turtles in the 1940s incredible video was taken of what is now estimated to be around 40 000 kemp's ridley turtles nesting in one area a turtle that today is the rarest and most endangered of all sea turtles by 1985 only 700 nests for this turtle were found worldwide the entire year the kemp's ridley turtle was on a fast track to extinction due to human damage but thanks to conservation efforts the trend slowly turned in the early 2000s a combination of nesting beach protection and improved fisheries regulation saved this rarest of all sea turtles from the brink of extinction and is now estimated to be over 22 000 individuals strong with more hard work these numbers can continue to improve hope for the turtles is very much alive we can do better we already have and we already are you

Channel: Real Science

Views: 293,192

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Id: q4fXD1mw_ic

Length: 16min 7sec (967 seconds)

Published: Sat Nov 13 2021