"Given that similar circling behavior was observed across a wide variety of marine megafauna taxa, it might be possible that it is a behavioral convergence having similar purposes," lead author Tomoko Narazaki, from the University of Tokyo, told Gizmodo. "But, for now, the purpose and the function of this behavior remain unknown."
The behavior was first discovered by accident, as New Scientist explained. Narazaki was studying the navigational abilities of green sea turtles (Chelonia mydas) in the Indian and Pacific oceans. Her team moved the turtles away from their breeding grounds to test their ability to find their way home again, but they noticed something odd. When the turtles were about to approach the waters off of their nesting beaches, they began to circle. One made 76 rotations lasting 16 to 20 seconds each.
At first, Narazaki said, she thought the tracking equipment was broken.
"To be honest, I doubted my eyes when I first saw the data because the turtle circles so constantly, just like a machine!" Narazaki said in a Cell Press release published by Phys.org.
The detailed observation of the turtles' movements was enabled by a new tracking technology that has made possible a 3D modeling of an animal's movements down to the meter and the second, as the study explained.
"When I got back in my lab, I reported this interesting discovery to my colleagues who use the same 3D data loggers to study a wide range of marine megafauna taxa," Narazaki further told Cell Press.
These researchers reported that they also had observed the strange behavior in species from tiger sharks to king penguins to Antarctic fur seals, as Gizmodo reported.
It is more efficient for an animal to swim in a straight line in order to reach its destination, so why is this behavior so common? The researchers have several ideas.
One possibility is that the animals circle in order to forage for food. Four tiger sharks, for example, circled 272 times in their known feeding grounds off Hawaii, the study authors wrote. However, some of the circling behavior seems clearly not related to eating. One male tiger shark circled before approaching a female, according to Gizmodo. However, seals, penguins and Cuvier's beaked whales all circled near the surface of the water, when normally they feed farther down, according to New Scientist. In addition, fur seals normally circled during the day, while they typically feed at night, Cell Press noted.
It is also possible that some animals circle to help with navigation.
"What surprised me most was that homing turtles undertake circling behavior at seemingly navigationally important locations, such as just before the final approach to their goal," Narazaki told Cell Press.
It is possible that the circling helps turtles detect magnetic fields, a technique that submarines also use when making geomagnetic observations. Previous research has suggested that turtles are capable of sensing magnetic fields, according to New Scientist.
But for now, the circling ultimately remains another mystery of the ocean.
Scientists have newly photographed three species of shark that can glow in the dark, according to a study published in Frontiers in Marine Science last month.
The sharks were found in the waters of Chatham Rise, off of New Zealand. And one of them, the kitefin shark (Dalatias licha), is now the largest known vertebrate capable of producing its own light, CNN reported.
"This first experimental study of three luminous shark species from New Zealand provides an insight into the diversity of shark bioluminescence and highlights the need for more research to help understand these unusual deep-sea inhabitants: the glowing sharks," the study authors wrote.
Bioluminescence is defined as the production of light by living organisms and it is caused by a biochemical reaction. It is common among marine life, and was first observed in sharks in the nineteenth century. Today, around 57 out of 540 known shark species are thought to be capable of producing bioluminescence, study co-author Jérôme Mallefet, head of the marine biology laboratory at the Catholic University of Louvain in Belgium, told CNN.
However, the study marks the first time this property has been observed in a shark as large as the kitefin, which can grow to be nearly six feet. Researchers had previously thought that kitefins might be bioluminescent, because specimens showed that they were capable of producing light. But they have never before been observed doing so because they live so far below the ocean's surface, at 656 to 2,953 feet deep.
In addition, the researchers from the Catholic University of Louvain and the National Institute of Water and Atmospheric Research (NIWA) in New Zealand also recorded the phenomenon in two other deepwater sharks: the blackbelly lanternshark (Etmopterus lucifer), and the southern lanternshark (Etmopterus granulosus).
"The two other Etmopterus sharks were also not documented, so it is the first time," Mallefet told The Guardian.
The three sharks were collected in January 2020 from a part of the ocean known as the mesopelagic or "twilight" zone, which is between 200 and 1,000 meters (approximately 656 to 3,281 feet) deep. Here, around 90 percent of life is thought to have some form of bioluminescence that it uses for attracting mates, catching prey or camouflage, among other things, according to Science Alert.
In the case of the sharks, scientists think that they use it to camouflage themselves from below. The bioluminescence is concentrated in their bellies and underbellies, and the glow could help them blend in with the light that is visible from the sky. This could protect the smaller two species from predators and help the kitefin shark both illuminate and sneak up on prey, according to The Guardian.
However, there is one mystery about the kitefin shark that does not fit this hypothesis: Its dorsal fin also lights up.
"The luminous pattern of the Kitefin shark was unknown and we are still very surprised by the glow on the dorsal fin," Mallefet told The Guardian. "Why? For which purpose?
More research will be needed to understand how and why these species use their self-made light. But the study shines its own light on the unique ecosystems of the deep sea, and the need to both understand and preserve them.
"I fear that we have done a lot of mistakes throwing stuff in the sea," Mallefet told CNN. "I fear what will happen for the next generations."
- 10 Little-Known Shark Facts - EcoWatch ›
- 4 New Walking Shark Species Discovered - EcoWatch ›
- 5 Incredible Species That Glow in the Dark - EcoWatch ›
Each product featured here has been independently selected by the writer. If you make a purchase using the links included, we may earn commission.
The bright patterns and recognizable designs of Waterlust's activewear aren't just for show. In fact, they're meant to promote the conversation around sustainability and give back to the ocean science and conservation community.
Each design is paired with a research lab, nonprofit, or education organization that has high intellectual merit and the potential to move the needle in its respective field. For each product sold, Waterlust donates 10% of profits to these conservation partners.
Eye-Catching Designs Made from Recycled Plastic Bottles
waterlust.com / @abamabam
The company sells a range of eco-friendly items like leggings, rash guards, and board shorts that are made using recycled post-consumer plastic bottles. There are currently 16 causes represented by distinct marine-life patterns, from whale shark research and invasive lionfish removal to sockeye salmon monitoring and abalone restoration.
One such organization is Get Inspired, a nonprofit that specializes in ocean restoration and environmental education. Get Inspired founder, marine biologist Nancy Caruso, says supporting on-the-ground efforts is one thing that sets Waterlust apart, like their apparel line that supports Get Inspired abalone restoration programs.
"All of us [conservation partners] are doing something," Caruso said. "We're not putting up exhibits and talking about it — although that is important — we're in the field."
Waterlust not only helps its conservation partners financially so they can continue their important work. It also helps them get the word out about what they're doing, whether that's through social media spotlights, photo and video projects, or the informative note card that comes with each piece of apparel.
"They're doing their part for sure, pushing the information out across all of their channels, and I think that's what makes them so interesting," Caruso said.
And then there are the clothes, which speak for themselves.
Advocate Apparel to Start Conversations About Conservation
waterlust.com / @oceanraysphotography
Waterlust's concept of "advocate apparel" encourages people to see getting dressed every day as an opportunity to not only express their individuality and style, but also to advance the conversation around marine science. By infusing science into clothing, people can visually represent species and ecosystems in need of advocacy — something that, more often than not, leads to a teaching moment.
"When people wear Waterlust gear, it's just a matter of time before somebody asks them about the bright, funky designs," said Waterlust's CEO, Patrick Rynne. "That moment is incredibly special, because it creates an intimate opportunity for the wearer to share what they've learned with another."
The idea for the company came to Rynne when he was a Ph.D. student in marine science.
"I was surrounded by incredible people that were discovering fascinating things but noticed that often their work wasn't reaching the general public in creative and engaging ways," he said. "That seemed like a missed opportunity with big implications."
Waterlust initially focused on conventional media, like film and photography, to promote ocean science, but the team quickly realized engagement on social media didn't translate to action or even knowledge sharing offscreen.
Rynne also saw the "in one ear, out the other" issue in the classroom — if students didn't repeatedly engage with the topics they learned, they'd quickly forget them.
"We decided that if we truly wanted to achieve our goal of bringing science into people's lives and have it stick, it would need to be through a process that is frequently repeated, fun, and functional," Rynne said. "That's when we thought about clothing."
Support Marine Research and Sustainability in Style
To date, Waterlust has sold tens of thousands of pieces of apparel in over 100 countries, and the interactions its products have sparked have had clear implications for furthering science communication.
For Caruso alone, it's led to opportunities to share her abalone restoration methods with communities far and wide.
"It moves my small little world of what I'm doing here in Orange County, California, across the entire globe," she said. "That's one of the beautiful things about our partnership."
Check out all of the different eco-conscious apparel options available from Waterlust to help promote ocean conservation.
Melissa Smith is an avid writer, scuba diver, backpacker, and all-around outdoor enthusiast. She graduated from the University of Florida with degrees in journalism and sustainable studies. Before joining EcoWatch, Melissa worked as the managing editor of Scuba Diving magazine and the communications manager of The Ocean Agency, a non-profit that's featured in the Emmy award-winning documentary Chasing Coral.
The oceans and space are two of the last frontiers of discovery. It is only fitting, then, that technology originally designed to help map stars imaged by the Hubble Space Telescope has now been adapted to match spot patterns on the world's largest fish, the whale shark, to help save it.
Whale sharks can grow up to 40 feet in length and weigh more than 20 tons, reported National Geographic. Despite their giant size, a lot remains unknown about these gentle, elusive giants. Currently, there is no robust estimate of the current global whale shark population, but, according to CNN, numbers have dropped more than 50% in the last 75 years.
The filter-feeding sharks are currently considered endangered by the International Union for Conservation of Nature (IUCN), with population numbers decreasing. This implies a "very high risk of extinction in the wild," reported The Nation Thailand.
The main reasons for this decline mirror those threatening the entire family of sharks, The Nation Thailand reported. These include impacts of fisheries, coastal pollution, by-catch loss and vessel strikes, reported IUCN. Another IUCN article also reported that international demand for shark fins, liver oil, skin and meat has driven the slaughter of thousands of whale sharks. In southern China, large-scale commercial take of whale sharks still appears to be increasing, the first IUCN report found.
Additionally, the climate crisis has had a "dramatic effect" on whale sharks, CNN reported, altering their prey, water temperatures, currents and hot spots where they might want to go.
Unfortunately, with the population declining, the species also does not replenish itself quickly, with slow growth, late maturation and low fecundity, Petch Manopawitr, a deputy director and Thailand programme coordinator of the IUCN Southeast Asia, told The Nation Thailand.
"It is alarming to see such emblematic species slide towards extinction," said Jane Smart, director of IUCN's Global Species Programme, reported The Nation Thailand.
To increase understanding about and conservation of the species, Brad Norman, a marine conservationist in Western Australia with Murdoch University, helped found a photo identification program for whale sharks.
"Each whale shark has distinctive markings – the lines and spots on their skin is like a fingerprint – with no two whale sharks the same," Norman said in a Murdoch University press release.
Users upload photos of the "special ID area" behind a whale shark's gills to Wildbook, and the technology behind the database reads the distinctive spot patterns like a fingerprint, CNN reported. It actually adapts an algorithm that NASA scientists use in the Hubble space telescope to map stars in the sky in order to identify unique spot patterns on whale sharks' skin and then scan them against the thousands of photos in the database to look for matching patterns, CNN reported. This is much like how fingerprint recognition works.
"If it's a match, it's the same shark," Norman told CNN.
That program has evolved into the world's largest and most effective wild shark monitoring program – the Wildbook for Whale Sharks, which calls on citizen scientists globally to get involved in marine research, the Murdoch University release said. Over 10,000 people from over 50 countries have uploaded images of whale sharks to the central, online database, which helps scientists to identify population hot spots and migration data, CNN reported. The crowdsourced data is vital to whale shark conservation and species management.
From analyzing the photos, "we're starting to find out areas of critical importance to whale sharks, where they're traveling to for important aspects of their life," Norman told CNN.
Software programmer Jason Holmberg helped develop the Wildbook after being inspired by a scuba diving encounter with one of the giants in the Red Sea. He said, "We're talking about an animal (once) considered to be rare, maybe a couple of hundred documented sightings in all of history," a NASA release noted. As of Feb. 2021, the library contained almost 76,0000 sighting reports of over 12,300 individual sharks.
"[Having] thousands of citizen scientists around the world really generates information about these fish and a lot of public interest that helps conservation of the species,'' Norman told National Geographic. "And the beauty of this is anyone can assist in whale shark research."
- Longest Recorded Whale Shark Migration - EcoWatch ›
- Shark and Ray Populations Declining Rapidly, Scientists Call for ... ›
- Whale Shark Found Dead, Plastic Spoon Stuck in Digestive System ... ›
- Following House Approval, U.S. Has a Chance to Ban the Cruel ... ›
- Sharks Are Vanishing From Many of the World's Reefs - EcoWatch ›
Juvenile great white sharks have historically spent their time in Southern California waters, but after a marine heat wave started in 2014, they began to spend more time further north in Monterey Bay. This is bad news for prey animals such as sea otters, whose area numbers have fallen 86 percent since the sharks moved in, The Guardian reported.
"White sharks aren't just another species — they're an apex predator and all eyes are on them in the ocean," Kyle Van Houtan from the Monterey Bay Aquarium, who co-authored a new study on the phenomenon, told The Guardian.
The study, published in Scientific Reports on Tuesday, used data from juvenile great white sharks tagged in 2002 to monitor their movements, according to a Monterey Bay Aquarium press release published in EurekAlert! Researchers used 22 million electronic data records from 14 sharks and compared them to 38 years of ocean temperature data to find the coldest temperature the sharks could stand.
Juvenile sharks range between five and nine feet long and often prefer warmer water, where they feast on fish, rays and squid, according to The Mercury News. After two or three years the sharks set out for colder, deeper waters after growing more than ten-feet long and developing wider, more serrated teeth.
Between 1982 and 2013, the young sharks never ventured further north of Santa Barbara, at 34 degrees North, according to the press release. However, after the marine heat wave in 2014, their range shifted 4.5 degrees North to Bodega Bay. The sharks' current range limit remains at 36 degrees North near Monterey Bay. The cold water limit for the sharks moved about 373 miles north between 2014 and 2020, according to The Guardian.
At the same time, the sharks' suitable water temperature range actually shrank by five percent. This is a problem for their prey.
"It doesn't seem big in the overall scheme of things but predators and prey are now compressed into a smaller place, where prey have fewer places to hide. So you're seeing a really rapid decline in fish, including salmon," Van Houten told the Guardian.
The shift has also impacted humans who now share their surfing and swimming spots with the predators.
"I've seen sharks right under surfers — just a few feet away," Chris Gularte, a Specialized Helicopters chief pilot who conducts tours in the area, told The Mercury News. "When the water is warm and they come in the bay, you can see them swim near people all day long. Standup paddlers and kayakers will go right up to them and not realize they are there."
A 2020 attack killed a surfer near Santa Cruz when a shark bit an artery in his leg. However, California shark attacks decreased 91 percent since 1950 because people are more informed on how to avoid sharks, The Guardian explained.
The scientists stressed how sharks are not to blame for their northward shift.
"White sharks, otters, kelp, lobsters, corals, redwoods, monarch butterflies — these are all showing us that climate change is happening right here in our backyard," Van Houtan said in the press release. "It's time for us to take notice and listen to this chorus from nature. We know that greenhouse gas emissions are rapidly disrupting our climate and this is taking hold in many ways... But let's be clear: The sharks are not the problem. Our emissions are the problem. We need to act on climate change and reduce our reliance on fossil fuels."
- Shark Attacks: Surfer Killed in Northern California, Another Escapes ... ›
- Why Is a Large Group of Great White Sharks Forming off the ... ›
An alarming new study reports that the global population of sharks and rays has declined 71 percent since 1970. The crash, due to overfishing, underscores the need for international policymakers to reverse the species' impending collapse.
Published in Nature, the study is one of the first global assessments of its kind, The New York Times reported. But the results may not capture the full extent of the loss, scientists warn. Due to incomplete data and growth in the fishing industry, before the study began, shark and ray numbers are most likely lower than reported.
"The decline isn't stopping, which is a problem," Nathan Pacoureau, a researcher at Simon Fraser University in Canada and the lead author of the study told The Guardian. "Everything in our oceans is so depleted now."
While oil and gas drilling and the increasing impacts of the climate crisis are threatening the species, increased overfishing is the main cause for the drastic population reduction, The Guardian reported.
Often depleting stocks faster than a species can restock itself, fishing has increased drastically since 1970, pushing more than half of the 31 oceanic shark species onto the endangered or critically endangered list by the International Union for Conservation of Nature, The Guardian reported.
Sharks and rays, which are often killed for their meat, fins and oil, are often caught accidentally by fishermen, The New York Times noted. But catching sharks and rays doesn't have to be an "inevitable" part of commercial fishing.
"We have volumes of scientific studies now about how you might avoid catching sharks to begin with, and certainly a lot about the best practices for releasing the shark safely and making sure it survives," Sonja Fordham, an author of the study and the president of Shark Advocates International told The New York Times. "It matters, for example, how long a shark struggles on the line, so fishermen should monitor their lines regularly. They should avoid shark hot spots and use shark-friendly gear that allows the creatures to break free while keeping tuna and swordfish on the line."
The study also exposes how lax international fishing rules directly impact the species. "We have this problematic disconnect between fisheries and environment agencies, I would say in just about every country in the world," Fordham added.
Many sharks are migratory, meaning they often are swimming in unprotected waters. While some countries have measures to prevent overfishing, this study, evidently, stresses the need to fix the "patchwork" of international oceanic rules, The Guardian reported.
"Strict prohibitions and precautionary science-based catch limits are urgently needed to avert population collapse," the authors of the study wrote. To reverse the rapid decline in ray and shark populations, international cooperation is necessary.
As the global food demand increases and economic livelihoods increasingly rely on the oceans, future international fishing rules will have a lot to account for. United Nations goals, like Sustainable Development Goal 14, are a step towards reaching such global agreements to conserve and sustainably use the oceans.
There is good news. Fishing regulation works, Science reported.
For example, attempts to protect the white shark in the U.S. has caused the species abundance to increase on both the U.S. east and west coasts, according to Science.
"The U.S. is one of the only countries that's been really successful in reversing sharp population declines through management," Fordham told Science.
Although the "findings of this paper are horrifying," Mariah Pfleger, a marine scientist at Oceana, told The Guardian, they also validate what scientists have long known about the pressures of commercial fishing.
"We need proactive measures to prevent total collapse – this should be a wake up call for policy makers," Pacoureau added.
- Sharks Are Vanishing From Many of the World's Reefs - EcoWatch ›
- Will 500000 Sharks Be Slaughtered for a COVID-19 Cure? - EcoWatch ›
- 4 New Walking Shark Species Discovered - EcoWatch ›
- NASA Technology Could Help Save the World's Largest Shark - EcoWatch ›
The future may be too hot for baby sharks, a study published Tuesday found.
Oceans are warming as a result of global climate change, causing harm to aquatic ecosystems across the planet. In response, researchers from Australia's ARC Centre of Excellence for Coral Reef Studies at James Cook University and the University of Massachusetts asked: How will climate change affect species who rely on their environment to regulate their biological processes?
The researchers chose to study the epaulette shark to better understand how ectotherms, species that match their body temperatures to the environment's, will respond to climate change.
"The epaulette shark is known for its resilience to change, even to ocean acidification," Dr. Jodie Rummer, co-author of the study told the ARC Centre in a statement.
Epaulette sharks are only found in the Great Barrier Reef, Australia and are often the subject of climate change studies because they thrive in captivity and are considered of little concern in the wild, the study reported. "So, if this species can't cope with warming waters then how will other, less tolerant species fare?" Rummer asked.
The scientists examined how 27 epaulette shark embryos grew and developed in average summer temperatures, 27 degrees Celsius, and temperatures predicted for the middle and end of the century, 31 degrees Celsius.
"The hotter the conditions, the faster everything happened, which could be a problem for the sharks," Carolyn Wheeler, lead author of the study, said.
In hotter temperatures "the creatures hatched earlier, were born smaller, and needed to feed straight away, but lacked energy," CNN reported, and emerged from their egg cases after 100 days, The Guardian added. But in the normal temperatures, the sharks emerged from the egg cases after 125 days.
Sharks could respond to warming temperatures in three likely ways, Rummer said, according to The Guardian. The first case is the sharks find colder temperatures, but only if they find the right habitat.
The second is the sharks could genetically adapt to warmer temperatures. But this is improbable because the sharks like the epaulette grow slowly and reproduce at low rates compared to other fishes, the ARC Centre wrote in a statement.
And the last case would be for the sharks to "disappear off the planet," Rummer told The Guardian.
Since 1910, the Great Barrier Reef has warmed by 0.8 degrees Celsius. This warming impacts more than a species' biological processes, according to Australia's Great Barrier Reef Marine Park Authority, impacting a fish's swimming abilities and behavior.
Why does this matter?
"When sharks change their behaviour it affects the whole ecosystem," The Conversation reported in an article that analyzed how the Port Jackson shark, a bullhead shark living in Southern Australia, responds to climate change.
Generally the top of the food chain, sharks play a critical role in ecosystem management.
"Port Jackson sharks, for example, are predators of urchins, and urchins feed on kelp forests — a rich habitat for hundreds of marine species. If the number of sharks decline in a region and the number of urchins increase, then it could lead to the loss of kelp forests," The Conversation reported.
Similarly, "Sharks are important as predators because they take out the weak and injured and keep the integrity of the population strong," Rummer told The Guardian.
The future of healthy ecosystems for baby sharks and other marine species seems grim. So what can be done?
Research on how individual species are impacted by climate change is a step in the right direction, The Conversation wrote, which can determine unknown resilience within species and highlight new populations at great risk.
Emphasizing "the importance of curbing our reliance on fossil fuels because climate change is affecting even the toughest little sharks," should come next, Rummer remarked. "Our future ecosystems depend us taking urgent action to limit climate change," she added.
- Climate Change Likely Drove Our Ancestors to Extinction, Study Finds ›
- Fast and Furious Star Joins Sea Shepherd to Show Impact of ... ›
Adult megalodons (Otodus megalodon) could grow to be about 50 feet in length. Now, new research published in Historical Biology on Monday shows that the sharks were fear-inducing from the moment they were born, as baby megalodons could be more than six-and-a-half-feet long.
"It is quite possible that they represent the largest babies in the shark world," Kenshu Shimada, a vertebrate paleontologist at DePaul University in Chicago and lead study author, told The New York Times.
Megalodons dominated prehistoric seas, where they lived between 15 and 3.6 million years ago, according to Taylor & Francis. In addition to their length, they also weighed as much as 110,000 pounds, The New York Times reported.
"They could pretty much do whatever they wanted, swim wherever they wanted, eat whatever they wanted," Jack Cooper, a Swansea University shark researcher who was not involved with the study, told The New York Times.
Despite their dominance of the prehistoric ocean and contemporary imaginations, megalodons are less prominent in the fossil record. That's because megalodons, like all sharks, have skeletons made of cartilage, which is less likely to last than bone, Live Science explained. So megalodons are mostly known to us from their teeth.
One exception to this is a collection of 150 megalodon vertebrae whose cartilage had mineralized. The specimen was discovered in Belgium in the 1860s, The New York Times reported, and is now housed at the Royal Belgian Institute of Natural Sciences in Brussels, according to the study. The authors wrote that it was the "only reasonably preserved vertebral column of the species in the entire world."
The researchers then took advantage of the fact that megalodon vertebrae have growth rings that function similarly to tree rings, Taylor & Francis explained. Researchers were able to use CT scans of the vertebrae to determine that the specimen was 46 years old and around 30 feet long when it died. By calculating what its body length would have been when each ring was formed, the researchers were able to pinpoint its birth size at around 6.6 feet.
"My students and I examine spiny dogfish shark anatomy in class and to think that a baby megalodon was nearly twice as long as the largest adult sharks we examine is mind-boggling," study co-author Matthew Bonnan of Stockton University told Taylor & Francis.
The baby megalodon's large size led the scientists to conclude that it had likely feasted on its siblings in the womb. That's because such a large baby would need to be born live, requiring a lot of energy from the mother.
"Oophagy — egg-eating — is a way for a mother to nourish its embryos for an extended period of time," Shimada told Live Science. "The consequence is that, while only a few embryos per mother will survive and develop, each embryo can become quite large at its birth."
The baby that survived would then be ready to ward off many ocean predators, The New York Times reported. A healthy appetite might have also contributed to the shark's growth.
The researchers also shed light on the megalodon's later growth, and calculated that it grew an average of 6.3 inches a year, according to the study. Researchers also compared the specimen's growth rate with the largest known megalodon sizes in order to calculate that megalodons had a potential life expectancy of 88 to 100 years, Live Science reported.
Shimada told Live Science that the life-expectancy calculations were still theoretical and required more research. Even so, the findings help scientists learn more about megalodons and the prehistoric ocean.
"As one of the largest carnivores that ever existed on Earth, deciphering such growth parameters of O. megalodon is critical to understand the role large carnivores play in the context of the evolution of marine ecosystems," Shimada told Taylor & Francis.
- 'Surprising' Fossil Discovery Could Rewrite Shark Evolution Story ... ›
- Will 500,000 Sharks Be Slaughtered for a COVID-19 Cure ... ›
- 4 New Walking Shark Species Discovered - EcoWatch ›
The island of Tristan da Cunha. VictoriaJStokes / iStock / Getty Images Plus
To reach Tristan da Cunha, a UK overseas territory, one must make a seven-day boat trip from South Africa, reported National Geographic. The island chain recently announced that 700,000 square kilometers (270,271 square miles), or 90% of its territorial waters, will be designated as a large marine protected area (MPA) to safeguard the area's rich biodiversity and endangered animals, The Guardian reported. At that size, it will be three times the size of Britain, the largest marine sanctuary in the Atlantic and the fourth largest in the world, providing refuge to sevengill sharks, whales and seals, AP News continued.
The new wildlife refuge will be a "no-take" zone, baning bottom-trawling fishing, deep-sea mining and other harmful and extractive harvesting from its waters, National Geographic reported. This will also protect the foraging grounds of tens of millions of seabirds that roost on the island, such as endangered Tristan and yellow-nosed albatross, Atlantic petrel and rockhopper penguins. Critically, these protections will bolster the small Tristan Rock Lobster commercial fishery outside the sanctuary, which is the territory's most important source of income, AP News reported. This luxury crayfish is sold to the U.S., Europe, Japan and China.
Experts believe that MPAs are a "silver bullet for conservation," Earth.org noted. The World Economic Forum (WEF) found that MPAs worldwide protect food supplies by leading to larger catch yields through "spillover," where fish from protected areas reproduce and enter fishing hotspots in greater abundance. Expanding the current network of protected areas by just 5% could boost global fish catch by at least 20%, the WEF asserted.
The protected area will join the UK's Blue Belt Programme, which has funded 27 million pounds ($35.5 million) to promote marine conservation in UK overseas territories, AP News reported. The initiative has protected 11.1 million square kilometers (4.3 million square miles) of marine environment, or 1% of the world's oceans, Prime Minister Boris Johnson said, the report added.
The program continues to inch closer to the global target of protecting 30% of the world's oceans by 2030. Scientists believe that this is the minimum required percentage of protected habitat to preserve biodiversity and safeguard ecosystems and their functions. According to National Geographic, roughly 8% of the world's oceans are currently designated as MPAs, but only 2.6% are totally off limits to fishing.
Johnson said, "We need collective global action if we are to bequeath a world that is every bit as wonderful and magnificent as the one we inherited," reported The Guardian.
According to Earth.org, the UK holds a duty to protect wildlife found in all its territories and will take charge of monitoring and enforcement within the new MPA. This is especially important because the nearest habitation, Saint Helena, is 2,400 km away. Through the Blue Belt Programme, Tristan da Cunha will receive more resources to patrol for illegal fishing activity. Earth.org reported.
The Pew Bertarelli project, which promotes the creation of marine reserves around the world, also committed to help the archipelago protect its waters with technology that uses real-time data to evaluate ocean conditions and human activity such as fishing, AP News reported. The project is a joint venture of the Pew Charitable Trusts and the Bertarelli Foundation.
"This small community is responsible for one of the biggest conservation achievements of 2020," Beccy Speight, chief executive of the Royal Society for the Protection of Birds (RSPB) told AP News. "This will protect one of the most pristine marine environments on the planet."
James Glass, the territory's chief islander, said in a statement, "Our life on Tristan da Cunha has always been based around our relationship with the sea, and that continues today. That's why we're fully protecting 90% of our waters, and we're proud that we can play a key role in preserving the health of the oceans," reported AP News.
While the British government lauded the effort and called on other governments to take similar action to meet the ambitious 30%, some critics were not impressed. They noted the hypocrisy of encouraging others to act when the UK allows bottom-trawling in all but two of its domestic offshore MPAs, in another Guardian article.
Jonathan Hall, head of UK overseas territory unit at the RSPB, told Earth.org, "We should also be looking at protecting UK waters. The contrast is stark. We have this small community that is showing leadership in protecting their waters, but there have been lots of examples this year where more effective management of our existing protected areas is needed."
- The UN Wants to Protect 30% of the Planet by 2030 - EcoWatch ›
- Visionary Study Shows How 30% of World's Oceans Could Be Made ... ›
- The Top 10 Ocean Biodiversity Hotspots to Protect - EcoWatch ›
- World's Most Remote Village Is About to Become Self-Sufficient ... ›
- Coral Sanctuary Discovered off Kenyan and Tanzanian Coast - EcoWatch ›
- The Atlantic Ocean Is Getting Wider, Scientists Think They Know Why - EcoWatch ›
Scientists are racing to create a cure for COVID-19, but the toll on sharks might be irreparable. Conservationists estimate that half a million of the predators may be killed to supply the world with a coronavirus vaccine when one is developed.
Shark liver oil is primarily made of squalene, which helps regulate a shark's buoyancy in deep water. The compound is also found in plants, humans and other animals. Used as a moisturizing agent in cosmetics, squalene also creates a stronger immune response in vaccines, making them more effective, reported Science Times.
Squalene has been used in flu vaccines since 1997, Boston 25 News reported, and has an "excellent safety record" according to the CDC, Miami Herald reported. It could also help reduce the amount of vaccine needed per person, the Boston news report said.
Shark Allies, an advocacy group fighting against shark overfishing, claims that five COVID-19 vaccine candidates use shark squalene; the California-based non-profit is petitioning the U.S. Food and Drug Administration, Europe, China and all vaccine developers to omit the compound or find an alternative that doesn't require sharks.
One British pharmaceutical that currently uses shark squalene in flu vaccines plans to manufacture a billion doses of the compound for potential use in coronavirus vaccines by May 2021, Sky News reported. VICE reported that roughly 3,000 sharks have to die to extract a single tonne of squalene.
"It's called harvesting, but really you're not growing it, you're taking it from the wild," Stefanie Brendl, executive director of Shark Allies, told Boston 25 News. "It's a limited resource."
Shark Allies worries that the development and production of enough vaccines to create worldwide immunization to the novel coronavirus and future coronaviruses that are identified could carry "an immense ecological cost," VICE reported.
"It's something we need to get ahead of ASAP, because we are facing many years of vaccine production, for a global population, for many more coronavirus vaccines to come," Brendl told VICE. "The real danger is in what this can turn into in the future. A reliance on shark oil for a global vaccine — it's truly insane. A wild animal is not a reliable source and cannot sustain ongoing commercial pressure. [And] the overfishing of sharks globally is already at critical levels."
The conservationists fear that a global vaccine using shark squalene will endanger most shark species and could potentially wipe out some more threatened species, Miami Herald reported. Shark populations are vulnerable because they reproduce in low numbers and are slow to mature. According to VICE, great whites, hammerheads and whale sharks are among those most often targeted for their livers. According to Oceana, deep-sea sharks are especially vulnerable because their livers contain more squalene than other species as it helps them adapt to their environment, reported Miami Herald.
"We're not trying to take anything away from humanity and say don't cure yourself, don't create a vaccine," Brendl told Boston 25 News. "What we're saying is the alternative is already there."
In a popular online campaign, Shark Allies outlined the non-shark alternatives for squalene already in existence. Plant-based oils can be harvested from things like yeast, wheat germ, sugarcane and olive oil, VICE and Miami Herald reported. Bacteria-created squalene has also been researched, the petition noted. The problem with these alternatives is that they are about 30% more expensive and harder to extract than shark-based squalene, Miami Herald reported.
A team of researchers in Poland who were working on a plant-based squalene alternative in 2013 stressed in their report that "in the interest of protecting biodiversity, raw materials of animal origin must be replaced by alternative sources that respect our environment."
Shark Allies also noted that there are coronavirus vaccines in development that do not require squalene at all and encouraged the development of those alternatives.
- Sharks Are Vanishing From Many of the World's Reefs - EcoWatch ›
- Sharks: Imperiled, Maligned, Fascinating - EcoWatch ›
- How to Protect Sharks From Overfishing - EcoWatch ›
- Coronavirus: Can We Trust Recent COVID Vaccine Successes? - EcoWatch ›
- Baby Megalodon Sharks Were Six-Foot-Long Cannibals, Study Finds ›
- Shark and Ray Populations Declining Rapidly, Scientists Call for Urgent Fishing Limits - EcoWatch ›
- Antarctica Wildlife May Be Impacted by COVID-19 ›
Sharks are different from other large fish like salmon or tuna in that they have softer, non-bony skeletons made out of a material called cartilage. It was previously thought that sharks split off from a common ancestor with a cartilage skeleton, before the bony skeletons favored by other fish and all terrestrial vertebrates evolved. But now, researchers have uncovered a fossil that is a common ancestor of both sharks and later fish, and has a bony skull.
"This fossil is probably the most surprising thing I have ever worked on in my career," study first author and Imperial College London senior lecturer D.r Martin Brazeau told The Guardian. "I never expected to find this."
Sharks' non-bony skeletons were thought to be the template before bony internal skeletons evolved, but a new fossil… https://t.co/xsAJOlL9Kn— Imperial College (@Imperial College)1599496071.0
The fossil, described in Nature Ecology and Evolution Monday, was dug up in western Mongolia in 2012. It is about 410 million years old and belongs to a group of fish called placoderms that are a common ancestor of sharks and all "jawed vertebrates," animals with jaws and backbones, an Imperial College London press release explained.
Until now, placoderm fossils had turned up with armored outsides but inner skeletons made of cartilage, enforcing the idea that sharks split from these ancient fish before bony fish evolved, according to The Guardian. But the new fossil, which consisted of a partial skull roof and brain case, was "wall-to-wall endochondral," or bone, according to the press release.
The fossil represents a new species of placoderm, which the researchers dubbed Minjinia turgenensis. Its discovery is part of a shift in where researchers search for the remains of early fish. Initial finds were dug up in Europe, Australia and the U.S., but now scientists are finding specimens in China and South America.
The bony placoderm was found by a team led by researchers from Imperial College London, London's Natural History Museum and Mongolia. They decided to dig in an area that had rocks of the right age that had never been examined before, and they still have many finds to sort through.
While the researchers cautioned that one fossil does not make a theory, they think it is now possible that sharks evolved bony skeletons and then "lost" them again. But for sharks, that "loss" would have been an evolutionary gain.
"If sharks had bony skeletons and lost it, it could be an evolutionary adaptation," Brazeau explained in the press release. "Sharks don't have swim bladders, which evolved later in bony fish, but a lighter skeleton would have helped them be more mobile in the water and swim at different depths. This may be what helped sharks to be one of the first global fish species, spreading out into oceans around the world 400 million years ago."
The bony placoderm is not the only evidence for this theory, Newsweek pointed out. In 2015, scientists announced a 380-million-year-old shark that had a skeleton made of cartilage, but with the remnants of what appeared to be bone cells.
University of Cambridge paleontologist Dr. Daniel Field, who was not involved with the research, told The Guardian that it was an example of the complexities of evolution.
"Evolutionary biologists were long guided by the assumption that the simplest explanation – the one that minimised the number of inferred evolutionary changes – was most likely to be correct. With more information from the fossil record, we are frequently discovering that evolutionary change has proceeded in more complex directions than we had previously assumed," he said.
That's what the crew of a U.S. Coast Guard ship discovered when their Pacific Ocean swim break was interrupted by an unexpected intruder.
"As if right out of a Hollywood movie, a 6-8 foot shark (no exaggeration) surfaced at the Rescue Door and was swimming toward 30-40 people in the water about 30 feet away," the U.S. Coast Guard Cutter Kimball (USCGC) wrote in a Tuesday Facebook post describing the incident.
The U.S. Coast Guard Cutter Kimball has been patrolling in the Pacific Ocean for the past several weeks conducting national security, search and rescue and fisheries operations, according to Military.com. To liven up the monotony of days at sea, the crew decided to take a swim break or "swim call," in official terminology.
More than 40 crew members, plus an inflatable unicorn, plunged into the water. Luckily, they had certain safety measures in place, such as a rescue swimmer, a smaller boat with extra crew and someone assigned to shark watch.
It is customary for Coast Guard and Navy vessels to set up shark or polar bear watches during breaks in these apex predators' habitats, Military.com explained. This precaution meant that bridge personnel were ready to alert the crew to the shark's presence.
To protect his crewmates, Maritime Enforcement Specialist 1st Class Samuel Cintron opened fire on the advancing shark to try and scare it away, CNN reported.
The USCGC described what happened next:
ME1 Cintron fired a well-aimed burst right at/on top of the shark to protect shipmates just feet away. It turned away for a few seconds then turned back. We kept directing people out of the water while keeping a clear line of sight on the shark. ME1 fired bursts as needed to keep the shark from his shipmates with amazing accuracy. The shark would wave off with each burst but kept coming back toward our shipmates.
The crew managed to get everyone out of the water safely, including the unicorn. And it appeared that the shark emerged unscathed too, a Coast Guard public affairs spokesperson told Military.com.
"Our goal was to keep it away from shipmates, not harm it if possible," the USCGC wrote on Facebook. "It was most likely curious and not looking for a meal. We picked our location to try and avoid such an encounter but it is their ocean after all. It later joined a few smaller buddies that showed up and they swam off together. "
A review of video footage of the incident revealed the shark to be a Long-Fin Mako or Pelagic Thresher Shark.
"Not something to mess with!" the USCGC wrote.
Mako sharks have been involved in three non-fatal unprovoked shark attacks, according to the Florida Museum's International Shark Attack File.
The overall risk of shark attacks is extremely low, according to the file. Any given individual has a one in 3,748,067 chance of dying in one.
In fact, sharks are at much greater risk from humans than we are from sharks, the museum pointed out.
"Most of the world's shark populations are in decline or exist at greatly reduced levels, as a consequence of overfishing and habitat loss. On average, there are only four fatalities attributable to unprovoked attacks by sharks worldwide each year. By contrast, fisheries remove about 100 million sharks and rays annually," it wrote.
Shark attacks are even rarer in the history of Navy or Coast Guard swim calls. Military.com found reports of one shark that turned up during a swim break off a submarine in Hawaii in 2009, but it did not have to be driven away by gunfire.
"We have hundreds of years at sea between all of us and no one has seen or heard of a shark actually showing up during a swim call," the USCGC wrote on Facebook. "This goes to show why we prepare for any and everything. We just didn't think it would be a swim call shark attack!"
- Sharks: Imperiled, Maligned, Fascinating - EcoWatch ›
- Why Is a Large Group of Great White Sharks Forming off the ... ›
- Sharks Are Polluted With Plastic, New Study Shows - EcoWatch ›
- 4 Amazing Shark Stories to Enjoy This Shark Week - EcoWatch ›
By Jonathan Booth
"We saw two swimming past our canoe the other day as we came to shore!"
"Yes, we saw one over towards the mangroves not so long ago…"
"There was one in our net near the big river…"
Scientists love having a mystery to solve and gathering clues to find out if something is real or not. Since January 2019 my organization, the Wildlife Conservation Society, has been collecting evidence to confirm whether highly endangered sawfish and their relatives — the wedgefish, guitarfish and giant guitarfish (collectively and affectionately known as "rhino rays") — live in the coastal waters of New Ireland Province, Papua New Guinea.
Sawfish and their rhino ray relatives — all cousins of sharks — are some of the most threatened species on Earth due to their slow growth, vulnerability to capture in fisheries, and high value in international trade. Recent studies indicate that Papua New Guinea is (together with northern Australia and the southeastern United States) one of the last few strongholds for sawfish populations, making the country a global priority for shark and ray conservation.
Currently sawfish and rhino rays have been well documented along the southern shores and adjacent river systems of Papua New Guinea, and also in the Sepik River, which drains into the Bismarck Sea on the northern coast of the mainland. Sawfish have also been documented in several other provinces in the country, yet no official records exist in New Ireland Province.
A Unique Site
The southwestern Pacific nation of Papua New Guinea is known for its renowned biodiversity, much of which lives nowhere else in the world. But that amazing animal and plant life is often both understudied and under threat.
This holds true in New Ireland.
The many islands of New Ireland Province, located in the Bismarck Archipelago, support coral reefs, mangroves, estuaries and tidal lagoons — typical habitats for rhino rays and sawfish. Some 77% of New Ireland's human population also lives in the coastal zone, where they're highly reliant on fish and other marine resources for food, livelihoods and traditional practices. Local communities also own most of this coastal zone through customary tenure systems, which may have been in place for centuries.
Human pressure, including population growth, could threaten potential sawfish and rhino ray populations unless sufficient management is in place — but local cooperation will be key to such action.
Over the past year and a half, WCS has conducted interviews in New Ireland's coastal areas. Part of the interviews involved showing images of each sawfish, wedgefish and guitarfish species, allowing respondents to identify what they saw. To date residents from 49 communities reported that they had seen sawfish and rhino rays in their local waters. There were 144 separate sightings reported by 111 respondents, which comprised 23 sawfish, 85 wedgefish and 36 guitarfish and giant guitarfish. Roughly half the respondents stated they had seen sawfish or rhino rays either often or sometimes.
Papua New Guinea occupies the western half of New Guinea and is the largest of the South Pacific Island nations. The uplifted reefs, limestone terrain and adjacent islands that form New Ireland Province comprise the north-easterly region of Papua New Guinea. From January 2019 to March 2020, fisher key informant surveys were conducted in coastal communities in western New Ireland Province to determine whether sawfish and rhino rays were observed within the customary waters of each community. A total of 144 sightings were made, including 85 wedgefish (blue), 36 guitarfish and giant guitarfish (green) and 23 sawfish (red) sightings. Source: WCS.
When asked if the animals were targeted by local fishers, more than half the respondents said no: The animals were mostly caught accidentally. Only 9% of the sighted sawfish and rhino rays were reported to have been purposefully caught.
Respondents also provided information on where, and in what condition, they had seen the animals: 77% were seen alive, 10% at the market and 2% entangled in nets.
The results suggest that while sawfish and rhino rays are in the region, they are not a key fishery commodity, which is promising news for developing conservation approaches.
Large-tooth sawfish (Pristis pristis) rostrum, beside a ruler, which was harvested by local community fishers from the Tigak Islands that lie to the west of mainland New Ireland. This rostrum measured nearly 30 inches in length. Photo: Jonathan Booth/WCS.
Further Evidence Needed
While physical and objective data has been lacking — I'm still waiting to see one of these animals in the water, myself — we have confirmed evidence of two large-tooth sawfish (Pristis pristis) in the region (two sawfish beaks, also known as rostra, have been found in community villages since this study began), and we've received reports of additional sightings.
WCS also conducted baited remote underwater video surveys (BRUVS) in 14 locations in the region in 2019-20, following a 2017 BURVS deployment by FinPrint in western New Ireland Province.
Collectively the BRUVS documented 13 species of sharks and rays, including wedgefish (which have also been photographed by local dive operators), but no sawfish.
Wedgefish in New Ireland Province: documented by BRUVS during the FinPrint project (left) and by scuba divers (Dorian Borcherds, Scuba Ventures) (right)
But with that success, we're expanding our search. Over the next 12 months, a further 100 BRUVS will be deployed in areas with a sandy seafloor, where wedgefish and giant guitarfish often rest. Because sawfish typically live in estuaries — where water is often murky — BRUVS will not work due to the poor visibility of the water. In these areas gillnets that have been carefully positioned in river outlets by trained local community members will be monitored for sawfish that may be present. If any sawfish are present in the nets, they will be documented and carefully released.
Opportunities for Conservation
Despite the vulnerability of sawfish and rhino rays — with five of the ten documented species in Papua New Guinea classified as critically endangered — there are currently no protection laws in place. However, since 2017, WCS has worked with over 100 communities in New Ireland Province to establish the country's largest network of marine protected areas.
The MPAs have been developed through a community-first approach, with extensive local outreach, engagement and education. In that way WCS has been actively informing local residents about the biology, threats and management opportunities for sawfish and rhino rays. We anticipate that new laws to protect and manage these endangered animals will be incorporated into the management rules for the new MPAs.
Example of education and outreach materials produced by the WCS team. This poster presents management methods that can be used by community residents to help manage sawfish and rhino ray populations in their customary waters.
While the mystery as to whether sawfish and rhino ray populations are alive and well in PNG has largely been solved, they are still rare and in need of additional conservation efforts. We hope that this work will help bring awareness and conservation action to these highly threatened species — and make sure they don't become mythical creatures of the past.
The opinions expressed above are those of the authors and do not necessarily reflect those of The Revelator, the Center for Biological Diversity or their employees.
Jonathan Booth is a marine conservation advisor with the Papua New Guinea Program at WCS (Wildlife Conservation Society).
Reposted with permission from The Revelator.