Global sea level rise associated with the possible collapse of the West Antarctic Ice Sheet has been significantly underestimated in previous studies, meaning sea level in a warming world will be greater than anticipated, according to a new study from Harvard researchers.
The report, published in Science Advances, features new calculations for what researchers refer to as a water expulsion mechanism. This occurs when the solid bedrock the West Antarctic Ice Sheet sits on rebounds upward as the ice melts and the total weight of the ice sheet decreases. The bedrock sits below sea level so when it lifts, it pushes water from the surrounding area into the ocean, adding to global sea level rise.
The new predictions show that in the case of a total collapse of the ice sheet, global sea level rise estimates would be amplified by an additional meter within 1,000 years.
"The magnitude of the effect shocked us," said Linda Pan, a Ph.D. in earth and planetary science in GSAS who co-led the study with fellow graduate student Evelyn Powell. "Previous studies that had considered the mechanism dismissed it as inconsequential."
"If the West Antarctic Ice Sheet collapsed, the most widely cited estimate of the resulting global mean sea level rise that would result is 3.2 meters," said Powell. "What we've shown is that the water expulsion mechanism will add an additional meter, or 30 percent, to the total."
But this is not just a story about impact that will be felt in hundreds of years. One of the simulations Pan and Powell performed indicated that by the end of this century global sea level rise caused by melting of the West Antarctic Ice Sheet would increase 20 percent by the water expulsion mechanism.
"Every published projection of sea level rise due to melting of the West Antarctic ice sheet that has been based on climate modeling, whether the projection extends to the end of this century or longer into the future, is going to have to be revised upward because of their work," said Jerry X. Mitrovica, the Frank B. Baird Jr. Professor of Science in the Department of Earth and Planetary Sciences and a senior author on the paper. "Every single one."
Pan and Powell, both researchers in Mitrovica's lab, started this research while working on another sea level change project but switched to this one when they noticed more water expulsion from the West Antarctic ice sheet than they were expecting.
The researchers wanted to investigate how the expulsion mechanism affected sea level change when the low viscosity, or the easy flowing material of the Earth's mantle beneath West Antarctica, is considered. When they incorporated this low viscosity into their calculations they realized water expulsion occurred much faster than previous models had predicted.
"No matter what scenario we used for the collapse of the West Antarctic Ice Sheet, we always found that this extra one meter of global sea level rise took place," Pan said.
The researchers hope their calculations show that, in order to accurately estimate global sea level rise associated with melting ice sheets, scientists need to incorporate both the water expulsion effect and the mantle's low viscosity beneath Antarctica.
"Sea level rise doesn't stop when the ice stops melting," Pan said. "The damage we are doing to our coastlines will continue for centuries."
Story Source:
Materials provided by Harvard University. Original written by Juan Siliezar. Note: Content may be edited for style and length.
Antarctic ice-sheet melting to lift sea level higher than thought, Harvard study says: New calculations show the rise due to warming would be 30% above forecasts - Science Daily
In August 2016 a massive storm on par with a Category 2 hurricane churned in the Arctic Ocean. The cyclone led to the third-lowest sea ice extent ever recorded. But what made the Great Arctic Cyclone of 2016 particularly appealing to scientists was the proximity of the Korean icebreaker Araon.
For the first time ever, scientists were able to see exactly what happens to the ocean and sea ice when a cyclone hits. University of Alaska Fairbanks researchers and their international colleagues recently published a new study showing that sea ice declined 5.7 times faster than normal during the storm. They were also able to prove that the rapid decline was driven by cyclone-triggered processes within the ocean.
"Generally, when storms come in, they decrease sea ice, but scientists didn't understand what really caused it," said lead author Xiangdong Zhang from the UAF International Arctic Research Center.
There was general speculation that sea ice declined solely from atmospheric processes melting ice from above. Zhang and his team proved this theory incomplete using "in-situ" observations from directly inside the cyclone. The measurements reflected things like air and ocean temperature, radiation, wind and ocean currents.
It was a stroke of good luck for science, and perhaps a bit nerve-racking for those onboard, that the icebreaker was in position to capture data from the cyclone. Usually ships try to avoid such storms, but Araon had just sailed into the middle of an ice-covered zone and was locked in an ice floe.
Thanks to the ship's position so close to the storm, Xiangdong and his team were able to explain that cyclone-related sea ice loss is primarily due to two physical ocean processes.
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First, strong spinning winds force the surface water to move away from the cyclone. This draws deeper warm water to the surface. Despite this warm water upwelling, a small layer of cool water remains directly beneath the sea ice.
That's where a second process comes into play. The strong cyclone winds act like a blender, mixing the surface water.
Together, the warm water upwelling and the surface turbulence warm the entire upper ocean water column and melt the sea ice from below.
Although the August storm raged for only 10 days, there were lasting effects.
"It's not just the storm itself," explained Zhang. "It has lingering effects because of the enhanced ice-albedo feedback."
The enlarged patches of open water from the storm absorb more heat, which melts more sea ice, causing even more open water. From Aug. 13-22, the amount of sea ice in the entire Arctic Ocean declined by 230,000 square miles, an area more than twice the size of the state of Arizona.
Xiangdong is now working with a new computer model for the Department of Energy to evaluate whether climate change will lead to more Arctic cyclones. Previous research shows that over the past half-century, the number and intensity of cyclones in the Arctic have increased. Some of those storms, like the biggest Arctic cyclone on record in 2012, also led to record low sea ice extent.
View from Patania II, a deep-sea mining robot trialled in the Clarion Clipperton Zone of the Pacific Ocean, April 2021. GSR/Handout via REUTERS
Belgium’s Global Sea Mineral Resources has resumed tests that could lead to the mining of battery minerals from the Pacific Ocean floor after it managed to recover a robot stranded at a depth of thousands of metres.
Global Sea Mineral Resources (GSR) has been testing Patania II, a 25-tonne mining robot prototype, 4 km (13,000 ft) below the surface in its concession in the Clarion Clipperton Zone since April 20.
The machine, named after the world's fastest caterpillar, became detached on Sunday from the 5km cable connecting it to GSR's ship, but a recovery operation reconnected it and brought it back to surface late on Thursday.
"We conduct these trials to better understand the challenges involved so we can continuously refine our technology," Kris Van Nijen, managing director of GSR, said.
Before the incident, the robot had collected rocks rich in manganese, cobalt, and nickel from the seabed.
These potato-sized rocks called "polymetallic nodules" are sought by GSR and other companies with seabed exploration contracts that say they could help meet the world's increasing demand for battery metals.
Independent scientists in a nearby ship are analysing data to establish the trial's environmental impact.
Deep-sea mining regulations have not been finalised by the International Seabed Authority, a U.N. body.
Some environmentalists and companies are calling for a moratorium, saying too little is known about the environmental impact of disturbing the ocean floor, while industry analysts have questioned the economics of technically challenging deep sea mining.
GSR says it will only apply for a mining contract if the science shows that the seabed can be a responsible source of the metals needed for the clean energy transition.
MEXICO CITY (AP) — Mexico said Friday it will try to regain U.S. certification for shrimp exports, after the country lost its registration because of inadequate protections for sea turtles.
Mexico’s agriculture department said it will take corrective measures and carry out training to ensure Mexican trawl-net shrimp boats don’t sweep up sea turtles as by-catch. The department said the U.S. ban coincides with the closure of Mexico’s shrimp fishing season.
Mexico had required fishermen to install sea-turtle-exclusion devices on shrimp nets. But the U.S. State Department said Friday that Mexico no longer met U.S. standards on the issue.
It was not clear whether that was because Mexico hadn’t been enforcing the protections, or because U.S. procedures became more stringent. However, Mexico acknowledged it will institute a “more aggressive program of inspection and oversight.”
The State Department said it “suspended the certification of Mexico because its sea turtle protection program is no longer comparable to that of the United States.”
Most of Mexico’s wild shrimp catch is exported to the United States.
(Reuters) – Belgium’s Global Sea Mineral Resources has resumed tests that could lead to the mining of battery minerals from the Pacific Ocean floor after it managed to recover a robot stranded at a depth of thousands of metres.
Global Sea Mineral Resources (GSR) has been testing Patania II, a 25-tonne mining robot prototype, 4 km (13,000 ft) below the surface in its concession in the Clarion Clipperton Zone since April 20.
The machine, named after the world’s fastest caterpillar, became detached on Sunday from the 5km cable connecting it to GSR’s ship, but a recovery operation reconnected it and brought it back to surface late on Thursday.
“We conduct these trials to better understand the challenges involved so we can continuously refine our technology,” Kris Van Nijen, managing director of GSR, said.
Before the incident, the robot had collected rocks rich in manganese, cobalt, and nickel from the seabed.
These potato-sized rocks called “polymetallic nodules” are sought by GSR and other companies with seabed exploration contracts that say they could help meet the world’s increasing demand for battery metals.
Independent scientists in a nearby ship are analysing data to establish the trial’s environmental impact.
Deep-sea mining regulations have not been finalised by the International Seabed Authority, a U.N. body.
Some environmentalists and companies are calling for a moratorium, saying too little is known about the environmental impact of disturbing the ocean floor, while industry analysts have questioned the economics of technically challenging deep sea mining.
GSR says it will only apply for a mining contract if the science shows that the seabed can be a responsible source of the metals needed for the clean energy transition.
(Reporting by Helen Reid; editing by Barbara Lewis)
Crying out the names of their loved ones as they scattered flower petals into the ocean, relatives of the 53 Indonesian navy crew members who died in a sunken submarine paid tribute at a ceremony at sea on Friday.
Servicemen in white navy uniforms holding ceremonial swords saluted in unison on the deck of the multi-purpose hospital ship KRI Dr. Soeharso, in a mark of respect to the victims at the location where the submarine was last seen.
The KRI Nanggala-402 was discovered at a depth of nearly 840 metres (2,756 ft) on Sunday, broken into at least three parts, four days after it lost contact while preparing to conduct a torpedo drill.
Around 150 family members attended the memorial aboard the ship. Some wept and tried to console each other.
Retrieval operations are still ongoing for German-built submarine, with help from international search teams, as authorities struggle to figure out how to lift the wreckage.
Families and colleagues of the sunken KRI Nanggala-402 submarine's crew members throw flowers and petals to pay tribute during a visit at the site of its last reported dive, on the deck of Indonesian Navy's KRI Dr. Soeharso, in the northern waters off the island of Bali, Indonesia April 30, 2021, in this photo taken by Antara Foto/Budi Candra Setya/via Reuters
"The position of the KRI Nanggala has remained in the area with no movement detected," Navy Chief of Staff Yudo Margono told reporters.
"We are looking at experiences of other countries, such as lifting using special ropes or using air balloons. We still don't know which approach to use," Yudo said.
Experts have said bringing the submarine to the surface will be a huge challenge requiring specialised salvage equipment.
The Nanggala was one of five submarines operated by Indonesia - two German-built Type 209s and three newer South Korean vessels.
The military has been seeking to modernise its defence capabilities but some of its equipment is old and there have been fatal accidents in recent years.
Marine biologists warn that the western Pacific leatherback could go extinct without immediate conservation measures and transnational cooperation.
This subpopulation has decreased at a rate of 5.6% each year for an overall 80% decline over a 28-year period, according to a recent study.
While the IUCN lists the species as a whole as vulnerable, the Pacific populations are critically endangered partly because of their long migratory routes through the high seas, where they face threats like drift gillnet fishing, ship strikes and pollution.
The eastern Pacific subpopulation, which nests in Mexico and Central and South America, faces similar threats. Both populations are at high risk of extinction.
Clear-skied, low-wind summer days are rare off the coast of California. But they’re a blessing if you’re a researcher tracking down critically endangered leatherback sea turtles.
Marine ecologists Scott Benson and Karin Forney, with NOAA’s Southwest Fisheries Science Center, spent many of those days tag-teaming a decades-long research effort to collect data on one of the world’s oldest and largest marine reptiles. Forney sits in the clear belly of a NOAA surveying plane, scanning the dark waters like a hawk, notifying the team when she spots a leatherback sea turtle (Dermochelys coriacea). Benson, her husband, is among the scientists on the boat below, prepped at the hull with a large net, anticipating the moment they can heave the prehistoric giant on board.
Then comes the sampling: blood tests, tissue samples, attaching transmitters, recording weight. It’s an hour-long ordeal, Benson says, and “an all-consuming task.” In a month and a half, the team gets maybe five good-weather opportunities to collect data on this massive but little-understood species. And it could be their last chance to save this population.
NOAA scientists on surveying vessels rely on directions from an aerial survey team, in a plane above, to locate and capture leatherbacks for sampling and tagging procedures. Image by Joel Schumacher (NOAA-ESA Permit #15634).
The western Pacific leatherback sea turtle is at high risk of extinction, according to a study published in Global Ecology and Conservation. The researchers, including lead author Benson and co-author Forney, used roughly three decades of data to assess the population’s status. Combining their observations of foraging turtles in California with data on nesting patterns in Indonesia, the researchers estimate the population has declined at a rate of 5.6% annually, suffering an overall 80% decline from 1990 to 2017.
Both on land and at sea, the turtles face a series of existential threats in the Pacific. The situation is so dire that scientists on both sides of the ocean have dedicated their lives to reeling the distinct populations back from a dangerous tipping point.
The leatherback in the Pacific
The world knew little about Pacific leatherbacks prior to the 1980s, when scientists started collecting more data. Without modern-day technology like satellite transmitters to track turtles’ movements, biologists couldn’t have known that the leatherbacks foraging off the Californian coast were the same as those nesting in the western Pacific.
Today we know that leatherback sea turtles span the globe with seven genetically distinct subpopulations: the eastern and western in the Pacific Ocean, as well as three in the Atlantic Ocean and two in the Indian Ocean. While the IUCN lists the species as a whole as vulnerable, both Pacific subpopulations are considered critically endangered.
“We know what a thriving sea turtle population needs, but the expanse over which this drama is playing out in the Pacific is so huge, it’s hard to understand the whole puzzle and which parts need to be leveraged,” said Kyle Van Houtan, chief scientist of the Monterey Bay Aquarium, who was not involved with the study.
All leatherback sea turtle populations are declining, but those in the Atlantic and Indian Oceans are more robust than the plummeting Pacific populations, Benson said.
Pacific leatherbacks feed in seven known areas of the ocean, stretching from New Zealand to Japan to California. While the eastern subpopulation nests in Mexico and parts of Central America, western Pacific leatherbacks nest primarily in Indonesia, Papua New Guinea and Vanuatu.
The research team recorded an average of 140 individuals in central California’s foraging patch from 1990 to 2003, but that number dropped to an average of 55 by 2017.
Still, the data only account for a fraction of a population that is scattered across the entire Pacific Ocean and migrates at unpredictable time intervals. Benson said the annual decline of nesting females in West Papua, Indonesia, closely mirrors the rate of decline his team calculated in California, providing further evidence that the entire western subpopulation is suffering.
There is no exact count of how many western Pacific leatherback turtles are left. An analysis in 2013 by the IUCN estimated around 1,400 adult turtles survived in the subpopulation. The IUCN also forecasts the population will dip below 1,000 individuals by 2030.
Scientists say a concrete population estimate is difficult given the nature of western Pacific leatherbacks. It is the only subpopulation with a bimodal nesting pattern, meaning some females nest in the summer while others nest in the winter. Compounding the uncertainty, western Pacific leatherbacks only visit foraging and nesting grounds every two to five years.
Western Pacific leatherbacks are attracted to the Monterey ecosystem in California due to the “the immense productivity … because of the upwelling, the deep offshore currents coming up to the surface, causing these cascades of nutrients and life,” Van Houtan said. “That’s why we have these leatherbacks.”
Unlike most reptiles, leatherback turtles can self-regulate their body temperature, allowing them “to go places where no other sea turtles can go,” Van Houtan added. These long-evolved marine reptiles — “living fossils,” as he describes them — date back to the Cretaceous Period, when dinosaurs roamed the Earth. Today, they are the only living species in the Demochelys genus.
Weighing up to 900 kilograms (2,000 pounds) and growing up to 2 meters (7 feet) long, leatherbacks are the largest turtle species on the planet. They are also the most migratory sea turtle, traveling up to 16,000 kilometers (10,000 miles) a year between nesting and feeding sites. These giants can dive more than 1,200 m (4,000 ft) deep — deeper than any other sea turtle — thanks to their soft shells, which won’t crack under pressure.
But even evolution’s long helping hand may not be enough to protect them from humanity’s reach.
Threats at sea and on land
Pacific leatherback turtles face a multitude of perils both at sea and on land. Among them are impoverished villagers who poach eggs or adults for meat, and habitat degradation in the Pacific islands, where coastal development and cyclones have eroded nesting beaches. But the biggest threat, according to scientists, are fishing vessels that accidentally kill turtles as bycatch.
Drift gillnet and longline fisheries — large-scale fishing operations on the open ocean that harvest an abundance of seafood, like swordfish — are notorious for killing sea turtles that get caught in nets and other fishing gear. Worse, scientists say existing bycatch data probably underestimate the true numbers.
“It’s the wild west out on the open ocean,” said George Shillinger, a marine biologist who has studied leatherbacks for three decades and is executive director of Upwell, an NGO dedicated to sea turtle conservation. He added that even if nests are protected, ship strikes and bycatch will continue to decimate the population. And then there’s the further obstacle of subsidized fisheries, expanding fishing fleets and more intense artisanal fishing, he said, noting “we are really challenged to stave off the relentless pressures.”
Across the Pacific, marine scientist Deasy Lontoh champions for leatherback protection in West Papua, Indonesia. She is the research coordinator for the Abun Leatherback Project, which seeks to combat threats that are difficult and costly to mitigate at sea by protecting what’s on shore: nesting females and eggs.
Lontoh co-authored a recent paper outlining threats to the largest remaining nesting population on two beaches in West Papua, known as Jamursba-Medi and Wermon. Lontoh’s team says it hopes to protect at least half of leatherback nests with the help of local communities.
A nesting female returns to the sea after laying her eggs on Jamursba Medi Beach, Indonesia. Image by Barakhiel Heri Nugroho.
Lontoh is trying to avoid what happened in Malaysia when a nesting population of western Pacific leatherbacks vanished entirely. Egg harvesting was a rampant, and legal, way for locals to make money until the Terengganu Turtle Sanctuary Advisory Council outlawed it in 1988. From the 1950s to 1995, Malaysia went from 10,000 nests annually to a mere handful. No nests have been reported in almost a decade.
But even when people don’t harvest turtle eggs, juvenile survival is naturally a gamble. Scientists estimate that only one in every 1,000 eggs survive to maturity, while females lay around 80 eggs in each nest.
“A lot of hatchlings will die, so we just need to produce high enough numbers … and assume that some of them will become adults in 15 or 20 years,” Lontoh said.
Climate change further mars the leatherbacks’ future. More extreme storms can decimate nesting sites, while rising temperatures can bake eggs to death. Lontoh said that, locally, sands can reach a lethal 33° Celsius (91° Fahrenheit), and temperatures are rising in the area alongside global trends.
Hatchlings emerge from a relocated nest. Scientists estimate only one in 500 to 1,000 hatchlings will survive to adulthood and reproduce. Image courtesy of Deasy Lontoh.
Under normal circumstances, leatherbacks would be less fragile, Benson notes. For one, they lay eggs in multiple locations and span much of the world’s oceans. They have also survived several natural climate changes over the past 80 million years. But scientists don’t know how the recent, and rapid, changes in water temperature, ocean currents, and upwelling of nutrients will affect leatherbacks.
“Climate change is thrusting all of those things that they depended on up into the air,” Van Houtan said. “We need to listen to these signals that the ocean is telling us, because the ocean is the driver of life on our planet.”
As the Pacific leatherback population size continues to shrink, climate change and human pressures become a daunting threat to their survival.
“Something more needs to be done,” Shillinger said.
Turtle needs: Regulations and tourism
For a species inhabiting millions of square miles, keeping it out of harm’s way is a monumental task. Scientists have spent the past two decades calling for stricter fishing regulations. But the lack of transnational cooperation and enforcement by governments has been an obstacle to protecting the turtles through policy and regulations.
“One government won’t solve it,” Shillinger said. “Everyone’s got to be involved.”
A leatherback sports a tracking beacon that relays data to satellites when leatherbacks come up for air from sensors that detect when it is underwater. The tags only last for as long as their batteries — about a year, usually — and have allowed scientists to piece together the species’s long migratory routes. Image by Kate Cummings.
By the mid-1990s, emerging data revealed high bycatch rates for large marine animals like sea turtles. To mitigate bycatch, the U.S. government created the Pacific Leatherback Conservation Area in 2001: a seasonal protected area off the U.S. West Coast that covers 650,000 square kilometers (250,000 square miles) of ocean and prohibits drift gillnet fishing during the months leatherbacks feast on jellyfish.
Dubbed a “time-area closure,” the new regulation helped reduce leatherback bycatch from an average of about 15 turtles per year to fewer than two a year after 2001, according to NOAA.
Additional regulations have helped save turtles in U.S. waters. For example, California’s commercial fisheries aren’t allowed to use pelagic longlines that can accidentally bait sea turtles. Meanwhile, HawaiÊ»i’s longline fishery comes with 100% observer coverage, meaning there is always someone documenting bycatch. California is also testing newer technology like deep-set buoy gear, which bypasses leatherbacks feeding on jellyfish to hook swordfish at lower depths.
However, none of these rules apply in international waters. For better protections, Benson and Forney say member countries of regional fishery management organizations like the Inter-American Tropical Tuna Commission need to encourage safer fishery practices.
For the leatherback populations to recover, scientists have suggested a 40% bycatch reduction over the next two decades.
It’s an ambitious goal, Shillinger said, adding “what really has to happen is to elevate political will … and make governments accountable for protecting their resources.”
In the meantime, Benson called on people to ask waiters at restaurants how and from where their fish is sourced.
“Please consume U.S.-caught swordfish or tuna, because it comes with a side dish of Endangered Species Act rather than a side dish of dead turtle or dead dolphin,” he said.
Leatherback conservation also needs to move forward at nesting sites. The Abun Leatherback Project, which works primarily in remote and impoverished villages in West Papua, attempts to protect western Pacific leatherbacks by employing the help of locals. A team of 10 monitors patrols the beaches while others help measure leatherbacks, release hatchlings or create shades made from palm fronds to keep nests cool.
Conservation success is contingent upon local people, Lontoh said: if they don’t care about leatherbacks, they won’t try to save them.
“[Locals] have strategic roles,” Lontoh said. “In the future, they’re probably the ones who will [either] help take care of the leatherbacks or help them go extinct.”
Indonesian children paint images of sea turtles during “turtle camp” at Jamursba Medi Beach. Instilling a love for the turtles in children is key to their conservation, says Deasy Lontoh, research coordinator for the Abun Leatherback Project. Image courtesy of the Research and Community Service Institute of the State University of Papua.
Local community members, Mesak Yekwam, right, and his wife, shading a turtle nest threatened by high sand temperatures with palm fronds. If sand gets too hot, it could kill hatchlings or produce a mostly-female clutch. Image by Deasy Lontoh.
Children learn how to identify a leatherback sea turtle by its soft carapace, or shell, during a turtle camp at Batu Rumah Beach, West Papua, Indonesia. Image courtesy of the Research and Community Service Institute of the State University of Papua.
An Abun Leatherback Project team member measures the carapace, or shell, of a nesting leatherback sea turtle. Image courtesy of the Research and Community Service Institute of the State University of Papua.
Abun Leatherback Project team members release leatherback hatchlings on a beach. Image courtesy of the Research and Community Service Institute of the State University of Papua.
But that requires incentives and income. Lontoh said the local government set forth an agenda in 2019 to develop the nearby area for tourism. In rural areas with limited resources, women have prepared to make souvenirs, such as the traditional noken woven bags, to sell to tourists.
“To get [rural people] to see that the leatherbacks are worth protecting, they need to feel benefits from conservation,” Lontoh said.
A local woman knits “noken,” a traditional woven handbag made from natural fibers. Noken are sold to tourists as a way to generate revenue for local communities. Image by Faris Luthfi.
Tourism has funded conservation efforts in other areas of the world already, Shillinger said.
“Leatherbacks bring in a lot of ecotourism projects around the world,” he said. “Turtles are really charismatic, benign, attractive animals, and no one wants to see them harmed. So culturally, economically and socially, turtles play an important role.”
An ocean without leatherbacks
The question remains: What if western Pacific leatherbacks do go extinct? Scientists warn it could happen in a matter of decades without immediate action.
“In the West Pacific, there’s a little bit of a window left, but it’s not much,” Benson said. “It’s definitely 11:55 on its way to midnight.”
Losing leatherbacks could throw the entire ecosystem off-balance. Leatherbacks, with their ferocious appetites (eating up 40% of their body weight daily), gobble down huge amounts of jellyfish that in turn devour fish larvae and plankton. By eating these bountiful yet low-nutrition “jellies,” the turtles help keep jellyfish numbers under control. In recent years, however, Benson said he’s noticed an increase of brown sea nettle (Chrysaora fuscescens), one of the leatherbacks’ favorite jellies, in California’s waters.
“Over time, this might be an illustration that the number of leatherbacks is so reduced now that they can’t serve part of their ecological roles,” Lontoh said.
An aerial shot from a surveying plane captures thousands of brown sea nettles, leatherbacks’ favorite jellyfish prey, swarming a NOAA surveying vessel off the coast of California. Image courtesy of Scott Benson.A camera trap suction-cupped to the back of a leatherback sea turtle captures a brown sea nettle, the turtle’s preferred jellyfish prey, moments before the leatherback gobbles it down. Image courtesy of Scott Benson (NOAA-ESA Permit #15634).
Because jellyfish eat fish larvae, more jellyfish may mean less fish overall, likely impacting small-scale artisanal fisheries and rural Pacific islanders who depend on fish for food or income. Fish provide about 3.3 billion people worldwide with nearly 20% of their animal protein, according to the most recent Fishery and Aquaculture Statistics report from the Food and Agriculture Organization of the U.N.
A world without leatherbacks “would still function,” Shillinger said, “but there would be some big shifts that we still don’t understand.”
As the forces of climate change are amplified — cyclones that wash away nests, sand temperatures so hot that hatchlings bake to death, a rapidly changing California Current — a conservation biologist’s job becomes no easier.
“This is kind of a higher calling,” Benson said. “This is a species threatened with extinction, a lot of people don’t know about it, so it’s my job to provide some data to increase the opportunities for recovery of the population.”
Ironically, Shillinger said, many Californians are unaware that their state marine reptile is the Pacific leatherback.
“Losing a species is a tragedy, something that humanity should really be concerned about,” Shillinger said. “As the turtles go, so too does everything else — including ourselves.”
Citations:
Benson, S. R., Eguchi, T., Foley, D. G., Forney, K. A., Bailey, H., Hitipeuw, C., … Dutton, P. H. (2011). Large-scale movements and high-use areas of western Pacific leatherback turtles, Dermochelys coriacea. Ecosphere, 2(7), 1-27. doi:10.1890/ES11-00053.1
Benson, S. R., Forney, K. A., Moore, J. E., LaCasella, E. L., Harvey, J. T., & Carretta, J. V. (2020). A long-term decline in the abundance of endangered leatherback turtles, Dermochelys coriacea, at a foraging ground in the California Current Ecosystem. Global Ecology and Conservation, 24, e01371. doi:10.1016/j.gecco.2020.e01371
Spotila, J. R., & Tomillo, P. S. (2015). The Leatherback turtle: Biology and conservation. JHU Press.
Carretta, J. V., Moore, J. E., & Forney, K. A. (2019). Estimates of marine mammal, sea turtle, and seabird bycatch from the California large-mesh drift gillnet fishery: 1990-2017. NOAA Technical Memorandum, U.S. National Marine Fisheries Service. doi:10.25923/s650-dd93
Eckert, K. L., Wallace, B. P., Frazier, J. G., Eckert, S. A., & Pritchard, P. C. H. (2012). Synopsis of the biological data on the leatherback sea turtle (Dermochelys coriacea). U.S. Department of Interior, Fish and Wildlife Service, Biological Technical Publication BTP-R4015-2012, Washington, D.C.
Jones, T. T., Bostrom, B. L., Hastings, M. D., Van Houtan, K. S., Pauly, D., & Jones, D. R. (2012). Resource requirements of the Pacific leatherback turtle population. PLOS ONE, 7(10), e45447. doi:10.1371/journal.pone.0045447
Liew, H. C. (2011). Tragedy of the Malaysian Leatherback Population. In Conservation of Pacific Sea Turtles (pp. 97-107). University of Hawaii Press.
National Marine Fisheries Service and U.S. Fish and Wildlife Service. 2020. Endangered Species Act status review of the leatherback turtle (Dermochelys coriacea). Report to the National Marine Fisheries Service Office of Protected Resources and U.S. Fish and Wildlife Service.
Pakiding, F., Zohar, K., Allo, A. Y., Keroman, S., Lontoh, D., Dutton, P. H., & Tiwari, M. (2020). Community engagement: An integral component of a multifaceted conservation approach for the transboundary Western Pacific leatherback. Frontiers in Marine Science, 7, 756. doi:10.3389/fmars.2020.549570
Banner image: A leatherback hatchling makes its way to the water on a beach in Indonesia. Image by Faris Luthfi.
CHARLOTTE COUNTY, Fla. — Sea turtle nesting season begins this May 1, and beachgoers can prepare by reviewing ways to be turtle-friendly this summer.
Florida is home to many species of sea turtles that nest on our coastline. Beaches in Southwest Florida host three species: loggerhead, green, and a few Kemp’s ridley sea turtles.
Each nesting season, local officials install temporary stakes and educational signs around nesting areas to create a buffer zone between humans and turtle nests.
When visiting SWFL beaches, be sure to give nests plenty of space and to fill any holes dug and knockdown sandcastles. Baby turtles often get stuck in holes in the sand and sandcastles create a barrier from the safety of the sea.
Beach chairs and other furniture can also create a barrier between land and sea, so be sure to pack up all your belongings when heading home from the beach.
If on the beach at night, do not use flashlights or cellphone lights as they can deter mother turtles from nesting and confuse hatchlings dashing to the water.
Contrary to popular belief, sea turtle hatchlings do not depend on lunar light to lead them to the ocean. The baby turtles have an inborn tendency to move in the brightest direction, according to the Florida Fish and Wildlife Conservation Commission.
On a natural beach, the brightest direction is most often the open view of the night sky over — and reflected by — the ocean. This sea-finding behavior can take place during any phase and position of the moon.
If you come across a hatchling that is wandering away from the water, take it to a dark area of the beach and let it walk into the surf on its own. Also, notify local natural resource or environmental protection agencies by calling 1-888-404-FWCC.
IMAGE: The Korean icebreaker Araon, which unexpectedly found itself in an Arctic cyclone in 2016, unlocked the key to how these storms wreak havoc on sea ice in the Arctic Ocean. view more
Credit: Photo by Joo-Hong Kim, Korea Polar Research Institute
In August 2016 a massive storm on par with a Category 2 hurricane churned in the Arctic Ocean. The cyclone led to the third-lowest sea ice extent ever recorded. But what made the Great Arctic Cyclone of 2016 particularly appealing to scientists was the proximity of the Korean icebreaker Araon.
For the first time ever, scientists were able to see exactly what happens to the ocean and sea ice when a cyclone hits. University of Alaska Fairbanks researchers and their international colleagues recently published a new study showing that sea ice declined 5.7 times faster than normal during the storm. They were also able to prove that the rapid decline was driven by cyclone-triggered processes within the ocean.
"Generally, when storms come in, they decrease sea ice, but scientists didn't understand what really caused it," said lead author Xiangdong Zhang from the UAF International Arctic Research Center.
There was general speculation that sea ice declined solely from atmospheric processes melting ice from above. Zhang and his team proved this theory incomplete using "in-situ" observations from directly inside the cyclone. The measurements reflected things like air and ocean temperature, radiation, wind and ocean currents.
It was a stroke of good luck for science, and perhaps a bit nerve-racking for those onboard, that the icebreaker was in position to capture data from the cyclone. Usually ships try to avoid such storms, but Araon had just sailed into the middle of an ice-covered zone and was locked in an ice floe.
Thanks to the ship's position so close to the storm, Xiangdong and his team were able to explain that cyclone-related sea ice loss is primarily due to two physical ocean processes.
First, strong spinning winds force the surface water to move away from the cyclone. This draws deeper warm water to the surface. Despite this warm water upwelling, a small layer of cool water remains directly beneath the sea ice.
That's where a second process comes into play. The strong cyclone winds act like a blender, mixing the surface water.
Together, the warm water upwelling and the surface turbulence warm the entire upper ocean water column and melt the sea ice from below.
Although the August storm raged for only 10 days, there were lasting effects.
"It's not just the storm itself," explained Zhang. "It has lingering effects because of the enhanced ice-albedo feedback."
The enlarged patches of open water from the storm absorb more heat, which melts more sea ice, causing even more open water. From Aug. 13-22, the amount of sea ice in the entire Arctic Ocean declined by 230,000 square miles, an area more than twice the size of the state of Arizona.
Xiangdong is now working with a new computer model for the Department of Energy to evaluate whether climate change will lead to more Arctic cyclones. Previous research shows that over the past half-century, the number and intensity of cyclones in the Arctic have increased. Some of those storms, like the biggest Arctic cyclone on record in 2012, also led to record low sea ice extent.
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Additional co-authors for this paper include two University of Alaska Fairbanks graduate students, Liran Peng and Han Tang, along with Korean researchers Joo-Hong Kim, Kyoung-Ho Cho and Baek-Min Kim, and Zhaomin Wang from China.
Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.
JUNO BEACH, Fla. — Loggerhead Marinelife Center is treating the largest female adult hawksbill sea turtle the hospital has ever had.
Hospital officials said the turtle's flippers were injured by a shark.
“Sea turtles can heal from some devastating injuries, much more so than mammals and other animals. We saw that in her case," said Dr. Max Polyak, the director of rehabilitation at LMC.
Heidi, a hawksbill sea turtle, was rescued at the beginning of March in Jensen Beach.
"She had injuries on all of her limbs. One severe injury on her rear left limb required partial amputation of that tissue. So we did that here at the hospital," Polyak said.
Polyak said Heidi has been healing quickly.
"Other things we do as part of her therapeutic plan are to make sure there’s no infection setting in both at the wound site and systemically throughout her body. We monitor any other thing that may be happening that is abnormal," Polyak said.
On Wednesday, marine staff took Heidi to Jupiter Medical Center to get a CT scan.
"What does an animal look like internally, what is of immediate concern, and how is that injury progressing and how is she doing before making a decision to clear her for release medically," Polyak said.
Heidi will be released back into the ocean very soon and will have a satellite tag attached on top of her shell so the center can monitor her for about a year.
"That will allow us to monitor her for about a year or so to see where she’s going, where she is feeding, her foraging grounds," Polyak said.
To learn more about Loggerhead Marinelife Center, click here.
For thousands of years during the last ice age, generations of maritime migrants paddled skin boats eastward across shallow ocean waters from Asia to present-day Alaska. They voyaged from island to island and ultimately to shore, surviving on bountiful seaweeds, fish, shellfish, birds and game harvested from coastal and nearshore biomes. Their island-rich route was possible due to a shifting archipelago that stretched almost 900 miles from one continent to the other.
A new study from the University of Kansas in partnership with universities in Bologna and Urbino, Italy, documents the newly named Bering Transitory Archipelago and then points to how, when and where the first Americans may have crossed. The authors' stepping-stones hypothesis depends on scores of islands that emerged during the last ice age as sea level fell when ocean waters were locked in glaciers and later rose when ice sheets melted. The two-part study, just published in the open-access journal Comptes Rendus Geoscience, may answer what writer Fen Montaigne calls "one of the greatest mysteries of our time . . . when humans made the first bold journey to the Americas."
The "stepping-stones" idea hinges on retrospective mapping of sea levels while accounting for isostacy -- deformation of the Earth's crust due to the changing depth and weight of ice and water, reaching its greatest extreme during the Last Glacial Maximum about 20,500 years ago.
"We digitally discovered a geographic feature of considerable size that had never been properly documented in scientific literature," said principal author Jerome Dobson, professor emeritus of geography at KU. "We named it the Bering Transitory Archipelago; it existed from about 30,000 years ago through 8,000 years ago. When we saw it, we immediately thought, 'Wow, maybe that's how the first Americans came across.' And, in fact, everything we've tested seems to bear that out -- it does seem to be true."
For more than a decade, researchers have pondered a mystery within a mystery. Mitochondrial DNA indicates that migrants were isolated somewhere for up to 15,000 years on their way over from Asia to North America. The Beringian Standstill Hypothesis arises from the fact that today Native American DNA is quite different from Asian DNA, a clear indication of genetic drift of such magnitude that it can only have happened over long periods of time in nearly complete isolation from the Asian source population. The Bering Transitory Archipelago provides a suitable refugium with internal connectivity and outward isolation.
Dobson said people crossing the Bering Sea probably didn't have sails but could have been experienced in paddling skin boats like the kayaks and umiaks that Inuits use today.
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"They probably traveled in small groups," he said, "either from Asia or islands off the coast of Asia. Some maritime people are known to have existed 27,000 years ago on northern Japanese islands. They probably were maritime people -- not just living on islands, but actually practicing maritime culture, economy and travel."
Dobson recently received the American Geographical Society's Cullum Geographical Medal (the same gold medal that Neil Armstrong won for flying to the moon and Rachel Carson won for writing "Silent Spring"). He named and continuously champions "aquaterra" -- all lands that were exposed and inundated repeatedly during the Late Pleistocene ice ages -- thus creating a zone of archeological promise scattered offshore from all coastal regions around the globe.
Recently, Dobson and co-authors Giorgio Spada of the University of Bologna and Gaia Galassi of Urbino University "Carlo Bo" applied an improved Glacial Isostatic Adjustment model to nine global choke points, meaning isthmuses and straits that have funneled transport and trade throughout history. Significant human migrations are known to have occurred across some of them, including "Beringia" -- all portions of the Bering Sea that were exposed before, during and after the Last Glacial Maximum.
"These Italian ocean scientists read my 'Aquaterra' paper and took it upon themselves to refine the boundaries of aquaterra for the whole world at coarse resolution and for Beringia itself at fine resolution," Dobson said. "Later we agreed to join forces and tackle those nine global choke points. At the end of that study, we suddenly spotted these islands in the Bering Sea, and that became our focus. This had an immediate potential because it could be a real game-changer in terms of all sciences understanding how migration worked in the past. We found startling results in certain other choke points and have begun analyzing them as well."
In Beringia, the three investigators contend, this action produced a "conveyor belt" of islands that rose from the sea and fell back again, pushing bands of people eastward. "The first islands to appear were just off the coast of Siberia," the KU researcher said. "Then islands appeared ever eastward. Most likely migrants kept expanding eastward, too, generally to islands within view and an easy paddle away."
By 10,500 years ago, when the Bering Strait itself first appeared, almost all islands in the west had submerged. Only three islands remained, and paddling distances had increased accordingly. Thus, occupants were forced to evacuate, and they faced a clear choice: return to Asia, which they knew to be populated and may even have left due to population pressures and resource constraints, or paddle east to less known territory, perhaps less populated islands with ample resources.
To fully confirm the idea set forth in the new paper, Dobson said researchers from many fields will need to collaborate as one geographer and two ocean scientists have done here.
"We ourselves are at a stage where we definitely need underwater confirmation," he said. "No doubt underwater archaeologists by title will prevail in that quest, but other disciplines, specialties and fields are essential. Working together plus scouring diverse literature, we presented a fundamentally new physical geography for scientists to contemplate. That should entice every relevant discipline to question conventional theory and explore new ideas regarding how, when and where people came to North America. More broadly, aquaterra can serve as a unifying theme for understanding human migrations, demic expansions, evolutionary biology, culture, settlement and endless other topics."
The Chinese defence ministry urged the United States on Thursday to rein in its frontline forces which Beijing has said have become more active in the air and seas near China this year.
China has frequently maintained that a U.S. military presence in the South China Sea, East China Sea and Taiwan Strait is the main destabilising factor in the region. The United States has said it has freedom of navigation in these areas, which China regards as its geo-strategic backyard.
Since U.S. President Joe Biden U.S. took office in January, operations of U.S. warships in the seas around China have risen by 20%, while the activity of U.S. reconnaissance aircraft has risen by 40% compared with last year, Chinese defence ministry spokesman Wu Qian told a press briefing on Thursday.
"We urge the U.S. side to strictly restrain its frontline forces, abide by regulations including the Rules of Behaviour for Safety of Air and Maritime Encounters and International Regulations for Preventing Collisions at Sea, and prevent similar dangerous incidents from happening again," Wu said.
Asked for a response, Biden's National Security Council referred Reuters to the U.S. Department of Defense, which declined to comment.
The U.S. Navy earlier this month took the rare step of publishing a photo on its main website of a U.S. guided missile destroyer, the USS Mustin, watching China's Liaoning aircraft carrier carry out an exercise.
Wu said the USS Mustin had interfered with the Chinese exercise and threatened the freedom of navigation of both vessels and the safety of their crews.
He said Chinese Navy ships warned away the Mustin and Beijing had lodged a formal complaint to the United States over the matter. "The aircraft carrier is no 'homebody'. It will routinely train in seas further from its shore."
Biden has maintained a tough-on-China stance inherited from the Trump administration. That has included more visible support for Taiwan, angering China, which deems the island part of its territory and sees Washington as giving succour to Taiwanese seeking independence, a red line for Beijing.
Citing a $715 billion U.S. defense budget request which the Biden administration has said will be used primarily to meet the challenge of China, Wu said some U.S. officials suffer from "persecutory delusion". He said "their hype" about an alleged China threat could become a self-fulfilling prophecy.
Raising the stakes, China's Navy said for the first time in early April that carrier drills near Taiwan would become routine. Another U.S. warship sailed through the Taiwan Strait two days after China's announcement.
A senior U.S. administration official said in mid-April that regardless of who Beijing's incursions near Taiwan were aimed at, their effect was direct "intimidation and coercion" of Taipei. read more
Sitting in the middle of Biscayne Bay, sea level rise threatens the small community of Palm Island.
“For us, it’s a pain,” said Juan Jose "Cheche" Vidal, who has lived in the neighborhood for 18 years.
He said the last five years had major growing pains.
“It’s been very tedious, very hard to deal with. But it’s fantastic what they’ve (the city) put together,” Vidal said.
The city of Miami Beach spent $40.9 million elevating the island’s roads and putting in drains and pumps to prevent flooding in the lower areas.
City photos show and neighbors told NBC 6 Investigators the project is working but we found it was difficult to get there.
A report from the Miami Beach Office of the Inspector General found the project, at times, didn’t have the proper permits, went over budget, and took longer than originally planned.
The city’s official response called portions of the report an attempt to “sensationalize” but noted there were “lessons learned.”
Some neighbors told NBC 6 elevating the roads now causes some yards to flood when they didn’t before. The city is working to fix the issue.
Melissa Berthier, a spokesperson for the city, wrote in a statement the project “will be completed within 7% of the anticipated construction cost in the next few months.” She went on to say, “The project functions as intended, and we have already avoided double digit flooding days as a result of the work performed. The schedule could have been better as a result of working through the details of a first mover project of this kind and challenges regarding changes of ownership and leadership of the contracted design/build firm.”
Berthier also said the city “has worked closely” with regulators to “make sure their concerns have been addressed.”
“It was a pain at times but it was a good pain because we’re getting the island where we need it to get to,” Vidal said.
In the bigger picture, the work done on Palm Island will be coming to other communities in South Florida.
NBC 6 Investigators reviewed data from the U.S. Census and National Oceanic and Atmospheric Administration (NOAA) and found 416,536 people in 196,981 homes in Broward, Miami-Dade, and Monroe counties are in jeopardy when the sea level rises two feet.
The NOAA sea level rise viewer shows some vulnerable areas including: Palm Island, the bay side of Miami Beach, Hollywood Beach, and the Florida Keys, which are also some of the most vulnerable areas in the country.
The viewer does not always factor in current or new sea level rise mitigation projects.
“The question becomes how much can they tolerate,” Jayantha Obeysekera said.
Obeysekera is the Director of Florida International University’s Sea Level Solutions Center. He estimates South Florida could see two feet of sea level rise in the next 25 to 50 years.
“It’s coming sooner than you think,” Obeysekera said.
Human activity causes two drivers of sea level rise. First, the oceans expand as the water warms. Second, melting ice sheets add more water volume.
According to Obeysekera, sea level will rise at different rates and in different levels across the globe. He said the impact of melting ice in Antarctica will cause a sooner “regional” sea level rise in South Florida.
The Biscayne Bay area, he said, will likely see impacts sooner than other parts of the world.
Obeysekera described what could happen in South Florida as a “triple whammy” - the sea will rise, a higher water table and stronger rains will cause more flooding.
“The geology is such that it’s very porous. It’s like Swiss cheese. Water will come underground,” Obeysekera said.
Back on Palm Island, neighbors told NBC 6 other communities should prepare for what they just went through.
“We are coastal. We need to deal with this and this is actually proof that you can do your best to prepare for what’s coming,” Vidal said.
Philippine president says Manila owes Beijing a ‘debt of gratitude’ but insists he will not compromise country’s sovereignty.
Philippine President Rodrigo Duterte has said he will not withdraw navy and coastguard boats patrolling the disputed South China Sea, insisting the country’s sovereignty over the waters is not negotiable. At the same time, he added that he wants to maintain friendly ties with China, citing Manila’s “debt of gratitude” for Beijing’s help with the coronavirus vaccine.
Tensions over the regional sea, which China claims almost entirely, have spiked as Beijing refuses to withdraw its vessels from the Philippines’s Exclusive Economic Zone (EEZ) and as Manila steps up maritime patrols.
Duterte is under growing domestic pressure to take a harder line but has been reluctant to confront China over the issue as he tries to foster closer ties with the economic giant.
He said late on Wednesday that while the Philippines is indebted to its “good friend” China for many things, including free COVID-19 vaccines, his country’s claims to the waterway “cannot be bargainable”.
“I’ll tell China, we do not want trouble, we do not want war. But if you tell us to leave – no,” Duterte said.
“There are things which are not really subject to a compromise, such as us pulling back. It’s difficult. I hope they understand, but I have the interest of my country also to protect.”
Duterte’s apparent attempt to hedge the issue has drawn the ire of Filipinos on social media with many condemning the president as a “traitor” for not taking a firmer stand on the South China Sea dispute.
In a statement on Thursday, retired Supreme Court Justice Antonio Carpio, who argued the Philippines’ case on the South China Sea before the International Court of Arbitration at The Hague, also criticised Duterte.
“Filipinos deserve, and should demand, a president who loves Filipinos first and foremost who will uncompromisingly defend Philippine sovereignty and sovereign rights in the West Philippine Sea,” he said.
Naval drills
Duterte’s remarks came after the country’s defence department said China had “no business telling the Philippines what we can and cannot do with our own waters”.
The Philippine coastguard is conducting drills near Thitu Island and Scarborough Shoal, as well as the Batanes islands in the north and the southern and eastern parts of the country.
Scarborough – one of the region’s richest fishing grounds – has long been a flashpoint between Manila and Beijing.
In response to the exercises, China’s foreign ministry said on Monday that the Philippines should “stop actions complicating the situation and escalating disputes”. Other littoral states, including Malaysia, Vietnam and Brunei, claim parts of the South China Sea. Taiwan also has a claim.
In recent weeks, Manila has boosted “sovereignty patrols” involving the navy coastguard and fisheries in the Spratly Islands – an archipelago contested by several countries.
The Philippines has also carried recently a joint military exercise with the United States.
Beijing has ignored a 2016 international tribunal decision that declared its historical claim over most of the South China Sea to be without basis.
Once-frosty ties between Manila and Beijing have warmed under Duterte, who set aside the ruling in exchange for promises of trade and investment – which critics say have not materialised.
Delays in COVID-19 vaccine deliveries has left the Philippines heavily reliant on the jab developed by China’s Sinovac.
About 3.5 million doses have been sent to the Southeast Asian country so far, including one million donated doses.
Viewers of "SpongeBob Squarepants" have been woefully misinformed about the reality of being a sponges. Far from being yellow, rectangular and hyperactive, sponges come in all shapes, sizes and colors; they are believed to lack even SpongeBob's child-like intelligence; and, far from being hyperactive, most of them are not known to move at all.
At least, they weren't known to move at all. New research may change what we know about them.
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In a recent study published by the journal "Cell Biology," scientists describe finding a group of demosponges — the most diverse class in the phylum known as Porifera — in the Arctic Sea. Notably, they observed that many of the individual sponges from the Geodia parva, Geodia hentscheli and Stelletta rhaphidophora species were living on a thick mat of spicules, a spike-like substance that helps a sponge support its body and ward off potential predators.
Given that the spicules were "connected directly to the underside or lower flanks of sponge individuals," and that there were long trails covering nearly 70 percent of the sea floor containing live sponges, the scientists hypothesize that they were probably left behind by those sponges as they slowly moved across the ocean floor.
This theory is further supported by the fact that many of the sponges were on the uphill portions of their trails in areas that lacked strong flows of water. This makes it unlikely that gravity or ocean currents could explain the shed body parts. Instead the scientists believe that the sponges stick their spicules into the ground and then slowly pull their bodies forward.
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They pay a grisly price for this, though: Like the honeybees that rip off part of their abdomen after stinging someone, the sponges seem to rip off their spicules in order to move. Unlike with honeybees, however, this process does not seem to kill the resilient creatures.
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While sponges had previously exhibited this kind of behavior in laboratory environments, this is the first time that this specific method for moving was displayed in the wild. When it came to sponges moving in natural environments, the most notable previous evidence was that certain types of encrusting sponges are able to remodel their bodies in a sliding fashion as they grow around rocks so they can move to a limited degree.
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"These trails may relate to feeding behavior and/or a strategy for dispersal of juveniles," the authors speculate. "Such trails may remain visible for long periods given the regionally low sedimentation rates."
Indeed, the researchers speculate that other types of sponges may leave these trails all the time. We just don't know it because they quickly get covered up by ocean sediments.
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"We thought sponges settled when juveniles, then had to put up with conditions where they settled," Autun Purser, a deep-sea ecologist at the Alfred Wegener Institute at the Helmholtz Center for Polar and Marine Research in Germany and co-author of the paper, told Live Science. "It seems now that, some species at least, can move if they feel conditions are not right."
Qatar plans to expand fish farming to meet growing demand for fresh fish in local markets and maintain stocks in offshore Gulf waters in the face of devastating climate change.
Although fish in the Gulf have generally adapted to higher water temperatures, the frequency and scope of coral reef bleaching in recent years suggest the region is at real risk of losing its bio-diverse ecosystem in the coming decades, said Pedro Range, Research Assistant Professor at Qatar University.
Global warming damaging to coral reefs, coupled with overfishing, could cause a 30% decline in future fish catch potential in Qatari waters by the end of the century, he said.
"In terms of climate change unfortunately the actions we can take on a local scale are irrelevant. What we can do is control local pressures that interact with climate change, in terms of controlling fishery stocks and habitat availability."
Last November, Qatar launched its first offshore aquaculture project, using floating cages producing seabass.
The Samkna fish farm, located 50 km (30 miles) offshore from Qatar's Ruwais region, produces 2,000 tonnes of fish annually.
"We have started an expansion plan to double our production capacity to 4,000 tonnes. We are obtaining permits for the expansion and building new cages," said Mahmoud Tahoun, operations and development director for marine aquaculture at Al-Qumra, the company running the Samkna fish farm. "Five years from now, we expect to cover 60% of local demand."
Fish farm production is supposed to prevent the depletion of fish stocks in offshore waters, where access is regulated by Qatari authorities. But Range said if that the broader international problem of excessive production of greenhouse gases that create climate change is not tackled, then none of the local fish-preservation efforts can be effective.
A University of British Columbia study in 2018 found that a third of marine species could become extinct in the Gulf by 2090 because of rising water temperature, changing salinity and oxygen levels, and human activities such as overfishing.
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