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Krill: The Disappearing Backbone of Marine Ecosystems

Krill: The Disappearing Backbone of Marine Ecosystems


Are we that close to krill-ing off biodiversity as we know it? Apparently so, because keystone species are feeling the pressure with every passing day.


When humans think of the “great deep,” outlandish, alien sea creatures come to mind: National Geographic images of anglerfish, vivid apparitions straight out of 20,000 Leagues Under the Sea, timeless sea shanties depicting the fearsome giant squid. Not often is it that some of the most vital organisms in marine ecosystems, keystone species, are at the forefront of our attention. One such linchpin, krill, is a miniscule, hardly visible, invertebrate that often passes for a shrimp look-alike. These finger-sized crustaceans tend to go unnoticed in modern society, their tangerine hue not bright enough to attract the interest of humans. Despite not being one of the more appetizing types of seafood for mankind, krill are a crucial main dish for animals of the Antarctic. For decades, krill has been harvested by humans without a care for the vital role they hold within the Southern Ocean food webs. Now a new threat has been recognized, as climate change threatens the existence of Antarctic sea ice which krill rely upon for nesting grounds. The key to their gargantuan presence on Earth, krill risk losing more than ever before.

Krill dominate the Antarctic Ocean from the shadows with their massive numbers, grouped together in swarms so dense they can be spotted by satellites in space. With eighty-five currently identified species, researchers estimate that the combined biomass of krill — which are individually no larger than a paper clip — worldwide could range from anywhere between 125 million and 600 million tons. Such swarms can drift through the waters at lengths of four miles, boasting densities of over 10,000 krill per square meter. Naturally, as with any resource present at such a scale on Earth, you’d be inclined to think that the statistical stability of krill would be able to overcome any threats to its population size; how could humans even attempt to jeopardize an organism of such a scope? Unfortunately, even the most abundant organism on the planet hardly stands a chance of escaping the all-encompassing nature of climate change. Direct and indirect anthropogenic influences — reflected in commercial fishing practices and the accelerated melting of sea ice — have developed into two, potent sources of stress for krill populations, signifying the greater doom that awaits these crustaceans.

What exactly makes these pinky-sized invertebrates so irreplaceable within the vast oceans of this planet? To answer this question, we must step back into one of the most fundamental topics of ecology: ecological efficiency. Within a food chain, trophic levels quantify the different stages of energy movement between categories of lifeforms, separated into producers and consumers; notably, only 10% of energy is passed from one level to the next. Sub-categories place primary producers (organisms with photosynthetic capabilities) at the bottom-most level, while top predators take the spots of tertiary or quaternary consumers.

In a typical marine food web, phytoplankton replace terrestrial plants as primary producers, and are considered the most energy efficient. As one of the few species capable of directly feeding upon phytoplankton, krill — categorized under zooplankton — take the spot of primary consumer within the food chain. What makes krill so potent as a food source for all predators alike is (1) sheer numbers, making it available to every Antarctic predator, and (2) its tendency to swarm in densely packed groups, which makes feeding much less work for large predators. Krill is a superfood, allowing even normally tertiary consumers to adopt an energy efficient food source into their diet and essentially gain more for less.

A food web depicting the role of Antarctic krill in Southern Ocean ecosystems. (Image Courtesy of Cool Antarctica)

The most populous species of krill, Euphausia superba, serves as a primary source of food for not one, but seventeen different marine animals, such as baleen whales, seals, penguins, fishes, birds, squid, and cephalopods. If they manage to evade the predation tactics of nearly every Antarctic organism larger than them, krill can persist in the Southern waters for an impressive lifespan of up to ten years. To prevent the rapid depletion of a common food source, the species’ predators have likewise taken steps to ensure that their feeding patterns do not overlap. Baleen whales, for example, stop by plankton blooms in polar waters over the summer before continuing their migration towards warm, tropical regions of the ocean.

With so many organisms dependent on krill for sustenance, what does krill, in turn, depend on? That would be phytoplankton–microscopic, buoyant algae which photosynthesize using chlorophyll at the ocean’s surface. During winter months, live phytoplankton form layers within and underneath Antarctic sea ice, which doubles as both a shelter and constant food source for larval and juvenile krill. Fast forward six months, and the bright polar summers create the perfect set of conditions for phytoplankton blooms: a combination of nutrient-rich waters brought up from the deep via Antarctic upwellings, 24-hour sunlight, and ideal ocean temperature. When the surface sea ice melts, both phytoplankton and krill are free to multiply endlessly. The result? An explosion of krill clouds overtaking the sub-Arctic and Antarctic Oceans, and the perfect rest stop for migrating consumers.

Krill feeding on phytoplankton located on sea ice, grazing the underside of the ice cap to collect the phytoplankton as they go. (Image Courtesy of Ice Stories)

As much as they provide shelter, the presence of sea ice is a figurative Achilles heel for our star organism. In addition to the multitude of predators waiting to eat them, that is. Temperature especially stands out as a weakness in that a fraction of a degree Celsius can make a significant difference for these tiny creatures. In fact, krill provide a concrete example of what exactly the implications of “rising ocean temperatures” — a term loved by media coverage — are. The ideal conditions for phytoplankton survival require ice cover to protect them from the harsh, stormy oceans of the South, as well as cold water, which is richer in nutrients. If the surface of the ocean were to be warm instead of cold, upwelling — the phenomenon in which nutrient-rich water rises from the deep to the surface via ocean currents — would not occur and nutrients would be locked below the surface. The following summer, phytoplankton blooms would be smaller in size, and krill would emerge from the melting ice to a noticeable lack of food and a significant difference of 1-2°C. Though researchers have found it difficult to track increases and decreases in Antarctic krill population due to the sheer scale of the endeavor, studies have theorized that krill populations may have dropped 80% since the 1970s.

Krill are not the sole bearers of this insufferable fate that threatens the collapse of entire ecosystems. Sea otters — regulators of the sea urchin population in coastal marine habitats — have been deemed “climate change warriors”, tasked with keeping kelp and seagrass ecosystems in check and promoting carbon sequestration. Starfish, when removed from their ecosystem, directly resulted in the widespread takeover of the unrestrained mussel population. Alarmingly so, recent research has established a direct connection between the warming of the oceans and sea star wasting syndrome, a term for cases of sea stars dying of hypoxia due to aerobic bacteria buildup at high temperatures.

The effects of the presence and lack of presence of starfish in its ecosystem.(Image Courtesy of Institute for Research for Development, Montpelier)

Looking back on history, it’s always been our old, persistent habits that produce the greatest consequences, and it’s past time we pull the plug on this one — once and for all. Krill serve as a dark example for the extent of influence humans have on this planet. One of the most extensive species in the world, research now shows that krill may one day face the same endangerment as many other species. It’s up to us to ensure that climate change is mitigated before it can topple entire ecosystems and sweep biodiversity from the face of this planet.

In some ways, these global phenomena feel so far from us, a disconnect heightened by sheer distance and the differences between nature and civilization. That doesn’t mean, however, that we get to pretend they are not happening. Spreading awareness is always a safe and easy first step, making sure these issues are felt within the bubbles we place ourselves in before breaking out of them entirely. Climate change communication is difficult, unfamiliar, but so incredibly necessary if anything is to be accomplished. Otherwise, humanity’s insatiable greed and sheer disregard for the Earth’s required natural balance causes us to willfully blind ourselves to the impacts of the climate on the world around us — impacts inherently caused by us. It is essential that we open our eyes and face our actions, before their consequences grow to a size much too large to control.

Source:

Karthy Sajeev at The Climate Change Review



The Enormous Hole That Whaling Left Behind

The Enormous Hole That Whaling Left Behind


The mass slaughter of whales destroyed far more than the creatures themselves.


In the 20th century, the largest animals that have ever existed almost stopped existing. Baleen whales—the group that includes blue, fin, and humpback whales—had long been hunted, but as whaling went industrial, hunts became massacres. With explosive-tipped harpoons that were fired from cannons and factory ships that could process carcasses at sea, whalers slaughtered the giants for their oil, which was used to light lamps, lubricate cars, and make margarine. In just six decades, roughly the life span of a blue whale, humans took the blue-whale population down from 360,000 to just 1,000. In one century, whalers killed at least 2 million baleen whales, which together weighed twice as much as all the wild mammals on Earth today.

All those missing whales left behind an enormous amount of uneaten food. In a new study, the Stanford ecologist Matthew Savoca and his colleagues have, for the first time, accurately estimated just how much. They calculated that before industrial whaling, these creatures would have consumed about 430 million metric tons of krill—small, shrimplike animals—every year. That’s twice as much as all the krill that now exist, and twice as much by weight as all the fish that today’s fisheries catch annually. But whales, despite their astronomical appetite, didn’t deplete the oceans in the way that humans now do. Their iron-rich poop acted like manure, fertilizing otherwise impoverished waters and seeding the base of the rich food webs that they then gorged upon. When the whales were killed, those food webs collapsed, turning seas that were once rain forest–like in their richness into marine deserts.

But this tragic tale doesn’t have to be “another depressing retrospective,” Savoca told me. Those pre-whaling ecosystems are “still there—degraded, but still there.” And his team’s study points to a possible way of restoring them—by repurposing a controversial plan to reverse climate change.


Baleen whales are elusive, often foraging well below the ocean’s surface. They are also elastic: When a blue whale lunges at krill, its mouth can swell to engulf a volume of water larger than its own body. For these reasons, scientists have struggled to work out how much these creatures eat. In the past, researchers either examined the stomachs of beached whales or extrapolated upward from much smaller animals, such as mice and dolphins. But new technologies developed over the past decade have provided better data. Drones can photograph feeding whales, allowing researchers to size up their ballooning mouths. Echo sounders can use sonar to gauge the size of krill swarms. And suction-cup-affixed tags that come with accelerometers, GPS, and cameras can track whales deep underwater—“I think of them as whale iPhones,” Savoca said.

Using these devices, he and his colleagues calculated that baleen whales eat three times more than researchers had previously thought. They fast for two-thirds of the year, subsisting on their huge stores of blubber. But on the 100 or so days when they do eat, they are incredibly efficient about it. Every feeding day, these animals can snarf down 5 to 30 percent of their already titanic body weight. A blue whale might gulp down 16 metric tons of krill.

Surely, then, the mass slaughter of whales must have created a paradise for their prey? After industrial-era whalers killed off these giants, about 380 million metric tons of krill would have gone uneaten every year. In the 1970s, many scientists assumed that the former whaling grounds would become a krilltopia, but instead, later studies showed that krill numbers had plummeted by more than 80 percent.

The explanation for this paradox involves iron, a mineral that all living things need in small amounts. The north Atlantic Ocean gets iron from dust that blows over from the Sahara. But in the Southern Ocean, where ice cloaks the land, iron is scarcer. Much of it is locked inside the bodies of krill and other animals. Whales unlock that iron when they eat, and release it when they poop. The defecated iron then stimulates the growth of tiny phytoplankton, which in turn feed the krill, which in turn feed the whales, and so on.

Just as many large mammals are known to do on land, the whales engineer the same ecosystems upon which they depend. They don’t just eat krill; they also create the conditions that allow krill to thrive. They do this so well that even in the pre-whaling era their huge appetites barely dented the lush wonderlands that they seeded. Back then, krill used to swarm so densely that they reddened the surface of the Southern Ocean. Whales feasted so intensely that sailors would spot their water spouts punching upward in every direction, as far as the eye could see. With the advent of industrial whaling, those ecosystems imploded. Savoca’s team estimates that the deaths of a few million whales deprived the oceans of hundreds of millions of metric tons of poop, about 12,000 metric tons of iron, and a lot of plankton, krill, and fish.

Whaling proponents sometimes argue that whales’ gargantuan appetites threaten the food security of coastal nations, dismissing modeling studies that disprove this idea, according to Leah Gerber, a marine-conservation biologist at Arizona State University who wasn’t involved in the new study. By contrast, the empirical results from Savoca’s study “will be hard to refute,” Gerber told me.

A whaler in Spitsbergen, Norway
Hulton-Deutsch Collection / Corbis / Getty

The new study, says Kelly Benoit-Bird, a marine biologist at the Monterey Bay Aquarium Research Institute, in California, is an important reminder of how “exploited species are part of a complex web, with many effects cascading from our actions.” Killing a whale leaves a hole in the ocean that’s far bigger than the creature itself.

There are more whales now than there were even a few years ago—in early 2020, scientists rejoiced when they spotted 58 blue whales in sub-Antarctic waters where mere handfuls of the animals had been seen in years prior. But that number is still depressingly low. “You can’t bring back the whales until you bring back their food,” Savoca said. And he thinks he knows how to do that.


In 1990, the oceanographer John Martin proposed that the Southern Ocean is starved of iron, and that deliberately seeding its waters with the nutrient would allow phytoplankton to grow. The blooming plankton would soak up carbon dioxide, Martin argued, and cool the planet and slow the pace of global warming. Researchers have since tested this idea in 13 experiments, adding iron to small stretches of the Southern and Pacific Oceans and showing that plankton do indeed flourish in response.

Such iron-fertilization experiments have typically been billed as acts of geoengineering—deliberate attempts to alter Earth’s climate. But Savoca and his colleagues think that the same approach could be used for conservation. Adding iron to waters where krill and whales still exist could push the sputtering food cycle into higher gear, making it possible for whales to rebound at numbers closer to their historical highs. “We’d be re-wilding a barren land by plowing in compost, and the whole system would recuperate,” says Victor Smetacek, an oceanographer at the Alfred Wegener Institute for Polar and Marine Research, in Germany. (Smetacek was involved in three past iron-fertilization experiments and has been in talks with Savoca’s group.)

The team plans to propose a small and carefully controlled experiment to test the effects of iron fertilization on the whales’ food webs. The mere idea of that “is going to be shocking to some people,” Savoca admitted. Scientists and advocacy groups alike have fiercely opposed past iron-addition experiments, over concerns that for-profit companies would patent and commercialize the technology and that the extra iron would trigger blooms of toxic algae.

But with Savoca’s new estimates, “we now have a much better idea of exactly the quantity of iron that whales were recycling in the system and how much to add back so we don’t get bad effects,” he said. His goal isn’t to do something strange and unnatural but to effectively act as a surrogate defecator, briefly playing the role that whales did before they were hunted to near extinction. These creatures would still face many challenges—ship strikes, noise pollution, entangling fishing gearpollutants—but at least food supplies would tilt in their favor.

Whaling almost destroyed a thriving food web, “but in the sliver we have left, I see a lot of hope,” Savoca said. He’s not talking about restoring long-lost ecosystems, such as those that disappeared when mammoths and other land-based megafauna went extinct tens of thousands of years ago. “This is a system that was alive and well when our grandparents were alive,” he said. “And we want to bring it back.”

Source:

Ed Yong at The Atlantic



Road to hell for marine life: Shell’s Wild Coast seismic assessment plans meet mounting public protest

Road to hell for marine life: Shell’s Wild Coast seismic assessment plans meet mounting public protest


‘Hell no, Shell must go’ — activists protest against the arrival of the Amazon Warrior in Cape Town on Sunday. This is the ship’s last stop before it carries out a seismic assessment in search of oil and gas off the Wild Coast, starting on 1 December.


Waving banners, beating drums and chanting, an array of protesters — including members of Extinction Rebellion Cape Town, Oceans Not Oil and the Green Connection — awaited the arrival of the Amazon Warrior, a 130-metre seismic blasting vessel hired by oil giant Shell, at Cape Town Harbour on Sunday morning. From the outset, their message was clear: “Shell can go to hell”.

“Hell no, Shell must go!” the protesters chanted. Placards with defaced Shell logos on them bobbed above the crowd.

Shell has appointed Shearwater GeoServices to conduct the survey, which will last from four to five months, and cover more than 6,000km² of ocean surface. The survey area is located more than 20km from the coast, with its closest point in water depths ranging between 700m and 3km, Daily Maverick reported.

Activists protest against Shell’s offshore exploration plan along the Wild Coast at the Waterfront in Cape Town on Sunday, 21 November 2021. Shell’s announcement that it will conduct a seismic survey to probe for oil and gas along the Wild Coast has drawn outrage from the public (Photo: Victoria O’Regan)

During this time, the seismic airgun blasts will increase the cacophony of sounds in the ocean, adding to those made by whales, dolphins and other marine life. Scientists and environmentalists alike have raised serious concerns about the “disastrous effects” of seismic assessments on the marine environment.  

shell protest
People protest at the Waterfront in Cape Town on Sunday, 21 November 2021 against Shell’s offshore exploration plan to probe for oil and gas along the Wild Coast. (Photo: Victoria O’Regan)

Climate activist organisation Extinction Rebellion (XR) Cape Town has said that there is increasing evidence that seismic blasting harms marine life. “Environmentalists are extremely concerned that seismic blasting of this scale will hurt our whales during breeding seasons, possibly separating mothers from their calves. But also fishing communities are sounding the alarm since the shockwaves will also scare off and harm their catch for unknown periods,” said XR Cape Town press coordinator, Michael Wolf.

In a statement on Saturday, XR Cape Town demanded that President Cyril Ramaphosa urgently intervene and withdraw the exploration licence from Shell and its partners, and send the Amazon Warrior home. 

People protest against Shell’s offshore exploration plan off the Wild Coast and the arrival of the Amazon Warrior at the Waterfront in Cape Town on Sunday, 21 November 2021. (Photo: Victoria O’Regan)

Shell’s announcement has spurred widespread public outrage and ignited a petition campaign to stop the survey. 

The Oceans Not Oil coalition started a petition calling on Environment, Forestry and Fisheries Minister Barbara Creecy to withdraw approval of Shell’s application to probe for oil and gas off the Eastern Cape shoreline. By Sunday morning, the petition had received more than 147,500 signatories. 

About 100-150 protesters and activists were at the Clock Tower at the V&A Waterfront when Daily Maverick arrived at around 5.30am on Sunday. From there, the demonstrators marched through the Silo District, eventually arriving at the edge of a pier near Shimmy Beach Club. 

Protesters demonstrate at the Waterfront in Cape Town on Sunday, 21 November 2021 against Shell’s offshore exploration for oil and gas along the Wild Coast. (Photo: Victoria O’Regan)

For about three hours the protesters waited to “unwelcome” the Amazon Warrior to Cape Town. The ship eventually arrived in the bay at about 8.15am, but remained outside the harbour.

“The reason why we’re here today is because we’re telling Shell to go to hell. We do not approve of their want to do seismic activity across the Wild Coast because it will not only affect marine life but will affect individuals and marginalised communities,” protester and youth coordinator at the African Climate Alliance, Gabriel Klaasen, told Our Burning Planet.

Klaasen said Shell’s plans for the Wild Coast will not only affect marine life, but will have social and economic impacts on communities in the area. 

“This needs to come to an end if we want to make sure our marine life is secure for future generations to benefit from. The ocean is one of the biggest carbon sinks in the world and if we don’t protect it, we are screwing humans over,” he said. 

Strategic lead for the Green Connection, Liz McDaid addresses protesters at Sunday’s action against Shell’s plan to carry out a three-dimensional seismic survey in search of oil and gas deposits from Morgan Bay to Port St Johns off the Wild Coast, starting on 1 December. (Photo: Victoria O’Regan)

Addressing protesters on Sunday, strategic lead for the Green Connection organisation Liz McDaid said that while there are currently groups of environmental lawyers trying to find ways to stop the project, public pressure on Shell is the way forward.  

“It’s us on the ground who have the best chance of public pressure building to stop them and to shut them down,” said McDaid.

McDaid said Sunday’s action was the first in a series of rolling actions planned before 1 December. There have been protests along the Wild Coast and pickets outside Shell petrol stations across the country, she said. 

A silent march from Muizenberg to Kalk Bay harbour to raise public awareness also took place at midday on Sunday. 

People gather at the Waterfront in Cape Town on Sunday, 21 November 2021 to protest against Shell’s offshore exploration plan along the Wild Coast. Demonstrators gathered to ‘unwelcome’ the ship commissioned to conduct the survey, which docked in Cape Town on Sunday. (Photo: Victoria O’Regan)

“What we are also planning to do — if we can raise the money — is hire a research vessel to shadow and monitor” the Amazon Warrior’s activity on the Wild Coast, said McDaid. 

“What we also think will put public pressure on Shell is to call on all the holidaymakers who are driving around to boycott Shell,” she said. 

“We were at the Paradise Motors Shell garage yesterday and it was very inspiring to see people look at the posters, drive in and then drive out without getting petrol,” she said.

“As long as we can resist and they know we are resisting, it makes their lives harder.”

Source:

Victoria O’Regan at Daily Maverick



20,000 Pounds of Trash Removed From Pacific Garbage Patch: ‘Holy mother of god. It worked!’

20,000 Pounds of Trash Removed From Pacific Garbage Patch: ‘Holy mother of god. It worked!’


“The Great Pacific Garbage Patch can now be cleaned,” announced Dutch entrepreneur Boyan Slat, the wonderkid inventor who’s spent a decade inventing systems for waterborne litter collection.


Recent tests on his Ocean Cleanup rig called System 002, invented to tackle the 1.8 trillion pieces of plastic pollution, were a success, leading Slat to predict that most of the oceanic garbage patches could be removed by 2040.

Intersections of ocean currents have created the massive floating islands of plastic trash—five slow-moving whirlpools that pull litter from thousands of miles away into a single radius.

The largest one sits between California and Hawaii, and 27-year-old Slat has been designing and testing his systems out there, launching from San Francisco since 2013.

GNN has reported on his original design for the floating device, but his engineering team improved upon it. System 002, nicknamed “Jenny,” successfully netted 9,000 kilograms, or around 20,000 pounds in its first trial.

It’s carbon-neutral, able to capture microplastics as small as 1 millimeter in diameter, and was designed to pose absolutely no threat to wildlife thanks to its wide capture area, slow motion, alerts, and camera monitors that allow operators to spy any overly-curious marine life.

Jenny consists of two boats dragging a very long net in a U-shape behind them.

They use computational modeling to predict where and at what speed the movements in the water will be shifting the plastic. They then fill up their net, pull it on board, and bring it ashore for recycling.

The team are also turning some of the trash they collect into designer sunglasses—and earnings from the stylish shades will go toward helping support the nonprofit so they can continue cleaning up the ocean. The new glasses are the first product to be created from the recovered ocean debris—but they say it will not be the last.

A timeline of hope

Slat estimates ten Jennies could clean half the garbage patch in five years, and if 10 Jennies were deployed to the five major ocean gyres, then 90% of all floating plastic could be removed by 2040.

There are obvious challenges, like the fact that millions of pieces of plastic flow into the oceans every year, and that investors may believe river cleanup is easier, cheaper, and doesn’t require the use of fossil fuels to power the boats.

And that’s why Slat’s nonprofit has also launched a number of ‘interceptor’ barges to clean up polluting rivers, intercepting plastic before it reaches the ocean.

Nevertheless—this is a huge breakthrough in the cleanup of ocean plastics, and one worth celebrating.

Source:

Andy Corbley at Good News Network



Underwater Gardens Boost Coral Diversity to Stave Off ‘Biodiversity Meltdown’

Underwater Gardens Boost Coral Diversity to Stave Off ‘Biodiversity Meltdown’


Corals are the foundation species of tropical reefs worldwide, but stresses ranging from overfishing to pollution to warming oceans are killing corals and degrading the critical ecosystem services they provide.


Because corals build structures that make living space for many other species, scientists have known that losses of corals result in losses of other reef species. But the importance of coral species diversity for corals themselves was less understood.

A new study from two researchers at the Georgia Institute of Technology provides both hope and a potentially grim future for damaged coral reefs. In their research paper, “Biodiversity has a positive but saturating effect on imperiled coral reefs,” published October 13 in Science AdvancesCody Clements and Mark Hay found that increasing coral richness by ‘outplanting’ a diverse group of coral species together improves coral growth and survivorship. This finding may be especially important in the early stages of reef recovery following large-scale coral loss — and in supporting healthy reefs that in turn support fisheries, tourism, and coastal protection from storm surges.

The scientists also call for additional research to better understand and harness the mechanisms producing these positive species interactions, with dual aims to improve reef conservation and promote more rapid and efficient recovery of degraded reefs.

But the ecological pendulum swings the other way, too. If more coral species are lost, the synergistic effects could threaten other species in what Clements and Hay term a “biodiversity meltdown.”

“Yes, corals are the foundation species of these ecosystems — providing habitat and food for numerous other reef species,” says Clements, a Teasley Postdoctoral Fellow in the School of Biological Sciences. “Negative effects on corals often have cascading impacts on other species that call coral reefs home. If biodiversity is important for coral performance and resilience, then a ‘biodiversity meltdown’ could exacerbate the decline of reef ecosystems that we’re observing worldwide.”

Clements and Hay traveled to Mo’orea, French Polynesia, in the tropical Pacific Ocean, where they planted coral gardens differing in coral species diversity to evaluate the relative importance of mutualistic versus competitive interactions among corals as they grew and interacted through time.

“We’ve done the manipulations, and the corals should be competing with each other, but in fact they do better together than they do on their own,” says Hay, Regents Professor and Teasley Chair in the School of Biological Sciences. Hay is also co-director of the Ocean Science and Engineering graduate program at Georgia Tech. “We are still investigating the mechanisms causing this surprising result, but our experiments consistently demonstrate that the positive interactions are overwhelming negative interactions in the reef settings where we conduct these experiments. That means when you take species out of the system, you’re taking out some of those positive interactions, and if you take out critical ones, it may make a big difference.”

Under the sea, in a coral-growing garden, in the shade

Coral reefs are under threat worldwide. Hay notes that according to the EPA, the Caribbean has lost 80 to 90 percent of its coral cover. The Indo-Pacific region has lost half of all its corals over the last 30 years. During the bleaching event of 2015-2016 alone, nearly half of the remaining corals along the Great Barrier Reef bleached and died.

“The frequency of these big bleaching and heating events that are killing off corals has increased fairly dramatically over the last 20 to 30 years,” he says. “There are hot spots here and there where coral reefs are still good, but they’re small and isolated in general.”

In their coral gardens in French Polynesia, Hay and Clements manipulated the diversity of the coral species that they planted on platforms resembling underwater chess tables, to try and see if species richness and density affected coral productivity and survival.

Hay notes that many previous, similar experiments involved bringing corals into a lab to “pit species against each other.” But he points out, “We do all of our experiments in the real world. We’re not as interested in whether it can happen, but whether it does happen.”

An experimental setup suggested by Clements involving Coke bottles helped the scientists arrange their garden. The end tables “have Coca-Cola bottlecaps embedded in the top of them,” Hay says. “We can then cut off the necks of Coke bottles, glue corals into the upside-down necks of these things, and then screw them in and out of these plots.  This allows us to not only arrange what species we want where, but every couple of months we can unscrew and weigh them so we can get accurate growth rates.”

The researchers found that corals benefitted from increased biodiversity, “but only up to a point,” Clements notes. “Corals planted in gardens with an intermediate number of species — three to six species in most cases — performed better than gardens with low, or one, species, or high, as in nine, species. However, we still do not fully understand the processes that contributed to these observations.”

Clements says their research demands more investigation. Why do corals perform better in mixed species communities than single-species communities? Why does this biodiversity effect diminish — rather than continue increasing — at the highest level of coral diversity?
“We need a better mechanistic understanding of how diversity influences these processes to predict how biodiversity loss will impact corals, as well as how we may be able to harness biodiversity’s positive influence to protect corals,” says Clements.

Source:

Georgia Institute of Technology

Climate Change Is Threatening Komodo Dragons, Earth’s Largest Living Lizards

Climate Change Is Threatening Komodo Dragons, Earth’s Largest Living Lizards


Scaly and with forked tongues, Komodo dragons are the largest lizards to still walk the Earth. But their days here may be numbered.


new report from an international biodiversity conservation organization says the fearsome reptiles are edging closer to global extinction.

According to the International Union for Conservation of Nature’s (IUCN) Red List, an assessment of the health of tens of thousands of species across the globe, Komodo dragons have gone from “vulnerable” to “endangered.”

Why is the Komodo dragon — or Varanus komodoensis — so threatened? Climate change.

Rising global temperatures and higher sea levels, IUCN says, will reduce the Komodo dragon’s habitat by at least 30% over the next 45 years.

“The idea that these prehistoric animals have moved one step closer to extinction due in part to climate change is terrifying,” said Dr. Andrew Terry, conservation director of the Zoological Society of London.

Komodo dragons are native to Indonesia and only live in Komodo National Park, a UNESCO World Heritage site, as well as the nearby island of Flores, according to IUCN.

“While the subpopulation in Komodo National Park is currently stable and well protected, Komodo dragons outside protected areas in Flores are also threatened by significant habitat loss due to ongoing human activities,” the report says.

Sharks and rays face major threats

The Red List update, released on Saturday and one day after the IUCN World Conservation Congress got underway in Marseille, bears other bad news.

Of the shark and ray species tracked by IUCN, some 37% are now threatened with extinction.

A zebra shark swims at the Aquarium of the Pacific in Long Beach, Calif., in 2012. The zebra shark is considered “endangered” by the IUCN.Joe Klamar/AFP via Getty Images

All of those threatened species are overfished, the group says, while some also face loss of habitat and are harmed by climate change.

It demonstrates the inability of governments to properly manage those populations in the world’s oceans, according to IUNC, but the report also includes a major success story of species management.

A revival of threatened tuna species offers hope

Of the seven most commercially fished tuna species, four of them — including albacore and bluefin tunas — showed signs of recovery in the latest assessment.

According to IUNC, the improvement among those species was the result of successful efforts to combat illegal fishing and enforce more sustainable fishing quotas.

A photo taken in 2014 shows a vendor holding an albacore for sale in the auction house at the Sydney Fish Market in Sydney.Peter Parks/AFP via Getty Images

“These Red List assessments are proof that sustainable fisheries approaches work, with enormous long-term benefits for livelihoods and biodiversity,” said Dr. Bruce Collette, chair of the IUCN Species Survival Commission’s Tuna and Billfish Specialist Group. “Tuna species migrate across thousands of kilometres, so coordinating their management globally is also key.”

Still, the group says many regional tuna populations remain significantly depleted due in part to overfishing.

Source:

Joe Hernandez at NPR



The Ocean Cleanup Deploys Full-Scale System to The Great Pacific Garbage Patch

The Ocean Cleanup Deploys Full-Scale System to The Great Pacific Garbage Patch


The Ocean Cleanup has deployed its first full-scale system designed to clean-up ocean plastics to the Great Pacific Garbage Patch.


The system, known as System002 or “Jenny”, left Victoria, British Columbia last Month on board a Maersk offshore supply vessel. “Jenny” builds on earlier tests conducted 2018 and 2019 and is the first full-scale system (800 meters in length) to be tested. Compared to the earlier systems, “Jenny” is larger and includes new technology such as active propulsion.

Founded in 2013, The Ocean Cleanup’s mission is to develop and advance technologies to cleanup plastic pollution at sea and also stop the inflow via rivers. Over the last several years, the company has been developing a large-scale system that essentially concentrates floating plastic for removal. The company then uses the plastic to create products that help raise funds for its efforts.

The company continues to aim for the removal of 90% of ocean plastic by 2040.

The Ocean Cleanup and Maersk Supply Service have been working together since 2018 and, earlier this year, agreed to a new 3-year partnership. Maersk Supply Service role is to provide marine offshore support and also end-to-end supply chain management.

With “Jenny” now in place at the Great Pacific Garbage Patch, The Ocean Cleanup is set to conduct more than 70 tests planned for the next 6 weeks.

The Ocean Cleanup ultimately aims to deploy dozens of the systems to the Great Pacific Garbage Patch over the coming years. If successful, the fleet could be enough to remove half of the nearly 2 trillion pieces of plastic estimated to be floating on or near the surface of the Pacific Ocean in just five years.

Located between California and Hawaii, the Great Pacific Garbage Patch is the largest concentration of ocean plastic in the world.

Source:

Mike Schuler at gCaptain



Leonardo DiCaprio Has Raised More Than $80m To Save The World’s Wildlands

Leonardo DiCaprio Has Raised More Than $80m To Save The World’s Wildlands


The Leonardo DiCaprio Foundation states its goal as ‘protecting the world’s last wild places’, and has 6 key areas of activity: Wildlands Conservation, Oceans Conservation, Climate Change, Indigenous Rights, Transforming California, and Innovative Solutions.


Leo is known as an activist and environmentalist, as anyone who has seen him pick up any of those aforementioned awards will know, as he rarely misses an opportunity to mention it on any public stage.

He’s addressed the United Nations, no less, and held meetings with everyone from Pope Francis to Vladimir Putin and Al Gore, as well as donating huge sums of money to environmental causes all over the world. While this public face is well known, behind the scenes, Leo is if anything more generous.

He set up the Leonardo DiCaprio Foundation back in 1998, right on the back of his success with Titanic, to fight for environmental justice, and it has raised a staggering $80 million (£60m) in the near twenty years of its existence.

With that in mind, let’s look through a few of their achievements. They save wild tigers in Nepal and protect the parks of Borneo, they defend indigenous rights from the Amazon to Alaska, helping Native Americans and First Nations people to preserve their culture, they monitor fishing and whaling to save marine life and they develop new and innovative solutions to assist in the fight against climate change.

In 1998, Leonardo DiCaprio established his foundation with the mission of protecting the world’s last wild places. LDF implements solutions that help restore balance to threatened ecosystems, ensuring the long-term health and well-being of all Earth’s inhabitants. Since that time the Leonardo DiCaprio Foundation (LDF) has worked on some of the most pressing environmental issues of our day.

Through grantmaking, public campaigns and media initiatives, LDF brings attention and needed funding to six program areas — Wildlands Conservation, Oceans Conservation, Climate Change, Indigenous Rights, Transforming California, and Innovative Solutions.. Several successful fundraising events have enabled LDF to scale up our grantmaking strategy, driving support for vitally important projects around the globe.



Hawaii Marks World Oceans Day With 9 New Laws To Protect Sharks And Marine Life

Hawaii Marks World Oceans Day With 9 New Laws To Protect Sharks And Marine Life


The measures cover a range of issues focused on ocean conservation, resource management, regulation and enforcement.


Beginning Jan. 1 there will be steep penalties for intentionally or knowingly capturing, entangling or killing a shark in state marine waters.

House Bill 553, which failed to pass in previous legislative sessions, was signed into law Tuesday by Gov. David Ige.

Opponents sought exemptions for research, subsistence fishing and incidental takes. While some exemptions will be allowed — e.g., killing in self defense, incidental captures or in accordance with protected cultural practices — the state Department of Land and Natural Resources is now tasked with establishing rules based on the bill.

The penalty for a first offense will be $500 and as much as $10,000 for a third or subsequent offense. Administrative fees, costs and attorney fees might also be levied.

Penalties could also involve seizure and forfeiture of any captured sharks or shark parts and commercial marine licenses, vessels and fishing equipment.

State Rep. Nicole Lowen, HB 553’s primary author, said the legislation was “many, many years in the making.” She credited its passage to Inga Gibson, policy director for Pono Advocacy, and Michael Nakachi and his son, Kaikea, a father-and-son duo who advocate for more culturally sensitive methods of academic shark research.

The bill-signing ceremony at the Governor’s Ceremonial Room at the state Capitol as well as via Zoom was timed to mark World Oceans Day, which was established by the United Nations in 2008 to inform the public of the impact of humans on the oceans and to mobilize sustainable management of them.

“They are the lungs of our Planet and a major source of food and medicine and a critical part of the biosphere,” the UN says of the oceans, which covers more than 70% of the Earth.

But, as Ige noted in his remarks, Hawaii is facing “unprecedented” challenges from climate change, heat waves, coral bleaching, degraded reefs, declining ocean populations and greater man-made pollution such as runoffs.

In addition to the shark-protection bill, Ige signed eight other related measures. They cover a range of issues focused on ocean conservation, resource management, regulation and enforcement.

Full story by Chad Blair at Honolulu Civil Beat



World’s Largest Seagrass Project Proves “You Can Actually Restore the Oceans”

World’s Largest Seagrass Project Proves “You Can Actually Restore the Oceans”


A “game changing” 20-year effort suggests that even severely depleted marine ecosystems can be brought back to life.


When Karen McGlathery used to swim in the coastal bays off Virginia’s Eastern Shore, the water would quickly turn cloudy and brown as sediment swirled around her. Now, 25 years later, for as far as she can swim the water remains clear. The sediment is anchored in place by lush green seagrass meadows, teeming with fish, scallops and crustaceans. “It’s like this beautiful underwater prairie,” says McGlathery. “It’s just gorgeous.” 

McGlathery, an environmental sciences professor at the University of Virginia, is part of a team running the largest seagrass restoration project in the world in these coastal bays — and one of the most successful. The two-decade-long project is a “blueprint for restoring and maintaining healthy ecosystems,” according to a 2020 research paper, and proof that marine habitats can be brought back to life in a way that’s self-sustaining. 

In the 1930s, a wasting disease swept along the U.S. east coast, wiping out huge swaths of eelgrass. Where Virginia’s coastal bays used to be carpeted in this species of seagrass, suddenly they were barren. “Everyone thought that eelgrass could never, ever get back,” says Robert Orth, who was a marine biologist at the Virginia Institute of Marine Sciences (VIMS) until his retirement this year, “but nobody really started doing any kind of experiments to see.” 

That changed in the late 1990s with the discovery of some small patches of seagrass in the bay, the existence of which proved that conditions could once again support the plants. 

Orth started with small-scale experiments, digging up adult seagrass from other areas and transplanting it into the bay. The seagrass survived, but the process wasn’t scalable — restoring thousands of acres through transplanting would have been a huge logistical challenge. So, says Orth, “We said, well, why not try to launch a restoration program using seeds?”

In 2001, he started an effort to physically rebuild the ocean ecosystem, seed by seed. From a moving boat, he and his team scattered seeds across four bays: South, Cobb, Spider Crab and Hog Island. The seeds survived, growing into plants which, in turn, produced their own seeds. “Nature kind of took over,” says Orth. “While we continue to put seeds in areas that don’t have eelgrass, nature has been spreading eelgrass naturally.” 

Over the last 20 years, supported by an army of volunteers, the project team has sown nearly 75 million seeds. Around 9,000 acres of coastal bays are now blanketed with eelgrass, which has improved water quality, increased marine biodiversity and helped mitigate climate change by capturing and storing carbon.

The project is “game changing,” says Carlos Duarte, a seagrass expert and marine science professor at King Abdullah University of Science and Technology in Saudi Arabia, both in its sheer scale and the raft of long-term data it provides on the climate benefits of seagrass. 

A decade ago, Duarte and Orth nicknamed seagrass “the ugly duckling” of environmental conservation, because so few cared about it. That’s slowly changing as the huge benefits it offers are recognized. Despite covering less than 0.2 percent of the ocean, it is responsible for about 10 percent of the ocean’s ability to store carbon. It provides a vital habitat for marine life, boosts commercial fishing, helps purify water, protects coastlines and even traps and stores microplastics

Full story by Laura Paddison at Reasons To Be Cheerful