Oxygen levels in many of the world’s freshwater lakes are declining rapidly — even faster than in the oceans — and this is suffocating wildlife and threatening drinking water supplies, a new study reports. Oxygen levels fell by 19% in deep waters and 5% at the surface of lakes since 1980 — three to nine times faster than in the oceans.
Previous studies have extensively reported on the declining oxygen levels in the ocean because of climate change. But lakes have been largely ignored, despite their importance for both wildlife and human communities. They comprise 3% of the planet’s land surface but are home to the bulk of the world’s biodiversity, making any alteration because of climate change concerning.
“All complex life depends on oxygen. It’s the support system for aquatic food webs. And when you start losing oxygen, you have the potential to lose species,” Kevin Rose, co-author, said in a statement. “Lakes are losing oxygen 2.75-9.3 times faster than the oceans, a decline that will have impacts throughout the ecosystem.”
The researchers looked at the effect of declining oxygen levels on lakes, analyzing more than 45,000 dissolved oxygen samples and temperature trends across 393 temperate lakes in North America and Europe. They looked at temperatures at the surface and deep-water levels as well as the concentration of dissolved oxygen. The team identified rising temperatures as the main cause behind lake’s oxygen loss, as warmer water can’t hold as much oxygen as cooler ones.
Physics further amplifies the problem. When water gets hotter, it is lighter and floats towards the surface of the lake. This hotter, oxygen-poorer water stays at the surface of the lake, while more of the oxygen supply falls towards the bottom.
The good, the bad, and the cyanobacteria
Researchers also observed an effect which, at first glance, is a way to counterbalanace this effect. When lakes get hotter (and especially if they are also polluted with nutrient-rich runoff), cyanobacteria blooms become more likely. These bacteria produce a lot of oxygen through photosynthesis, but this is not a healthy process for the lake.
“The fact that we’re seeing increasing dissolved oxygen in those types of lakes is potentially an indicator of widespread increases in algal blooms, some of which produce toxins and are harmful. Absent taxonomic data, however, we can’t say that definitively, but nothing else we’re aware of can explain this pattern,” Rose said in a statement.
The concentration of oxygen in aquatic systems influences biodiversity, nutrient biogeochemistry, greenhouse gas emissions, the quality of drinking water, and, ultimately, human health. Many aquatic species require well-oxygenated habitats and cool water to survive warm summers. Loss of oxygen degrades water quality by promoting the release of accumulated nutrients from sediments into water.
“Lakes are indicators or ‘sentinels’ of environmental change and potential threats to the environment because they respond to signals from the surrounding landscape and atmosphere,” lead author Stephen Jane said in a statement. “We found that these disproportionally more biodiverse systems are changing rapidly.”
Ocean trawling, a fishing method that involves dragging heavy nets across the seafloor to catch seafood, generates as much carbon as the entire aviation industry, a new study finds. The practice has been repeatedly condemned by environmental groups for destroying ecosystems and depleting fish populations but continues to be widespread
Marine sediments are the largest pool of organic carbon on the planet and a crucial reservoir for long-term storage. If left undisturbed, organic carbon can remain there for millennia. They’re also essential for marine wildlife. However, disturbance of these carbon stores can reactivate sedimentary carbon to CO2 — which can then increase ocean acidification and add to the build-up of atmospheric CO2.
“The ocean floor is the world’s largest carbon storehouse. If we’re to succeed in stopping global warming, we must leave the carbon-rich seabed undisturbed,” Trisha Atwood of Utah State University, a co-author of the paper, told AFP. “Yet every day, we are trawling the seafloor, depleting its biodiversity and mobilizing millennia-old carbon and thus exacerbating climate change.”
Atwood and a group of US researchers found that ocean trawling is responsible for between 0.6 and 1.5 gigatons of carbon emissions a year, compared with the aviation industry’s emissions of close to one gigaton. Most of this pollution happens in less than 4% of the ocean, specifically in the sovereign fishing waters of countries, known as Exclusive Economic Zones (EEZ).
This is the good news in a sense, because it means that the practice could be stopped much easier than if it were in international waters — which are often a sort of no man’s land where enforcing rules is difficult.
Trawling carried out by boats in Chinese EZZ generates the largest volume of emissions or about 770 million metric tons of CO2, the study found, followed by Russia, Italy, UK, Denmark, France, the Netherlands, Norway, Croatia, and Spain. Since most trawling occurs within countries’ waters, governments could halt the practice, the researchers argued
To figure out the numbers, the researchers reviewed mining records and other data to compile a map of the carbon stored in seabeds globally. Then they overlaid the map with data from the NGO Global Fishing Watch, showing where trawlers were active. Finally, they modeled the emissions released when carbon-rich sediment is disturbed by the vessels.
But the massive number of emissions from trawling isn’t the only impressive finding. The researchers found that an area isn’t depleted of carbon after being trawled once. Emissions are still released for up to 400 years at a rate of 40% of the initial year’s emissions as new layers of sediments are disrupted. For Atwood, this was “the extremely shocking part” of the study.
The researchers suggested countries start documenting these ocean emissions along with land-based emissions in their greenhouse gas inventories. This would help hold the trawling industry accountable, just as the electricity and the transportation industries are targeted for emissions reductions. This should be accompanied by a global agreement to protect further areas of the ocean, they argued.
Campaigners have proposed to preserve 30% of the ocean by 2030, a target the researchers support and encourage. To stop 90% of the seabed emissions from trawling, only 3.6% of the ocean would need to be protected, according to the study. Now 2.7% of the ocean is fully or highly protected, meaning that no fishing, mining, or habitat destruction is allowed there.
The ocean is the ultimate sink for plastics in the world, and two new studies have just shed new light into the extent of the problem. Plastic is floating all around the ocean, being eaten by marine wildlife, and eventually by all of us.
A study led by the UK National Oceanography Centre found that there are between 12 to 21 million tons of tiny plastic fragments floating in the Atlantic Ocean. This suggests that the supply of plastic to the ocean has been substantially underestimated. Such an amount of plastic would be enough to fully load almost 1,000 container ships, the study found.
The researchers looked through layers of the upper 200m (650 feet) of the ocean during a research expedition through the middle of the Atlantic.
“Previously, we couldn’t balance the mass of floating plastic we observed with the mass we thought had entered the ocean since 1950. This is because earlier studies hadn’t been measuring the concentrations of ‘invisible’ microplastic particles beneath the ocean surface,” said Katsiaryna Pabortsava, lead author of the paper.
Pabortsava and her team collected samples of particles from 12 sites spanning 10,000 kilometers of the Atlantic Ocean (between the UK and the Malvinas Islands) and then analyzed them for the three most commonly used found ocean plastics. They found an average of 7,000 particles per cubic meter of seawater.
A better understanding of the extent of plastic pollution in the Atlantic Ocean will allow future research to gauge the environmental damage they could cause. The findings provide a more “robust measure” of the accumulation of plastic in remote parts of the ocean, say the authors.
“This paper demonstrates that scientists have had a totally inadequate understanding of even the simplest of these factors, how much is there, and it would seem our estimates of how much is dumped into the ocean has been massively underestimated,” said co-author Richard Lampitt
Another recent study on five popular kinds of seafood obtained from a market in Australia also showed the extent to which microplastics pollution affects us. As plastic breaks down, it transforms into microplastics, which are plastic fragments less than 5 mm, or about 0.2 inches.
A group of researchers bought ten wild squid, ten farmed oysters, five wild blue crabs, and ten farmed tiger prawns and found traces of plastics in all of them. While the effect of microplastics on human health is not clear, studies have long warned about their harmful effect on wildlife.
“Considering an average serving, a seafood eater could be exposed to approximately 0.7 milligrams of plastic when ingesting an average serving of oysters or squid, and up to 30 mg of plastic when eating sardines, respectively,” said Francisca Ribeiro, lead author, in a press release.
“For comparison, 30 milligrams is the average weight of a grain of rice.”
The findings showed that the amount of plastic varied greatly among species and between individuals of the same species. The samples of squid were the ones with the fewest traces, while sardines had the most, the researchers found,.
This is in line with previous research, which has shown that this category of food items facilitates most of the plastic intake in humans. Studies have suggested that in places where seafood is eaten regularly people swallow at least 11,000 microplastic particles per year.
It turns out that you can help change the world by just changing your laundry settings. A new study out of Northumbria University in partnership with Proctor & Gamble — makers of products such as Ariel, Tide, Downy and Lenor — found that 13,000 tons of microfibers are being released into European marine environments every year and that this figure could be reduced by up to 30 percent if the Earth’s residents just changed their laundry habits.
The findings, published by the scientific journal PLOS ONE, suggest that every time you wash your clothes, thousands of tiny microfibers from the fabric are released into rivers and oceans, causing marine pollution. Each wash load released an average of 114 mg of microfibers per kilogram of fabric during a standard washing cycle.
A 2013 report by the International Association for Soaps, Detergents and Maintenance Products suggested 35.6 billion wash loads are completed in 23 European countries each year, and the researchers suggest a massive 12,709 tons of microfibers are being released from washing machines into rivers, the sea and the ocean each year in Europe alone.
Global fiber production, both synthetic and natural, has more than doubled in the past 20 years, reaching 107 million metric tons in 2018 and expected to reach 145 million metric tons in 2030. If current trends continue (and there is no reason to believe they won’t), this would create some serious microfibers in our seas.
“This is the first major study to examine real household wash loads and the reality of fiber release,” says John R. Dean, Professor of Analytical and Environmental Sciences at Northumbria, who led the study. “We were surprised not only by the sheer quantity of fibers coming from these domestic wash loads, but also to see that the composition of microfibers coming out of the washing machine does not match the composition of clothing going into the machine, due to the way fabrics are constructed.”
The researchers found that 96 percent of the fibers released were natural, coming from cotton, wool, and viscose, with synthetic fibers, such as nylon, polyester, and acrylic accounting for just four percent. However, a recent study by Newcastle University suggests that this four percent makes up almost a fifth of microplastics in our oceans.
The best way, according to the Northumbria researchers, to reduce the number of polluting microfibers is to make small changes such as using cold water and shorter washing cycles. A 30-percent reduction was recorded when they performed a 30-minute 15-degree Celsius (59 Farenheit) wash cycle, in comparison to a standard 85-minute 40-degree (104 F) cycle, based on typical domestic laundering. These changes alone would save 3,813 tons of microfibers being released into European marine ecosystems.
The group found even more dramatic differences when comparing different microfibers released from different types of North American washing machines. Households in that part of the globe have historically used high volume traditional top loading washing machines with an average 64 liter (16.9 gallons) wash water volume. The market is gradually moving to high-efficiency machines which use up to 50 percent less water and energy per load.
As a consequence, these high-efficiency machines released less microfibers than traditional top-loading machines, with notable examples including a 70 percent drop in microfibers from polyester fleece fabrics and a 37 percent decline from polyester T-shirts.
Other key findings emerging from the study include:
Larger wash loads led to a decrease in the release of microfibers due to a lower ratio of water to fabric. As such, the research team advises consumers fill – but do not overfill – their washing machines. A correctly filled washing machine should be around three-quarters full.
New clothes release more microfibers than older clothes. Microfiber release was more prominent in new clothes during the first eight washes.
Fabric softeners were found to have no direct impact on microfiber release when tested in both European and North American washing conditions.
“This study has proven that consumer choices in the way they do their laundry can have a significant and immediate impact on microfiber pollution,” said Dr. Neil Lant, Research Fellow at Procter & Gamble. “These won’t eliminate the issue but could achieve a meaningful short-term reduction while other solutions such as washing machine filters and low-shedding clothing are developed and commercialized.”
COVID-19 might be terrifying the rest of the world, but the whales sure are probably enjoying it. Declines in the economy due to the coronavirus have slowed exports and imports by around 20 percent and this has caused a dramatic decrease in the ocean noise.
Oceanographer David Barclay of Canada’s Dalhousie University and his team have been analyzing ocean sound signals from seabed observatories run by Ocean Networks Canada near the port of Vancouver. Their observations of sound power in the 100 Hz range from two sites have revealed a decrease in noise level of up to five decibels.
“There has been a consistent drop in noise since January 1, which has amounted to a change of four or five decibels in the period up to April 1,” Barclay told The Guardian. “Generally, we know underwater noise at this frequency has effects on marine mammals.”
The two research locations include a deep-ocean site approximately 60 kilometers (37 miles) from the Vancouver port in 3,000 meters (9,842 feet) of water and a more shallow inland site. The deepwater location recorded a drop in weekly noise of 1.5 decibels.
A study of baleen whales after the 9/11 attacks in 2001 showed that the reduction in ship and air traffic was associated with a reduction in chronic stress in marine mammals.
“We are facing a moment of truth,” Michelle Fournet, a marine acoustician at Cornell University, who studies humpback whales in southeast Alaska, told The Guardian. “We have an opportunity to listen – and that opportunity to listen will not appear again in our lifetime. “
“We have a generation of humpbacks that have never known a quiet ocean,” said Fournet.
The drop in tourism has also been a source of the decline of ocean traffic, another added benefit for cetaceans. Late April generally marks the beginning of the cruise ship season in southeast Alaska with boats docking in Vancouver before heading to the 49th state.
“What we know about whales in southeast Alaska is that when it gets noisy they call less, and when boats go by they call less,” said Fournet. “I expect what we might see is an opportunity for whales to have more conversation and to have more complex conversation.”
“The clearest benefit of the reduction in vessel traffic is to humpback mothers and nursing calves, who tend to be somewhat reclusive,” Marc Lammers, research coordinator for the Hawaiian Islands Humpback Whale National Marine Sanctuary, told Hawaii’s Star-Advertiser. “Not having humans either trying to view them or, in some cases, interact with them will be a huge benefit for the mother, whose priority is to protect and nurse her calf so it can be strong enough to make the trip to Alaska. It allows her to conserve her energy and transfer that energy to her calf in peace, without having to respond to stand-up paddlers and five or six boats approaching at a time.”
If you ever went swimming in warm waters, you may have experienced a curious phenomenon: the calm and crystalline waters suddenly became a stinging substance uncomfortable to the touch. But when you look around, there’s nothing there.
Or so it seems to you.
Researchers were aware of this reported phenomenon and believed it to be part of a defensive strategy of anemones, sea lice or inverted jellyfish — all of them typical species of warm water. The latter of them recently caught the attention of a group of researchers in the US, whose results were published in Nature Communications Biology. According to their study, even the water surrounding upside-down jellyfish often stings to the touch.
The scientists thought that the mucus generated by inverted jellyfish, also known as Cassiopea xamachana, could be responsible for this curious itching. This type of jellyfish is commonly found in Florida, Hawaii and the Caribbean, usually stuck to the ocean floor. They took samples of the mucus and observed it under the microscope, noting that it contains a series of curious balls, spinning and moving to the sound of the gelatinous substance that envelops them.
A closer look showed that these spheres were composed of different cells, most of them very sharp.
“This discovery was both a surprise and a long-awaited resolution to the mystery of stinging water,” said Cheryl Ames, associate professor at Tohoku University. “We can now let swimmers know that stinging water is caused by upside-down jellyfish, despite their general reputation as a mild stinger.”
The team also observed a series of unusual cylindrical filaments, which are believed to help these balls travel more efficiently through the water.
They even noticed the presence of a specific type of algae, which normally live within jellyfish, establishing with them a symbiotic relationship, in which jellyfish provide protection and algae generate nutrients.
When studying some specimens of the jellyfish, the researchers realized that the balls found in the mucous were concentrated in the tentacles of the animal. They saw that the jellyfish tended to release the balls and pass them into the water through the mucus. This way they were defending against their enemies and capturing prey from which to feed. These structures, called cassiosomes, can kill prey and are the likely cause of ‘stinging water’ — the phantom stinging reported by many snorkelers and fishermen in tropical waters.
They reached this conclusion by checking that in contact with the spheres some small crustaceans, such as brine shrimp, died or were weak enough to be easily ingested by the jellyfish. All this is due to the presence of three toxins, which could be characterized by the researchers. It is true that symbiotic algae provide the jellyfish with some of the energy necessary for its survival, but this is not always enough.
“Venoms in jellyfish are poorly understood in general, and this research takes our knowledge one step closer to exploring how jellyfish use their venom in interesting and novel ways,” Anna Klompen, a graduate student at the University of Kansas who was part of the study, said.
Know that we know the reason for the stinging sensation, the next challenge for researchers will be to know how to avoid that from happening. The team is now looking at whether the jellies release the venom more at certain times of the day or in response to certain types of disturbances.
This discovery could also make an impact in biotechnology, researchers conclude.
The image of Neanderthals has changed quite a lot in the past few decades thanks to new discoveries. We now know that they may have decorated their bodies, buried their dead and created art. Now, we can add another skill to the list, diving under the ocean for shells that they fashioned into tools, according to a new study.
A group of researchers analyzed clamshells and volcanic rocks from an Italian cave, which showed Neanderthals collected shells and pumice from beaches. Due to specific indicators on some of the shells, the researchers also believe Neanderthals waded and dove into the ocean to retrieve shells, meaning they may have been able to swim.
Only about ten feet above the beach in central Italy’s Latium region, the Grotta dei Moscerini cave was excavated in 1949. Archaeologists recovered 171 clamshells that were modified into sharp tools. They all belonged to a local species called Callista chione, or the smooth clam.
University of Colorado researcher Paolo Villa and colleagues looked at such tools, which had been stored at the Italian Institute of Human Paleontology because the cave itself is no longer accessible. They concluded some must have been gathered from the seafloor by Neanderthals.
“The fact they were exploiting marine resources was something that was known,” said Paola Villa to CNN, study author and curator of the University of Colorado at Boulder’s Museum of Natural History. “But until recently, no one really paid much attention to it.”
Most of the shell tools had abraded surfaces. But nearly a quarter of them had shiny, smooth exteriors, typical of shells picked live from the seafloor. In their study, Villa and her colleagues argued that diving for clams may have been a routine part of Neanderthal life in this region.
The shells were modified to be used as scrapers. These were more efficient than thin flinty rocks, which can’t sustain a sharp edge. It’s possible that stone was hard to come by, which is why they sought out shells. Or perhaps the shells suited their needs better, the researchers said.
The findings align with evidence from a recent study by Prof Erik Trinkaus suggesting that some Neanderthals suffered from “surfer’s ear,” based on bony growths found on the ears belonging to a few Neanderthal skeletons. And previous research has pointed to the fact that Neanderthals engaged in fishing.
The new study “reinforces what is becoming increasingly evident from a variety of different sources of archaeological data: Neanderthals were able to do, and occasionally did, most of these kinds of behaviors that had been considered to be special to modern humans,” said Trinkaus to the Smithsonian Magazine.
Key facts on Neanderthals
Neanderthals are considered the closest extinct human relative. Among the features of their skulls, they had a large middle part of the face, angled cheekbones, and a huge nose for humidifying and warming cold air. They also had shorter and stockier bodies as an adaptation to living in cold environments.
They made and use a diverse set of sophisticated tools, controlled fire, lived in shelters, made and wore clothing, were skilled hunters of large animals and also ate plant foods, and occasionally made symbolic or ornamental objects. Evidence has been found of them burring the dead and marking graves with offering as flowers.
All oceans across the world are warning at growing pace and the heat is already having devastating consequences on marine life as well as intensifying extreme weather events, according to new research, which examined data going back to the 1950s.
A global team of researchers looked at temperatures from the ocean surface to 2,000 meters deep. The study, published in the journal Advances in Atmospheric Sciences, showed that the past decade was the warmest on record for global ocean temperatures, with the hottest five years ever recorded happening in the last five.
“The upward trend is relentless, and so we can say with confidence that most of the warming is man-made climate change,” said Kevin Trenberth, a senior scientist in the Climate Analysis Section at the National Center for Atmospheric Research.
The study compared ocean temperature data from the last three decades (1987-2019) to the three decades before that (1955-1986) and found that the rate of warming has increased 450%, reflecting a major increase in the rate of climate change.
Using an energy unit common in physics, the researchers found that the oceans absorbed 228 sextillion joules of heat in the past 25 years. That is equivalent to 3.6 billion Hiroshima-size atom bomb explosions to the oceans, “irrefutable proof of global warming,” according to Lijing Cheng, co-author of the study.
The fact that the oceans are warming has a whole set of consequences. It is causing marine heatwaves, fuels hurricanes and coastal downpours, increases harmful toxin-producing algal blooms and also contributes to heat waves on land, according to the researchers.
“The ocean heat content changes are the primary memory of global warming,” Trenbeth said. “This manifestation of global warming has major consequences. Hurricanes pump the ocean heat content into the atmosphere in the form of moisture. That results in extreme and record rainfall from storms.”
The average temperature for the upper 2000 meters of the oceans increased by 0.12 degrees Celsius from 1960 to 2019, according to the study. Nevertheless, the ocean surface, where hurricanes draw their energy, and the air just above it has warmed almost 1 degree Celsius from the pre-industrial era.
This is almost irreversible on a human timescale, Trenberth said. “Imagine mixing a pot of hot and cold water in the sink. It gets warm, and you can never get the hot or the cold back,” he said. Nevertheless, there’s hope, as the speed of warming is entirely dependent on the world’s actions on climate change.
The new study of ocean heat content strengthens other recent signs of global warming. The past decade was the warmest on record since measurements started, and 2019 ended up the second-warmest year on record, although it was the warmest in the oceans.
The recent bleak results at the COP25 climate summit in Madrid created enough reasons to be pessimistic about the future of the planet.
But next year could see a big shift thanks to three key summits, which could help to reduce greenhouse gas emissions, protect biodiversity and look after the oceans. In many ways, it seems like 2020 will be a make-or-break year for the environment.
Every global environmental report warns that more ambitious action is needed to protect life on land and water and to reduce the growing greenhouse gas emissions. There is a mountain of evidence that if we don’t up our game, we will be causing catastrophic, irreversible damage.
Nevertheless, action has been slow.
Countries agreed to limit global warming to 2 degrees Celsius with the Paris Agreement. But emissions are still growing due to fossil fuels, agriculture, and transportation, among other sectors. Global temperature has increased by 1.1 degrees Celcius compared to pre-industrial levels and is set to keep increasing. Almost no countries are on course with their contributions to the Paris Agreement.
At the same time, biodiversity is being threatened. The size of populations of mammals, birds, fish, reptiles, and amphibians declined 60% in the last 40 years, according to the Living Planet Report of the NGO WWF – warning over the effects of human activity.
But there could be a light at the end of the tunnel. Countries are set to meet in 2020 at three major international summits, seeking commitments to avoid some of these effects. Here is what you should have on your radar for next year that could help improve the future of the planet
Climate change summit COP26 — Glasgow, Scotland
Grouped under the United Nations Framework Convention on Climate Change (UNFCCC), countries meet every year to discuss better ways to address the climate emergency. But so far, they haven’t moved at the required speed, with big differences between developed and developing countries.
This year, the summit was held in Madrid, after being moved from Brazil and then Chile, and the results were quite weak. Countries had to finalize the rulebook of the Paris Agreement, securing funding and creating carbon markets to make it operational. But none of that happened.
Next year’s climate talks, COP26, will be in November 2020 in Glasgow, Scotland. They will have to pick up from the bleak summit in Madrid, hoping to get the Paris Agreement moving as well as increasing ambition from countries – which will have to present next year’s new pledges.
“We will pull no punches next year in getting clarity and certainty for natural carbon markets and will work with everyone including the private sector for clear rules and transparent measurement,” said UK clean energy minister Claire Perry O’Neill, who will lead the talks.
Biodiversity summit COP15 — Kunming, China
In October, delegates from more than 190 countries will arrive in the Chinese city of Kunming to finalize and sign a new international agreement to protect biodiversity, which can be compared to the Paris Agreement on climate change signed in 2015 in France.
The new deal will replace the existing one, called the Aichi Goals, a set of 20 targets to be achieved by 2020 to stop the biodiversity loss. Nevertheless, countries failed short to deliver on them. More than 70% of the national strategies to protect biodiversity were less ambitious than what was stipulated in the global goals.
“Natural systems essential to our survival—forests, oceans, and rivers—remain in decline. Wildlife around the world continues to dwindle. It reminds us we need to change course. It’s time to balance our consumption with the needs of nature, and to protect the only planet that is our home,” said WWF head Carter Roberts.
Out of the 20 Aichi Goals, some have seen more progress than other ones. For example, the goal 11, which asks to safeguard 10% of the marine areas and 17% of the land areas for biodiversity, was met by more than 80% of the countries that signed the agreement.
On the other hand, goal 20, which calls for an increase in the financial resources to protect biodiversity, was one of the less successful ones. Less than 15% of the countries that signed the agreement were able to fulfill their commitment, providing lower funding.
Now it’s time for countries to step up their game and create a new set of goals, learning from their previous mistakes. There’s a large expectation for the Kunming summit to create a momentum for further protection of biodiversity, as it happened initially with the Paris climate deal.
High-level conference on oceans — Lisbon, Portugal
Finally, there are the oceans. Lisbon will hold a high-level conference in June with the objective of scaling up ocean-based action to implement the Sustainable Development Goal (SDG) 14, which states to conserve and sustainably use the oceans and its marine resources.
This will be the second year of the conference and it will be co-hosted by the governments of Portugal and Kenya. Its goal will be to adopt a declaration from governments to take action on ocean protection, agreeing to a set of voluntary commitments.
Oceans absorb up to 90% of the anthropogenic heat and one-third of the carbon emissions we produce, and this has consequences for marine life. Oceans are becoming more acidic, sea-level rise is growing as glaciers and the polar ice melts and biodiversity is facing huge stress.
The growing number of greenhouse gas emissions and the loss of nutrients are taking oxygen out of the oceans, threatening all marine biodiversity.
The report “Ocean deoxygenation: Everyone’s problem” looked at the causes, impacts and solutions to the loss of oxygen of oceans. It showed that about 700 ocean sites now have low levels of oxygen, a steep increased from the 45 registered in the 1960 – threatening species such as tuna and sharks.
“With this report, the scale of damage climate change is wreaking upon the ocean comes into stark focus. As the warming ocean loses oxygen, the delicate balance of marine life is thrown into disarray,” said Dr Grethel Aguilar, acting director-general at The International Union for the Conservation of Nature (IUCN).
The report argued that the threat to oceans from chemicals such as nitrogen from agriculture has long been known and still remains as the main problem. Nevertheless, the effects of climate change have been underestimated — and as our emissions continue to grow, so do the ocean problems. Oceans absorb most of the heat generated because of the greenhouse effect, but having warmer water means less oxygen can be held.
Between 1960 and 2010, the report estimates that the amount of oxygen dissolved in the oceans declined by an average of 2%, reaching 40% in tropical countries.
Both small and large changes in the level of oxygen can have an impact on marine life, according to the report. Water with less oxygen can favor species such as jellyfish but can also affect larger ones such as tuna, who are driven into shallow water with more oxygen and then get more exposed to excessive fishing.
“The potentially dire effects on fisheries and vulnerable coastal communities mean that the decisions made at the ongoing UN Climate Change Conference are even more crucial. To curb ocean oxygen loss alongside the other disastrous impacts of climate change, world leaders must commit to immediate and substantial emission cuts,” Aguilar said.
Keeping the business-as-usual approach regarding emissions would mean for the world’s oceans to lose between 3% and 4% of the oxygen by 2100. This will probably be worst for tropical countries. Most of the loss will happen in the first 1.000 meters of water, which is the area with most biodiversity.
This year’s climate change conference has been labeled as a “blue COP”, putting a special focus on oceans and their link with climate change. This was a decision by Chile, this year’s COP President, seeking countries to come up with specific measures linked to oceans and climate.
Oceans cover more than 70% of our planet. They include some of the most fragile ecosystems and species on Earth but are continuously abused and ill protected. Marine protected areas are a key solution to that problem, protecting marine and coastal biodiversity.
The term Marine Protected Areas (MPA) includes marine reserves, fully protected marine areas, no-take zones, marine sanctuaries, ocean sanctuaries, marine parks, locally managed marine areas, to name a few. Many of these have quite different levels of protection, and the range of activities allowed or prohibited within their boundaries varies considerably too.
WWF uses the term Marine Protected Area as “an overarching description of an area designated and effectively managed to protect marine ecosystems, processes, habitats, and species, which can contribute to the restoration and replenishment of resources for social, economic, and cultural enrichment.”
Governments establish MPAs to help protect marine ecosystems that are threatened by human activity, such as overfishing or petroleum drilling. An MPA may also be established to protect underwater archaeological sites, shipwrecks, and other historically important places. For example, the Thunder Bay Marine Sanctuary was created in 2000 to protect shipwrecks in the Great Lakes.
An MPA may be defined by a range of rules. Restrictive MPAs might prohibit any human activity in the area. Others might simply establish limits on how many fish can be caught or what kind diving or boating can take place. The ways MPAs are managed vary quite a bit depending on the unique features of that area.
Despite their importance and a recent expansion during the last few years, there’s a long way to go. Only about 4% of the world’s oceans are protected, and the vast majority of existing marine parks and reserves are either poorly managed, or not looked after at all.
Why do we need MPAs?
Modern technology has increased the range of uses of, and access to, marine environments, supporting industries such as fishing, tourism, aquaculture and the development of new forms of drugs from marine biodiversity. But unless managed sustainably, the uses and users of marine ecosystems can threaten, change and destroy the very processes and resources that they depend on.
Current management systems are failing to maintain the productivity, biological diversity and the ecosystems of marine ecosystems. The consequences of this failure are serious and far-reaching. The most obvious effect is seen in impacts on the longstanding and widespread use of marine resources for seafood.
The global fish catch has been in a consistent decline since 1989 and the downward trend is projected to continue. Marine biodiversity, ecosystems, and resources are also endangered by threats reaching the sea from the land. These include pollution by nutrients, chemicals and silt, as well as changing river flows
MPAs provide a range of benefits for fisheries, local economies and the marine environment, including conservation of biodiversity and ecosystems; arresting and possibly reversing the global and local decline in fish populations; raising the profile of an area for marine tourism and broadening local economic options; providing opportunities for education, training, heritage and culture; and providing broad benefits as sites for reference in long-term research.
How do MPAs benefit fisheries?
Marine protected areas with core ‘no-take’ reserves can play an important role in arresting and possibly reversing the global and local decline in fish populations and productivity.
Indications of this decline include fishing for smaller and lower-value species; having to fish further from home bases; and the destruction or degradation of fish habitats in coastal areas. The effects of a declining fish catch fall disproportionately on poor coastal communities, as an estimated 94% of all fishers are subsistence fishers.
In the face of an increasing world population, reversing the decline and maintaining the high-quality protein supply from the sea will require considerable improvement in the management of wild capture fisheries, aquaculture and the health of the ecosystems upon which they depend.
There is a substantial weight of evidence in favour of the beneficial role of MPAs in a range of different types of fisheries, in different global localities, and within different fisheries management regimes. MPAs on their own are not sufficient as a single management tool, except possibly in small-scale subsistence fisheries where other management systems may not be very effective.
For fisheries, MPAs generally can be considered to provide four basic benefits: support for stock management, improved socio-economic outcomes for local communities; support for fishery stability; and better understanding of impacts and options.
How do MPAs benefit tourism?
Tourism is now a primary source of income in many developing countries and frequently exceeds the value, particularly the foreign currency value, of marine fisheries in those nations. In Australia, the Great Barrier Reef attracts about 1.8 million tourist visits with the industry valued at over $AUD1 billion per year, compared to estimates of $A359 million for the annual worth of Great Barrier Reef fisheries.
Despite the importance of tourism of the quality of the natural environment, coastal and marine tourism areas are vulnerable to hasty and inappropriate development. Poorly managed tourism can lead to site degradation and a decline in visitor numbers.
Well-managed marine protected areas with core ‘no-take’ reserves are often major tourist attractions. An important attraction for many visitors is to view abundant marine life from observatories, with glass-bottomed boats, by snorkeling or scuba diving. The quality of these experiences depends on the ability to see large fish and the diverse life of algal beds, rocky seabeds, and reefs undisturbed and undamaged in their natural environment.
The establishment of a marine protected area is an excellent way to raise the profile of an area for marine tourism and to broaden the local economic options. It is important that the introduction and development of tourism is carefully planned to ensure that it is acceptable and sustainable for the local human communities.
With appropriate training and support, local communities can gain additional economic benefit through managing the MPA and involvement in businesses that take visitors to the marine reserve, as well as receiving the benefits of improved local fishing. Many countries have shown that protected areas often earn significant revenue and make an important contribution to local economies.
Are there any risks of MPAs?
MPAs may well be a compelling tool to use in fisheries and conservation management regimes but they are subject to the same pitfalls and difficulties as any other available tool. Blanket MPA targets with a ‘one size fit all’ approach will not suit all habitat types or objectives and must be treated with caution.
Poorly informed and over-optimistic implementation of MPAs will result in more failures arising from inappropriate use, faulty design, poor implementation, or all three. Therefore, the establishment of MPAs must be seen as one of the tools to be considered in the overall goal of achieving sustainable use of oceans.
A major risk of excessive emphasis on MPAs alone is that it will, and probably already has in some cases, divert limited and already over-stretched international, national and local resources from other priorities and approaches that, in many cases, may have been more effective and appropriate for the problems being addressed.
Deadly to marine life, fishing gear either lost or abandoned by crews represent the majority of the plastic pollution in the oceans, according to a new report by Greenpeace, which draws on the most up-to-date research on “ghost gear” polluting the oceans.
The NGO said more than 640,000 tonnes of nets, lines, pots, and traps used in commercial fishing are dumped and discarded in the sea every year, the same weight as 55,000 double-decker buses.
The new data should be a push to international action to stop plastic pollution deadly to wildlife, Greenpeace said. One of the most recent examples is the death of 300 sea turtles last year due to the entanglement in ghost gear off the coast of Oaxaca, Mexico.
Louisa Casson, an oceans campaigner at Greenpeace UK, told The Guardian: “Ghost gear is a major source of ocean plastic pollution and it affects marine life in the UK as much as anywhere else. The world’s governments must take action to protect our global oceans.”
Nets and lines can pose a threat to wildlife for years or decades, ensnaring everything from small fish and crustaceans to endangered turtles, seabirds and even whales, according to the report. Lost and discarded fishing gear is now drifting to Arctic coastlines, washing up on remote Pacific islands.
Up to 10% of ocean plastic pollution is made up by ghost gear, which forms the majority of large plastic littering the waters. One study found that as much as 70% (by weight) of microplastics (in excess of 20cm) found floating on the surface of the ocean was fishing related.
At the same time, a recent study of the “great Pacific garbage patch”, an area of plastic accumulation in the north Pacific, estimated that it contained 42,000 tonnes of megaplastics, of which 86% was fishing nets.
Greenpeace said ghost gear was particularly prevalent from illegal, unregulated and unreported fishing, but overcrowded fisheries also contributed to the problem. “Poor regulation and slow political progress in creating ocean sanctuaries that are off-limits to industrial fishing allow this problem to exist and persist,” the report said.
As a solution to the current problematic, Greenpeace is calling for the UN treaty to provide a comprehensive framework for marine protection, paving the way for a global network of ocean sanctuaries covering 30% of the world’s oceans by 2030.
A long-held theory about the last great mass extinction event in history and how it affected Earth’s oceans was just confirmed by a new study by Yale University, which may also answer questions about how marine life eventually recovered.
The researches argued this is the first direct evidence that the Cretaceous-Paleogene extinction event 66 million years ago coincided with a sharp drop in the pH levels of the oceans—which indicates a rise in ocean acidity.
The Cretaceous-Paleogene die-off occurred when an asteroid slammed into Earth at the end of the Cretaceous period. The impact and its aftereffects killed roughly 75% of the animal and plant species on the planet.
“For years, people suggested there would have been a decrease in ocean pH because the meteor impact hit sulfur-rich rocks and caused the raining-out of sulphuric acid, but until now no one had any direct evidence to show this happened,” said lead author Michael Henehan.
Researchers looked at the foraminifera, tiny plankton that grow a calcite shell and have an amazingly complete fossil record going back hundreds of millions of years. An analysis of the chemical composition of foraminifera fossils from before, during and after the event produced a wealth of data about changes in the marine environment.
Previous research of the die-off had shown that some marine calcifiers—animal species that develop shells and skeletons from calcium carbonate—were disproportionately wiped out in the mass extinction. This new study showed higher ocean acidity may have prevented the calcifiers from creating the shells.
This was important, according to the researchers, because these calcifiers made up an important part of the first rung on the ocean food chain, supporting the rest of the ecosystem.
“The ocean acidification we observe could easily have been the trigger for mass extinction in the marine realm,” said senior author Pincelli Hull, assistant professor of geology and geophysics at Yale.
The team’s boron isotope analysis and modeling techniques may have reconciled some competing theories and puzzling facts relating to ocean life after the die-off event. One theory, for example, argued that for a time after the die-off event, the ocean was essentially dead, and the normal carbon cycle just stopped.
Another popular theory called the “Living Ocean” suggested that the die-off killed off larger plankton species, disrupting the carbon cycle by making it harder for organic matter to sink to the deep sea, but allowed for some marine life to survive.
The new study splits the difference. It says the oceans had a major, initial loss of species productivity—by as much as 50% —followed by a transitional period in which marine life began to recover.
“In a way, we reconciled both of these ‘Strangelove’ and ‘Living Ocean’ scenarios,” Henehan said. “Both of them were partially right; they just happened in sequence.”
Despite initially thought to come from land, most plastic debris in the sea can be linked to merchant ships, according to a new study which analyzed plastic bottles and containers from the past three decades.
Researchers looked at the waste that arrived at the coast of Inaccessible Island – an isolated, uninhabited island in the central South Atlantic Ocean – and found that plastic drink bottles were the fastest-growing source of debris.
While tides could be blamed for the South American bottles that washed up there, they didn’t explain why most of the bottles there now are from Asia. Their recent manufacturing dates suggest that ships are the main culprits.
This means that the vast garbage patches floating in the middle of oceans, which have sparked much consumer handwringing in recent years, are less the product of people dumping single-use plastics in waterways or on land than initially thought.
The island examined by the researchers is located roughly midway between Argentina and South Africa in the South Atlantic gyre, a vast whirlpool of currents that has created what has come to be known as an oceanic garbage patch.
Despite an initial inspection of the trash showed labels indicating it had come from South America (some 2,000 miles / 3,000 kilometers to the west), by 2018 three-quarters of the garbage appeared to originate from Asia, mostly China. Many of the plastic bottles had been crushed with their tops screwed on tight, as is customary on-board ships to save space.
Around 90 percent of the bottles found had been produced in the previous two years, ruling out the possibility that they had been carried by ocean currents over the vast distance from Asia, which would normally take three to five years.
Since the number of Asian fishing vessels has remained stable since the 1990s, while the number of Asian—and in particular, Chinese—cargo vessels has vastly increased in the Atlantic, the researchers concluded that the bottles must come from merchant vessels, which toss them overboard rather than dumping them as trash at ports.
“It’s inescapable that it’s from ships, and it’s not coming from land,” Peter Ryan, director of the FitzPatrick Institute of African Ornithology at the University of Cape Town in South Africa. “A certain sector of the merchant fleet seems to be doing that, and it seems to be largely an Asian one.”
The ocean is warmer, more acidic, and less productive, melting glaciers and ice sheets are causing sea level rise, and coastal extreme events are becoming more severe, according to a new landmark report from the United Nations’ Intergovernmental Panel on Climate Change (IPCC).
More than 100 scientists from 36 countries worked on the report — titled the Special Report on the Ocean and Cryosphere in a Changing Climate. It is the last of three special reports from the IPCC following last October’s urgent report that showed the world may only have until 2030 to keep global warming below 1.5 degrees.
“The open sea, the Arctic, the Antarctic, and the high mountains may seem far away to many people,” said Hoesung Lee, Chair of the IPCC. “But we depend on them and are influenced by them directly and indirectly in many ways – for weather and climate, for food and water, for energy, trade, transport, recreation, and tourism, for health and wellbeing, for culture and identity.”
The scientists said there may be some impacts to the global climate — like some amount of sea-level rise — that can no longer be stopped. But even though there is uncertainty in the report about what exactly the future holds, the authors are unambiguous on this: Despite the damage that has been done, humanity still has a choice.
“If we reduce emissions sharply, consequences for people and their livelihoods will still be challenging, but potentially more manageable for those who are most vulnerable,” Lee said. “We increase our ability to build resilience and there will be more benefits for sustainable development.”
People in mountain regions are increasingly exposed to hazards and changes in water availability, the report said. Glaciers, snow, ice, and permafrost are declining and will continue to do so. This is projected to increase hazards for people, for example through landslides, avalanches, rockfalls, and floods.
Glaciers and ice sheets in polar and mountain regions are losing mass, contributing to an increasing rate of sea-level rise, together with the expansion of the warmer ocean. While sea level has risen globally by around 15 cm during the 20th century, it is currently rising more than twice as fast – 3.6 mm per year – and accelerating, the report showed.
Sea level rise will increase the frequency of extreme sea-level events. Indications are that with any degree of additional warming, events that occurred once per century in the past will occur every year by mid-century in many regions, increasing risks for many low-lying coastal cities and small islands.
Warming and changes in ocean chemistry are already disrupting species throughout the ocean food web, with impacts on marine ecosystems and people that depend on them, the report said.
To date, the ocean has taken up more than 90% of the excess heat in the climate system. By 2100, the ocean will take up 2 to 4 times more heat than between 1970 and the present if global warming is limited to 2°C and up to 5 to 7 times more at higher emission levels.
The growing emissions trend will likely lead to even more difficulties in the world’s oceans and glaciers in the near future, the IPCC warned. Global warming has already reached 1°C above the pre-industrial level.
Global-scale glacier mass loss and decline in snow cover are projected to continue in the near-term due to surface air temperature increases. The ocean is projected to transition to unprecedented conditions with increased temperatures, further acidification, and oxygen decline.
At the same time, the terrestrial and freshwater ecosystems of high-mountain regions like the Andes will continue to be altered, leading to species redistribution and loss of unique biodiversity. Fisheries will also be more challenged, with decreases in fish abundance and distribution.
Strongly reducing greenhouse gas emissions, protecting and restoring ecosystems, and carefully managing the use of natural resources would make it possible to preserve the ocean and cryosphere, the IPCC said, limiting risks to livelihoods and offer multiple additional societal benefits.
“The ambitious climate policies and emissions reductions required to deliver the Paris Agreement will also protect the ocean and cryosphere – and ultimately sustain all life on Earth,” said Debra Roberts, Co-Chair of IPCC Working Group II.
Flowing through rivers and oceans, plastic waste has become an important environmental threat across the globe. Trying to deal with the problem, researchers in Australia developed a way to purge water sources of microplastic without harming microorganisms, using a set of magnets.
Microplastics are ubiquitous pollutants. Some are too small to be filtered during industrial water treatment, such as exfoliating beads in cosmetics, while others are produced indirectly when larger debris like soda bottles or tires weather amid sun and sand.
“Microplastics adsorb organic and metal contaminants as they travel through water and release these hazardous substances into aquatic organisms when eaten, causing them to accumulate all the way up the food chain,” said senior author Shaobin Wang, a professor at the University of Adelaide (Australia).
Wang and the research team generated short-lived chemicals, called reactive oxygen species, which trigger chain reactions that chop the polimers (long molecules) that makeup microplastics into tiny and harmless segments that dissolve in water. The study was published in the journal Matter.
The problem was reactive oxygen species are often produced using heavy metals such as iron or cobalt, which are dangerous pollutants in their own right and thus unsuitable in an environmental context. To get around this, they used carbon nanotubes laced with nitrogen to help boost the generation of reactive oxygen species.
“Having magnetic nanotubes is particularly exciting because this makes it easy to collect them from real wastewater streams for repeated use in environmental remediation,” says Xiaoguang Duan, a chemical engineering research fellow at Adelaide who also co-led the project.
The carbon nanotube catalysts removed a significant fraction of microplastics in just eight hours while remaining stable themselves in the harsh oxidative conditions needed for microplastics breakdown. Their coiled shape increased stability and maximized reactive surface area. Chemical by-products of this microplastic decomposition, such as aldehydes and carboxylic acids, aren’t major environmental hazards. The team, for example, found that exposing green algae to water containing microplastic by-products for two weeks didn’t harm the algae’s growth.
The next step of the research will be to ensure that the nano springs work on microplastics of different compositions, shapes, and origins, as all microplastics are chemically different. They also think that the byproducts of microplastic decomposition could be harnessed as an energy source for microorganisms.
“If plastic contaminants can be repurposed as food for algae growth, it will be a triumph for using biotechnology to solve environmental problems in ways that are both green and cost-efficient,” Wang says.
If you thought that going to the deepest point on the planet, the Mariana Trench, is far enough to get away from plastics, you’re wrong. At 36,000 feet (11 kilometers) beneath the ocean surface, scientists found a plastic bag. That’s right: a plastic bag, like they give away at grocery stores, now lies on the deepest point on Earth.
Plastics are ubiquitous in even the deepest points of the ocean, a new study reveals. The study reports plastic debris pollution in the deep-sea based on the information from a recently developed database, launched by the Global Oceanographic Data Center (GODAC) of the Japan Agency for Marine-Earth Science and Technology (JAMSTEC).
While scientists have known about the Mariana Trench bag for a while now, this is the most accurate quantification of deep-ocean plastic — and it paints a pretty discouraging picture: our oceans are riddled with plastic, from the surface to the very depths.
The vast majority of the plastic (89%) was single-use — the kind of disposable plastic you use once and then throw away. Single-use plastics have become widespread in most parts of the world because they’re so cheap and useful, resulting in a huge problem.
The problem with plastic is that it doesn’t really decompose — it simply breaks off into smaller and smaller pieces, accumulating in the oceans.
“This study shows that plastic debris, particularly single-use products, has reached the deepest parts of the ocean,” researchers write in the study. “Whereas regulation on the production of single-use plastic and the flow of such debris into the coast are the only effective ways to prevent further threats to deep-sea ecosystems, successful management of plastic waste is possible through internationally harmonized practices based on scientifically sound knowledge”
Plastic pollution is already one of the most serious threats to ocean ecosystems. Previous studies have found that there are trillions of plastic pieces in oceans, and the ocean sediments are already a plastic cemetery. Plastic pollution threatens wildlife in a number of ways. First, through ingestion — we’ve seen many times the dramatic effects ingested plastic can have on unfortunate creatures. Microplastic can even be ingested by zooplankton and then transferred up the food chain, including to some species of economic importance, which means that ultimately, we humans may be ingesting the plastic ourselves. Lastly, toxic chemicals released from fragmented plastic can severely impact the biological function of marine organisms, as studies have already shown.
To be perfectly honest, things aren’t looking very good, but there is a silver lining: efforts to fight plastic pollution are working, even though the process is slow and tedious. Even something as small as a five pence tax per plastic bag can make a massive difference, and several states are already implementing full-scale bans. Of course, all of us can make a difference by just saying no to plastic — especially to single-use plastic.
Journal Reference: Chiba et al. “Human footprint in the abyss: 30 year records of deep-sea plastic debris.” https://doi.org/10.1016/j.marpol.2018.03.022
Ocean-dwellers have to brave through heat waves too — according to a new study, much more often than we’d believed. The incidence of such events increased by 54% from 1925 to 2016, and their frequency has risen by nearly 35% over the same period, the paper reports.
Image via Pixabay.
As the Earth heats up, mean ocean temperatures have also been steadily rising. This latter change makes it easier for extreme marine heating events — similar to heat-waves, but involving bodies of how water instead of air — to occur. Compared to air, however, water can absorb far more heat and is better at retaining it, making marine heatwaves long-lived periods of extreme temperatures.
One example of such an event took place in the Pacific in 2015: water temperatures surged by as much as 10 degrees Fahrenheit (5.55 Celsius) above average in an area stretching from Alaska to Mexico. It might not sound like much of a difference, but for marine life, it was almost unbearable. Animals from a number of sea-dwelling species, including sea lions and birds, died to the heat. There were also nearly 50 reported cases of whale deaths that are believed to be linked to the heatwave.
Boil, broil, heat, and toil
Heat waves tend to be one of the most deadly weather phenomena on dry land. One such event claimed the lives of about 70,000 Europeans in 2003, most of those deaths occurring in only two months, July and August (when the predominant rise in temperatures was recorded).
Although marine heat waves are far less studied or understood, we still do know that they are just as devastating as their land counterparts (which are set to become worse, both in Europe and the USA). Waves of extreme heat, among other things, bear the lion’s share of responsibility for coral bleaching events. For example, such events repeatedly battered Australia’s Great Barrier Reef until 2016, when one heat wave pushed the ecosystem past its limit, killing off nearly 70% of corals in a 430-mile area of (what we considered to be a) pristine reef. In essence, it was the final blow to an ecosystem already shaking after prolonged exposure to abnormally high temperatures.
To get a better understanding of such events, the team pooled together data on sea surface temperatures stretching back to over a century ago. Despite the wealth of recordings they had at their disposal, the team noted that the ‘best data’ (as in, the most reliable and comprehensive) comes after 1982, specifically satellite-recorded data collected by National Oceanic and Atmospheric Administration (NOAA) over the course of over 30 years.
The team suggests that climate-change-induced rises in global temperatures, which drove an increase in average ocean temperatures, is behind this increase in marine heatwaves. Having warmer oceans simply makes it easier for temperatures to fall to extremes and make such events possible, they note.
We’re causing it
Globally averaged time series of total marine heatwave (MHW) days from 1982 to 2016 (NOAA dataset). Image credits E. Oliver et al., 2018, N.Comm.
The most reliable and accurate part of the dataset (1982-2016) falls a bit on the short side, and so it can’t be used to draw an unassailable link between the two. In other words, while the findings point to anthropic climate change as the main driving force behind the increase in marine heat wave, they can’t specifically rule our natural temperature swings right now.
In light of how things are going right now, this means that ocean temperatures will almost certainly continue to rise this century. Though there is a global push to mitigate the release of greenhouse gases into the atmosphere, we’re still releasing a lot. The ones already floating around will also take time to break down, so it will take time for our efforts to yield results. Lastly, there’s the problem of willingness: the US, the second-largest single emitter of greenhouse gasses, and the largest per capita emitter don’t seem interested in playing ball in this regard — if anything, the current administration seems determined to undermine as many climate regulations as it can.
Still, the team is confident that a global, concerted effort to limit powerful greenhouse gas emissions would help limit the severity of ocean temperature increase.
Future extreme warming events in the oceans will be especially likely to occur during longer-term (i.e. measured in years or more) warming trends, the team notes. These include El Niño events in the Pacific Ocean and the Pacific Decadal Oscillation, which can warm vast regions of the Pacific Ocean for decades. The main concern is that — piled over the growing pollution, overfishing, and acidification issues — marine heat waves might push tip the ocean’s ecosystem beyond their tipping point.
The paper “Longer and more frequent marine heatwaves over the past century” has been published in the journal Nature Communications.
The putative oceans on Mars may have been aided by an unlikely ally: volcanoes.
A depiction of how oceans on Mars might have looked like. Image credits: Kevin McGill / Flickr.
The saga of Martian oceans — and if they truly existed or not — continues with a new episode. A team of geophysicists at the University of California, Berkeley, suggests that volcanoes may have helped pave the way for liquid water, by raising temperatures.
“Volcanoes may be important in creating the conditions for Mars to be wet,” said Michael Manga, a UC Berkeley professor of earth and planetary science and senior author of a paper appearing in Nature this week and posted online March 19.
While there is significant evidence that Mars used to have oceans of liquid water, not everybody is convinced of their existence. The main argument against this existence is that… we don’t see them today. The estimated mass of the oceans just doesn’t fit with the how much water could be hidden today as permafrost underground and how much could have escaped into space. In other words, if Mars once had oceans, we should still see some water.
But Manga and his colleagues developed a new model which would help explain this disparity. They propose that the first ocean on the Red Planet (called Arabia) formed at about the same time as the planet’s largest volcanic feature, Tharsis, or even a bit sooner — instead of after it, as previous models suggested.
“The assumption was that Tharsis formed quickly and early, rather than gradually, and that the oceans came later,” Manga said. “We’re saying that the oceans predate and accompany the lava outpourings that made Tharsis.”
In particular, because Tharsis was smaller in its earlier days, it didn’t distort the seabed as much, meaning that the oceans were much shallower than previously assumed. This theory can also help explain another counterargument to Martian oceans: the seashore problem. The proposed seashores are highly irregular, varying in height by up to 1 kilometer (0.6 miles), whereas on Earth seashores are largely at the same level (sea level).
If oceans were formed in the initial stages of Tharsis’ development, the volcano would have significantly depressed the land and deformed the shoreline, which would help explain the irregularity.
“These shorelines could have been emplaced by a large body of liquid water that existed before and during the emplacement of Tharsis, instead of afterwards,” said first author Robert Citron, a UC Berkeley graduate student.
Lastly, this model also proposes that Tharsis spewed gases into the atmosphere, creating a global warming or greenhouse effect, which favored the formation of liquid water. However, more studies will be needed before this theory can be confirmed.
Journal Reference: Robert I. Citron, Michael Manga & Douglas J. Hemingway. Timing of oceans on Mars from shoreline deformation. doi:10.1038/nature26144.
EDIT: A previous version of this article wrongly claimed that the article had not been peer-reviewed.
TheU.S. ban on microbeads(small beads made out of plastic)signed into law by President Barack Obama in 2015continues into 2017.Over the next few years, manufacturers must cease using these tiny plastic polymers in our everyday products.
Microbeads are in a swarm of everyday products, and they’re having a massive effect on the environment. Image via Oregon State University.
Many of us may not realize microbeads are present in common household items such as makeup, shampoos, body/exfoliating washes, eventoothpaste. They could also be hiding in fish or in foods seasoned with healthy,natural sea salt.
The ban on microbeads is a positive step toward stopping the flow of these marinelife–choking polymers into our waterways. A bright horizon for microbead-free products lies ahead.
What Are Microbeads?
“Microbead” is a loose term that manufacturers use to define several types of plastic polymer beads. Microspheres, microcapsules, or nanospheres better describe the ultra-small plastic particles primarily used in medicine and industry.
These plastic particles contaminate waterways and end up in our oceans, creating microplastic pollution.The majority of microbeads used commercially are made of polyethylene, the same type of plastic used in the manufacture ofplastic bags, milk jugs, and water bottles.
These tiny beads(most often, in the sizerange of millimeter to micrometer) are added to products to enhance performance, appearance or durability.
What Products Have Microbeads?
Microbeads are found in several products. For example, millimeter-size microbeads in some facial washes provide an improved exfoliating performance. In other words, they help your face get that deep, fresh clean.Microbeads also give exfoliating face and body washes their gritty texture. The majority of consumer products with microbeads are face washes, cleansers, and scrubs.
Another notable example of microbeads are the colorful specks in toothpaste. However, some manufacturers chose to remove microbeads from their products due to consumer pressure.
While these microbeads are considered safe for us to use, their disposal down drains and their eventual journey into aquatic habitats adds more pollution to our oceans.
Our OceansAre Looking Bad
There’s a lot of plastic floating around in our oceans. We even give names to these island-size plastic gyres such as one popular example,the great “Pacific Garbage Patch.” These masses of floating plastic pollutioninclude both large items such as plastic garbage bags and small microplastics that we can’t see without the help of a microscope.
Some toothbrushes contain microbeads. Image credits: Thegreenj.
Even if you don’t eat fish, you may have vegetables in your kitchen pantry that containsnatural sea salt. Natural sea salt is considered a healthier condiment than regular salt, which can be bad for human health.
But I wonder: Where and how do manufacturers get their natural sea salt? If my natural sea salt was obtained by the evaporation of seawater, microplasticand anypotential toxins it soaked up could be present in my food.
Will We See ‘Microbead-Free’ Food Labels in the Future?
It is unclear where manufacturers obtain natural sea salt, but we can assume that food grade quality products exclude any known substances or particles harmful to humans. But the key emphasis is on “known.”
Manufacturers cater to consumer demands. Historically, companies have made adjustments to suit consumer preferences by creating foods that arelow–fat, fat-free, low(er) salt, gluten-free, GMO-free, sugar-free, no caffeine, all naturaland no artificial ingredients.
This list will lengthen as consumer trends and demandschange. If microbeads or any type-size of microplastic pollution is found in natural sea salt, an opportunity for “Microbead-Free” labeling exists.
This is a guest post by Dr. Christy A. Rothermund-Franklin, an associate professor for the School of STEM at American Public University. She earned her B.S. in Biotechnology from the University of Nebraska and a Ph.D. in Biochemistry and Molecular Biology from the University Nebraska Medical Center.