A new U.N. treaty to protect the world’s oceans was signed by 67 countries on Wednesday, another step in efforts to reverse the damage done to fragile marine environments by overfishing and other human activities.
The global pact to conserve biodiversity on the high seas was finally agreed in March and formally adopted by the United Nations in June. It is seen as a crucial tool to meet a target agreed last year to protect 30% of the earth’s land and sea by 2030, known as “30 by 30.”
Despite the nearly 70 signatures at the United Nations General Assembly on Wednesday, the treaty needs to be ratified on a national level before it goes into effect.
“With the signature of the High Seas Treaty, we can safeguard the ocean from human pressures, and get closer to our objective of protecting at least 30% of the planet by 2030,” said European Environment Commissioner Virginijus Sinkevičius, calling the treaty “our constitution for the ocean.”
Mads Christensen, interim executive director of Greenpeace International, described the signings as a “powerful signal” which should help maintain momentum to meet the “30 by 30” target.
“But this signing is a purely symbolic moment,” he said. “Now politicians must bring the treaty home and ensure it is ratified in record time.”
The agreement will create ocean sanctuaries where fishing will be prohibited, and also ensure human activity on the high seas is subject to environmental impact assessments.
The International Union for the Conservation of Nature estimates that $500 million in funding will be required to kickstart the treaty, and a special implementation and capacity-building fund could require another $100 million per year.
Threats to the ocean environment have been mounting in recent years as a result of overfishing as well as rising temperatures, and new threats could also emerge from ocean-bed mining and the use of geoengineering technologies to boost the ocean’s capacity to absorb carbon dioxide.
Environmental groups say the treaty must be brought fully into effect by 2025 at the latest to ensure the “30-by-30″ protection target is reached.”The ocean can’t wait, and with the treaty being in the making for the better part of the past 20 years, there is absolutely no time to waste,” said Jessica Battle, an ocean expert with the Worldwide Fund for Nature.
Pollution from treated and untreated sewage is the greatest threat to river biodiversity, causing more damage than runoff from farms, according to research.
There is a need for more regulation of water companies and improvements at their treatment plans to protect rivers, say the authors of the study.
The research from the University of Oxford was released on World Rivers Day. No river in England passes tests for chemical or biological pollution, and government targets to improve the water quality in rivers will not be met.
“Improvements to wastewater plants should be implemented along with more regulations. These efforts are crucial in safeguarding the integrity and safety of our rivers – fundamental elements of both ecosystems and human wellbeing,” said the lead author, Dr Dania Albini, of Oxford’s biology department.
Treated sewage released by water companies into rivers and raw effluent that is dumped in rivers via storm overflows is the primary driver of increased nutrients, algae and sewage fungus in rivers, according to the study.
Sewage discharge radically alters plant, animal and microbe communities and increases the abundance of harmful species. While runoff from farmland has negative impacts on river water quality, the research reveals that sewage discharge into rivers has a greater impact on water quality and the animals and plants that live in rivers.
The findings were published in the journals Global Change Biology and Ecological Solutions and Evidence.
Albini said: “Our study highlights the disproportionate impact that sewage discharge has on river quality, presenting an urgent need for a comprehensive action plan targeting the sewage discharge problem.”
Sewage from households and businesses is treated by water companies at treatment plants and then discharged into rivers. Raw sewage is also discharged via storm overflows, but this should only take place in exceptional circumstances. Water companies are at the centre of a criminal investigation by the Environment Agency and an inquiry by the financial regulator Ofwat into failures in the way they run their treatment plants.
James Wallace, of the UK-based charity River Action, said: “This important research demonstrates yet again the damage from unregulated water companies and agriculture. In addition to the catastrophic impact on wildlife from nutrient pollution, the public should be aware that sewage systems do not remove dangerous bacteria such as E.coli and intestinal enterococci from treated sewage.
“When will the government make water companies and farms clean up their act, especially in places where human lives and sensitive protected habitats are threatened?”
Separate research by Dr Leon Barron, part of the Environmental Research Group at Imperial College, which involved hundreds of samples taken from 14 waterways in Greater London over three years, reveals that 21 compounds were detected that posed a potential risk to the environment in freshwater ecosystems. The pollutants included antibiotics, pain medication and pet parasite medications, which contain neonicotinoids.
The study showed that water companies’ treatment plants and combined sewer overflows, which release raw sewage and runoff, were the main sources of chemical risks to rivers overall.
The team found that smaller rivers feeding into the Thames were most affected by wastewater pollution.
The research compared sampling taken during Covid lockdowns with those taken when society opened up again. Barron, a senior author of the research, said it was the largest study of a heavily urbanised river system and provided uniquely detailed insights into London’s water quality.
Guy Woodward, a professor of ecology in the department of life sciences at Imperial, and a co-author of the paper, said: “This … picks up on several [chemicals] that are at potentially harmful concentrations for wildlife, but which have seemingly been overlooked in traditional surveys of our water quality in urban areas at this resolution.”
The New Orleans mayor, LaToya Cantrell, signed an emergency declaration for the city on Friday amid concerns about saltwater from the the Gulf of Mexico that has been creeping up the drought-hit Mississippi River in Louisiana.
The declaration came amid concerns the saltwater, which is impacting the river because it is at such low levels, could impact the drinking water of thousands of residents in the next few weeks
The Louisiana governor, John Bel Edwards, said the state would be requesting an emergency declaration from the federal government in the next couple of days as well to get federal funds and agencies involved.
For those who rely on the Mississippi River for drinking water, the saltwater intrusion is a potential health risk, as high concentrations of salt in drinking water may cause people to develop increased blood pressure and corrode drinking water infrastructure.
The saltwater has already entered the drinking water of communities south of New Orleans – from Empire Bridge to Venice, Louisiana – making the water undrinkable for about 2,000 residents and causing water outages at local schools. As the saltwater moves upriver, it could affect the drinking water for another 20,000 people in Belle Chasse. After that it could reach the drinking water intake for the New Orleans community of Algiers, across the river from the French Quarter.
To slow the progression of the saltwater, the army corps of engineers constructed an underwater barrier downriver from New Orleans in July.
On Friday, the corps released an updated timeline of the saltwater intrusion in the river that includes the delay added by the underwater barrier. With the barrier in place, the saltwater would not reach the Belle Chasse drinking water intake until 13 October and the Algiers intake until 22 October.
Governor Edwards said his team is working with the four parishes at the end of the Mississippi River that are already affected by the low river water. “I found out today that the forecast is for above average amounts of precipitation in winter. But that’s still several months away,” he said. “And what we need most in Louisiana right now, for the Mississippi River, we need rain further up north in the Ohio Valley.”
Colonel Cullen Jones of the army corps of engineers said that 10in of rain would be needed across the entire Mississippi Valley to increase the Mississippi River flow high enough to push back the seawater.
The mouth of the Mississippi River is below sea level. Because saltwater is denser than freshwater it is moving underneath the freshwater along the bottom of the river in a wedge shape.
The lowest Mississippi River levels recorded in modern history were in 1988, when seawater entered the water systems of New Orleans for a couple of days before it was pushed back down the river by freshwater. But forecasts show the current day low river levels could become more severe, potentially allowing saltwater to remain in the system from a couple of weeks to a couple of months, said Colonel Jones.
The corps is also working on a plan to deliver 15m gallons to the southern parishes by next week. Together the water treatment systems that could be contaminated with saltwater by 24 October use 36m gallons of water per day.
The barrier was intended to slow the upstream movement of the saltwater, but the salt wedge has overtopped the barrier. Similar barriers were constructed in 1988, 2012 and 2022. This is the first time the barrier has needed to be built in back-to-back years. Last year, the barrier wasn’t overtopped, he added.
Communities along the river are keeping a close eye on the upstream movement of the saltwater wedge and testing the salinity levels near their water system intakes, said Dr Joseph Kanter, the state health officer and medical director for the Louisiana department of health. “Everyone along the river knows where the wedge is and when it’s approaching. That’s not going to be a surprise,” he said.
While salt is not a federally regulated contaminant, it could be a health concern for people who are on low salt diets and for those who are pregnant. The World Health Organization’s drinking water guideline suggests that 200mg of sodium a liter is the threshold at which most people will not want to drink the water because of taste. When saltwater is pumped through a water distribution system it can cause pipes to corrode, potentially leaching heavy metals from the pipes and pipe fittings into drinking water.
But it is difficult to predict which metals might leach from pipes, as distribution systems are all different and some do not have full maps of their systems. “So, a hallmark of the response is going to be frequent testing of the water that is going through the water systems distribution network,” Kanter said.
The corps of engineers is exploring barging river water from upriver to areas being affected by the saltwater intrusion and smaller communities south of Louisiana are sourcing reverse osmosis devices capable of desalinating water, Kanter said. But those measures would probably not be able to replace the amount of water used by New Orleans, which has a population of nearly 370,000 people.
Kanter reiterated that the current estimates are worst-case scenarios.
Multiple days of rainfall in the Missouri and Ohio River Basins would be necessary to increase the freshwater flow of the Mississippi River, said Julie Lesko, a senior service hydrologist with the National Weather Service New Orleans/Baton Rouge office. “When we look at what could happen over a two-week period we’re not seeing anything significant that would make its way down river to alleviate the problems,” she said.
Coastal communities across the US are facing similar challenges with saltwater intrusion, said Allison Lassiter, an assistant professor at the University of Pennsylvania focused on urban water management.
Desalination systems have limitations because they are expensive and don’t produce a lot of water. “This will be a difficult nut to crack,” she said.
Sea level rise will make the conditions that allow saltwater intrusion into the Mississippi River more likely in the future, said Soni Pradhanang, an associate professor of hydrology and water quality at the University of Rhode Island. Climate change is also expected to exacerbate droughts by making them longer and more frequent. “We’re only going to see this happening more,” she said. “Sea level rise will lead to increased salinity as more of this seawater pushes up into the estuaries and inland.”
Montana’s legislature designated $3.7 million this spring to remove lead from school drinking water supplies, then the state received $565,000 more on Aug. 1 from the $50 billion federal infrastructure package aiming to improve water systems nationally.
But even with these two new pools of money intended to last two years, the state’s schools may struggle to remove all but the most dangerous sources of lead, considering about half the schools that tested their water between July 2020 and February 2022 found high lead levels. Medical experts say no amount of lead is safe to ingest.
“When you start replacing faucets and drinking fountains in the hundreds of schools that we have in Montana, that gets eaten up pretty quickly,” said Democratic state Rep. Paul Tuss, who added the state funding to an infrastructure bill passed this spring.
If the total were divided evenly among the approximately 590 schools that need to meet the state’s new lead testing rules, each school would receive less than $8,000 from the state to test and upgrade its faucets, pipes and water fountains. The state already knows that 110 schools have had at least one water fixture with lead levels of 15 parts per billion or higher, three times the level that requires action under Montana rules.
Most schools with lead levels over the state limit could address their “exceedances” with the state money, according to state Department of Environmental Quality spokesperson Moira Davin. “Our plan is to address as many schools as possible with this funding,” she said.
But part of the challenge for Montana is that it doesn’t yet know how extensive a problem its schools have. More than a fifth of the state’s schools facing the new rules — 129 facilities — hadn’t completed any sampling as of Aug. 3, said Greg Montgomery, the director of the department’s Lead in Schools program. And replacing a single school’s pipes can cost hundreds of thousands of dollars.
Ronnie Levin, an environmental health instructor at the Harvard T.H. Chan School of Public Health, said the money Montana has in hand is not a lot when it comes to fixing pipes but that it could be enough to get filters on all the faucets.
“We are not talking about solving the whole problem here,” said Levin, who worked on lead exposure during her nearly 40 years at the U.S. Environmental Protection Agency.
Lead is particularly harmful to children and can lead to brain and nervous system damage and slowed development and growth. It typically gets into drinking water in schools through piping or fixtures. A 2020 state rule requires schools to test water supplies every three years. If lead concentrations surpass 5 parts per billion, fixtures must be addressed — and shut off if higher than 15 ppb.
Jessica Reyes, an economics professor at Amherst College, said prioritizing fountains or pipes with high lead levels after a “first draw” test could help a lot. The test measures lead in water the first time a faucet is turned on for the day, after the water’s been sitting in a pipe all night. That sample provides the best data to pinpoint the greatest risks, she said.
Running all faucets for a few minutes before kids get to school is quite protective for kids, Reyes added, because the quantity of lead diminishes as the water runs. But Reyes likes to imagine a kindergartner who gets to school early for free breakfast and drinks from a water fountain before anyone in the building clears the pipes.
“Everything kids need to grow — lead is the opposite of those,” Reyes said.
Montana officials will decide how to distribute the money from the legislature, reimbursing schools for costs such as installing new faucets, water filters, plumbing and water bottle filling stations. The federal grant, meanwhile, will be used for covering costs related to testing, Montgomery said.
Schools will have to participate in the state’s Lead in Schools program by sampling their drinking water to get any of the state funding, he said, and they won’t be able to use the money on projects completed before the state bill was signed into law.
Montgomery said the amount available to schools would depend on whether they have any fixtures over the “action level,” or fixtures with lead concentrations over 5 ppb. Funding will be prioritized on a first-come, first-served basis, he said.
Even if a school doesn’t have high samples of lead in its test results, Montgomery said, it could seek money to install water bottle filling stations with filters. Schools could also use the money for larger projects such as replacing piping, but, Montgomery said, the state will set a limit on how much each school can get. And, he said, it’s unlikely the money will be able to cover something like a $100,000 pipe replacement project.
The goal is to make money available to all schools, regardless of size, and ensure a couple of schools aren’t “gobbling” the entire amount, Montgomery said. That means schools with extensive issues will likely need to pick which areas to fix.
“We want to make sure the small schools have equal footing as the large schools,” Montgomery said.
Many Montana schools have already launched remediation projects after receiving high lead results.
One sink at Skyview High School in Billings had one of the highest levels of lead detected in schools across the state. Scott Reiter, the executive director of facilities for Billings Public Schools, said the sink was in a control room in the auditorium and people rarely used it. After the results came in, the fixture was removed to make the sink unusable.
On a larger scale, he said, all cold-water piping for drinking and sinks was replaced at Rimrock Learning Center in Billings last summer. Reiter said the school had been remodeled and all fixtures replaced about five years ago, so when lead was detected all over the school, it was clear it wasn’t just one fixture.
“We knew that it had to be in the lines,” Reiter said.
Reiter said the school district used leftover money from a 2013 elementary school district bond to replace Rimrock’s pipes, which he estimated cost $100,000.
While Reiter said he was disappointed costs from the Rimrock pipe replacements and other projects that have already happened couldn’t be reimbursed retroactively, he welcomed the state’s additional funding. “Any help to the schools for something like this is great,” he said.
The Great Falls Public Schools district also exemplifies how extensive and expensive such work can be. The district used $19,511 from an earlier $40,000 state allocation for drinking fountains, water bottle fillers and filters across schools in the district, said Brian Patrick, its director of business services and operations. He said the district also got 783 tests covered by the state, each costing $25.
His district used a bond passed in 2017 to fund a pipe replacement at Lewis and Clark Elementary School, where 23 tests came in at 5 ppb or higher. The pipes were replaced last summer, Patrick said, costing $411,252.
PITTSBURGH (Reuters) – The mining industry is working to boost freshwater recycling while also developing direct lithium extraction (DLE) technologies as it races to reinvent how the battery metal is produced for the green energy transition, executives said.
The surging global demand for lithium has sparked widespread interest in DLE technologies, which use less land and can operate far faster than hard rock mining and brine evaporation ponds – the traditional ways to process the white metal.
Some types of DLE technologies, though, require 180 metric tons or more of water to produce a single metric ton of lithium, a usage that has sparked controversy in arid regions seeking to conserve potable water and one that has offset DLE’s purported promise of curbing the mining industry’s large water use.
Now, DLE developers are racing to boost freshwater recycling as they fine tune technology, part of a push to ensure they do not lose community support before their industry has a chance to go fully commercial.
“If we cannot do a good job of recycling that water and reducing our water footprint, we’re going to get crushed,” John Burba, executive chairman of International Battery Metals, told the Reuters Events Industry Transition conference in Pittsburgh this week. “DLE is a very water-intensive process.”
Burba told the conference that IBAT – which has held talks to license its DLE technology with Exxon Mobil, Chevron and others – recovers 98.5% of the freshwater used during its lithium production process, and is aiming to boost that further.
Privately-held EnergyX, which counts General Motors as an investor, said it can recover as much as 90% of its freshwater, a number its scientists are working to increase.
“Getting it down to maybe five or 10 or 15 (metric) tons of freshwater per ton of lithium is kind of where you want to be,” said EnergyX CEO Teague Egan.
Controlled Thermal Resources, which is developing a geothermal lithium project in California’s Salton Sea to supply GM and Stellantis, recycles a gallon of water at least eight times and will produce water via steam from its geothermal power process, said CEO Rod Colwell.
“How many times we can recycle? That’s really the big question,” said Colwell.
E3 Lithium, which is backed by Exxon’s Imperial Oil, began testing three DLE technologies last month in Alberta and aims to install water recycling facilities as it goes commercial, said CEO Chris Doornbos.
“You end up having a small water treatment facility with your processing facility so they can reuse that water over and over and over again,” said Doornbos.
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Each of the developers said they expect at least one DLE technology to commercially launch by early 2025, a step that is expected to boost the entire industry.
“DLE is a tool that is growing and improving to allow us to unlock brines that might have been uneconomic in the past,” said Emily Hersh, CEO of privately-held mining explorer Luna Lithium.
Whereas DLE once had many questioning if it even could replace traditional lithium mining, those worries have now faded, executives said.
“The question of ‘if DLE works’ is gone now. It’s an engineering challenge. It’s not a technological challenge,” said E3’s Doornbos.
The push to curb water use, executives said, should in time help assuage some concerns from the EV industry about mining’s environmental impact amid the rising demand for lithium, executives added.
“Every single (automaker) realizes that lithium is the limiting factor in them producing electric vehicles,” said EnergyX’s Egan.
SINGAPORE (Reuters) – Governments have no time to lose when it comes to implementing a new global ocean treaty to protect the high seas as threats from human activities intensify, a report by environmental group Greenpeace said on Thursday.
In March, more than 100 countries completed a groundbreaking treaty to protect the high seas after years of negotiations. It was adopted at the United Nations in June and states can signal their intent to ratify it at the U.N. General Assembly on Sept. 20.
The treaty will create ocean sanctuaries that are off-limits to fishing and other human activities. Environmental groups said the agreement was a crucial part of efforts to meet a goal enshrined in last year’s global biodiversity accord to protect at least 30% of the world’s land and seas by 2030 – a target known as “30 by 30”.
The high seas, or international waters, constitute more than 60% of the world’s oceans but have not been under any protection. While the treaty addresses a major regulatory gap, it still needs to be ratified at a national level before it goes into effect.
Greenpeace said fishing hours on the high seas increased by 8.5% from 2018 to 2022, and were up 22.5% in areas that need special protection.
Unsustainable practices have also risen, including longlines that ensnare marine mammals or seabirds. Species like Pacific Bluefin tuna have lost more than 90% of their population in 30 years, the report said.
Sea temperatures hit a record 21.1 degrees Celsius (70 degrees Fahrenheit) in April and are driving ocean acidification and deoxygenation. The problems of plastic, oil and noise pollution have still not been brought under control, according to the environmental group.
Greenpeace warned that “new industries wait in the wings”, including the mining of minerals in the seabed as well as ocean carbon removal technology, which are not yet properly regulated.
The U.N. treaty will only go into effect when it has been ratified by 60 countries. Greenpeace said that needs to happen before 2025 if there is any hope of achieving the “30 by 30” target. Funding the treaty could be the next challenge.
“We believe over 60 countries intend to sign the Treaty (at the U.N. General Assembly) on Sept. 20, which would send a very strong signal of continued global unity and momentum towards ratification,” said Chris Thorne of Greenpeace’s Protect the Oceans campaign.
“Reaching 30 by 30 means protecting more than 11 million square kilometres (4.3 million square miles) every year from now to 2030, so there is hardly any time to waste.”
Rivers are warming and losing oxygen faster than oceans, according to a Penn State-led study published today (Sept. 14) in the journal Nature Climate Change. The study shows that of nearly 800 rivers, warming occurred in 87% and oxygen loss occurred in 70%.
The study also projects that within the next 70 years, river systems, especially in the American South, are likely to experience periods with such low levels of oxygen that the rivers could “induce acute death” for certain species of fish and threaten aquatic diversity at large.
“This is a wake-up call,” said Li Li, Penn State’s Isett Professor of Civil and Environmental Engineering and corresponding author on the paper. “We know that a warming climate has led to warming and oxygen loss in oceans, but did not expect this to happen in flowing, shallow rivers. This is the first study to take a comprehensive look at temperature change and deoxygenation rates in rivers — and what we found has significant implications for water quality and the health of aquatic ecosystems worldwide.”
The international research team used artificial intelligence and deep learning approaches to reconstruct historically sparce water quality data from nearly 800 rivers across the U.S. and central Europe. They found that rivers are warming up and deoxygenating faster than oceans, which could have serious implications for aquatic life — and the lives of humans. The National Oceanic and Atmospheric Administration estimates that most Americans reside within a mile of a river or stream.
“Riverine water temperature and dissolved oxygen levels are essential measures of water quality and ecosystem health,” said Wei Zhi, an assistant research professor in the Department of Civil and Environmental Engineering at Penn State and lead author of the study. “Yet they are poorly understood because they are hard to quantify due to the lack of consistent data across different rivers and the myriad of variables involved that can change oxygen levels in each watershed.”
The research team developed novel deep learning approaches to reconstruct consistent data to enable systematic comparison across different rivers, he explained.
“If you think about it, life in water relies on temperature and dissolved oxygen, the lifeline for all aquatic organisms,” said Li, who is also affiliated with Penn State’s Institute of Energy and the Environment. “We know that coastal areas, like the Gulf of Mexico, often have dead zones in the summer. What this study shows us is this could happen in rivers as well, because some rivers will no longer sustain life like before.”
She added that declining oxygen in rivers, or deoxygenation, also drives the emission of greenhouse gases and leads to the release of toxic metals.
To conduct their analysis, the researchers trained a computer model on a vast range of data — from annual precipitation rates to soil type to sunlight — for 580 rivers in the United States and 216 rivers in Central Europe. The model found that 87% of the rivers have been getting warmer in the past four decades and 70% have been losing oxygen.
The study revealed that urban rivers demonstrated the most rapid warming, whereas agricultural rivers experienced the slowest warming but fastest deoxygenation. They also used the model to forecast future rates and found that across all the rivers they studied, future deoxygenation rates were between 1.6 and 2.5 times higher than historical rates.
“The loss of oxygen in rivers is unexpected because we usually assume rivers do not lose oxygen as much as in big water bodies like lakes and oceans, but we found that rivers are rapidly losing oxygen,” Li said. “That was really alarming, because if the oxygen levels get low enough, it becomes dangerous for aquatic life.”
The model predicted that, within the next 70 years, certain species of fish could die out completely due to longer periods of low oxygen levels, which Li said would threaten aquatic diversity broadly.
“Rivers are essential for the survival of many species, including our own, but they have historically been overlooked as a mechanism for understanding our changing climate,” said Li. “This is our first real look at how rivers throughout the world are faring — and it’s disturbing.”
Researchers have genetically engineered a marine microorganism to break down plastic in salt water. Specifically, the modified organism can break down polyethylene terephthalate (PET), a plastic used in everything from water bottles to clothing that is a significant contributor to microplastic pollution in oceans.
“This is exciting because we need to address plastic pollution in marine environments,” says Nathan Crook, corresponding author of a paper on the work and an assistant professor of chemical and biomolecular engineering at North Carolina State University.
“One option is to pull the plastic out of the water and put it in a landfill, but that poses challenges of its own. It would be better if we could break these plastics down into products that can be re-used. For that to work, you need an inexpensive way to break the plastic down. Our work here is a big step in that direction.”
To address this challenge, the researchers worked with two species of bacteria. The first bacterium, Vibrio natriegens, thrives in saltwater and is remarkable — in part — because it reproduces very quickly. The second bacterium, Ideonella sakaiensis, is remarkable because it produces enzymes that allow it to break down PET and eat it.
The researchers took the DNA from I. sakaiensis that is responsible for producing the enzymes that break down plastic, and incorporated that genetic sequence into a plasmid. Plasmids are genetic sequences that can replicate in a cell, independent of the cell’s own chromosome. In other words, you can sneak a plasmid into a foreign cell, and that cell will carry out the instructions in the plasmid’s DNA. And that’s exactly what the researchers did here.
By introducing the plasmid containing the I. sakaiensis genes into V. natriegens bacteria, the researchers were able to get V. natriegens to produce the desired enzymes on the surface of their cells. The researchers then demonstrated that V. natriegens was able to break down PET in a saltwater environment at room temperature.
“This is scientifically exciting because this is the first time anyone has reported successfully getting V. natriegens to express foreign enzymes on the surface of its cells,” Crook says.
“From a practical standpoint, this is also the first genetically engineered organism that we know of that is capable of breaking down PET microplastics in saltwater,” says Tianyu Li, first author of the paper and a Ph.D. student at NC State. “That’s important, because it is not economically feasible to remove plastics from the ocean and rinse high concentration salts off before beginning any processes related to breaking the plastic down.”
“However, while this is an important first step, there are still three significant hurdles,” Crook says. “First, we’d like to incorporate the DNA from I. sakaiensis directly into the genome of V. natriegens, which would make the production of plastic-degrading enzymes a more stable feature of the modified organisms. Second, we need to further modify V. natriegens so that it is capable of feeding on the byproducts it produces when it breaks down the PET. Lastly, we need to modify the V. natriegens to produce a desirable end product from the PET — such as a molecule that is a useful feedstock for the chemical industry.
“Honestly, that third challenge is the easiest of the three,” says Crook. “Breaking down the PET in saltwater was the most challenging part.
“We are also open to talking with industry groups to learn more about which molecules would be most desirable for us to engineer the V. natriegens into producing,” Crook says. “Given the range of molecules we can induce the bacteria to produce, and the potentially vast scale of production, which molecules could industry provide a market for?”
The paper, “Breakdown of PET microplastics under saltwater conditions using engineered Vibrio natriegens,” is published open access in the AIChE Journal. The paper was co-authored by Stefano Menegatti, an associate professor of chemical and biomolecular engineering at NC State.
In the frigid waters surrounding Antarctica, an unusual seasonal cycle occurs. During winter, from March to October, the sun barely rises. As seawater freezes it rejects salts, creating pockets of extra-salty brine where microbes live in winter. In summer, the sea ice melts under constant daylight, producing warmer, fresher water at the surface.
This remote ecosystem is home to much of the Southern Ocean’s photosynthetic life. A new University of Washington study provides the first measurements of how sea-ice algae and other single-celled life adjust to these seasonal rhythms, offering clues to what might happen as this environment shifts under climate change.
The study, published Sept. 15 in the International Society for Microbial Ecology’s ISME Journal, contains some of the first measurements of how sea-ice microbes respond to changing conditions.
“We know very little about how sea-ice microbes respond to changes in salinity and temperature,” said lead author Hannah Dawson, a UW postdoctoral researcher who did the work while pursuing her doctorate in oceanography at the UW. “And until now we knew almost nothing about the molecules they produce and use in chemical reactions to stay alive, which are important for supporting higher organisms in the ecosystem as well as for climate impacts, like carbon storage and cloud formation.”
The polar oceans play an important role in global ocean currents and in supporting marine ecosystems. Microbes form the base of the food web, supporting larger life forms.
“Polar oceans make up a significant portion of the world’s oceans, and these are very productive waters,” said senior author Jodi Young, a UW assistant professor of oceanography. “These waters support big swarms of krill, the whales that come to feed on those krill, and either polar bears or penguins. And the start of that whole ecosystem are these single-celled microscopic algae. We just know so little about them.”
The tiny organisms are also important for the climate, since they quietly perform photosynthesis and soak up carbon from the atmosphere. Polar algae are especially good at producing sulfur-containing molecules that give beaches their distinctive smell and, when lofted into the air in sea spray, promote formation of clouds that can reduce penetration of solar rays.
Antarctic sea ice, though long stable, is at an all-time record low this year.
In other oceans, satellite instruments can capture dramatic seasonal phytoplankton blooms from space — but that isn’t possible for microbes hidden under sea ice. And Antarctic waters are particularly challenging to visit, leaving researchers with almost no measurements in winter.
In late 2018, Dawson and co-author Susan Rundell traveled to Palmer Station, a U.S. research station on the West Antarctic Peninsula. They used a small boat to sample seawater and sea ice at the same nearby sites every three days.
Back on shore, the two graduate students performed 10-day experiments in tanks to see which microbes grew as temperature and salinity were adjusted to mimic sea-ice formation and melt. They also shipped samples back to Seattle for more complex measurements of the samples’ genetics and metabolites, the small organic molecules produced by the cell.
Results revealed how single-celled algae deal with their fluctuating environments. As temperatures drop, the cells produce cryoprotectants, similar to antifreeze, to prevent their cellular fluid from crystallizing. Many of the most common cryoprotectant molecules were the same across different microbial lifeforms.
As salinity changes, to avoid either bursting in freshening waters or becoming desiccated like raisins in salty conditions, the cells change the concentration of salt-like organic molecules. Many such molecules serve a dual role as cryoprotectants, to balance conditions inside and outside the cell to maintain water balance.
The results show that under short-term temperature and salinity changes, community structure in each sample remained stable while adjusting the production of protective molecules. Different microbe species showed consistent responses to changing conditions. This should simplify modeling future responses to climate change, Young said.
Results also hint that the production of omega-3 fatty acids may decline in lower-salinity environments. This would be bad news for consumers of krill oil supplements, and for the marine ecosystem that relies on those algae-derived nutrients. Future research now underway by the UW group aims to confirm that result — especially with the prospect of increasing freshwater input from melting sea ice and glaciers.
“We’re interested in how these sea-ice algae contend with changes in temperature, salinity and light under normal conditions,” Dawson said. “But then we also have climate change, which is completely remodeling the landscape in terms of when sea ice is forming, how much sea ice forms, how long it stays before it melts, as well as the quantity of freshwater input from glaciers. So we’re both trying to capture what’s happening now, and also asking how that can inform what might happen in the future.”
The study was funded by the National Science Foundation, the Simons Foundation, and the Alfred P. Sloan Foundation. Other co-authors are Anitra Ingalls, Jody Deming, Joshua Sacks and Laura Carlson at the UW; Natalia Erazo, Elizabeth Connors and Jeff Bowman at Scripps Institution of Oceanography; and Veronica Mierzejewski at Arizona State University.
OAKLAND, Calif. (AP) — An unprecedented red tide in the San Francisco Bay Area is killing thousands of fish and other marine life whose carcasses are washing ashore, creating a foul odor that experts say could get worse during this weekend’s expected heat wave.
At Oakland’s Lake Merritt, a popular spot for joggers, walkers and those looking to be in nature, crews on Wednesday began removing dead crabs, bat rays, striped bass and other fish that began piling up on its rocky shores over the weekend.
The fish die-off at Lake Merritt and throughout the Bay Area may be due to a harmful algae bloom that has been spreading in the region since late July, said Eileen White, executive officer of San Francisco Bay Regional Water Quality Control Board.
“We normally have algae blooms during the summertime. But what’s unusual about this one is how large it is and the fact that there are fish kills,” White said.
Most algae blooms end after a week or so. But a triple-digit heat wave forecast for the holiday weekend may help the Bay Area’s grow even more, White said. She said that reports of dead fish started coming in last week.
“This was a natural occurrence of Mother Nature and so, we don’t know when it’s going to end,” she said
A microorganism called Heterosigma akashiwo formed a bloom first spotted in the Alameda Estuary, White said. It is present in the bay all the time, but scientists are trying to determine what caused it to spread so far and wide and for so many weeks.
They say a years-long drought has prevented stagnant water from flowing into the ocean and unseasonably warm and sunny weather may be helping the algae spread.
Jon Rosenfield, a scientist with the San Francisco Baykeeper conservation group, said high levels of nutrients like phosphorus and nitrogen in wastewater also drive the growth of algae blooms.
“The only lever that we have to control the problem is to reduce nutrients put into the bay from the 40 wastewater treatment plants that operate around the bay,” he said.
Rosenfield said sewage treatment plants are cleaning the water of solid material and bacteria, but they’re not designed to pull out nitrogen and phosphorus.
Treating the water for nutrients would cost billions of dollars, and those costs would be passed on to residents, White said. She said water districts are funding studies to understand the effects of nutrients that have been present in the water since people settled in the area.
“The goal is to make the appropriate regulations based on sound science,” White said.
Experts are also trying to determine what exactly is killing the fish.
Algae blooms produce a toxin that is lethal to fish and other marine life, and as they spread, bacteria in the water start to consume the algae. As it decays, it depletes the water of oxygen, leading the fish to suffocate, Rosenfield said.
“Which of those mechanisms is operating here, the toxin or the low dissolved oxygen? We just don’t know yet,” he said.
Algae bloom has been reported in Contra Costa and Marin counties to the north and San Mateo County to the west. In the South Bay, concentrations of chlorophyll — an indicator of algae density —measured on Aug. 10 were the highest observed in more than 40 years, White said.
In Oakland, people turned to social media to post photos of some of the thousands of dead fish at Lake Merritt, where visitors have started complaining about the stench.
“It doesn’t smell very good right now, so it’s a bit of a nuisance,” said Graham Webster, who jogs around the lake once or twice a week.
“But the bigger question is what’s happening to the lake and the bay? And what’s causing it? Is it our fault? Can it be fixed?” he asked.
White said the algae aren’t known to be toxic to people, but they can cause skin and eye irritation. Her office is recommending people and pets stay out of any water that looks reddish-brown.
Cely Aquino said she visits Lake Merritt regularly and seeing all the dead fish was sad.
“I saw a lot of the dead fish, and I saw a couple of stingrays that were dead also. It’s pretty sad,” she said. “But I figure nature it’s going to take care of it all.”
