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Study: Solitary electric eels sometimes hunt in groups with synchronized zaps

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Volta’s electric eels can gather in groups, working together to corral smaller fish in shallower waters, a new study finds. Then, smaller groups of about 10 eels attack in unison with high-voltage discharges.

Electric eels were long believed to be solitary predators, preferring to hunt and kill their prey alone by sneaking up on unsuspecting sleeping fish at night and shocking them into submission. But according to a recent paper published in the journal Ecology and Evolution, there are rare circumstances in which eels employ a social hunting strategy instead. Specifically, researchers have observed more than 100 electric eels in a small lake in the Brazilian Amazon River basin forming cooperative hunting parties to capture small fish called tetras.

“This is an extraordinary discovery,” co-author C. David de Santana, of the Smithsonian National Museum of Natural History, said. “Nothing like this has ever been documented in electric eels. Hunting in groups is pretty common among mammals, but it’s actually quite rare in fishes. There are only nine other species of fishes known to do this, which makes this finding really special.”

Electric eels are technically knife fish. The eel produces its signature electric discharges—both low and high voltages, depending on the purpose for discharging—via three pairs of abdominal organs comprised of electrocytes, located symmetrically along both sides of the eel. The brain sends a signal to the electrocytes, opening ion channels and briefly reversing the polarity. The difference in electric potential then generates a current, much like a battery with stacked plates.

Enlarge / Multiple Volta’s electric eels attack as a group, shocking fish out of the water and into a stupor so that they can easily be eaten.

Douglas Bastos

This isn’t the first time researchers have made surprising discoveries about electric eels. For instance, the 19th-century physicist Michael Faraday conducted several experiments with electric eels in 1838. He noted that he only felt mild shocks because the water dissipated the discharges so quickly. Vanderbilt University biologist and neuroscientist Kenneth Catania is one of the most prominent scientists studying electric eels these days. He has found that the creatures can vary the degree of voltage in their electrical discharges, using lower voltages for hunting purposes, and higher voltages to stun and kill prey. Those higher voltages are also useful for tracking potential prey, akin to how bats use echolocation.

And in 2016, Catania reported evidence in support of Alexander von Humboldt’s 1800 account of how Venezuelan natives at the time used wild horses to lure and trap electric eels (“horse fishing”). The stamping and snorting of horses in the shallow waters favored by electric eels caused the latter to leap up and stun the horses with a series of high-voltage electric discharges as a defense mechanism. Once the eels were exhausted, the natives could catch them easily using small harpoons on ropes.

For centuries, naturalists dismissed Humboldt’s account, because nobody since had noted such behavior—until Catania spotted eels in his lab reacting much like Humboldt’s description to the sight of the net used to transfer the eels from their cages to the chamber Catania used for experiments. He conducted experiments with LEDs mounted on a fake alligator head (outfitted with conductive tape to visualize the discharges). The eels aggressively attacked the fake alligator head just as described by Humboldt. Catania believes the response kicks in under certain conditions, such as when eels are stranded in small bodies of water with the sudden arrival of the dry season.

Until 2019, scientists thought that the electric eel was the only species in its particular genus. That was the year de Santana published a paper effectively tripling the number of known species of electric eels. Among those was the subject of the current paper: Volta’s electric eel (Electrophorus voltai).

“An individual of this species can produce a discharge of up to 860 volts, so in theory if 10 of them discharged at the same time, they could be producing up to 8,600 volts of electricity,” said de Santana. “That’s around the same voltage needed to power 100 light bulbs.” He has been shocked several times in the field and notes that, while it only lasts a fraction of a second, a shock can still cause painful muscle spasms.

Schematic illustration of the stages involved in the social predation observed in electric eels.
Enlarge / Schematic illustration of the stages involved in the social predation observed in electric eels.

D.A. Bastos et al., 2021

De Santana and his co-authors first noticed the unusual group hunting behavior on a 2012 field expedition to explore the diversity of fish of the Iriri River, when team member (and co-author) Douglas Bastos found a small lake packed with over 100 electric eels. A second expedition in 2014 found a similarly sized group in the same location, and the team would ultimately log some 72 hours of continuous observation, recording the eels’ behavior.

Most of the time, the eels just hung out in the deeper end of the lake, occasionally surfacing to breathe. But the eels became active at dusk and dawn. De Santana’s team noted how the eels would work together to herd schools of tetras into a densely packed areas in the shallow waters, by swimming in a large circle to create the equivalent of a corral. Then the eels spit into smaller hunting parties of about 10 eels, surrounding the ball of tetras and stunning the small fish with synchronized high-voltage discharges. That made it very easy to snap up the stunned tetras.

“This is the only location where this behavior has been observed, but right now we think the eels probably show up every year,” said de Santana. “Our initial hypothesis is that this is a relatively rare event that occurs only in places with lots of prey and enough shelter for large numbers of adult eels.” If the behavior were commonplace, he reasoned, it would have come up in their interviews with the locals.

De Santana and his team will continue their investigation of this unusual behavior; they are hoping to make direct measurements of the synchronized discharges on their next expedition. And they have a launched a citizen scientist program called Project Poraque to track down additional packs of electric eels in the region. The team will also collect eight to 10 adult eels and bring them to a lab in Germany, the better to study them under more controlled settings.

DOI: Ecology and Evolution, 2021. 10.1002/ece3.7121 (About DOIs).

Listing image by L. Sousa

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Biden says US will halve carbon emissions by 2030

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Getty Images | Bloomberg

President Joe Biden announced Thursday that the US would cut carbon emissions by 50 to 52 percent by 2030 compared with 2005 levels. It’s an aggressive target that aims to put the country on a path to limit warming to below 1.5˚C.

The pledge comes as Biden hosts dozens of world leaders for a virtual climate summit today. It nearly doubles the targets set by former President Barack Obama when the Paris Agreement was initially signed.

“This is a moral imperative, an economic imperative. A moment of peril but also a moment of extraordinary possibilities,” Biden said.

The US reduced its carbon emissions to 13 percent below 2005 levels in 2019, the most recent “normal” year for energy use. While the number represents a notable decline given that the economy grew in that time, it’s still short of where the country should be if it is to achieve either Obama’s or Biden’s goals.

The US isn’t the only country that has come up short in terms of actual reductions. The world as a whole is far from meeting the goals set forth in the Paris Agreement. We’re currently on track for 3˚C of warming by 2100, an amount that would result in catastrophic consequences for people around the globe.

Emissions targets pledged as part of the Paris Agreement aren’t binding, but they do offer roadmaps for countries to decarbonize. The agreement also encourages countries to make their pledges more ambitious over time, with the hopes that emissions will decline more rapidly as technological advancements and diplomatic pressure make significant reductions more appealing.

Other leaders used the forum to announce new commitments as well. Prime Minister Yoshihide Suga of Japan said his country would aim for a reduction of 46 percent below 2013 levels, almost double its previous commitment. Canada’s Prime Minister, Justin Trudeau, increased his country’s pledge to 40 to 45 percent below 2005 levels by 2030, a bump above the previous 30 percent commitment. The European Union and the UK didn’t update their pledges, but both have already committed to major cuts over the next nine years, with the EU targeting 55 percent and the UK shooting for 68 percent.

China’s Xi Jinping also reiterated his country’s previous commitment to halt the growth of emissions by 2030 and reach net zero by 2060. China’s carbon pollution has grown precipitously over the last 20 years, to the point where the country now produces more than twice as much as the next largest polluter, the US. India, another country with swiftly rising emissions, did not put forth any targets, nor did it add to its previous commitments. Instead, Prime Minister Narendra Modi restated his country’s promise to install 450 GW of renewable energy capacity by 2030.

Globally, carbon emissions dropped 6.4 percent last year as the world hunkered down to weather the pandemic. The US contributed the most to that decline with a 13 percent drop, and most of that happened in the transportation sector, which produces the largest share of the nation’s carbon pollution. Globally, the decline in air travel allowed the aviation sector to halve its emissions.

The Biden administration again signaled that it’s considering a “border carbon adjustment”—basically a carbon tariff. Such a tariff would apply to imports from countries where carbon regulations aren’t as stringent.

For many countries, the energy transition has become less of a burden and more of an opportunity to leapfrog laggards by developing early leads in a host of promising and increasingly affordable clean technologies, including solar, wind, and batteries. Biden appears to agree with that idea and is hoping to position the US among countries taking the lead. “The countries that take decisive action now to create the industries of the future will be the ones who reap the economic benefits of the clean energy boom that’s coming,” he said.

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Contractor that ruined 15M doses of J&J vaccine hiked price of another by 800%

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Enlarge / The Emergent BioSolutions plant, a manufacturing partner for Johnson & Johnson’s COVID-19 vaccine, in Baltimore, Maryland, on April 9, 2021.

Things are not looking good for Emergent BioSolutions, the contract manufacturer that ruined 15 million doses of Johnson & Johnson’s one-shot COVID-19 vaccine and millions more doses of AstraZeneca’s COVID-19 vaccine at its production facility in Baltimore.

The Food and Drug Administration on Wednesday released a searing inspection report of the facility, finding a slew of significant violations and failings.

Meanwhile, federal lawmakers have opened a multi-pronged investigation into whether Emergent used ties to the Trump administration to get billions of dollars in federal contracts despite a history of failing to complete contracts, inadequately training staff, persistent quality-control issues, and an “unjustified” 800% price increase for an anthrax vaccine.

In a letter sent to Emergent’s top executives Tuesday, Rep. Carolyn Maloney, chairwoman of the House Committee on Oversight and Reform, and Rep. James Clyburn, chairman of the Select Subcommittee on the Coronavirus Crisis, laid out the investigation, writing:

Emergent received $628 million in June 2020 to establish the primary US facility for manufacturing vaccines developed by Johnson & Johnson and AstraZeneca. Dr. Robert Kadlec, who served as Assistant Secretary for Preparedness and Response under President Trump and previously worked as a consultant for Emergent, appears to have pushed for this award despite indications that Emergent did not have the ability to reliably fulfill the contract.

800% drain

But the investigation stretches back much farther than the start of the pandemic—through years of questionable federal contracts.

In 1998, Emergent (then called BioPort) bought the license to an anthrax vaccine. The vaccine, BioThrax, was approved by the FDA in 1970 but remains the only FDA-approved vaccine for anthrax. As such, Emergent is the sole supplier of anthrax vaccine for the federal government’s Strategic National Stockpile (SNS). When Emergent bought the vaccine in 1998, a dose went for about $3.35. By 2010, the price was up to $28 a dose. Now, the price is over $30, and average wholesale prices are even higher, reaching $90 per dose, the lawmakers note.

“Emergent has raised the government purchasing price of the anthrax vaccine by 800% since acquiring the drug in 1998,” the lawmakers write in their letter. “As a result, through most of the last decade, nearly half of the SNS’s budget has been spent purchasing Emergent’s anthrax vaccine. These spiraling costs contributed to shortages of critical supplies, including ventilators, reusable respirator masks, and other personal protective equipment, which severely impacted the government’s ability to respond to the coronavirus crisis.”

This drain on the SNS budget was particularly apparent during the pandemic—which Robert Kadlec, the former Emergent consultant, himself acknowledged.

Kadlec was nominated in 2017 by President Trump to lead the Office of the Assistant Secretary for Preparedness and Response (ASPR). Following his confirmation, Emergent received millions of dollars in federal contracts from ASPR, including contracts for the SNS that were awarded without competitive bidding, the lawmakers note in their letter.

In 2020—just before the pandemic hit the US—Kadlec’s office awarded Emergent around $3 billion in long-term contracts for anthrax and other bioterrorism threats. According to the lawmakers, Kadlec later suggested this was a bad move, saying: “If I could spend less on anthrax replenishment, I could buy more N95s. I could buy more ventilators. I could buy more of other things that quite frankly I didn’t have the money to buy.”

Failures and an inspection

Aside from the skyrocketing prices, the lawmakers suggest Emergent didn’t even deserve the contracts in the first place. In 2012, the Department of Health and Human Services awarded Emergent a $163 million contract to renovate its (currently troubled) Baltimore manufacturing plant. The idea was for the plant to become a manufacturing hub for rapidly producing vaccine in the event of an infectious disease outbreak or bioterror attack. Part of the contract stipulated that Emergent would be required to do a test run, producing 50 million doses of a pandemic influenza vaccine in the span of four months, and obtain manufacturing approval from the FDA by June 2020.

Emergent failed to meet those requirements.

Reading the FDA’s inspection report of Emergent’s Baltimore facility, it’s clear why. During the nine-day inspection, which ended April 20, FDA inspectors logged a long list of problems at the facility.

First on the list is that Emergent failed to thoroughly investigate how the millions of Johnson & Johnson and AstraZeneca doses became contaminated. The agency concluded that, without a thorough review of what happened, it’s possible that other finished batches of vaccine may also be ruined. “There is no assurance that other batches have not been subject to cross contamination,” the inspectors wrote.

The FDA inspectors went on to note unsanitary conditions, paint peeling off of the walls and floors, residue on equipment, improperly trained staff, and numerous opportunities for vaccine products to be contaminated.

The potential for cross contamination—spread of viral ingredients back and forth between Johnson & Johnson’s vaccine and AstraZeneca’s vaccine—appeared rampant at the facility. Inspectors witnessed Emergent employees dragging unsealed, non-decontaminated bags of medical waste across different manufacturing areas. In some cases, employees tossed bags of medical waste, unsealed, into a service elevator. Emergent did not have proper written procedures for how to decontaminate waste, the inspection report notes. Security footage also caught employees moving from different areas of the facility without following proper procedures for donning and removing protective gowns.

At the request of the FDA, vaccine production at the Baltimore facility has been halted since April 16.

In a statement Wednesday, Emergent said that the FDA’s findings “provide direction on the necessary steps to improve operations.” The company went on:

The FDA’s feedback will help us continue to improve and strengthen the supply chain for Johnson & Johnson’s COVID-19 vaccine. While we are never satisfied to see shortcomings in our manufacturing facilities or process, they are correctable and we will take swift action to remedy them.

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Trump EPA sidelined its own scientists when rewriting fuel economy rules

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Enlarge / Former EPA Administrator Scott Pruitt.

The Trump administration effectively muffled scientific staffers at the Environmental Protection Agency when it rewrote automobile pollution rules, the agency’s watchdog said.

When drafting fuel economy and greenhouse gas pollution rules for cars and light trucks, former EPA Administrator Scott Pruitt decided to cede various EPA duties to the National Highway Transportation Safety Administration in what is typically a collaborative process, the independent inspector general said in a report released yesterday. Though Pruitt signed the final report for the EPA, he allowed NHTSA staff to write a significant portion of the rules and to complete all modeling and analysis for both agencies.

The NHTSA’s modeling efforts did not use the EPA’s established tools that had been created to evaluate greenhouse gas emissions standards. Instead, the NHTSA hacked its own Corporate Average Fuel Economy models and sent EPA experts the results late in the process. “Technical personnel were unable to fully collaborate on rule development,” the report said.

The EPA and the NHTSA have collaborated on fuel economy and emissions standards since 2010 in an effort to streamline and harmonize regulations for automakers. In rules written during the Obama administration, the EPA and NHTSA called for 5 percent annual increases in fuel economy. After Trump was elected, though, automakers wrote to his transition team to request that the annual increases be frozen. The Trump administration obliged, reviewing the rule and issuing a new one calling for 1.5 percent increases in fuel economy. The reason for the reduction, the Trump administration said, was that it would help keep auto prices lower, allowing consumers to buy newer, safer vehicles. Not everyone was convinced by that logic.

That the final rule included such a rationale is not surprising in light of the inspector general’s report. When making fuel economy rules, the Energy Policy and Conservation Act directs the NHTSA to consider four different variables—“technological feasibility, economic practicability, the effect of other government standards on fuel economy, and the need of the nation to conserve energy,” the report points out. None of those includes pollution or its effects.

The EPA, on the other hand, is the only agency that the Clean Air Act allows to regulate greenhouse gas emissions from new vehicles.

Career EPA staff, who are not political appointees, reportedly felt shut out of the process, a drastic departure from the previous four times they worked with the NHTSA to jointly issue pollution and fuel economy rules.

The inspector general’s report also noted that the EPA skipped major milestones in its rule-making process. According to the report, the agency “did not document who decided to skip these milestones and why.”

New EPA Administrator Michael Regan said he would be reviewing the Trump-era fuel economy standards and will release a revised rule by the end of July. The new rules could effectively phase out fossil fuel vehicles.

Stifling science

This latest report isn’t the only one to find fault with the way the Trump administration went about writing or rewriting environmental regulations. EPA political appointees also ordered career staff to scale back efforts to monitor ethylene oxide pollution in the Chicago area. The flammable gas is used to sterilize medical equipment, but it’s also a proven carcinogen.

Chicago EPA staff, barred from an official effort to document ethylene oxide pollution, installed air pollution-monitoring equipment outside an agency warehouse that abutted a large sterilization plant owned by Sterigenics, a major emitter of ethylene oxide. The scientists discovered that pollution from the plant was at such high levels that it significantly increased the cancer risk in the surrounding neighborhood by orders of magnitude, according to a report by the Chicago Tribune. The company couldn’t get the plant’s pollution under control and ultimately closed the site after significant opposition from the community.

The EPA is also undertaking a broader review of decisions in which the agency’s scientific integrity may have been compromised. Regan asked employees to bring “items of concern” to scientific integrity officials or the inspector general, who would investigate accordingly.

Trump administration officials at the Centers for Disease Control and Prevention are also under fire for their meddling in scientific affairs. Earlier this month, documents released to the public showed political appointees pushing for changes in how the CDC framed reports about COVID-19 and the agency’s Morbidity and Mortality Weekly Reports. The alterations helped frame the CDC’s reporting on the pandemic in terms that hewed more closely to then-President Trump’s rosy outlook.

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