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      The U.S.’s first open-air genetically modified mosquitoes have taken flight

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      The first genetically modified mosquitoes that will be allowed to fly free outdoors in the United States have started reaching the age for mating in the Florida Keys.

      In a test of the biotech company Oxitec’s GM male mosquitoes for pest control, these Aedes aegypti started growing from tiny eggs set out in toaster-sized, hexagonal boxes on suburban private properties in late April. On May 12, experiment monitors confirmed that males had matured enough to start flying off on their own to court American female mosquitoes.

      This short-term Florida experiment marks the first outdoor test in the United States of a strain of GM male mosquitoes as a highly targeted pest control strategy. This strain is engineered to shrink local populations of Ae. aegypti, a mosquito species that spreads dengue and Zika (SN: 7/29/16). That could start happening now that the GM mosquitoes have reached mating age because their genetics makes them such terrible choices as dads.

      The mosquitoes now waving distinctively masculine (extra fluffy) antennae in Florida carry genetic add-ons that block development in females. No female larvae should survive to adulthood in the wild, says molecular biologist Nathan Rose, Oxitec’s chief of regulatory affairs. Half the released males’ sons, however, will carry dad’s daughter-killing trait. The sons of the bad dads can go on to trick a new generation of females into unwise mating decisions and doomed daughters (SN: 1/8/09).

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      The trait is not designed to last in an area’s mosquitoes, though. The genetics just follow the same old rules of natural inheritance that mosquitoes and people follow: Traits pass to some offspring and not others. Only half a bad dad’s sons will carry the daughter-killing trait. The others will sire normal mosquito families.

      Imagined versions of live-mosquito pest control in Florida have been both glorified and savaged in spirited community meetings for some time (SN: 8/22/20). But now it’s real. “I’m sure you can understand why we’re so excited,” said Andrea Leal, executive director of the Florida Keys Mosquito Control District, at the mosquito test (virtual) kickoff April 29.

      The debate over these transgenic Ae. aegypti mosquitoes has gone on so long that Oxitec has upgraded its original more coddled version with one that is essentially plug and play. The newer strain, dubbed OX5034, no longer needs a breeding colony with its (biting) females and antibiotics in easy reach of the release area to produce fresh males.

      Instead, Oxitec can just ship eggs in a phase of suspended development from its home base in Abingdon, England, to whatever location around the world, high-tech or not, wants to deploy them. Brazil has already tested this OX5034 strain and gone through the regulatory process to permit Oxitec to sell it there.

      The targets for these potential living pest controls will be just their own kind. They represent only about 4 percent of the combined populations of the 45 or so mosquito species whining around the Keys. Other species get annoying, and a more recent invader, Ae. albopictus, can also spread dengue and Zika to some extent. Yet Leal blames just about all the current human disease spread by mosquitoes in the Keys, including last year’s dengue outbreak, on Ae. aegypti.

      It’s one of the top three mosquitoes in the world in the number of diseases it can spread, says Don Yee, an aquatic ecologist at the University of Southern Mississippi in Hattiesburg, who studies mosquitoes (SN: 3/31/21). His lab has linked at least three dozen human pathogens, including some viruses and worms, to Ae. aegypti. Although most mosquitoes lurk outdoors in vegetation, this one loves humankind. In the tropics, “the adults are literally resting on the walls or the ceiling,” he says. “They’re hanging around the bathroom.” The species bites humans for more than half of its blood meals.

      In a long-running battle with this beast, staff in Florida in late April added water to boxes of shipped eggs and set them out at selected suburban private properties on Vaca, Cudjoe and Ramrod Keys. Other spots, with no added mosquitoes, will be watched as controls. All locations were chosen in part because American-hatched females of the same species were already there to be wooed, Rose says.

      Toaster-sized hexagonal boxes (one pictured) that contain eggs of genetically modified Aedes aegypti were set out on selected private property in the Keys in late April. There the males develop normally — and then fly away to mate.Oxitec

      Males typically don’t billow out of their boxes in a gray cloud but emerge sporadically, a few at a time. If all goes well in this preliminary test, up to 12,000 GM mosquitoes in total across the release sites will take to the air each week for 12 weeks.

      Neighboring households will host mosquito traps to monitor how far from the nursery boxes the Oxitec GM males tend to fly. That’s data that the U.S. Environmental Protection Agency wants to see. Based on distance tests elsewhere, 50 meters might be the median, Rose estimates. 

      The distance matters because pest controllers want to keep the free-flying GM mosquitoes away from outdoor sources of the antibiotic tetracycline. That’s the substance the genetic engineers use as an off switch for the self-destruct mechanism in female larvae. Rearing facilities supply the antibiotic to larvae, turning off the lethal genetics and letting females survive in a lab to lay eggs for the next generation.

      If GM males loosed in Florida happened to breed with a female that lays eggs in some puddle of water laced with the right concentration of tetracycline, daughters that inherited the switch could survive to adulthood as biters and breeders. The main possible sources in the Keys would be sewage treatment plants, Rose says. The test designers say they have selected sites well away from them.

      After the distance tests, bigger releases still start looking at how well males fare and whether pest numbers shrink. Up to 20 million Oxitec mosquitoes in total could be released in tests running into the fall.

      Despite some high-profile protests, finding people to host the boxes was not hard, Rose says. “We were oversubscribed.” At public hearings, the critics of the project typically outshout the fans. Yet there’s also support. In a 2016 nonbinding referendum on using GM mosquitoes, 31 of 33 precincts in Monroe County, which comprises the Keys, voted yes for the test release. Twenty of those victories were competitive though, not reaching 60 percent.

      The males being released rely on a live-sons/dead-daughters strategy. That’s a change from the earlier strain of Oxitec mosquitoes. Those males sabotaged all offspring regardless of sex. The change came during the genetic redesign that permits an egg-shipping strategy. Surviving sons, however, mean the nonengineered genes in the new Oxitec strain can mix into the Florida population more than in the original version.

      Those mixed-in genes from the test are “unlikely” to strengthen Floridian mosquitoes’ powers to spread disease, researchers from the EPA and the U.S. Centers for Disease Control and Prevention wrote in a May 1, 2020 memorandum. Many factors besides mosquito genetics affect how a disease spreads, the reviewers noted. Oxitec will be monitoring for mixing.

      There may be at least one upside to mixing, Rose says. The lab colonies have little resistance to some common pesticides such as permethrin that the Floridian mosquitoes barely seem to notice.

      Pesticide resistance in the Keys is what drives a lot of the interest in GM techniques, says chemist Phil Goodman, who chairs the local mosquito control district’s board of commissioners. During the dengue outbreak in 2009 and 2010, the first one in decades, the district discovered that its spray program had just about zero effect on Ae. aegypti. With some rethinking of the program’s chemicals, the control district can now wipe out up to 50 percent of mosquitoes of this species in a treated area. That’s not great control, at best. Then when bad weather intervenes for days in a row, the mosquitoes rebound, Goodman says.

      The invasive mosquito species Aedes aegypti (shown), which can spread Zika, dengue and yellow fever, is now under attack in the Florida Keys by GM males genetically tweaked to sabotage the American mosquito populations.Joao Paulo Burini/Moment/Getty Images Plus

      Since that 2009–2010 outbreak, catching dengue in Florida instead of just through foreign travel has become more common. In 2020, an unusually bad year for dengue, Florida reported 70 cases caught locally, according to the CDC’s provisional tally. 

      Traditional pesticides can mess with creatures besides their pest targets, and some critics of the GMO mosquitoes also worry about unexpected ecological effects. Yet success of the Oxitec mosquitoes in slamming the current pests should not cause some disastrous shortage of food or pollination for natives, Yee says. Ae. aegypti invaded North America within the past four centuries, probably too short a time to become absolutely necessary for some native North American predator or plant.

      For more details on pretrial tests and data, the Mosquito Control District has now posted a swarm of documents about the GM mosquitoes. The EPA’s summary of Oxitec’s tests, for instance, reports no effects noticed for feeding the aquatic mosquito larvae to crawfish.

      Yee doesn’t worry much about either crustaceans or fish eating the larvae. “That’s somewhat analogous to saying, well, we’re concerned about releasing buffalo back into the prairies of the Midwest because they might get eaten by lions,” he says. Crawfish and fish, he notes, don’t naturally inhabit the small containers of still water where Ae. aegypti mosquitoes breed.

      Still, new mosquito-fighting options are springing up: Radiation techniques might become precise enough to sterilize males but leave them attractive enough to fool females into pointless mating. And researchers are developing other genetic ways to weaponize mosquitoes against their own kind.

      One technique that uses no GM wizardry just infects mosquitoes with Wolbachia bacteria that make biting unlikely to spread dengue. The latest data from Mexico and Columbia suggest this infection “could be effective in the southern U.S. and across the Caribbean,” says biologist Scott O’Neil, based in Ho Chi Minh City, Vietnam, founder of the World Mosquito Program.

      He has no plans for working in the United States but is instead focusing on places with much worse dengue problems. His version of the Wolbachia strategy just makes bites less dangerous (SN: 6/29/12). The mosquito population doesn’t shrink or grow less bloodthirsty, so this approach might not appeal to Floridians anyway. More

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      Rivers might not be as resilient to drought as once thought

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      Rivers ravaged by a lengthy drought may not be able to recover, even after the rains return. Seven years after the Millennium drought baked southeastern Australia, a large fraction of the region’s rivers still show no signs of returning to their predrought water flow, researchers report in the May 14 Science.

      There’s “an implicit assumption that no matter how big a disturbance is, the water will always come back — it’s just a matter of how long it takes,” says Tim Peterson, a hydrologist at Monash University in Melbourne, Australia. “I’ve never been satisfied with that.”

      The years-long drought in southeastern Australia, which began sometime between 1997 and 2001 and lasted until 2010, offered a natural experiment to test this assumption, he says. “It wasn’t the most severe drought” the region has ever experienced, but it was the longest period of low rainfall in the region since about 1900.

      Peterson and colleagues analyzed annual and seasonal streamflow rates in 161 river basins in the region from before, during and after the drought. By 2017, they found, 37 percent of those river basins still weren’t seeing the amount of water flow that they had predrought. Furthermore, of those low-flow rivers, the vast majority — 80 percent — also show no signs that they might recover in the future, the team found.

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      Many of southeastern Australia’s rivers had bounced back from previous droughts, including a severe but brief episode in 1983. But even heavy rains in 2010, marking the end of the Millennium drought, weren’t enough to return these basins to their earlier state. That suggests that there is, after all, a limit to rivers’ resilience.

      What’s changed in these river basins isn’t yet clear, Peterson says. The precipitation post drought was similar to predrought precipitation, and the water isn’t ending up in the streamflow, so it must be going somewhere else. The team examined various possibilities: The water infiltrated into the ground and was stored as groundwater, or it never made it to the ground at all — possibly intercepted by leaves, and then evaporating back to the air.

      But none of these explanations were borne out by studies of these sites, the researchers report. The remaining, and most probable, possibility is that the environment has changed: Water is evaporating from soils and transpiring from plants more quickly than it did predrought.

      Peterson has long suggested that under certain conditions rivers might not, in fact, recover — and this study confirms that theoretical work, says Peter Troch, a hydrologist at the University of Arizona in Tucson. Enhanced soil evaporation and plant transpiration are examples of such positive feedbacks, processes that can enhance the impacts of a drought. “Until his work, this lack of resilience was not anticipated, and all hydrological models did not account for such possibility,” Troch says.

      “This study will definitely inspire other researchers to undertake such work,” he notes. “Hopefully we can gain more insight into the functioning of [river basins’] response to climate change.”

      Indeed, the finding that rivers have “finite resilience” to drought is of particular concern as the planet warms and lengthier droughts become more likely, writes hydrologist Flavia Tauro in a commentary in the same issue of Science. More

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      A common antibiotic slows a mysterious coral disease

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      Slathering corals in a common antibiotic seems to temporarily soothe a mysterious tissue-eating disease, new research suggests.

      Just off Florida, a type of coral infected with stony coral tissue loss disease, or SCTLD, showed widespread improvement several months after being treated with amoxicillin, researchers report April 21 in Scientific Reports. While the deadly disease eventually reappeared, the results provide a spot of good news while scientists continue the search for what causes it.

      “The antibiotic treatments give the corals a break,” says Erin Shilling, a coral researcher at Florida Atlantic University’s Harbor Branch Oceanographic Institute in Fort Pierce. “It’s very good at halting the lesions it’s applied to.”

      Divers discovered SCTLD on reefs near Miami in 2014. Characterized by white lesions that rapidly eat away at coral tissue, the disease plagues nearly all of the Great Florida Reef, which spans 580 kilometers from St. Lucie Inlet in Marin County to Dry Tortugas National Park beyond the Florida Keys. In recent years, SCTLD has spread to reefs in the Caribbean (SN: 7/9/19).

      As scientists search for the cause, they are left to treat the lesions through trial and error. Two treatments that show promise involve divers applying a chlorinated epoxy or an amoxicillin paste to infected patches. “We wanted to experimentally assess these techniques to see if they’re as effective as people have been reporting anecdotally,” Shilling says.In April 2019, Shilling and colleagues identified 95 lesions on 32 colonies of great star coral (Montastraea cavernosa) off Florida’s east coast. The scientists dug trenches into the corals around the lesions to separate diseased tissue from healthy tissue, then filled the moats and covered the diseased patches with the antibiotic paste or chlorinated epoxy and monitored the corals over 11 months.

      Treatment with an amoxicillin paste (white bands, left) stopped a tissue-eating lesion from spreading over a great star coral colony up to 11 months later (right).E.N. Shilling, I.R. Combs and J.D. Voss/Scientific Reports 2021

      Within about three months of the treatment, some 95 percent of infected coral tissues treated with amoxicillin had healed. Meanwhile, only about 20 percent of infected tissue treated with chlorinated epoxy had healed in that time — no better than untreated lesions. 

      But a one-and-done treatment doesn’t stop new lesions from popping up over time, the team found. And some key questions remain unanswered, the scientists note, including how the treatment works on larger scales and what, if any, longer-term side effects the antibiotic could have on the corals and their surrounding environment.“Erin’s work is fabulous,” says Karen Neely, a marine biologist at Nova Southeastern University in Fort Lauderdale, Fla. Neely and her colleagues see similar results in their two-year experiment at the Florida National Marine Sanctuary. The researchers used the same amoxicillin paste and chlorinated epoxy treatments on more than 2,300 lesions on upwards of 1,600 coral colonies representing eight species, including great star coral.Those antibiotic treatments were more than 95 percent effective across all species, Neely says. And spot-treating new lesions that popped up after the initial treatment appeared to stop corals from becoming reinfected over time. That study is currently undergoing peer-review in Frontiers in Marine Science.

      “Overall, putting these corals in this treatment program saves them,” Neely says. “We don’t get happy endings very often, so that’s a nice one.” More

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      Mangrove forests on the Yucatan Peninsula store record amounts of carbon

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      Coastal mangrove forests are carbon storage powerhouses, tucking away vast amounts of organic matter among their submerged, tangled root webs.

      But even for mangroves, there is a “remarkable” amount of carbon stored in small pockets of forest growing around sinkholes on Mexico’s Yucatan Peninsula, researchers report May 5 in Biology Letters. These forests can stock away more than five times as much carbon per hectare as most other terrestrial forests.

      There are dozens of mangrove-lined sinkholes, or cenotes, on the peninsula. Such carbon storage hot spots could help nations or companies achieve carbon neutrality — in which the volume of greenhouse gas emissions released into the atmosphere is balanced by the amount of carbon sequestered away (SN: 1/31/20).

      At three cenotes, researchers led by Fernanda Adame, a wetland scientist at Griffith University in Brisbane, Australia, collected samples of soil at depths down to 6 meters, and used carbon-14 dating to estimate how fast the soil had accumulated at each site. The three cenotes each had “massive” amounts of soil organic carbon, the researchers report, averaging about 1,500 metric tons per hectare. One site, Casa Cenote, stored as much as 2,792 metric tons per hectare.

      Mangrove roots make ideal traps for organic material. The submerged soils also help preserve carbon. As sea levels have slowly risen over the last 8,000 years, mangroves have kept pace, climbing atop sediment ported in from rivers or migrating inland. In the cave-riddled limestone terrain of the Yucatan Peninsula, there are no rivers to supply sediment. Instead, “the mangroves produce more roots to avoid drowning,” which also helps the trees climb upward more quickly, offering more space for organic matter to accumulate, Adame says.

      As global temperatures increase, sea levels may eventually rise too quickly for mangroves to keep up (SN: 6/4/20). Other, more immediate threats to the peninsula’s carbon-rich cenotes include groundwater pollution, expanding infrastructure, urbanization and tourism. More

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      These climate-friendly microbes recycle carbon without producing methane

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      Earth’s hot springs and hydrothermal vents are home to a previously unidentified group of archaea. And, unlike similar tiny, single-celled organisms that live deep in sediments and munch on decaying plant matter, these archaea don’t produce the climate-warming gas methane, researchers report April 23 in Nature Communications.

      “Microorganisms are the most diverse and abundant form of life on Earth, and we just know 1 percent of them,” says Valerie De Anda, an environmental microbiologist at the University of Texas at Austin. “Our information is biased toward the organisms that affect humans. But there are a lot of organisms that drive the main chemical cycles on Earth that we just don’t know.”

      Archaea are a particularly mysterious group (SN: 2/14/20). It wasn’t until the late 1970s that they were recognized as a third domain of life, distinct from bacteria and eukaryotes (which include everything else, from fungi to animals to plants).

      For many years, archaea were thought to exist only in the most extreme environments on Earth, such as hot springs. But archaea are actually everywhere, and these microbes can play a big role in how carbon and nitrogen cycle between Earth’s land, oceans and atmosphere. One group of archaea, Thaumarchaeota, are the most abundant microbes in the ocean, De Anda says (SN: 11/28/17). And methane-producing archaea in cows’ stomachs cause the animals to burp large amounts of the gas into the atmosphere (SN: 11/18/15).

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      Now, De Anda and her colleagues have identified an entirely new phylum — a large branch of related organisms on the tree of life — of archaea. The first evidence of these new organisms were within sediments from seven hot springs in China as well as from the deep-sea hydrothermal vents in the Guaymas Basin in the Gulf of California. Within these sediments, the team found bits of DNA that it meticulously assembled into the genetic blueprints, or genomes, of 15 different archaea.

      The researchers then compared the genetic information of the genomes with that of thousands of previously identified genomes of microbes described in publicly available databases. But “these sequences were completely different from anything that we know,” De Anda says.

      She and her colleagues gave the new group the name Brockarchaeota, for Thomas Brock, a microbiologist who was the first to grow archaea in the laboratory and who died in April. Brock’s discovery paved the way for polymerase chain reaction, or PCR, a Nobel Prize–winning technique used to copy small bits of DNA, and currently used in tests for COVID-19 (SN: 3/6/20).

      Brockarchaeota, it turns out, actually live all over the world — but until now, they were overlooked, undescribed and unnamed. Once De Anda and her team had pieced together the new genomes and then hunted for them in public databases, they discovered that bits of these previously unknown organisms had been found in hot springs, geothermal and hydrothermal vent sediments from South Africa to Indonesia to Rwanda.

      Within the new genomes, the team also hunted for genes related to the microbes’ metabolism — what nutrients they consume and what kind of waste they produce. Initially, the team expected that — like other archaea previously found in such environments — these archaea would be methane producers. They do munch on the same materials that methane-producing archaea do: one-carbon compounds like methanol or methylsulfide. “But we couldn’t identify the genes that produce methane,” De Anda says. “They are not present in Brockarchaeota.”

      That means that these archaea must have a previously undescribed metabolism, through which they can recycle carbon — for example in sediments on the seafloor — without producing methane. And, given how widespread they are, De Anda says, these organisms could be playing a previously hidden but significant role in Earth’s carbon cycle.

      “It’s twofold interesting — it’s a new phylum and a new metabolism,” says Luke McKay, a microbial ecologist of extreme environments at Montana State University in Bozeman. The fact that this entire group could have remained under the radar for so long, he adds, “is an indication of where we are in the state of microbiology.”

      But, McKay adds, the discovery is also a testimonial to the power of metagenomics, the technique by which researchers can painstakingly tease apart individual genomes out of a large hodgepodge of microbes in a given sample of water or sediments. Thanks to this technique, researchers are identifying more and more parts of the previously mysterious microbial world.

      “There’s so much out there,” De Anda says. And “every time you sequence more DNA, you start to realize that there’s more out there that you weren’t able to see the first time.” More

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      Climate change may have changed the direction of the North Pole’s drift

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      A sudden zag in which way the North Pole was drifting in the 1990s probably stemmed in large part from glacial melt caused by climate change, a new study suggests.

      The locations of Earth’s geographic poles, where the planet’s axis pierces the surface, aren’t fixed. Instead, they wander in seasonal and near-annual cycles, largely driven by weather patterns and ocean currents (SN: 4/15/03). But in addition to moving about in relatively tight swirls just a few meters across, the poles drift over time as the planet’s weight distribution shifts and alters its rotation around its axis.

      Before the mid-1990s, the North Pole had been drifting toward the western edge of Canada’s Ellesmere Island. But then the pole veered eastward by about 71 degrees toward the northeastern tip of Greenland. It’s continued to head that way, moving about 10 centimeters per year. Scientists aren’t quite sure why this shift occurred, says Suxia Liu, a hydrologist at the Institute of Geographic Sciences and Natural Resources Research in Beijing.

      Liu and colleagues checked how well the polar drift trends matched data from previous studies on glacial melt worldwide. In particular, glacier melt in Alaska, Greenland and the southern Andes accelerated in the 1990s (SN: 9/30/20). The timing of that melting, as well as the effects it would have had on Earth’s mass distribution, suggests that glacial melt induced by climate change helped trigger the change in polar drift, the team reports in the April 16 Geophysical Research Letters.

      The team’s analysis shows that while glacier melting can account for much of the change in polar drift, it doesn’t explain all of it. So other factors must be at play. With copious irrigation, for example, groundwater pumped from aquifers in one region can end up in an ocean far away (SN: 10/9/19). Like glacial melt, water management alone can’t explain the North Pole’s tack, the team reports, but it can give the Earth’s axis a substantial nudge.

      The findings “reveal how much human activity can have an impact on changes to the mass of water stored on land,” says Vincent Humphrey, a climate scientist at the University of Zurich not involved in this study. And they show how large these mass shifts can be, he says. “They’re so big that they can change the axis of the Earth.” More

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      A new technique could make some plastic trash compostable at home

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      A pinch of polymer-munching enzymes could make biodegradable plastic packaging and forks truly compostable.

      With moderate heat, enzyme-laced films of the plastic disintegrated in standard compost or plain tap water within days to weeks, Ting Xu and her colleagues report April 21 in Nature.

      “Biodegradability does not equal compostability,” says Xu, a polymer scientist at the University of California, Berkeley and Lawrence Berkeley National Laboratory. She often finds bits of biodegradable plastic in the compost she picks up for her parents’ garden. Most biodegradable plastics go to landfills, where the conditions aren’t right for them to break down, so they degrade no faster than normal plastics.

      Embedding polymer-chomping enzymes in biodegradable plastic should accelerate decomposition. But that process often inadvertently forms potentially harmful microplastics, which are showing up in ecosystems across the globe (SN: 11/20/20). The enzymes clump together and randomly snip plastics’ molecular chains, leading to an incomplete breakdown. “It’s worse than if you don’t degrade them in the first place,” Xu says.

      Her team added individual enzymes into two biodegradable plastics, including polylactic acid, commonly used in food packaging. They inserted the enzymes along with another ingredient, a degradable additive Xu previously developed, which ensured the enzymes didn’t clump together and didn’t fall apart. The solitary enzymes grabbed the ends of the plastics’ molecular chains and ate as though they were slurping spaghetti, severing every chain link and preventing microplastic formation.

      Filaments of a new plastic material degrade completely (right) when submerged in tap water for several days.Adam Lau/Berkeley Engineering

      Adding enzymes usually makes plastic expensive and compromises its properties. However, Xu’s enzymes make up as little as 0.02 percent of the plastic’s weight, and her plastics are as strong and flexible as one typically used in grocery bags.

      The technology doesn’t work on all plastics because their molecular structures vary, a limitation Xu’s team is working to overcome. She’s filed a patent application for the technology, and a coauthor founded a startup to commercialize it. “We want this to be in every grocery store,” she says. More

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      A new book explores how military funding shaped the science of oceanography

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      Science on a MissionNaomi OreskesUniv. of Chicago, $40

      In 2004, Japanese scientists captured the first underwater images of a live giant squid, a near-mythical, deep-ocean creature whose only interactions with humans had been via fishing nets or beaches where the animals lay dead or dying.

      Getting such a glimpse could have come much sooner. In 1965, marine scientist Frederick Aldrich had proposed studying these behemoths of the abyss using Alvin, a submersible funded by the U.S. Navy and operated by the Woods Hole Oceanographic Institution in Massachusetts. During the Cold War, however, studying sea life was not a top priority for the Navy, the main funder of U.S. marine research. Instead, the Navy urgently needed information about the terrain of its new theater of war and a thorough understanding of the medium through which submarines traveled.

      In Science on a Mission, science historian Naomi Oreskes explores how naval funding revolutionized our understanding of earth and ocean science — especially plate tectonics and deep ocean circulation. She also investigates the repercussions of the military’s influence on what we still don’t know about the ocean.

      The book begins just before World War II, when the influx of military dollars began. Oreskes describes how major science advances germinated and weaves those accounts with deeply researched stories of backstabbing colleagues, attempted coups at oceanographic institutions and daring deep-sea adventures. The story flows into the tumult of the 1970s, when naval funding began to dry up and scientists scrambled to find new backers. Oreskes ends with oceanography’s recent struggles to align its goals not with the military, but with climate science and marine biology.

      Each chapter could stand alone, but the book is best consumed as a web of stories about a group of people (mostly men, Oreskes notes), each of whom played a role in the history of oceanography. Oreskes uses these stories to explore the question of what difference it makes who pays for science. “Many scientists would say none at all,” she writes. She argues otherwise, demonstrating that naval backing led scientists to view the ocean as the Navy did — as a place where men, machines and sound travel. This perspective led oceanographers to ask questions in the context of what the Navy needed to know.

      One example Oreskes threads through the book is bathymetry. With the Navy’s support, scientists discovered seamounts and mapped mid-ocean ridges and trenches in detail. “The Navy did not care why there were ridges and escarpments; it simply needed to know, for navigational and other purposes, where they were,” she writes. But uncovering these features helped scientists move toward the idea that Earth’s outer layer is divided into discrete, moving tectonic plates (SN: 1/16/21, p. 16).

      Through the lens of naval necessity, scientists also learned that deep ocean waters move and mix. That was the only way to explain the thermocline, a zone of rapidly decreasing temperature that separates warm surface waters from the frigid deep ocean, which affected naval sonar. Scientists knew that acoustic transmissions depend on water density, which, in the ocean, depends on temperature and salinity. What scientists discovered was that density differences coupled with Earth’s rotation drive deep ocean currents that take cold water to warm climes and vice versa, which in turn create the thermocline.

      Unquestionably, naval funding illuminated physical aspects of the ocean. Yet many oceanographers failed to recognize that the ocean is also an “abode of life.” The Alvin’s inaugural years in the 1960s focused on salvage, acoustics research and other naval needs until other funding agencies stepped in. That switch facilitated startling discoveries of hydrothermal vents and gardens of life in the pitch black of the deep ocean.

      As dependence on the Navy lessened, many Cold War scientists and their trainees struggled to reorient their research. For instance, their view of the ocean, largely driven by acoustics and ignorant of how sound affects marine life, led to public backlash against studies that could harm sea creatures.

      “Every history of science is a history both of knowledge produced and of ignorance sustained,” Oreskes writes. “The impact of underwater sound on marine life,” she says, “was a domain of ignorance.”

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