The UW’s new AAAS Fellows are:

, a professor of biology and resident scientist at the UW’s , is honored for her research contributions in biomechanics and ecophysiology, as well as efforts to promote diversity and inclusion in science. Her research has shown how marine life in near-shore ecosystems, especially invertebrates and seaweeds, respond to both short-term fluctuations in their environment and long-term shifts due to climate change. Carrington’s research has illuminated the many ways that expected shifts in oceans due to climate change — including heat waves and increases in dissolved CO2 — will negatively impact shellfish, algae and other organisms in coastal ecosystems and aquaculture. Her investigations of the biomaterials that mussels use to adhere to underwater surfaces have also aided the design of wet adhesives and antifouling surfaces for biomedical and maritime applications. A member of the UW faculty since 2005, Carrington also served as a program director in the National Science Foundation’s Directorate for Biological Sciences from 2016 to 2019.

Gabriela Chavarria, the executive director of the Burke Museum, is honored for her work on ecosystem sustainability, as well as leadership in education and conservation programs. Chavarria is an expert on native bees. She studies tropical bumblebees, and has long advocated for conservation of native pollinators. Chavarria was also trained as wood anatomist, and has helped to combat illegal traffic of hardwoods. An interest in conservation and policy led Chavarria to work for the U.S. Fish and Wildlife Service as a science adviser to the director, and later became a senior science adviser and head of forensic science at the agency’s wildlife forensic laboratory in Ashland, Oregon. Since 2018, she has served as Chief Curator and Vice President of the Science Division at the Denver Museum of Nature & Science. In announcing Chavarria as the next executive director of the Burke Museum last month, Dianne Harris, Dean of Arts and Sciences at the UW, said: “Chavarria’s experience as a museum administrator, scholar and visionary leader in the scientific community uniquely positions her to lead the Burke in its exciting next chapter.” That chapter commences March 1.

, a professor of chemistry, was selected for her studies of a large class of enzymes that promote biochemical reactions in living cells for functions such as suppressing tumor growth, removing toxic compounds and synthesizing antibiotics. Kovacs’ research focuses on how the bonds between atoms in these enzymes shift as they catalyze reactions, revealing details of the underlying mechanism that these key cellular players use to carry out their functions. She is also studying how oxygen atoms form bonds with one another — a process that occurs naturally during photosynthesis, but details of which are poorly understood. Elucidating this mechanism could help the green energy industry develop efficient fuel-storage technologies. Kovacs joined the UW faculty in 1988 and has previously chaired the American Chemical Society’s Division of Inorganic Chemistry.

, a professor emeritus in the Paul G. Allen School of Computer Science & Engineering, is recognized for his advocacy and inclusion efforts for people with disabilities in computer science and related fields. Trained in mathematics, Ladner spent much of his career researching fundamental issues in computer science — including optimization, computational complexity and distributed computing. He also co-founded what is now the Theory of Computation Group at the Allen School. In the latter half of his career, Ladner worked largely on accessibility in computer science. These endeavors included development of numerous tools to perform specific tasks, for example: translating textbook figures into formats accessible to persons with disabilities, or allowing people to communicate via cell phones using American Sign Language. Among numerous honors, Ladner was a Guggenheim Fellow, a Fulbright Scholar, an Association for Computing Machinery Fellow and an IEEE Fellow. He joined the UW faculty in 1971 and retired as a professor emeritus in 2017.

, a professor of chemistry, is honored for developing new techniques and tools in chemistry, particularly novel algorithms and methods for electron paramagnetic resonance spectroscopy. Stoll uses this unique form of spectroscopy — which can explore the microscopic details and fast dynamics of chemical compounds that have unpaired electrons — to measure distances as small as a few nanometers, which is roughly 1/5000th the diameter of the thinnest human hair. Stoll applies this to study the structure of cellular proteins and discern the conformational changes that they undergo while performing their functions, such as catalyzing reactions or regulating heartbeat. These fundamental insights broaden our understanding of the human body and how it works. Stoll joined the UW faculty in 2011.

Scientists from the ����Ӱ�Ӵ�ý have found evidence that ocean acidification caused by carbon emissions can prevent mussels attaching themselves to rocks and other substrates, making them easy targets for predators and threatening the mussel farming industry.

“A strong attachment is literally a mussel’s lifeline,” said UW biology professor , who presented these findings July 6 at of the .

Mussels attach themselves to hard surfaces so that they can filter plankton from seawater for food. They generally live in tidal zones, where the strong waves and currents protect them from predators such as crabs, fish and sea stars. But if a mussel falls off its perch, it sinks down into calmer waters where it is readily eaten.

Future conditions may make it more difficult for mussels to attach themselves and stay out of harm’s way. This is because the pH level appears to be critical during the attachment process, and our oceans are becoming more acidic from absorbing CO₂ emissions from the atmosphere.

“Our early laboratory studies showed mussels made weaker attachment threads when seawater pH dropped below 7.6,” said Carrington, who is based primarily at UW’s .

These results could have severe implications for aquaculture. In mussel farms, the mussels attach themselves to ropes suspended in the water for six to 12 months while they grow to market size. Currently, weak attachments can cause up to 20 percent of the crop to fall off and be lost on the seafloor.

The researchers have shown that the change in pH specifically affects the adhesive plaque which cements the mussel to the underlying surface.

“We investigated whether lowering seawater pH would affect the curing process of the attachment threads,” said Carrington.

Threads made by mussels in seawater with a “normal” pH of 8 were then kept at either pH 8, 7 or 5 to cure for 12 days. Using a materials testing machine, the team found that threads cured at the lower pH values were 25 percent weaker than the controls.

“We conclude that mussels rely on the high pH of seawater to cure their adhesive effectively and form strong attachments,” said Carrington.

Furthermore, one mussel species, Mytilus trossulus, also made fewer and weaker threads when the temperature of the water was increased above 64°F. In contrast, a closely related non-native species, Mytilus galloprovincialis, made more and stronger threads. This suggests warming oceans will increasingly favor the non-native species, allowing it to expand its distribution polewards and push out native species.

Although the global average ocean pH is only predicted to lower from 8.0 to 7.8 by the end of the century, this could still have a profound effect on mussel communities, says Carrington.

“Due to upwelling and local productivity, our seawater in Washington is already at a baseline of pH 7.8,” said Carrington. “Moreover, mussels live in highly dynamic coastal environments that routinely fluctuate up or down 0.5 pH units.”

This means that mussels are already exposed at times to conditions that weaken attachment and these periods may be longer and more severe in the future.

Carrington’s colleagues on this study include UW doctoral student , former UW doctoral student and recent graduate , with , UW professor of aquatic and fishery sciences and former UW researcher , who is now with the University of California.

The research was by .

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For more information, contact Carrington at ecarring@uw.edu.

Adapted from by the .

The creature in question is Acetabularia acetabulum, commonly called the mermaid’s wineglass. Reaching a height of just a few inches, this single-celled alga lives on shallow seafloors, where sunlight can still filter down for photosynthesis. Like many marine creatures, the mermaid’s wineglass sports a supportive skeleton made of calcium carbonate. Its skeleton is thought to deter grazing by predators and keep the alga’s thin stem rigid to support the round reproductive structure on top, said UW biology professor and senior author .

Increasing acidity of ocean water disrupts calcium carbonate levels. The more acidic the water is, the less calcium carbonate is available to living organisms. No studies had shown if even a slight increase in ocean acidity could weaken the shell of the mermaid’s wineglass. But three years ago a colleague told Carrington and UW biology doctoral student that the mermaid’s wineglass grows differently in certain parts of the Mediterranean Sea.

“ from Plymouth University came to Friday Harbor to talk about his research on underwater carbon dioxide seeps in Europe,” said Carrington. “He said the mermaid’s wineglass looks different when it grows close to the seeps, and asked us if anyone might be interested in finding out why.”

Carrington and Newcomb, who want to understand how marine organisms adapt to changing environmental conditions, were intrigued by the differences Hall-Spencer reported.

“The algae far from the seeps appeared whiter — probably because of their well-developed skeletons,” said Newcomb, who is lead author on the paper. “But ones found closer to the vents are more brown and green.”

Underwater volcanic activity creates CO₂ seeps, which spew gas and minerals into the water column. This includes dissolved carbon dioxide, which makes ocean waters near the vents more acidic. Newcomb wondered if mermaid’s wineglass algae growing closer to the seeps had weaker calcium carbonate skeletons. She measured the composition, morphology and stiffness of preserved algae that Hall-Spencer had collected, and found that algae near the vents were thinner and droopier.

But Newcomb and Carrington worried that the preservative the algae had been stored in might have affected the measurements. There was only one thing to do.

“She needed to go to Italy to work with live algae,” said Carrington. “Poor thing.”

The CO₂ seeps were located near , an island off the northern coast of Sicily. Newcomb collected fresh samples of the mermaid’s wineglass — both near and far from the seeps — and measured the carbon dioxide levels of the water at each site.

“The sites around the CO₂ seeps are pretty shallow,” said Newcomb. “So we could just snorkel and dive down to collect samples. We looked at three different sites — low, medium and high carbon dioxide levels.”

Carbon dioxide levels were five times higher at sites closest to the seeps. The CO₂ readings indicated how acidified the water is at each site — the more carbon dioxide, the more acidified.

The high carbon dioxide levels affected the composition and flexibility of mermaid’s wineglass skeletons. Newcomb found that near seeps in high carbon dioxide conditions, mermaid’s wineglass skeletons contained 32 percent less calcium carbonate. As a result, the straw-like stems were 40 percent less stiff and 40 percent droopier than their counterparts from low carbon dioxide waters.

“We saw a big loss in skeletal stiffness with even a small increase in carbon dioxide,” said Carrington.

Newcomb and Carrington hypothesize that the less fortified mermaid’s wineglass algae might be more susceptible to damage from ocean currents and grazing by marine animals. Their droopy posture may also make it difficult to disperse offspring. On the other hand, the thinner skeletons may transmit more sunlight to make food, and neither Newcomb nor her co-authors found snails — a common wineglass muncher — near the CO₂ seeps.

“The beauty of these seep systems is that we can go back to these sites and test these hypotheses,” said Carrington. “We can really try to see how increased flexibility affects the algae.”

Carrington and Newcomb hope that field studies like these, which look at the mechanical function of the calcium carbonate skeletons and not just their composition, will help biologists and oceanographers understand how climate change could affect creatures like the mermaid’s wineglass.

“Calcium carbonate skeletons are quite widespread in marine life, found in algae and plankton and even in larger creatures like snails and corals,” said Newcomb. “And in a more acidified ocean, some creatures are able to cope and do just fine. Some, like the mermaid’s wineglass here, suffer but still persist. Others will really struggle.”

As human activity pumps more carbon dioxide into the atmosphere, the oceans are absorbing a greater share than they have for millennia, and ocean acidification overall is expected to increase. These conditions may just bend the mermaid’s wineglass, but they could break others.

Newcomb, Carrington and Hall-Spencer were joined on the paper by co-author from the University of Palermo. This study was funded by the National Science Foundation (EF-1041213) and the Program.

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For more information, contact Carrington at 201-221-4676 or ecarring@uw.edu and Newcomb at the same phone number or newcombl@uw.edu.

, a ����Ӱ�Ӵ�ý professor of , reported Saturday (Feb. 16) that the fibrous threads she calls “nature’s bungee cords” become 60 percent weaker in water that was 15 degrees F (7 C) above typical summer temperatures where the mussels were from. She spoke at the American Association for the Advancement of Science meeting in Boston.

“Conditions that harm mussel populations affect commercial growers and, because mussels are at the foundation of the marine food web, also deprive predators such as crabs, lobsters and sea anemones of food,” Carrington said.

Such research might one day help natural resources managers in Washington, where Carrington’s work was done, and elsewhere estimate future abundance correctly and recognize areas with conditions most favorable to mussel survival. It might lead commercial growers to breed resistant varieties or be on the lookout to invest in the most promising locations for the future.

Carrington was the sole environmental biologist on a panel at the American Association for the Advancement of Science symposium on how to develop adhesives similar to mussels.

“Certainly spider silk is the darling of the biomaterials world because of its high strength. But the spotlight is getting brighter for mussels because they make strong, tough, durable attachments that can set underwater,” Carrington said.

“What biologists can contribute to the materials science arena is an appreciation of biodiversity,” she said. “Mussels live in all kinds of habitats. Some species are experts at gluing onto sea grass, some to other shells, some even adhere in the harsh conditions of hydrothermal vents. They each may have different genes that code for different proteins so the adhesive will be a little different and worth exploring.”

Mussels form attachments to rocks, fellow mussels and other surfaces with what’s called the byssus, a mass of golden-colored threads or filaments. Although each strand is only three to 10 times the width of a human hair, the threads are extraordinarily strong and stretchy, she says.

That’s good, given the forces at work where mussels live in the intertidal zone, the part of the shore covered by water when the tide is in and high and dry when it’s out.

Carrington says a modest wave on the outer coast of Washington clips along at 10 meters per second.

“An inland stream with water moving at only one meter per second is very hard to stand in,” she said. “Imagine something going 10 times that speed – over your whole body.”

Carrington calculates that wind would have to blow 600 miles per hour to generate the same force as water traveling 10 meters per second.

Carrington’s work, based at the UW’s and by the National Science Foundation, involves field observations of natural populations that she and her team try to repeat in the laboratory. In the lab they change one factor at a time – considering such stressors as temperature and ocean acidification – to understand which of many possible environmental culprits are most important, she said.

For example in led by UW doctoral student Laura Newcomb, the strength of byssal threads formed in water at 77 degrees F (25 C) were 60 percent weaker compared to those formed at 50 F and 65 F (10 C and 18 C). The waters in the natural habitat around Friday Harbor Laboratories is typically 50-54 F (12-14 C) in the summer, she said, although in places like shallow bays it can be much higher.

Scientists have previously found that the byssus weakens naturally in late summer and early fall. When autumn hurricanes and storms hit, both wild and commercially farmed mussels are then more prone to “fall off.” In work she did on the U.S. east coast, for example, the early storms of fall wiped one third of the mussels from where they’d been attached. Even winter’s nor’easters cause less fall off because the byssus by then has regained strength.

“We’re trying to learn what causes this seasonal weakening – is it related to warmer weather, their spawning cycle or something else,” she said. “And now we want to know if increased environmental fluctuations will help put them over the edge.”

“The mussel is a keystone species in rocky intertidal areas,” says David Garrison, director of the National Science Foundation’s Biological Oceanography Program, which funded the research. “Detachment of mussels results in lost habitat for myriad other organisms.”

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For more information:

Carrington is currently on sabbatical working on mussel byssus and energetics in Sicily and will return to the U.S. for the AAAS meeting, contact her via email to arrange interview by phone or Skype, ecarring@uw.edu