Early Exposure to Heat and Low Oxygen Makes Oysters More Vulnerable to Same Stressors Later On
by Kristen Minogue
Eastern oyster (Crassostrea virginica) taken from the Choptank River on Maryland’s Eastern Shore. (Credit: Sarah Donelan)
Early exposure to tough conditions—particularly warmer waters and nightly swings of low oxygen—could leave lasting scars on oysters’ ability to grow meaty tissue. A team of biologists at the Smithsonian Environmental Research Center (SERC) reported the discovery in a new study, published in the journal Ecological Applications.
Eastern oysters in Chesapeake Bay live mostly in shallow tributaries. It’s a rough environment for shellfish that can’t move. During hotter months, oxygen levels can swing drastically, from perfectly healthy levels in the day to near zero at night. To save energy, some oysters react by focusing more on shell growth than tissue growth. That could pose a problem for anyone involved in the seafood industry.
“What we all of course want to eat at the raw bar is the oyster tissue,” said Sarah Donelan, a SERC postdoctoral fellow and lead author of the new report. “Customers and restaurants might be less pleased if there’s less tissue in what looks to be a large oyster.”
A little brown bat (Myotis lucifugus) from Williams Mine, New York, where bats have evolved mutations to resist white-nose syndrome. (Credit: Sarah Gignoux-Wolfsohn)
by Kristen Minogue
For decades, a fungal disease known as white-nose syndrome has devastated bat colonies across North America. But evolution may finally be turning in the bats’ favor. In a new study, Smithsonian Environmental Research Center postdoc Sarah Gignoux-Wolfsohn discovered genetic evidence that some bats are evolving traits that help them survive the disease—and passing those traits onto their descendants.
Two decades ago, it was almost impossible to find eelgrass in Virginia’s South Bay—or many of the other small bays behind the barrier islands along the state’s eastern shore. After a barrage of disease followed by a powerful hurricane wiped them out by 1933, many thought the eelgrasses would never return. With the eelgrass went the brant goose, a popular waterfowl for sport hunting, and a lucrative bay scallop industry that had brought in millions of dollars per year.
“Because the bay scallop relies on the eelgrass as it’s growing up, it just completely disappeared and never came back,” said Jonathan Lefcheck, a marine biologist with the Smithsonian Environmental Research Center.
Today, a 20-year restoration has transformed South Bay and its neighboring bays into an oasis. But for the scientists leading the effort, restoring the eelgrass wasn’t enough. They wanted to find out if all the benefits eelgrasses provide would return as well. A new Science Advances report finally gave them their answer. Click to continue »
Postdoc Anya Hopple stands atop freshwater tanks for the new TEMPEST experiment. Each tank can hold 10,000 gallons of water, which will saturate forest soils to simulate heavy rainfall events. (Credit: Rick Smith)
Heavy rainfall and storm surges rank among the most common natural-weather events in the United States. They can occur in every state. They’re also one of the most widely felt impacts of climate change, making it impossible to ignore the economic and physical harm they leave in their wakes.
In a forest at the Smithsonian Environmental Research Center (SERC), scientists are working to uncover how sudden deluges could impact forests in decades to come. Called TEMPEST, the new experiment will mimic intense freshwater rainstorms and saltwater storm surges by inundating parts of the forest.
In the coastal waters of the mid-Atlantic, an endangered shark is making a comeback. Led by former Smithsonian postdoc Chuck Bangley, scientists at the Smithsonian Environmental Research Center (SERC) tagged and tracked nearly two dozen dusky sharks over the course of a year as part of the Smithsonian’s Movement of Life Initiative. They discovered a protected zone put in place 15 years ago is paying off—but it may need some tweaking with climate change.
Dusky sharks are what Bangley calls “the archetypal big, gray shark.” Born three feet long, as babies they’re already big enough to prey on some other shark species. But they’re slow growing. It can take 16 to 29 years for them to mature. If their populations take a hit, recovery can take decades.
The sharks’ numbers plummeted in the 1980s and 1990s, when well-intentioned managers offered sharks as an “alternative fishery” while other stocks, like cod, were collapsing. The overfishing that followed wiped out anywhere from 65 to 90 percent of the Chesapeake’s duskies, said Bangley, now a postdoc at Dalhousie University in Nova Scotia. Managers banned all intentional dusky shark fishing in 2000. Five years later, they created the Mid-Atlantic Shark Closed Area encompassing most of the North Carolina coast. The zone prohibits bottom longline fishing, which can accidentally ensnare dusky sharks, for seven months of the year.
A yellowtail fish approaches a “squid pop” in the coastal waters off Mexico. By planting squid pops (stakes with dried squid bait) in coastal waters around the world, ecologists were able to sketch a global “BiteMap” of fish feeding. (Credit: Brigitta van Tussenbroek/Universidad Nacional Autónoma de México)
Where are small marine animals most vulnerable to getting eaten? The answer has big consequences for coastal ecosystems, where most of the world’s fishing takes place, since predators can radically change underwater communities. In a new study published in Proceedings of the National Academy of Sciences Oct. 26, an international team of scientists sketched the first global “BiteMap” showing where the ocean’s mid-sized predators are most active. By fishing with dried squid baits called “squid pops,” they discovered rising temperatures can shape entire communities of predators and have potential impacts lower down the food web.
“We know that communities around the world are changing with climate warming,” said Emmett Duffy, co-author on the paper and director of the Smithsonian’s Marine Global Earth Observatory program. But while warmer temperatures generally increase animal activities like eating, researchers are only just starting to grasp what those changes mean for marine ecosystems as a whole. “We might expect a soccer team, for example, to perform better in warm weather than in really cold conditions. But what if in the warmer conditions, the team switches out for different players? That can completely change the game.”
A white-tailed deer browses for food in the forests of the Smithsonian Environmental Research Center. (Credit: John Parker/SERC)
For years, scientists have attempted to unravel why some invasive plants escape the grazing of hungry herbivores.
It turns out, the chemical makeup of some invasive plants protects them from being eaten. In a new paper, scientists have taken a closer look at invasive plant species in forests of the Smithsonian Environmental Research Center (SERC) in Maryland. In the new study, published in the August issue of Ecology and Evolution, they found that five common plant invaders have a chemistry just quirky enough to make animals like deer and insects avoid them. The results suggest that their strange chemistry has helped fuel some successful invasions into SERC’s Maryland forests.
Charlie Schmidt, a student in SERC’s virtual river otter class, poses with his poster presentation. (Photo courtesy of the Schmidt Family)
In spring, the SERC campus comes alive. Snow thaws, peeper frogs start calling, and troops of schoolchildren descend on campus to get their hands dirty and experience science in the field. For some, this could be the first time they’ve seen the Chesapeake Bay, walked through a forest or spent time in nature.
This year, the pandemic forced schools to close and SERC had to cancel all its spring and summer programs. However, thanks to the efforts of the SERC education team, the pandemic hasn’t stopped science education, just changed it. Karen McDonald, SERC’s education specialist, is working with her staff, interns and a dedicated volunteer team to develop virtual programs that bring SERC science into the homes of eager learners, from elementary students to adults.
Fall color in the Dolly Sods Wilderness, part of Monongahela National Forest in West Virginia. “Natural forest regrowth,” a climate-mitigation strategy where forests regrow without human interference, could store 1.6 billion metric tons of carbon annually. (Credit: Kent Mason)
Trees have a powerful ability to absorb carbon dioxide, and a lot of it. According to the Environmental Protection Agency, American forests offset about 12% of the carbon emissions the U.S. creates each year from fossil fuels. While it’s great to plant trees, it can be costly. It’s also important to plant the right species in the right places to avoid disrupting other ecosystems. A major new study published Sept. 23 highlights the potential of an alternate strategy—natural forest regrowth—which can soak up excess carbon and help mitigate climate change.
Plastic buoy in the Great Pacific Garbage Patch, colonized by gooseneck barnacles and crabs. (Credit: Justin Hofman/Greenpeace)
This article is part of a series of posts highlighting research the Smithsonian Environmental Research Center is continuing to do amid the COVID-19 pandemic, and adaptations its staff have been making in a more socially distant world.
In nature, adaptation is key to survival. This year more than ever, being adaptable and resilient has also been essential to working as a scientist. Faced with a pandemic, researchers around the world have had to find creative ways to continue their work.
SERC postdoc Linsey Haram is part of the FloatEco Project, a research collaboration that studies artificial ecosystems made of floating ocean plastic. By hitchhiking on pieces of plastic, coastal organisms can drift into the Great Pacific Garbage Patch and survive in the middle of the ocean.
