Publications

...now browsing by category

Stressed-Out Young Oysters May Grow Less Meat On Their Shells

Tuesday, March 2nd, 2021

Early Exposure to Heat and Low Oxygen Makes Oysters More Vulnerable to Same Stressors Later On

by Kristen Minogue

Gloved hand holding up a brown and white oyster next to the water

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.”

Click to continue »

Posted in Ecology, Fisheries, Publications, Water Quality | Comments Off on Stressed-Out Young Oysters May Grow Less Meat On Their Shells

“Soft Sweep” Evolution Helps Bats Resist Deadly White-Nose Syndrome

Friday, February 26th, 2021

Two hands with purple gloves hold one of the New York brown bats with wings outstretched

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.

Click to continue »

Posted in Ecology, Endangered Species, Publications | Comments Off on “Soft Sweep” Evolution Helps Bats Resist Deadly White-Nose Syndrome

Seagrass Restoration Brings New Life To Virginia’s Once-Forsaken Bays

Tuesday, December 15th, 2020

by Kristen Minogue

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 »

Posted in Ecology, Fisheries, Participatory Science, Publications, Volunteers, Water Quality | Comments Off on Seagrass Restoration Brings New Life To Virginia’s Once-Forsaken Bays

Sharks Tags Reveal Endangered Species Returning To Natural Refuge

Wednesday, November 18th, 2020

by Kristen Minogue

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.

But is the partial refuge working?

Click to continue »

Posted in Climate Change, Ecology, Endangered Species, Fisheries, Movement Of Life, Publications | Comments Off on Sharks Tags Reveal Endangered Species Returning To Natural Refuge

Global “BiteMap” Reveals How Marine Food Webs May Change With Climate

Monday, October 26th, 2020

by Kristen Minogue

Blue and yellow fish approaching stick in sandy, turquoise water

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.”

Click to continue »

Posted in Climate Change, Ecology, Fisheries, Publications | Comments Off on Global “BiteMap” Reveals How Marine Food Webs May Change With Climate

When Forests Grow Back Naturally, Climate Change Takes A Hit.

Friday, September 25th, 2020

by Aliya Uteuova

Mountain forests with red, purple, yellow and green foliage.

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.

Click to continue »

Posted in Climate Change, Ecology, Land Use, Publications | Comments Off on When Forests Grow Back Naturally, Climate Change Takes A Hit.

U.N. Report Puts Spotlight on Seagrasses

Friday, July 31st, 2020

by Isabella Eclipse

Video created by United Nations Environment Programme

Appearances can be deceiving. At first glance, the humble seagrass meadow resembles a weedy underwater lawn. A closer look reveals one of the most important—and threatened—marine ecosystems in the world. Unfortunately, conservation efforts have often overlooked seagrass habitats.

“For a long time, people saw seagrass as a nuisance,” explained Jonathan Lefcheck, a biologist with the Smithsonian Environmental Research Center. It had a reputation for clogging boat propellers and washing up on beaches. “Tropical resorts would hire people to dig up seagrass in front of their beach because people would complain,” he added.

Though public perceptions have been changing, many people today are still unaware that seagrass meadows are rich and vibrant ecosystems like coral reefs or rainforests. A new report from the United Nations Environment Programme hopes to change that. Released June 8 on World Oceans Day, Out of the Blue compiles the latest findings from around the world on seagrasses and the valuable services they provide. SERC biologist Emmett Duffy served on the steering committee and helped synthesize the report.

Click to continue »

Posted in Climate Change, Endangered Species, Fisheries, Publications, Water Quality | Comments Off on U.N. Report Puts Spotlight on Seagrasses

Who’s Left Swimming in Chicken Manure…and Its Bacteria?

Friday, June 19th, 2020

New study finds antibiotics from poultry farms can lead to drug-resistant bacteria in the water

by Kristen Minogue

Chickens stand in a Pennsylvania poultry barn. Crowded conditions in poultry barns increase the danger of a disease spreading through the flock, leading many poultry farmers to rely on antibiotics. (Credit: Steve Droter/Chesapeake Bay Program. Creative Commons License)

90 tons. That’s how much chicken manure—mixed with feathers, uneaten feed and leftover bedding—a Maryland poultry farmer scrapes out of a single barn each year.

Manure is just one of many issues poultry farmers on the Delmarva peninsula have to wrestle with. Poultry farming isn’t an easy industry, for the chickens or the farmers. To get started, a farmer generally needs to borrow hundreds of thousands of dollars to build a poultry barn to house roughly 45,000 birds. Companies like Purdue and Tyson supply the chicks, and pay the farmers based on how many pounds the flock puts on. To have any chance of making a profit, there’s enormous pressure to grow broiler chickens as fat and as fast as possible. A typical poultry barn can go through five to seven flocks a year. After each flock moves out, the farmers are left to deal with the muck.

“The folks that grow the chickens, it’s a really tough job that they do and hard to make a buck at it,” said Tom Jordan, an ecologist with the Smithsonian Environmental Research Center who specializes in how farming impacts Chesapeake Bay.

Another thing that’s hiding in the chicken manure? E. coli bacteria. Some of these E. coli don’t cause disease. But others can inflict both chickens and people with diarrhea and other unsavory side effects, like urinary tract infections.

Some E. coli bacteria have become resistant to our antibiotics. This May, scientists reported that because chicken manure fertilizes farms throughout the Chesapeake, that antibiotic resistance can also spread in the water. Besides the already-prevalent problem of nutrient pollution, this could put swimmers and boaters who use the water for recreation at further risk.

“Right now, sometimes the poultry barns get cleaned and they immediately apply it on land, so it’s just fresh waste going directly on our land,” said Jay Graham, lead author of the new study and a public health researcher with the University of California, Berkeley. “So if it rains, then all that ends up in our waterways.”

Click to continue »

Posted in Ecology, Land Use, Publications, Water Quality | Comments Off on Who’s Left Swimming in Chicken Manure…and Its Bacteria?

Preserving Salmon in Alaska’s Kenai Lowlands

Wednesday, April 15th, 2020

by Kristen Minogue

“Not everybody in Alaska is a fisherman. But all of us live on salmon land….If you look at a map of the Kenai Peninsula, it just looks like a cardiovascular system. Salmon are like the heartbeat.”

These words, spoken by a young Alaska fisherwoman named Hannah Heimbuch, open a short documentary the Smithsonian created called The Heartbeat. Featured in the D.C. Environmental Film Festival this March, it tells the story of Alaska’s Kenai Lowlands—one of the few places on Earth where sustainable salmon management remains possible. Click to continue »

Posted in Alaska, Climate Change, Fisheries, Publications | Comments Off on Preserving Salmon in Alaska’s Kenai Lowlands

In Florida’s Oceans, It’s DNA vs. Disease

Tuesday, April 14th, 2020

Patch of mostly brown branching corals underwater, with one infected yellow and white coral

Staghorn coral (Acropora cervicornis) with white band disease. (Credit: Sarah Gignoux-Wolfsohn)

by Kristen Minogue

Parasitic slime nets attacking seagrasses. A disease that melts coral tissue down to the skeleton, whose exact cause remains unknown. If these aren’t the first places you’d look for optimism, you’re not alone.

Katrina Lohan heads SERC’s Marine Disease Ecology Lab. She and postdoc Sarah Gignoux-Wolfsohn studied both ailments in Florida. They look for hope in the microscopic realm of DNA. Click to continue »

Posted in Ecology, Parasite Hunting, Publications | Comments Off on In Florida’s Oceans, It’s DNA vs. Disease

Shorelines

Life and science at the Smithsonian Environmental Research Center

Publications

...now browsing by category

Stressed-Out Young Oysters May Grow Less Meat On Their Shells

Early Exposure to Heat and Low Oxygen Makes Oysters More Vulnerable to Same Stressors Later On

“Soft Sweep” Evolution Helps Bats Resist Deadly White-Nose Syndrome

Seagrass Restoration Brings New Life To Virginia’s Once-Forsaken Bays

Sharks Tags Reveal Endangered Species Returning To Natural Refuge

Global “BiteMap” Reveals How Marine Food Webs May Change With Climate

When Forests Grow Back Naturally, Climate Change Takes A Hit.

U.N. Report Puts Spotlight on Seagrasses

Who’s Left Swimming in Chicken Manure…and Its Bacteria?

Preserving Salmon in Alaska’s Kenai Lowlands

In Florida’s Oceans, It’s DNA vs. Disease