Water Quality

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Hunt for a Missing Nutrient: Part III

Wednesday, February 3rd, 2016

by Kristen Minogue

Image: Tom Jordan beside a V-shaped weir that tracks nutrients in a SERC stream. (SERC)

Tom Jordan beside a V-shaped weir that tracks nutrients in a SERC stream. (SERC)

For years, a team of scientists has been trying to solve a mysterious disappearance at a drainage ditch on the Choptank River Basin, on Maryland’s eastern shore. Every year roughly 32,000 pounds of human-generated nitrogen enters the ditch’s watershed, from fertilizers, air pollution and other sources. But less than a third of that nitrogen typically flows out of the stream.

Tom Jordan has seen it before. A nutrient ecologist at the Smithsonian Environmental Research Center (SERC), Jordan has wrestled with the mystery of the missing nitrogen for more than twenty years.

“It feels like a sort of fatal attraction,” Jordan said. Two decades of trial and error and dead ends only fueled his determination to find answers. Now, according to a new January study, Jordan and his colleagues finally have some.

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Top 12 Highlights of 2015: Arctic Sailing, Cownose Rays and an Orchid Showdown

Thursday, December 31st, 2015

by Kristen Minogue

It’s been another wild year at the Smithsonian Environmental Research Center. We sent a sailboat to the Arctic, pitted our orchids in a showdown against the Hope Diamond and discovered a couple new species. And somewhere along the way we celebrated the center’s 50th anniversary. Scroll below for the 2015 #YearInReview, a collection of the top 12 stories, journeys and biggest surprises of 2015.

Image: Cownose Rays (Credit: SERC/Laura Patrick)

Cownose Rays (SERC/Laura Patrick)

Exploring the Ocean

Totes Adorbs! Cownose Rays Take Internet
These marine heartthrobs have earned a top billing. Besides making a 900-mile migration every year, which SERC marine ecologists are tracking with acoustic tags, the kite-shaped rays (whose mouths are stretched so that they seem to be wearing a perpetual smile) also won a Twitter #CuteOff in September.

What Does Life in the Ocean Sound Like?
Postdoc Erica Staaterman listens to the ocean for a living. Often seen as a silent landscape broken only by whale or dolphin songs, Staaterman is helping uncover a wealth of noise from the ocean’s hidden creatures. She shared some of the recordings with us in this edited Q&A.

Cruising the Arctic’s Forgotten Fjords
Ocean acidification researcher Whitman Miller sent one of his CO2-monitoring devices on a 100-day journey to the Arctic. Its mission: Venture to some of Greenland’s never-before-seen fjords and discover how melting glaciers are changing the water. And do it all in a small, 42-foot sailboat. Click to continue »

Oyster Disease Thrives in Nightly Dead Zones

Wednesday, February 11th, 2015

by Kristen Minogue

Image: Slides of oysters suffering different Dermo intensities as the parasite multiplies, from healthy (left) to severely infected (right). (Credit: SERC Marine Ecology Lab)

Slides of oysters suffering different Dermo intensities as the parasite multiplies, from healthy (left) to severely infected (right). (SERC Marine Ecology Lab)

In shallow waters around the world, where nutrient pollution runs high, oxygen levels can plummet to nearly zero at night. Oysters living in these zones are far more likely to pick up the lethal Dermo disease, a team of scientists from the Smithsonian Environmental Research Center discovered in a new study published Wednesday.

Oxygen loss in the shallows is a global phenomenon, but it is not nearly as well known as the dead zones of the deep. Unlike deep-water dead zones, which can persist for months, oxygen in shallow waters swings in day-night cycles, called diel-cycling hypoxia. In nature it works like this: When algae photosynthesize during the day, they release oxygen into the water. But at night, when photosynthesis stops, plants and animals continue to respire and take oxygen from the water, causing dissolved oxygen to drop. Nutrient pollution, because it fuels massive algal blooms, can make the cycle even more drastic. The resulting lack of oxygen can cripple the oysters’ ability to fight off the parasite Perkinsus marinus that causes Dermo and slowly takes over their bodies.

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Oysters and the Chesapeake’s Jellyfish Wars

Tuesday, September 30th, 2014

Image: Jellyfish Chrysaora quinquecirrha (Credit: Lori Davias)

Jellyfish Chrysaora quinquecirrha (Lori Davias)

by Kristen Minogue

Every summer, the food web in Chesapeake Bay gets jostled around as two plankton-eating predators jockey for power: comb jellies and jellyfish. Most smaller species don’t have a stake in the battle—both predators eat zooplankton and fish eggs, after all. But for young oyster larvae, the victor could make the difference between being protected civilians or collateral damage.

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Urban kids, urban waterways: Citizen science improves lives and environment

Thursday, August 21st, 2014

By Sarah Hansen

Tony Thomas (left) supervises while Donovan Eason (center) and DaWayne Walker run a chemical test on a water sample.

Tony Thomas (left), education program coordinator at the Anacostia Community Museum, supervises while students Donovan Eason (center) and DaWayne Walker run a chemical test on a water sample.

“Is the net like a Spongebob jellyfish net?” student Cristal Sandoval asked.  Alison Cawood, citizen science coordinator at the Smithsonian Environmental Research Center (SERC), used another analogy to explain: “It’s like a bowl with holes in it for pasta.”  Light bulbs came on around the room and a knowing, “Oh,” escaped the lips of at least a dozen students.

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Marshes: Pollution Sponges of the Future

Thursday, August 21st, 2014

by Melissa Pastore, biology graduate student at Villanova University

Image: Melissa Pastore in a marsh near Delaware Bay. (Credit: Lori Sutter)

Melissa Pastore in a marsh near Delaware Bay.
(Lori Sutter)

What if we could create a giant sponge capable of soaking up nitrogen pollution? It turns out that the Chesapeake Bay, which has experienced a rapid increase in nitrogen pollution from municipal and agricultural sources over the last few decades, already contains a natural version of this sponge: marshes fringing the Bay. But global change—and the nitrogen pollution itself—could change how this natural sponge operates.

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Using Computer Models to Help Rescue Bay’s Underwater Flora

Thursday, July 17th, 2014

By Sarah Hansen

SERC intern Bridget Smith, immersed in a sea of environmental data.

SERC intern Bridget Smith, immersed in a sea of environmental data. (SERC)

Underwater plants like sea grasses provide habitat and feeding areas for a wide range of aquatic life.  They also help filter the water and put the brakes on erosion.   But in Chesapeake Bay, the coverage of underwater plants, or submerged aquatic vegetation (SAV), has been low for decades, and restoration attempts have had mixed results.  That’s why this summer, Smithsonian Environmental Research Center intern Bridget Smith is grappling with 28 years of data to explore which of a host of factors affects SAV in the Bay and how.

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How much could streamside forests reduce nitrogen pollution in the Bay?

Monday, June 23rd, 2014

by Sarah Hansen

Chester_river_queen_annes_co_md

A buffer on the Chester River in Queen Anne’s County, MD protects the river from nitrogen pollution. (USDA)

Nitrogen pollution in the Chesapeake Bay became a serious concern in the mid-20th century after the advent of nitrogen-rich chemical fertilizers. Bay restoration efforts have reduced nitrogen pollution somewhat, but achieving healthy nitrogen levels in the Bay is still a long way off. Croplands remain an important source of the nitrogen that pollutes Chesapeake Bay.

Don Weller, senior scientist at the Smithsonian Environmental Research Center, and his colleague Matthew Baker, associate professor of geography and environmental systems at the University of Maryland, Baltimore County, report in a new study that just over half the nitrogen from croplands might never reach the Bay—if all crop fields were protected by streamside forests and wetlands.

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What’s Hurting the Chesapeake’s Underwater Plants?

Monday, May 5th, 2014

by Kristen Minogue

Photo: A flounder in a bed of eelgrass. (NOAA)

A flounder in a bed of eelgrass. Seagrasses and other underwater plants provide food and shelter to many iconic Bay creatures, including blue crabs. (NOAA)

It’s been a difficult century for the submerged flora of Chesapeake Bay.

In the 1930s, wasting disease nearly wiped out the eelgrasses of the North Atlantic. In the ‘50s and ‘60s, they faced onslaughts from invasive grasses like water chestnut and Eurasian milfoil. Finally, in the summer of 1972, Hurricane Agnes pummeled underwater plants to the lowest levels ever reported in the Bay. This April, they received news that, at first glance, seemed positive: Submerged grasses rose 24 percent between 2012 and 2013, according to aerial surveys of the Chesapeake Bay Program.

But those increases were largely limited to a single species: widgeon grass, a plant known for wild fluctuations. At 60,000 acres total, submerged plants still didn’t come near a recent mini-peak in 2002, they’re a far cry from the ultimate goal of 185,000 acres across the Bay. What is holding them back? And—more importantly—how we can we help ensure the latest expansion isn’t just a blip?

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Cracking Down on Mercury

Monday, December 9th, 2013

by Kristen Minogue

Ally Bullock, a technician in SERC's mercury lab, draws pore water samples from Berry's Creek. (SERC)

Ally Bullock, a technician in SERC’s mercury lab, draws pore water samples from a mid-Atlantic Superfund site. (SERC)

There are places in the U.S. so polluted, eating fish or crabs from their waters isn’t just unhealthy—it can be illegal. The Environmental Protection Agency calls sites like that “Superfund sites,” a label for abandoned or neglected sites that became dumping grounds for hazardous waste. Some of the highest levels of mercury contamination in the U.S. exist in Superfund sites. Cynthia Gilmour knows this first-hand. As a microbial ecologist at the Smithsonian Environmental Research Center, she has worked in several.  But short of digging up the polluted sediments and dumping them elsewhere (an expensive and ecologically risky proposition), not many methods exist to get rid of the problem.

“If we use the traditional technologies of removing that and putting it in a landfill, we don’t have a wetland anymore,” says Upal Ghosh, an environmental engineer from the University of Maryland, Baltimore County, who works with Gilmour.

This fall, Gilmour and Ghosh explored a new technique: using charcoal to trap it in the soil.

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