By Sarah Hansen
Keryn Gedan collects mussels and oysters “by the handful” for her research. (Chris Judy)
Oyster restoration has long been championed as key to cleaning up Chesapeake Bay, because oysters’ filter-feeding lifestyle improves water quality by removing plankton. But oysters aren’t the only ones that can do the job. A new study reports that another bivalve, the hooked mussel, also removes its share of plankton from the clogged Bay. Click to continue »
By Sarah Hansen
Experimental chambers and blowers give the marsh a spooky feel on this cloudy morning at SERC.
At first encounter, the marsh looks as if it came out of a Heinlein novel. Boxy white robots dot the wetland, igloo-shaped encampments litter the landscape, and thick black tubes snake across the mud—wait, did that one just move? On closer inspection, clusters of human beings appear crouched in the sedge, carefully taking measurements for the annual Global Change Research Wetland (GCREW) Summer Marshfest.
“These two weeks are the most important two weeks of the year for us,” said Smithsonian Environmental Research Center biogeochemist Patrick Megonigal. During Marshfest, senior scientists, postdocs, volunteer citizen scientists, interns, lab techs and visiting students all join forces to collect data for three experiments focused on climate change and nutrient cycling, all managed by Megonigal. Click to continue »
by Kristen Minogue
Male blue crabs can mate with multiple females. But with fewer men to go around, their female partners are left with less sperm to reproduce. (SERC)
The practice of selectively fishing male blue crabs in the Chesapeake—intended to give females a chance to reproduce—may have a hidden cost. A Bay without enough males could reduce the number of offspring females produce, ecologists at the Smithsonian Environmental Research Center found in a paper published in the July issue of Marine Ecology Progress Series.
Maryland and Virginia began reducing the harvest of female crabs by commercial and recreational watermen in 2008, the year officials declared the blue crab fishery a federal disaster. Since then, the crabs have shown signs of a shaky recovery. But a lasting comeback hinges on females producing enough offspring to sustain the population.
by Dejeanne Doublet
SERC intern Dejeanne Doublet heads out to sample marsh elder.
(Megan Palmer)
As we’re knee-deep in the marsh surrounding the Chesapeake Bay, working under the relentless sun during 90-degree weather with 90 percent humidity, sweat dripping down our faces, waving off the summer bugs and trying to collect as much field data as possible, the idea of winter becomes abstract and far-fetched. It’s hard to believe we are out here in the blazing heat of summer studying the effects of this past winter— one of harshest winters this area has endured in many years.
By Sarah Hansen
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.
By Sarah Hansen
A cluster of downy rattlesnake plantain, the orchid species SERC intern Christopher Robinson is studying this summer. (Wikimedia Commons user Cdc25A)
Orchids are beautiful plants to be treasured, and fungi are gross moldy blobs to avoid at any cost. At least, that’s what some people may think. But it turns out that no orchid can germinate and grow without a fungal partner. Smithsonian Environmental Research Center scientist Melissa McCormick has been learning about the relationship between orchids and fungi for 15 years. This summer, though, intern Christopher Robinson is helping put a new twist on the research. Click to continue »
By Sarah Hansen
James Biddle, SERC intern, twists a soil augur into the ground to collect a 50- to 100-centimeter deep soil core.
It’s well-known that carbon dioxide levels are rising in Earth’s atmosphere and that extra CO2 contributes to climate change. You might also have learned that trees are “carbon sinks” – they take carbon out of the air and store it in their trunks, roots and leaves. But what about carbon in forest soil?
If you’re not sure, you’re in good company. “We’re just learning how carbon moves through the forest at the surface, and that’s the most accessible part of the forest,” said Sean McMahon, senior scientist at the Smithsonian Environmental Research Center (SERC). “Below ground is much more of a mystery.” Click to continue »
by Kristen Minogue
Technician Laura Patrick holds up a blue crab caught in the Rhode River. (SERC)
This summer and fall, biologists at the Smithsonian Environmental Research Center are looking to tag 10,000 blue crabs in Chesapeake Bay. They’re pursuing the project in spite of the two-year slump the crabs have suffered in the latest reports of the Chesapeake Bay Stock Assessment Committee. They’re hoping some of those crabs will help answer two unresolved questions on the path to recovery: the role of recreational crabbing, and the struggling population of adult females.
Every year watermen on Chesapeake Bay haul in between 40 and 110 million pounds of blue crabs on trotlines or in crab pots. The vast majority come from commercial watermen who rely on the crustaceans for their livelihoods. But recreational crabbers also take their share, and today no one knows exactly how large or small that share is.
“We really have very little idea how big the recreational fishery is now,” says Matt Ogburn, a postdoc at SERC’s Fish and Invertebrate Ecology Lab. Click to continue »
By Sarah Hansen
Shelby Paschal, SERC intern, takes the “Secchi depth,” a measure of water clarity, while balancing on the fish weir.
In the Chesapeake Bay region, water quality is a big deal. It can affect populations of economically important animals such as crabs and oysters, or shift ecological relationships among other species. Differences in water quality might even determine whether an invasive species can establish a foothold in the Bay.
But water quality is a nebulous thing. Even collecting water samples can be tricky, something intern Shelby Paschal knows first-hand.
“This is our obstacle course training,” Paschal says with a laugh, after a climbing onto a rickety fish weir at the Smithsonian Environmental Research Center (SERC). Paschal and the rest of the Nutrient Lab, headed by senior scientist Tom Jordan, are running one piece of an ambitious 6-year project studying the effects of multiple factors in shallow near-shore habitats. These critical habitats for small fish, crabs, and plants face threats from invasive species and construction, as well as from degradation of water quality caused by release of excessive nutrients from cropland into the Bay. Click to continue »
by Sarah Hansen
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.
