Thousands of Tags Could Unearth Clues to Saving Blue Crabs

Posted by KristenM on July 8th, 2014

by Kristen Minogue

Photo: Technician Laura Patrick holds up a blue crab caught in the Rhode River. (Credit: SERC)

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 »


SERC and NOAA model Bay’s murky water quality

Posted by KristenM on July 3rd, 2014

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 »


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

Posted by KristenM on June 23rd, 2014

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.

Click to continue »


Do forest canopy gaps help invasive plants thrive?

Posted by KristenM on June 20th, 2014

By Sarah Hansen


An upland forest plot at SERC. Lauren Emsweller, David Gorchov, and Julia Mudd (left to right) search for five invasive plant species.

Invasive plants are rampant throughout the United States.  Some have been here for tens or even hundreds of years, while others are relative newcomers.  They compete with native plants for resources, and more often than not they win the fight.

David Gorchov, visiting scientist from Miami University of Ohio, is leading a project to map five invasive plant species in upland forests at the Smithsonian Environmental Research Center (SERC).  In particular, he’s interested in how gaps in the forest canopy, usually created by a tree falling, affect the abundance of these invasives.  One of his graduate students, Lauren Emsweller, is here working on the project for her master’s thesis.  Julia Mudd, a SERC intern from Florida State University, is getting college credit to help them out.

“There are a few studies that have looked at the importance of gaps, but there’s none that have done complete maps like this that I’m aware of,” said Gorchov.

Click to continue »


Intern Logs: A Bloody Welcome

Posted by KristenM on June 17th, 2014

by Dejeanne Doublet, terrestrial ecology intern

Photo: Dejeanne Doublet inspects a red oak in BiodiversiTree. (Credit: SERC)

Dejeanne Doublet inspects a red oak in BiodiversiTree. (SERC)

Ecological research usually doesn’t evoke thoughts of Stephen King horror movie scenes. Working with plants and animals in the open air shouldn’t provoke nightmares of being drenched in blood. Green is a very different color from red.

However, fellow intern Megan Palmer and I learned on our first week that sometimes, just sometimes, Stephen King references are the best way to describe a day’s work in the field. During our first days at the Smithsonian Environmental Research Center, Palmer and I were asked to do something that made my non-red-meat-eating stomach turn.

“Go spray pig’s blood on all our trees,” Dr. John Parker, the lead terrestrial ecology scientist and our boss told us during one of our first meetings with him. He was referring to the 24,000 tree saplings planted last summer as part of a 100-year experiment on biodiversity, fittingly called BiodiversiTree.

Click to continue »


Seeking Life in the Mud

Posted by KristenM on June 13th, 2014

By Sarah Hansen


Dean Janiak (left) and Ben Rubinoff collect a sample from the Rhode River.

Most of us think of the Chesapeake Bay as a single entity – one big body of water.  But Smithsonian Environmental Research Center (SERC) ecologist Dean Janiak and his intern, Ben Rubinoff, have a more nuanced perspective.  They’ve collected more than 150 samples from eight different habitats within the Bay and along its shoreline that contain mud, sand and lots of tiny animals.

Their ultimate goal: Discover how differences in habitats in the Rhode River (a sub-estuary of the Chesapeake Bay) can change biodiversity among creatures at the bottom of the river, and how those patterns change over time.  If it turns out that some habitats host more diverse animal communities than others, land managers can focus conservation efforts on those areas. Click to continue »


Invasive plant may protect forests from drowning

Posted by KristenM on June 12th, 2014

Citizen scientists brave dense swamps to find truth behind Phrag

By Sarah Hansen

JH bands a tree

Jack Hays bands a tree in the marsh.

Sea-level rise triggered by climate change affects coastal ecosystems first.  Marshes and wetlands along the shoreline creep inland, infringing on forest habitats.  Scientists have strong evidence that too much water will gradually drown the trees.  But an invasive reedy plant, known as “Phrag” from its scientific name, Phragmites australis, might be the forests’ unlikely protector, delaying drowning by about a decade.

Invasive Phrag (there is a native subspecies, as well) first came to the U.S. from Europe over 200 years ago.  The native variety coexists peacefully with other plants, but the invader takes over a habitat, choking off other flora.  Only recently, however, has its population growth exploded.   Scientists at the Smithsonian Environmental Research Center are trying to find out whether large Phrag populations in wetlands help or hurt tree growth.  It might seem counterintuitive, but scientists hypothesize that the Phrag is actually helping trees survive as sea level rises.  By removing some of the water, Phrag may prevent trees from drowning.     Click to continue »


The Strange, Controversial Way Plants Trap CO2

Posted by KristenM on June 11th, 2014

by Kristen Minogue

Swamp Rose Mallow surrounded by blades of Schoenoplectus, a sedge in Drake's marsh experiment. (SERC)

Swamp Rose Mallow with blades of Schoenoplectus americanus, a sedge in Drake’s marsh experiment. (SERC)

Plants are among the world’s best carbon sinks, but there’s a side to the plant-CO2 love affair that’s rarely discussed. When carbon dioxide rises, plants cling to it more, releasing less back into the air—and until recently, scientists couldn’t figure out why. With a new paper published June 11 in Global Change Biology, ecologist Bert Drake believes he finally has the answer.

The process is called respiration, and it’s one of the most overlooked parts of the carbon cycle. Unlike photosynthesis, in which plants absorb carbon dioxide and release oxygen, respiration reverses it. And plants respire constantly. Much of the CO2 plants take from the atmosphere for photosynthesis finds its way back via respiration from plants and soil. Which leaves a major question: How much carbon can the world’s ecosystems store as CO2 rises and climate changes?

Click to continue »


Learning by Digging: Archeology Project Explores Colonial Life

Posted by KristenM on June 10th, 2014

Scientists, students, and volunteers unearth late 17th- and 18th-century objects behind Sellman House

by Sarah Hansen

Volunteers excavate a new pit at the “Shaw’s Folly” site behind Sellman House.

On a sunny June afternoon at the Smithsonian Environmental Research Center, students and volunteers are hard at work in a cornfield behind the Sellman House.  Some shovel soil out of pits.  Others screen it with giant sieves, looking for artifacts.  Still others use trowels to smooth the bottom and sides of the pit, hoping to reveal differences in soil coloration and texture.  This scene will repeat every Monday, Tuesday, and Friday from about 9a.m. to 4 p.m. until June 20.  Guided by Laura Cripps, acting Chair of Social and Cultural Sciences at Howard Community College, and Jim Gibb, head of SERC’s Archaeology Lab, the group is excavating a site that contains objects and building materials that provide a window into 17th- and 18th-century life.

Click to continue »


Arctic Unguarded: Melting Ice Opens Way
for Invaders

Posted by KristenM on May 28th, 2014

by Kristen Minogue

Arctic sea ice (Patrick Kelley/U.S. Coast Guard)

Arctic sea ice (Patrick Kelley/U.S. Coast Guard)

For the first time in roughly 2 million years, melting Arctic sea ice is connecting the north Pacific and north Atlantic oceans. The new sea routes leave both coasts and Arctic waters vulnerable to a large wave of invasive species—a problem the Arctic has largely avoided until now.

Click to continue »