Invasive Species browsing by category


All About That Base…Pairs: Using DNA Barcoding to Identify Fish Gut Contents

Tuesday, November 10th, 2015

by Heather Soulen

Rob Aguilar takes photos of all DNA barcoding reference specimens collected in the Chesapeake Bay

Rob Aguilar takes photos of all DNA barcoding reference specimens they collect in the Chesapeake Bay

Rob Aguilar of SERC’s Fish and Invertebrate Ecology Lab co-authored a DNA barcoding paper this past September in the journal Environmental Biology of Fishes. Rob spoke with us about his paper and the DNA barcoding work going on in the Fish and Invertebrate Lab. While the term DNA barcoding may seem difficult to understand, it’s easiest to think about it as a uniquely identifiable species level code.

Click the sound file below to listen to the interview.

Additional barcoding details are available in the full podcast transcript.

Click to continue »

Remembering Hurricane Katrina by Studying Marshes of the Future

Friday, August 28th, 2015

by Heather Soulen

The Need for Healthy Marshes

Ten years ago, on August 28, 2005, Hurricane Katrina nicked south Florida and entered the heat-charged waters of the Gulf of Mexico, transforming from a Category 1 hurricane into a super-charged Category 5. In the early morning hours of August 29, it ripped through Louisiana and Mississippi. Thousands died, and hundreds of thousands of homes and businesses were destroyed. Today, much of the Louisiana and Mississippi coasts, and its people, are still recovering from the devastation.

When Katrina hit, some coastal marshes east of the Mississippi River lost approximately 25 percent of their area. In the decade that followed, salt marshes and wetlands in Louisiana have continued to disappear in some places, but not others. The scientific community soon zeroed in on keeping marshes healthy, since, as one scientist remarked “A healthy marsh is pretty resilient, A stressed marsh – storms will physically break the marsh down.” Marshes and wetlands are ecologically and economically important ecosystems. During storms they act like buffers, reducing storm surge and flood damage, but only if they’re healthy. The question is, what factors make a marsh strong or weak?
Click to continue »

Bucket Buffets Divulge Deer Preferences

Friday, August 21st, 2015
Lisa Koetke prepares a motion-activated camera for another trial. (Lisa Koetke)

Lisa Koetke prepares a motion-activated camera. (Courtesy of Lisa Koetke)

by Chris Patrick

Imagine a swimming creature. It holds an antlered head above the water as its skinny, hooved legs tread underneath. A black stripe runs from its head to its tail, outlining a waggling white rump, revealing it to be a sika deer.

In 1916, a man named Clemment Henry released between four and six sika (the number isn’t certain) for hunting on James Island, off Maryland’s Eastern Shore. But it turns out sika are great swimmers—by 1962 they migrated to the Delmarva Peninsula and they now occupy every county of the lower Eastern Shore. Click to continue »

Smashing Logs to Uncover a Body-Snatcher’s Secrets

Friday, August 14th, 2015

Darin Rummel smashes a stick against the dock. (SERC)

by Chris Patrick

Darin Rummel, intern in the marine invasions lab at the Smithsonian Environmental Research Center (SERC), raises a piece of wood twice the length of his arm and slams it onto a dock in the Patuxent River at Greenwell State Park in Hollywood, Md.

The soggy stick crumbles and a white-fingered mud crab scurries from the wreckage. Rummel adds the crab to a modest collection in a Tupperware container and raises the stick above his head again. Connor Hinton, another marine invasions lab intern, wades into a cove of muddy water in search of more crab-concealing wood. Click to continue »

Under the Apron, into the Genome

Tuesday, June 23rd, 2015

by Chris Patrick

Tepolt holding a Humboldt squid at Hopkins Marine Station, where she did her doctorate research. (Tom Hata)

Tepolt holding a Humboldt squid at Hopkins Marine Station in Pacific Grove, California. (Tom Hata)

Before I was the science writing intern at the Smithsonian Environmental Research Center (SERC), I volunteered in SERC’s marine invasions lab sorting white-fingered mud crabs with Monaca Noble, researcher and public relations coordinator. The mud crabs are tiny, ranging from the size of a tick to the size of a quarter. They reek of preservative alcohol, and milky mittens glove their pincers. While sorting, I met Carolyn Tepolt, a postdoctoral fellow at SERC.

34-year-old Tepolt (which sounds like a fusion of “teapot” and “catapult”) offered me homemade lemon bars the day we met. Working together, we discovered we were both undergraduates at the College of William and Mary—we lived on the same floor of the same freshman hall 14 years apart. Tepolt visited the lab to learn the crab-sorting process because this summer she will use genetics to study how mud crabs are adapting to their parasite, Loxothylacus panopaei, or Loxo. Click to continue »

DNA Detects Two Hidden Oysters in Panama

Thursday, May 21st, 2015

by Monaca Noble and Katrina Lohan

Image: Oysters and other life grow on dock pilings at the Smithsonian Tropical Research Institute (Credit: Kristina Hill-Spanik)

Oysters and other life grow on dock pilings at the Smithsonian Tropical Research Institute in Panama
(Kristina Hill-Spanik)

A robin is a robin. It isn’t often confused with other birds. But some marine organisms are very difficult to identify because they look similar, too similar even for taxonomists trained to detect differences. Oysters are like this.

Oyster shells come in all shapes and sizes. As oysters fight for space and battle to survive in tough environments, their shells can change appearance based on conditions where they live. This makes it very hard to distinguish similar-looking species. Using DNA, we can identify these difficult species and provide new insights into their distribution, ecology, and ranges—insights not possible using shell morphology alone. In Panama, this DNA detective work led to two surprising discoveries.

Click to continue »

Four Invaders That Seduced Us (And One
That Could)

Thursday, January 29th, 2015

by Kristen Minogue

Image: School of blue-green damselfish (Chromis viridis) in the Coral Sea (Credit: Richard Ling)

School of blue-green damselfish, Chromis viridis, in the Coral Sea (Richard Ling)

You could be forgiven if, on the long list of environmental threats, the site of an empty aquarium doesn’t fill you with dread.

Most invasive species cross our borders by accident, stuffed into crates with packing material, or clinging to the hulls or floating in the ballast of cargo ships. Often we don’t even realize they’re here until years after they arrive. But there are a few that we welcome into our homes (or fish tanks) with open arms, because they are beautiful and exotic and, well, we’re human. Sometimes they’re harmless, and sometimes our infatuation has deadly consequences.

Click to continue »

From the Field: Diving Into the Kelp Forest

Monday, December 15th, 2014

by Michelle Marraffini, SERC marine biologist

Image: SERC diver Lina Ceballos carries sampling equipment down to depth to survey species underwater. (by Michelle Marraffini/SERC)

SERC diver Lina Ceballos carries sampling equipment down to depth to survey species underwater.
(Michelle Marraffini/SERC)

The sun shimmers on the still waters of Monterey Bay, Calif., this beautiful October morning as we prepare for our dive survey. As we stand on the shore unloading our sampling gear, we can see the tops of giant kelp break the surface and an otter munching on a freshly caught crab. We’re about to dive into the Pacific Ocean in search of nonnative species on the outer coast.

Click to continue »

Do forest canopy gaps help invasive plants thrive?

Friday, 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 »

Invasive plant may protect forests from drowning

Thursday, 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 »