Invasive Species

...now browsing by category

 

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

OLYMPUS DIGITAL CAMERA

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 »

Arctic Unguarded: Melting Ice Opens Way
for Invaders

Wednesday, 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 »

Nonnatives in Your Garden:
A Curse or a Blessing?

Tuesday, April 29th, 2014

by Kristen Minogue

Three nonnative flowers in Maryland. Left to right: Queen Anne's Lace, Moth Mullein and Lesser Celandine. (Susan Cook Patton)

Three nonnative flowers in Maryland. Left to right: Queen Anne’s Lace, Moth Mullein and Lesser Celandine. (Susan Cook-Patton)

“I just want to plant something that will grow in my yard. If a nonnative species grows better than a native, why shouldn’t I plant it?”

It’s a valid question, one that SERC postdoc Susan Cook-Patton remembers hearing from her father while still in high school. In the quest to preserve native plants, it’s become almost taboo to talk about the benefits of nonnatives. But not all nonnative plants are rampant invaders, and sometimes they could be good for gardens as a whole. Cook-Patton broke down the pros and cons of gardening with nonnative species at the Smithsonian Environmental Research Center’s first evening lecture on April 15. Here are a few to consider when deciding what to put in your garden:

Click to continue »

Before It Was Cool: The Father
of Marine Invasions

Thursday, April 24th, 2014

by Kristen Minogue

Photo: Jim Carlton tracked invasive species in the ocean for years when most scientists thought the sea was "invasion-proof." (Anna Sawin)

Jim Carlton tracked invasive species in the ocean for years when most scientists thought the sea was “invasion-proof.” (Anna Sawin)

There’s no official “father of marine invasions biology.” But if anyone could compete for the title, Jim Carlton, director of the Williams College – Mystic Seaport Program, would almost certainly top the list. More than 50 scientists from the U.S., Canada, Italy, Argentina and New Zealand voiced some version of that view, when they descended on the Smithsonian Environmental Research Center for a three-day symposium in April informally dubbed “Jimfest.”

Like so much in science, his career began by sheer accident. In 1962, 14-year-old Carlton stepped on a strange worm while picnicking with his family in Lake Merritt, a small lagoon near San Francisco Bay. A few weeks later he discovered the same worm in an exhibit at a local nature center. The label identified it as a tubeworm from the South Seas. “This thing in my backyard as it were, not far from my house, in this estuarine lagoon, how could this thing be from the South Seas?” Carlton remembered thinking. “So I got fascinated by that concept.”

Click to continue »

From the Field: Two Weeks in Panama

Friday, April 4th, 2014

Linda McCann is a marine biologist studying invasive species with the Smithsonian Environmental Research Center. This March she and three other researchers spent 17 days exploring marine life on both sides of Panama, at the Smithsonian Tropical Research Institute (STRI).

Sloth in Isla Galeta, near the Smithsonian's marine station on the Panama Canal. (Photo: Kristen Larson/SERC)

Sloth in Isla Galeta, near the Smithsonian’s marine station on the Panama Canal.
(Kristen Larson/SERC)


March 10
Got up at o-2:30 to catch a shuttle to the airport, after singing a concert the night before and not getting to bed until 12:30. Finally arrived at our lodging in Panama about 10:30 p.m., bleary-eyed but happy to be back in this special place!

March 11
Our first day. Usually we start out a bit slowly, shopping for food, getting our IDs at Tupper, getting set up, but today we dive right in. We collect samples from the STRI dock in Naos and begin the process of reacquainting ourselves with the species in Panama. Warmer water means we are looking at a whole different suite of species than we see back in San Fran or Chesapeake. The lab is on an island situated just outside the canal on the Pacific side.

Click to continue »

Intern Logs: Mussels and the Melting Arctic

Thursday, April 3rd, 2014

by Amanda Guthrie, Marine Invasions Lab Intern

Mytilus mussels in Point Judith Marina, Rhode Island. (Photo by Kim Holzer)

Mytilus mussels in Point Judith Marina, Rhode Island. (Kim Holzer)


Imagine after settling down on a place to stay, your home picks up speed and moves without any forewarning, bringing you along with it to a new place. You get off to explore. It seems livable and similar to home, but a few adjustments will be necessary.

This story would be possible — if you were a mussel, a barnacle, or a myriad of other intertidal organisms. Once there, these new arrivals are sometimes able to escape their predators at home and thrive—often at the expense of native species, or the ecosystem as a whole.

Such is the dilemma of Mytilus galloprovincialis, a mussel from the Mediterranean. Mytilus galloprovincialis is native to southern Europe but has branched out to numerous non-native regions around the globe. It is the most prevalent non-native marine species in South Africa. There, it not only competitively displaced native species but also catalyzed the decline of swimming crabs and the increase of whelks.

Click to continue »