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Environmental “Forensics” Pieces Together Mysterious Phragmites Invasion

Monday, July 27th, 2015
Eric Hazelton in a Phragmites patch on the Nanjemoy River in Maryland. (Rebekah Downard of Utah State University)

Eric Hazelton in a Phragmites patch on the Nanjemoy River in Maryland. (Rebekah Downard of Utah State University)

by Chris Patrick

On crime scene investigation shows, DNA forensic scientists sit in a darkened room, wearing lab coats and clutching clear vials over dramatic music. In a matter of hours, they conjure perpetrators to the scene of a crime or prove relations between separated kin simply from remnants of genetic material.

Researchers in the Plant Ecology and Molecular Ecology Labs at the Smithsonian Environmental Research Center (SERC) published a paper in July in Wetlands that has more in common with a CSI episode than you’d expect—though in their case, the process took months instead of hours.

There’s a strain of Phragmites australis, the common reed, that’s native to North America. But the population of an invasive strain from Europe, introduced in the 1800s, suddenly boomed without warning in wetlands around the Chesapeake Bay in the 1980s. SERC scientists had some ideas about what might have caused the sudden explosion, so the team attempted to recreate the history of this sudden, aggressive invasion to test their theories. Click to continue »

Yet Another Reason Lionfish Make Such Good Invaders

Friday, July 24th, 2015

by Chris Patrick

Red Lionfish. (Jacek Madejski)

Red Lionfish. (Jacek Madejski)

The lionfish (Pterois volitans) resembles a psychedelic fish-shaped peppermint, striped in red and white and decked with feathery, fan-like fins. But its venomous spines and invasive-species status make it much less innocuous than candy.

Lionfish are native to the Indo-Pacific. They’re popular aquarium fish—it’s likely ex-aquarium-owners introduced them into the Atlantic. They spread rapidly along the southeastern coast of the United States, into the Gulf of Mexico and the Caribbean.

Lionfish flourish in their introduced range, where they have no predators. They breed quickly—a female can produce up to two million eggs per year. They live a long time, sometimes more than 15 years. And they’ll eat basically anything that fits into their mouths, decimating populations of native marine animals with their voracious, indiscriminate appetites. When they arrive at a reef, they can reduce the number of native fish by 80 percent.

But lionfish may also be harmful to the native fish they can’t eat. A recently published PLOS ONE study reports that invasive lionfish are parasitized less than native fish. Click to continue »

Fish Don’t Fear Selfie Sticks

Thursday, July 16th, 2015

by Chris Patrick

Lovers of both the Smithsonian and the selfie stick, rejoice! Though the infamous monopods are banned in Smithsonian museums and galleries, they’ve found a new arena of use: labs.

Well, in one lab at least. Researchers in the marine ecology lab at the Smithsonian Environmental Research Center (SERC) are using selfie sticks to record fish behavior without scaring them. SERC’s marine ecology team wants to see if fish raised in low-oxygen conditions acclimate to breathing less oxygen. “I have never heard of someone else using the selfie stick for science,” said Seth Miller, a postdoctoral fellow in the marine ecology lab and collaborator on the project. “Although it probably occurs. Ecologists are pretty resourceful.”

Ashley Collier records a fish without scaring it by using a selfie stick. (SERC)

Ashley Collier records a fish without scaring it by using a selfie stick. (Chris Patrick)

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Interns Compete in Oyster Olympics

Monday, July 13th, 2015
Interns Julianne Rolf and Emily Bulger. (Chris Patrick)

Interns Julianne Rolf and Emily Bulger. (Chris Patrick)

by Chris Patrick

When 11 Smithsonian Environmental Research Center interns piled into a van headed for the Oyster Olympics, they had no idea what was in store. For the next three hours, they shoveled, scooped, scraped, sweated, poured, piled, folded, clamped, ran, and acquired minor injuries competing against interns from other environmental organizations in the area. Though the Chesapeake Bay Foundation (CBF) holds the Oyster Olympics annually at its Discovery Village in Shady Side, Md., this was the first year SERC interns vied for the golden oysters (think of gold-painted shells hanging from rope). From the get-go, it was clear SERC interns were the underdogs. Click to continue »

Pollution Makes Mangroves Weaker Against Hurricanes

Friday, June 5th, 2015

by Kristen Minogue

Image: Candy Feller inspects a white mangrove stand. (Credit: Anne Chamberlain)

Candy Feller inspects a white mangrove stand in Florida. (Anne Chamberlain)

Mangroves—those tangled trees with strange roots common along tropical coastlines—are masters at protecting their territory from hurricanes. So, logically, tall mangroves should be stronger than short ones.

Except when they’re not. Sometimes tall mangroves are weaker, something Smithsonian ecologist Candy Feller discovered after two hurricanes tore through her experiments in Florida. Click to continue »

The Scavenger Bug That Fights Climate Change

Friday, May 29th, 2015

by Kristen Minogue

Common pillbug Armadillidium vulgare (Walter Siegmund)

Common pillbug Armadillidium vulgare
(Walter Siegmund)

In the battle to hold back climate change, Mother Nature has supplied several allies, from the rainforest to bacteria. Now we can add one more to the list: Woodlice, tiny scavenger bugs that feed off rotting plants.

More than 3,000 species of woodlice are known to man, and they go by many names. If you’re American, chances are you know them as pillbugs or roly-polies. They’ve inherited stranger-sounding titles in other parts of the world, from monkeypigs to granfy croogers. (For a list of 40-some-odd British variations, see here.) But they all point to the same thing: a 14-legged, millipede-like crustacean roughly half the size of a dime.

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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.

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Mangrove Trees Divided on Journey North

Thursday, April 30th, 2015

by Kristen Minogue

Image: John Parker samples a red mangrove tree in Florida. (Credit: SERC)

John Parker samples a red mangrove tree in Florida. (SERC

Deep in the Florida swamps, black, white and red mangrove trees have lived together for thousands of years. But warmer winters are pulling the ecological fellowship apart, creating a new landscape in the north.

The story begins decades ago. Once, when Florida winters were chillier, mangroves remained trapped in the subtropics. As the climate warmed, Smithsonian ecologists discovered that fewer cold snaps were empowering mangroves to push north. But the trees aren’t moving in sync. Black mangroves have outstripped their cousins, passing St. Augustine, while white mangroves are lagging almost 30 miles behind. Until now, there weren’t any hard data explaining why.

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Two New Bryozoan Species Discovered Off Portugal

Tuesday, March 10th, 2015

by Kristen Minogue

Image: SERC research associate and Portuguese native João Canning-Clode. (Credit: Valentyna Chan)

SERC research associate and Portuguese native João Canning-Clode. (Valentyna Chan)

Since he began surveying the waters of Madeira two years ago, João Canning-Clode has discovered a new invasive species almost every month. The archipelago off the coast of Portugal is a hot spot for biodiversity, especially for bryozoans – “moss animals” that often cover rocks, piers and other artificial substrates. But he didn’t anticipate finding a completely new species, let alone two.

Bryozoans are easy to mistake for plants or corals from a distance. Some resemble moss as they form encrusting colonies on underwater rocks. Others form branching, bush-like colonies that look more like algae or corals. Up close, though, a single colony can contain millions of individual, tube-shaped zooids. The zooids support each other. But break a piece off, and a single zooid can start a new colony of its own.

The team named the new species Favosipora purpurea (for its pinkish-purple color) and Rhynchozoon papuliferum (for its special triangular-shaped zooids). In this Q&A, Canning-Clode, a research associate with the Smithsonian Environmental Research Center, details the dual discovery published this month.

FavasiporaPurpurea_PatricioRamalhosa

 Rhynchozoon_papuliferum_Web
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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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