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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.


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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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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.

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2014 in Review: The Good, the Scary and the Weird

Wednesday, December 31st, 2014
Photo: Dejeanne Doublet inspects a red oak in BiodiversiTree. (Credit: SERC)

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

by Kristen Minogue

We sprayed pig’s blood on baby trees, studied a strange ménage a trois in the orchid world and met the father of marine invasions science himself. It’s been an odd year at the Smithsonian Environmental Research Center. But we like living in interesting times. Here are 10 of our favorite stories from 2014. Here’s hoping 2015 is even stranger.

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Dead Zones Likely to Expand as Coastal Waters Warm

Monday, November 10th, 2014

by Kristen Minogue

Image: Menhaden fish kill in Narragansett Bay, Rhode Island. (Credit: Chris Deacutis)

Menhaden fish kill in Narragansett Bay, Rhode Island. (Chris Deacutis)

A full 94 percent of the world’s dead zones lie in regions expected to warm at least 2 degrees Celsius by the century’s end according to a new report from the Smithsonian Tropical Research Institute and the Smithsonian Environmental Research Center published Nov. 10 in Global Change Biology. The paper states that warmer waters—mixed with other climate change factors—make for a dangerous cocktail that can expand dead zones.

Dead zones form in waters where oxygen plummets to levels too low for fish, crabs or other animals to survive. In deeper waters, dead zones may last for months, as with the annual summer dead zone in the Chesapeake Bay. Temporary dead zones may occur in shallow waters at night. The largest dead zones in the Gulf of Mexico and Baltic Sea can cover more than 20,000 square miles of the sea floor. The number of dead zones across the world is growing exponentially, doubling each decade since the 1960s.

“They’re having a big impact on life in the coastal zone worldwide,” said Keryn Gedan, a co-author and marine ecologist at the Smithsonian Environmental Research Center and the University of Maryland. “A lot of people live on the coast, and they’re experiencing more fish kills and more harmful algal blooms. These are effects of dead zones that have an impact on our lives.”

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Oysters and the Chesapeake’s Jellyfish Wars

Tuesday, September 30th, 2014

Image: Jellyfish Chrysaora quinquecirrha (Credit: Lori Davias)

Jellyfish Chrysaora quinquecirrha (Lori Davias)

by Kristen Minogue

Every summer, the food web in Chesapeake Bay gets jostled around as two plankton-eating predators jockey for power: comb jellies and jellyfish. Most smaller species don’t have a stake in the battle—both predators eat zooplankton and fish eggs, after all. But for young oyster larvae, the victor could make the difference between being protected civilians or collateral damage.

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