Oyster Disease Thrives in Nightly Dead Zones

Posted by KristenM on 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)

Posted by KristenM on 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

Posted by KristenM on 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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Not Your Everyday Martha Stewart Glue Sticks

Posted by KristenM on December 19th, 2014

by Heather Soulen, research technician

When I mention that we use “glue sticks” at the Smithsonian Environmental Research Center to help answer research questions about wetland ecology, I get looks of confusion and amusement. People often think I am using:

Glue Sticks (Credit: Heather Soulen/SERC) or GlueGun (Credit: Heather Soulen/SERC)

But, what I really mean is that I use these:

+ +

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From the Field: Diving Into the Kelp Forest

Posted by KristenM on 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.

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Saving the River Herring: Don’t Let the Good Die Young

Posted by KristenM on November 26th, 2014

by Kristen Minogue

Image: Alewives, a species of River Herring. (Credit: Geoffrey Gilmour-Taylor)

Alewives, one of two species of River Herring in Chesapeake Bay. (Geoffrey Gilmour-Taylor)

It’s no secret that River Herring are in trouble. There was a time, back in the 1950s, when Maryland fishermen regularly pulled in 4 million pounds or more a year of the silver fish. Then something mysterious happened. Herring harvests generally fluctuate from year to year. But in the 1970s, they fell and never came back up. For the last four decades, commercial fishermen in Maryland have been lucky to catch a few hundred thousand a year. Now they catch none.

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Feeding the World in the Age of Humans

Posted by KristenM on November 18th, 2014

Image: Bread, flour, cornmeal, rice and pasta. (Credit: Scott Bauer/USDA)

Bread, flour, cornmeal, rice and pasta. (Scott Bauer/USDA)

by Kristen Minogue

Food doesn’t typically get the spotlight in talks on climate change. Even when human health enters the picture, heat waves and category 5 hurricanes often dominate coverage. But as the Earth changes, so does agriculture. That raised just one of several questions scientists wrestled with at the Smithsonian’s second climate change symposium, titled “Living in the Anthropocene”: What will the world’s 7 billion people eat?

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Dead Zones Likely to Expand as Coastal Waters Warm

Posted by KristenM on 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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Mathias Lab Opens New Era of Sustainability
at Smithsonian

Posted by KristenM on October 9th, 2014
Image: Charles McC. Mathias Laboratory (Credit: Smithsonian Environmental Research Center)

Charles McC. Mathias Laboratory (Smithsonian Environmental Research Center)

by Kristen Minogue

On September 19, the doors officially opened inside what’s targeted to be the Smithsonian’s first LEED-Platinum building: the Charles McC. Mathias Laboratory at the Smithsonian Environmental Research Center.

The vision for a more sustainable lab emerged in the 1990s. Six years ago, SERC director Tuck Hines shared the idea with the then-new Secretary of the Smithsonian, Wayne Clough, on his first visit to the SERC campus.

“Tuck’s enthusiasm was infectious, and I told him then and there, you have my full support. We have to get this done,” Clough said. “But back then, it was just a dream….Today, six years from that first discussion, we’re here today to say, the dream has been fulfilled.”

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Oysters and the Chesapeake’s Jellyfish Wars

Posted by KristenM on 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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