by Jaylene Lopez

You may have heard of invasive species like mitten crabs, emerald ash borers and zebra mussels that wreak havoc on the ecosystems they enter. But have you ever considered the invasive species that are invisible to the naked eye?  

“There’s been a lot of research on the transport of larger organisms and the role of shipping,” said Katrina Lohan, head of the Coastal Disease Ecology Lab at the Smithsonian Environmental Research Center and a coauthor of a recent paper about invasive parasites. “My interest in it, though, was thinking about how these organisms that are larger, that we can see, are also potentially transporting, transmitting or dispersing organisms that are smaller, that we can’t see.”  

by Kristen Goodhue

This July, Woodlawn House—the oldest building in the Smithsonian still in its original spot—opened to the public for the first time. Built in 1735 by the Sellman family, it’s now received a new name: the Woodlawn History Center. Visitors can walk through the first floor, encounter centuries-old artifacts and learn about the lives of enslaved and free people who lived on the land. For this feature, we collected a few stories from the exhibit and the people who helped create it.

The Woodlawn History Center is open for free to visitors on select dates (see the Woodlawn History Center visitors page for current dates). It’s located just past the brick security kiosk when visitors first enter the SERC campus.

Dennis Simms: The Enslaved Testifier

Born in 1841, Dennis Simms worked as an enslaved laborer on the Java Farm, a plantation next to Woodlawn run by the Contee family. There are no photographs or illustrations of him. Other than the color of his skin, we have no idea what he looked like. But in 1937 he left a detailed oral history of slavery at Java. Below are a few excerpts.

“We lived in rudely constructed log houses, one story in height, with huge stone chimneys, and slept on beds of straw.”

by Nathaniel Humpal

Before the pandemic, widespread illegal poaching already had negative impacts on local, state and nationwide systems, from the food system to the economy. A new paper, which compiles reports from over five years in a marine protected area (MPA) off the east coast of Brazil, notes how rates of illegal poaching in this MPA have doubled during the pandemic, and how protection of this area has struggled to keep up.

Despite organizations’ attempts to prevent and punish illegal poaching, it seems to remain the rule rather than the exception, especially in MPAs. As of this article’s publication, less than 10% of the world’s MPAs have successfully reduced illegal poaching. The percentage will likely decline further, due to the pandemic reducing tourism. This reduction means less money to support the MPAs and the staff needed to monitor and enforce restrictions.

Past Migration, Pleistocene Ice Ages Still Impact Size and Structure of Modern Eelgrass Communities

by Kristen Goodhue

Deep evolution casts a longer shadow than previously thought, scientists report in a new paper published Aug. 1 in the Proceedings of the National Academy of Sciences. Smithsonian scientists and colleagues looked at eelgrass communities—the foundation of many coastal marine food webs along the north Atlantic and Pacific coasts—and discovered their ancient genetic history can play a stronger role than the present-day environment in determining their size, structure and who lives in them. And this could have implications for how well eelgrasses adapt to threats like climate change.

About a half-million years ago, when the world was warmer, some eelgrasses made the difficult journey from their homes in the Pacific to the Atlantic. Not all the plants were hardy enough to make the journey across the Arctic. For those that succeeded, a series of ice ages during the Pleistocene Epoch further affected how far they could spread. Those millennia-old struggles left lasting signatures in their DNA. Even today, eelgrass populations in the Atlantic are far less genetically diverse than those in the Pacific. 

Still, in the classic “nature versus nurture” debate, scientists were stunned to discover that genetic legacy sometimes does more to shape modern eelgrass communities than the current environment.

The Smithsonian’s Oldest In-Place Building Opens to Visitors for the First Time

by Kristen Goodhue

This summer, a new history exhibit opens in the brick house at the entrance of the Smithsonian Environmental Research Center (SERC): the Woodlawn History Center. Built in 1735, Woodlawn is the oldest Smithsonian building still in its original location. Visitors will hear stories from generations who lived and worked on the land, and see how their lives wove into the American tapestry.

For nearly two centuries, Woodlawn served as the plantation home of the Sellman family. Coming to America in indentured servitude, the Sellmans left a double-sided legacy as soldiers, innovators and slaveowners. Their descendants, who spread across the country, fought on both sides of the Civil War.

Marine Predation Intensifies in Warmer Waters; Could Reshape Ocean Communities as Climate Changes

by Kristen Goodhue

_{Triggerfish and pufferfish consume marine invertebrates on a panel exposed to predators in Panama City. Scientists deployed this panel during a previous experiment using similar communities to the ones in the current study. (Credit: Edited by Michele Repetto. Footage from Freestone et al. 2021 Archives)}

A hotter ocean is a hungrier ocean—at least as far as fish predators are concerned. In a new field study published online June 9 in Science, Smithsonian scientists discovered predator impacts in the Atlantic and Pacific peak at higher temperatures. The effects cascade down to transform other life in the ocean, potentially disrupting balances that have existed for millennia.

“It’s taken thousands of years to get to this state, and then suddenly we’re ramping up the temperature at a much higher rate,” said Gail Ashton, lead author of the report and marine biologist with the Smithsonian Environmental Research Center (SERC). “And we don’t really know the implications of that temperature increase.”

Beneficial Effects of Rising CO₂ for Plants Disappear Under Flooding, 33-Year Field Experiment Reveals

by Kristen Goodhue

Wetlands across the globe are in danger of drowning from rising seas. But for decades, scientists held out hope that another aspect of climate change—rising carbon dioxide (CO₂)—could trigger extra plant growth, enabling coastal wetlands to grow fast enough to outpace sea-level rise. That helpful side effect is disappearing, they discovered in a new study published May 18.

Rainforest Trees May Be Dying Twice as Quickly Since the 1980s as a Hotter, Thirstier Atmosphere Dries Them Out

by David Bauman and Kristen Goodhue

Tropical trees in Australia’s rainforests have been dying at double the previous rate since the 1980s, potentially because of climate change, according to an international study published May 18 in the journal Nature. Researchers found the death rates of tropical trees have doubled in the past 35 years as global warming increases the drying power of the atmosphere.

Intact tropical rainforests are major stores of carbon, absorbing around 12% of human-caused carbon dioxide emissions. But their deterioration reduces biomass and carbon storage, making it increasingly difficult to keep global peak temperatures well below the target 2 degrees Celsius required by the Paris Agreement.

“It was a shock to detect such a marked increase in tree mortality, let alone a trend consistent across the diversity of species and sites we studied,” said lead author David Bauman, a tropical forest ecologist at the Smithsonian Environmental Research Center (SERC) and the University of Oxford. “A sustained doubling of mortality risk would imply the carbon stored in trees returns twice as fast to the atmosphere.”

A pattern that existed since the age of dinosaurs is now disappearing—with profound implications for ecosystems

by Christian Elliott, Northwestern University

Sitting on couches at an Airbnb in Montreal for the 2018 Marine World Conference, Jon Lefcheck, the Coordinating Scientist for the MarineGEO program at the Smithsonian Environmental Research Center, and his colleagues started tossing around the sort of questions scientists do in their free time. Questions like, is there a general pattern between what animals eat and how big they are?

Four years later, that conversation has culminated in a new study in Nature Ecology & Evolution, with the most comprehensive analysis yet of the relationship between vertebrate animals’ body sizes and their places on the food chain. The study reaches across taxonomic groups, ecosystems and 150 million years of evolutionary history. Humans, they found, are starting to disrupt a longstanding balance.