Seal collects data with other interns for Smithsonian scientists who are investigating the impact of global change on tidal marshes.
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Ecology
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Day at the Museum: Battle of the Smithsonian Marsh
Thursday, August 5th, 2010Click to continue »
Five Minutes for Mangroves
Monday, July 26th, 2010Hallmark may not have a card for it, but today is International Mangrove Action Day.
Photo: Ilka C. Feller/Smithsonian Institution
The occasion is a small but vibrant tradition that has been observed annually on July 26th for nearly a decade in countries around the globe, including the U.S., India, Ecuador, Micronesia and many others. To celebrate, some communities organize protests or restoration projects. Some convene discussions or offer educational lectures about mangrove ecology. Others simply take a moment to appreciate the importance of mangrove forests.
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Seagrasses and Sunlight: Rethinking Water Quality Measurements
Wednesday, July 14th, 2010
Around the world seagrasses are being lost. Turbidity is one factor that impedes their growth. However, in some places water quality has improved, but the grasses have not rebounded. SERC scientists wonder if a 'carpet of fluff'—a mix of organic and inorganic particles that floats just above the sediment—is blocking the sunlight seedlings need to grow. Photo: Tim Carruthers courtesy of IAN/UMCES.
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Nitrogen Weakens Marshes’ Ability to Hold Back Climate Change
Wednesday, June 30th, 2010Scientists Find Excess Nitrogen Favors Plants That Respond Poorly to Rising CO2
The Smithsonian's Global Change Research Wetland. Photo: SERC
Plants build their tissue primarily with the CO2 they take up from the atmosphere. The more they get, the faster they tend to grow—a phenomenon known as the “CO2 fertilization effect.” However, plants that photosynthesize greater amounts of CO2 will also need higher doses of other key building blocks, especially nitrogen. The general consensus has been that if plants get more nitrogen, there will be a larger CO2 fertilization effect. Not necessarily so, says a new paper published in the July 1 issue of Nature.
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Introducing Tintinnophagus acutus
Thursday, June 24th, 2010
A Tintinnophagus acutus dinospore, with a flagellum. Photo: Wayne Coats
Of the approximately 2,000 known species of living dinoflagellates, about 150 are parasitic. These organisms can alter the marine food web, in some cases destroying prey that consumers like copepods and larval fish rely upon. Coats first spotted T. acutus in the 1980s, in plankton samples he had collected from the Chesapeake Bay. Through his microscope, he noticed a ciliate being edged out of its lorica (shell) by a dinoflagellate. It looked different from others he had observed.
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Three questions for a novice, but well-informed beekeeper
Wednesday, June 9th, 2010The Smithsonian Environmental Research Center’s outreach coordinator, Karen McDonald, has assumed a second title: beekeeper. This spring she and Elio Cruz, from the National Museum of Natural History, set up three hives in a remote field on SERC’s campus. The bees feast on the nectar and pollen of tulip poplars, walnut trees, clover and other nearby plants. With help from NMNH’s Insect Zoo, McDonald is doing her part to help the struggling bees.
Have scientists figured out what’s causing Colony Collapse Disorder (CCD)?
No. They’ve been studying the large-scale losses of hives since American beekeepers began reporting the phenomenon in 2006. Scientists think a combination of factors—not just one—is leading to CCD. They’re currently exploring the role of pesticides, parasites, pathogens and overall stress on the bees.
They produce honey, they sting…what else do bees do?
Humans, not to mention, alfalfa, apples and almonds owe a great deal of gratitude to the honey bee. In its quest for nectar and pollen, one bee can visit several thousand flowers in a single day. In the United States, more than 3.5 million acres of crops rely on bees for pollination, which helps the plant’s flowers turn into fruits and nuts. That figure doesn’t include all the wild plants that need bees as well.
What do you find most interesting about the insect?
It’s amazing to me that they live—and work—mostly in the dark. The bees seal the hives with propolis, a sticky resin collected from plants. This helps them regulate the temperature of the hive. The dark also helps them secrete more wax for the comb. Without light, bees communicate by touch, smell and taste. The queen produces chemical pheromones that tell the worker bees that everything in the hive is okay. And after collecting nectar and pollen, workers return to the hive and perform waggle dances to communicate where they gathered the food. Again it’s all in the dark, so the others line up behind the returning bee as it dances and tap it with their antennae to figure out where the nectar and pollen are. Bees can even distinguish intruder bees from other hives simply by their smell; it’s a remarkable set of adaptations.
One species, 20 genotypes, 3,808 plants and a plague of voles: Study reveals new benefits of genetic diversity
Thursday, May 27th, 2010If you’re designing an ambitious field experiment that involves more than 3,800 plants and 240 deer cages, ecologist John Parker has some words of wisdom for you: beware of the unexpected. Beware of meadow voles. Parker is a senior scientist at the Smithsonian Environmental Research Center, in Edgewater, Maryland. He studies the relationship between plants and the herbivores that eat them.
Ecologist John Parker examines one of his plants in the field. Photo: Alex Smith
In a recent paper published in Ecology Letters, Parker chronicles the ups, downs and findings of a study investigating the links between genetic diversity in plants and herbivory. “Most people think about biodiversity in terms of species diversity, where you have a rich variety of plants and animals living in an ecosystem,” explains Parker. “I’m interested in exploring the importance of genetic diversity within a species.” Scientists have recently discovered that plants can benefit from growing in genetically-rich polycultures, where neighboring plants of the same species have different genotypes. Parker’s new research shows that these benefits include better protection against hungry herbivores like deer and voles.
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Close encounters with science: SERC’s annual open house
Wednesday, May 19th, 2010
Volunteers Richard Hohn and Carla Downes mug for the camera and show off their crab crowns. Photo: Karen McDonald
Face-painted kids and smiling parents fanned out across the Smithsonian Environmental Research Center this past Saturday for the annual open house. They learned about horseshoe crabs, underwater research robots, toe-biting bugs and the rich history of the land. The official count is not yet in, but ask SERC’s outreach coordinator Karen McDonald if she was happy with the turnout and the answer is: yes. Ask her if she’s still recovering from organizing the day’s activities and the answer is also yes.
Thank you to our volunteers, partner organizations, board members and staff for making the day a success. A special thanks to The Chaney Foundation for sponsoring the event and to Peter G. Cane for photographing the day.
Mark your calendars for next year’s open house: Saturday, May 14, 2011.
Key to invasive plants’ success is not simply a matter of taste
Thursday, May 6th, 2010
The woolly bear caterpillar (Pyrrharctia isabella) is a generalist herbivore; it feeds on many of the trees and plants in the woods surrounding SERC. Photo: John Parker
Unless you are a famished hiker on the Appalachian Trail, chances are you have not given much thought to how the forest tastes. Plant flavor is an important area of study for ecologists examining invasive plants. A common theory holds that the success of kudzu and other exotic species is due to foreign biochemistry that makes them repugnant to native herbivores. In a new study published in PLoS ONE, scientists at the Smithsonian Environmental Research Center in Edgewater, Md., have cast doubt on this popular but little-tested idea.
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A census of a different sort
Tuesday, April 27th, 2010If you’re a fish or crab living in the Chesapeake Bay, it’s quite possible that at some point during your life, you’ll make your way into one of the creeks, rivers or subestuaries that feed the Chesapeake. These areas provide important nursery and spawning habitat for many of the Bay’s aquatic residents. For more than 25 years, researchers from the Smithsonian Environmental Research Center’s Fish and Invertebrate Ecology Lab have taken a weekly survey of the species that make their way into and out of one of these creeks. Its name is Muddy Creek and it feeds into the Rhode River, which flows into the Chesapeake Bay.
View Muddy Creek and the Rhode River in a larger map
To survey the animals swimming up and down Muddy Creek, the researchers use a fish weir — an expanse of nets, gates and boardwalks — that temporarily blocks aquatic traffic. Once a week, the researchers close the weir, set out the nets and identify and count all the species that get trapped. Their data go back to 1983.
This type of fine-scale surveying, that’s done on a weekly basis, is rare. It’s even more unique to have such long-term data. Many ecological studies are funded for just a few years at a time. These short time frames can make it difficult for scientists to observe changes and patterns in species populations and composition.
Human activity and environmental conditions can affect which species are swimming in Muddy Creek. The water is brackish and salinity levels change seasonally and from year to year. During winter and early spring, when freshwater flow is usually the highest, researchers will generally catch more freshwater species like bluespotted and banded sunfish – two protected species in Maryland. During periods of high salinity, researchers can catch many species indicative of the higher saline lower Bay such as, red drum, spotted sea trout, and Spanish mackerel.
In honor of the 2010 U.S. Census, we thought we’d share photos from one of this month’s surveys. The salinity on this April day was fairly low (~ 5 ppt) and nearly a dozen golden shiners (a freshwater minnow) were caught along with several estuarine-resident and a few diadromous (fish that migrate between fresh and saltwater) species. Among the highlights: a sizeable snapping turtle, many white perch in spawning condition, juvenile American eels and a parasite.
You can read more about SERC’s Muddy Creek survey on our website.