Grant to study effects of oil and dispersants on Louisiana salt marsh ecosystem

Aug 17, 2010
The coast of Louisiana is lined with extensive salt marshes whose foundation is two species of Spartina grass. Credit: USGS

As oil and dispersants wash ashore in coastal Louisiana salt marshes, what will their effects be on these sensitive ecosystems?

The National Science Foundation (NSF) has awarded a rapid response grant to scientist Eugene Turner of Louisiana State University and colleagues to measure the impacts on Gulf Coast salt marshes.

The researchers will track short-term (at the current time, and again at three months) and longer-term (at 11 months) exposure to oil and dispersants.

NSF-funded scientists are studying the effect of oil and dispersants on Louisiana salt marshes. Credit: NOAA

The coast of Louisiana is lined with extensive salt marshes whose foundation is two species of Spartina grass.

In brackish marshes, Spartina patens is the dominant form. It's locally known as wiregrass, marsh hay and paille a chat tigre (hair of the tiger).

In more saline marshes closer to the Gulf of Mexico, Spartina alterniflora, also called smooth cordgrass and oyster grass, takes over. A tall form of this wavy grass grows on the streamside edge of the marsh; a shorter form grows behind it.

In their NSF study, the biologists will document changes in these critically-important Spartina grasses, as well as in the growth of other salt marsh plants, and in marsh animals and microbes.

Field investigators will collect samples three times at 35 to 50 sites and analyze the oil and dispersants after each expedition.

The first field effort is now underway.

"Data are being collected that may be used as indicators of the long-term health of the salt marsh community," says Turner. "From these data, we will obtain information that precedes potentially far-reaching changes.

"This exceptionally large oil spill and subsequent remediation efforts are landmark opportunities to learn about short- and long-term stressors on salt marsh ecosystems."

Salt marsh stressors, such as those from , can have dramatic, visible, and immediate direct impacts, Turner says, on marshes and surrounding uplands.

"They also have indirect effects because, as and dispersants begin to degrade, they enter food webs via primary consumers such as suspension-feeding oysters, deposit-feeding bivalves, and grazing gastropods," says David Garrison of NSF's Division of Ocean Sciences, which funded the research.

These "primary consumers," in turn, serve as food sources for those at higher trophic levels--including humans.

As contaminants make their way up the food chain, they may become concentrated, as in the well-known example of mercury in fish.

"The effects of environmental stressors can cascade through ecosystems as metabolic pathways are altered," says Todd Crowl of NSF's Division of Environmental Biology, which co-funded the research. "The result may be an ecosystem that's radically altered well into the future."

The research, says Turner, is a benchmark study in salt marsh ecosystem change, and will answer key questions about salt marsh stability.

Explore further: Predicting bioavailable cadmium levels in soils

add to favorites email to friend print save as pdf

Related Stories

UH salt marsh expert studies damage to Gulf Coast

Aug 02, 2010

A giant vacuum powered by a lawnmower engine may not seem like a tool for scientific study, but salt marsh experts from the University of Houston are using the contraption to study the effects of the oil spill on insects ...

Newest marsh villain: the periwinkle snail

Dec 19, 2005

Oil companies, levees and the burrowing nutria have been blamed for destroying Louisiana's marshes -- and now a new culprit arrives: the periwinkle snail.

Study: Old oil spill affects wildlife

Apr 25, 2007

U.S. scientists have found the first evidence of biological effects of an oil spill that occurred 38 years ago in a marsh that apparently had recovered.

Scientists Warn of Louisiana Coastal Erosion

Aug 06, 2010

(PhysOrg.com) -- A team of researchers, including three from Boston University, have released findings suggesting that current plans to introduce fresh water to inland marshes around the Louisiana Gulf Coast may weaken protective ...

Recommended for you

Predicting bioavailable cadmium levels in soils

17 hours ago

New Zealand's pastoral landscapes are some of the loveliest in the world, but they also contain a hidden threat. Many of the country's pasture soils have become enriched in cadmium. Grasses take up this toxic heavy metal, ...

Oil drilling possible 'trigger' for deadly Italy quakes

21 hours ago

Italy's Emilia-Romagna region on Tuesday suspended new drilling as it published a report that warned that hydrocarbon exploitation may have acted as a "trigger" in twin earthquakes that killed 26 people in ...

Snow is largely a no-show for Iditarod Trail Sled Dog Race

21 hours ago

On March 1, 65 mushers and their teams of dogs left Anchorage, Alaska, on a quest to win the Iditarod—a race covering 1,000 miles of mountain ranges, frozen rivers, dense forest, tundra and coastline. According ...

UN weather agency warns of 'El Nino' this year

22 hours ago

The UN weather agency Tuesday warned there was a good chance of an "El Nino" climate phenomenon in the Pacific Ocean this year, bringing droughts and heavy rainfall to the rest of the world.

Study shows less snowpack will harm ecosystem

22 hours ago

(Phys.org) —A new study by CAS Professor of Biology Pamela Templer shows that milder winters can have a negative impact both on trees and on the water quality of nearby aquatic ecosystems, far into the warm growing season.

User comments : 0

More news stories

Warm US West, cold East: A 4,000-year pattern

Last winter's curvy jet stream pattern brought mild temperatures to western North America and harsh cold to the East. A University of Utah-led study shows that pattern became more pronounced 4,000 years ago, ...

UN weather agency warns of 'El Nino' this year

The UN weather agency Tuesday warned there was a good chance of an "El Nino" climate phenomenon in the Pacific Ocean this year, bringing droughts and heavy rainfall to the rest of the world.

Making 'bucky-balls' in spin-out's sights

(Phys.org) —A new Oxford spin-out firm is targeting the difficult challenge of manufacturing fullerenes, known as 'bucky-balls' because of their spherical shape, a type of carbon nanomaterial which, like ...