Another piece of the puzzle: New study sheds light on oil’s effects on plant life

January 13, 2015 | Posted by Delta Dispatches in BP Oil Disaster, Science

By Matt Phillips, National Wildlife Federation

The 2010 BP Deepwater Horizon oil disaster spilled nearly 200 million gallons of oil into the Gulf of Mexico. Oil coated the shore, covering hundreds of miles of coastline, including some of Louisiana’s coastal wetlands. Scientists have spent the years since the spill assessing its continuing impacts on Gulf wildlife and ecosystems. And next Tuesday in New Orleans, Phase III of the BP oil spill trial will start in New Orleans.

In a recent study, “Physiological relationship between oil tolerance and flooding tolerance in marsh plants,” Keri L. Caudle and Brian R. Maricle of Fort Hays State University in Kansas studied how oil affects plant health. Studies have demonstrated that oil can poison plants, and toxic chemicals in oil can prevent photosynthesis – the process by which plants convert sunlight to food. Since all Gulf Coast wildlife, including birds, turtles, dolphins and insects, ultimately rely on plants for food and shelter, the effects of oil on plant life could impact the entire Gulf Coast ecosystem.

Switchgrass (Panicum virgatum) is a flooding-sensitive species.

Switchgrass (Panicum virgatum) is a flooding-sensitive species.

Besides a general toxic effect, relatively little is known about how oil impacts plant health. However, substantial research has assessed how plants deal with flooding. The authors of this study hypothesized that a plant’s response to flooding might be similar to its response to oil. In both situations, plants have a harder time absorbing oxygen from their surroundings. Oxygen is critical to a plant’s survival: Plants breathe similarly to humans at times, absorbing oxygen and exhaling carbon dioxide. If oil seeps into the soil, it could cover the plant’s roots, preventing them from absorbing oxygen.

The authors wanted to determine if oil harmed plants by preventing oxygen absorption or by poisoning them. To do so, they labeled nine species of plants as either flooding tolerant, moderately flooding tolerant or flooding sensitive. Because flooding prevents plants from absorbing oxygen from soil, flooding tolerance was an appropriate stand-in for oil tolerance. The researchers reasoned that if oil’s effects primarily prevented plants from getting oxygen, plants would have to breathe without taking in oxygen.

Prairie cordgrass (Spartina pectinata) is a moderately flooding-tolerant species.

Prairie cordgrass (Spartina pectinata) is a moderately flooding-tolerant species.

Plants are able to breathe without oxygen temporarily and produce a certain chemical compound in their roots when doing so. Therefore, the researchers measured whether this chemical was being produced to determine if the plants were still breathing but forgoing oxygen. If the effects of oil were instead due to toxic effects, then the plants would be less able to photosynthesize because their cells would be poisoned and unable to function properly.

The experimenters observed three important results. They found that flooding-sensitive plant species were breathing without oxygen, suggesting that they were struggling to absorb it from the soil. They also observed that flooding-tolerant species were not having trouble absorbing oxygen, suggesting that their tolerance to flooding afforded them a higher tolerance to oil. Third, they discovered that, regardless of tolerance to flooding, plants exposed to oil were photosynthesizing less than under normal conditions. The researchers determined that the toxic effects of the oil were interrupting the photosynthetic process.

Smooth cordgrass (Spartina alterniflora) is a flooding-tolerant plant species.

Smooth cordgrass (Spartina alterniflora) is a flooding-tolerant plant species.

The study concluded that oil affected plants most harmfully by preventing oxygen absorption, rather than through its toxic properties. Flooding-tolerant plants were better able to withstand the effects of oil, and continue absorbing oxygen, whereas flooding-sensitive plants had a harder time. They also recognized that across the board, oil proved toxic to plants. Oil tolerance followed flooding tolerance, but the toxic effects of the oil were still present across all species.

Plants are the foundation of the Gulf Coast ecosystem. Discovering the effects of oil on plant health is critical to understanding the full effects of the BP oil spill on Gulf Coast wildlife, as wildlife depend on plants for food and habitat. With this study, we have another piece of the puzzle.

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River diversion model debuted at Plaquemines Parish Orange Festival

January 9, 2015 | Posted by Delta Dispatches in Diversions, Hurricanes, Meetings/Events, Restoration Projects

By Philip Russo, Outreach Coordinator, Restore the Mississippi River Delta Coalition

Land along a river has long been coveted for its agricultural productivity, but few rivers can compete with the mighty Mississippi.

Philip Russo shows off with the Restore the Mississippi River Delta coalition's diversion model at the Plaquemines Orange Festival.

Philip with the Restore the Mississippi River Delta coalition's diversion model.

With a drainage basin stretching across 31 U.S. states and parts of Canada, it is no surprise that the Mississippi River carries a lot of sediment. Historically, the river would deposit this sediment near its mouth in what is now southeast Louisiana, creating new land. But since leveeing of the river, the majority of this sediment is lost out the mouth of the river and into the deep waters of the Gulf of Mexico.

Near the mouth of the Mississippi, the final 85-mile stretch of the Mississippi River in Plaquemines Parish is home to prodigious citrus farming land. And with cool temperatures and clear skies, the weather of early December was ripe for the 68th Annual Plaquemines Parish Orange Festival.

Plaquemines Orange Festival

Sunset at the Orange Festival

Nestled between the Mississippi River levee and historic Fort Jackson, the focus of the festival is all things citrus. In Louisiana, that means copious displays of red navels, tangelos, ruby red grapefruits, sweet oranges, satsumas, kumquats and more.

While we attended and blogged about our trip down to the Orange Festival last year, this was the first year we actively engaged the crowds about protecting and restoring our coast – and we got to do so while debuting our tabletop river delta model! Watch this short video of the diversion model in action.

There are some sections of Plaquemines Parish where the distance between the Mississippi River levee and the Barataria Bay levee is only a few hundred yards, so Plaquemines residents are familiar with and usually eager to talk about their coast. But having a model demonstrating the process which built the very land everyone is standing adds another dimension to conversations about restoring barrier islands, ridges and marsh.

Fort Jackson entrance to the festival.

Fort Jackson entrance to the festival.

This year’s Orange Festival celebrated yet another successful harvest, but the celebration – originally organized in 1947 to promote Plaquemines’ citrus crop – has known its setbacks, most significantly due to Hurricanes Betsy, Camille and Katrina. If we are going to ensure the success of future harvests, we need to restore our multiple lines of defense against storm surge and maintain our protective coastal wetlands with strategically located and operated diversions along the river.

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What can the Caernarvon Diversion and Bohemia Spillway teach us about coastal restoration?

December 23, 2014 | Posted by Elizabeth Van Cleve in Diversions, Reports, Restoration Projects, Science

By Theryn Henkel, Ph.D., Lake Pontchartrain Basin Foundation

The Coastal Sustainability Program at the Lake Pontchartrain Basin Foundation (LPBF) recently released an article titled “Examination of Deltaic Processes of Mississippi River Outlets–Caernarvon Delta and Bohemia Spillway in Southeastern Louisiana in the Gulf Coastal Association of Geological Societies Journal. The article details work that LPBF has done investigating the development of the Caernarvon Delta and operation of the Bohemia Spillway, both located in Plaquemines Parish, La.

Natural land-building deltaic processes of the Mississippi River Delta have been severely limited by artificial river levees, which prevent water and sediment from flowing over the banks during spring floods. To counteract the effects of severing the connection between the river and the delta, focus has been placed on reconnecting the river to the surrounding wetlands by the creation of artificial outlets, also called diversions.

The Caernarvon Diversion

The Caernarvon Freshwater Diversion was designed to deliver up to 8,000 cubic feet per second (cfs) of water from the Mississippi River. For reference, a flow rate of 8,000 cfs could fill up an Olympic-size swimming pool in 11 seconds or the Superdome in 4.5 hours. The Mississippi River also contains sediment that is carried along with the fresh water through the Caernarvon Diversion into the adjacent wetlands or open water, where it can nourish the wetlands and/or build land.

Record of Caernarvon Freshwater Diversion discharge and turbidity for 2012, as an example of the discrepancy between timing of diversion operations and sediment spikes entering the Caernarvon Receiving Basin. Also illustrated is the under- operation of the diversion during high stage events in the Mississippi River. The difference between the solid blue area and the hachured is the potential additional flow that was not allowed due to management of the diversion. The orange line is the turbidity of the discharge, which shows that the few times when the diversion was operated at higher flow it was often not when turbidity was elevated.

Record of Caernarvon Freshwater Diversion discharge and turbidity for 2012, as an example of the discrepancy between timing of diversion operations and sediment spikes entering the Caernarvon Receiving Basin.

LPBF collects data on the turbidity, or cloudiness, of the water diverted through the diversion. Through established equations, the cloudiness of the water can be related to sediment load or the amount of sediment carried in the water. From this, it was calculated that the total amount of sediment carried into the wetlands and open waters areas from 2009 to 2012 was 264,000 cubic yards, or a volume equal to 81 swimming pools. Due to other considerations, the diversion is not always operated when the sediment load in the river is high and therefore does not maximize potential sediment capture. Despite this variability in operation of the diversion – and the fact that the Caernarvon Diversion was built to minimize sediment capture, as it was built solely for salinity control, not land building – there actually has been enough sediment diverted by the Caernarvon Diversion to build a new delta. Total wetland growth of the delta in the open water area receiving diverted water from 1998 to 2011 was 600 acres. This new wetland area is lush and thriving with a variety of plant species (trees and herbaceous) growing, and alligators, birds and insects abound.

The Bohemia Spillway

The Bohemia Spillway is an 11-mile stretch along the east side of Mississippi River south of New Orleans where the federal protection levees were removed. It was created in 1926 by the removal of existing artificial river levees, thereby allowing river water to flow over the banks and into the adjacent wetlands when the river was high. This overflowing process is how the river would have operated historically.

Location of the Caernarvon Diversion and Bohemia Spillway in relation to New Orleans and other river outlets.

Location of the Caernarvon Diversion and Bohemia Spillway in relation to New Orleans and other river outlets.

In 2011, the Mississippi River watershed experienced an historic flood which provided an ideal opportunity to investigate and study how the spillway operates. When the river overflows its banks, if brings fresh water, nutrients and sediment to the wetlands. This cannot happen when the connection is cut off by levees. The severing of the connection of the river to the wetlands is one of the contributing factors to the high rates of land loss rates experienced by southeast Louisiana.

Current land loss rates in the Bohemia Spillway are negligible, perhaps due to receiving inputs of fresh water, nutrients and sediment during high river events since 1926. We have not observed delta formation in the Bohemia Spillway, as we did at the Caernarvon Diversion, but we have observed the infilling of defunct navigation and oil and gas canals as they slowly convert back to land.

In many parts of Louisiana’s coast, man-made canals often contribute to increased land loss. Poorly maintained canals erode and become wider, and salt water is conveyed through the canals into adjacent fresh marshes, killing plants and converting land to open water. Therefore, seeing canals infilling and low rates of land loss in the Bohemia Spillway indicates that the restoration of somewhat normal processes, by reconnecting the river to the wetlands since 1926, has had a positive effect on the area.

Looking Ahead

For both Bohemia Spillway and the Caernarvon Diversion, there are clearly benefits to sustaining or increasing wetland areas. However, the two outlets also provide a contrast in the future possibilities. Precisely replicating the Bohemia Spillway by levee removal is generally not feasible because of the ongoing need for protection from river floods. However, a controlled diversion built and operated to more efficiently capture and deliver sediment in ways that emulate more natural processes, such as in the Bohemia Spillway, may hold great promise for coastal restoration, rather than the obsolete design and operational goals of a diversion such as Caernarvon.

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Job Opening: Avian Biologist, Audubon Louisiana

December 16, 2014 | Posted by Elizabeth Van Cleve in Job openings

Audubon Web stacked colorOverview:

Now in its second century, Audubon is dedicated to protecting birds and other wildlife and the habitat that supports them. Audubon’s mission is engaging people in bird conservation on a hemispheric scale through science, policy, education and on-the-ground conservation action. By mobilizing and aligning its network of Chapters, Centers, State and Important Bird Area programs in the four major migratory flyways in the Americas, the organization will bring the full power of Audubon to bear on protecting common and threatened bird species and the critical habitat they need to survive. And as part of BirdLife International, Audubon will join people in over 100 in-country organizations all working to protect a network of Important Bird Areas around the world, leveraging the impact of actions they take at a local level. What defines Audubon’s unique value is a powerful grassroots network of nearly 500 local chapters, 22 state offices, 41 Audubon Centers, Important Bird Area Programs in 46 states, and 700 staff across the country. Audubon is a federal contractor and an Equal Opportunity Employer (EOE).

Position Summary:

The Avian Biologist will be responsible for assisting Audubon Louisiana’s Director of Bird Conservation and other staff in field and office activities associated with conservation, research, and education programs.

This is a full-time position providing field and analytic support for the Coastal Bird Stewardship Program and other monitoring and research initiatives principally in Louisiana.

Essential Functions:
  • Collect and analyze data on birds to support research projects through a variety of techniques including point and transect counts, nest searching, mist-netting, and radio telemetry and input bird data into databases.
  • In collaboration with the Director of Conservation and others, lead and assist in the writing of technical reports and scientific manuscripts.
  • Develop and lead educational programs, aimed at increasing awareness of the threats birds face, for a variety of audiences. Engage volunteers and community leaders to participate in conservation efforts.
  • Cultivate and maintain productive working relationships with internal and external stakeholders including other Audubon offices and chapters, state and federal agencies, other non-governmental organizations, and community and government leaders.
  • Maintain vehicles and all assigned field gear.
Qualifications and Experience:
  • Bachelor’s degree in biology, ornithology, ecology, or a related field required.
  • 2+ years of applied field experience is required; understanding and respect of the scientific method is paramount.
  • Knowledge in the identification and ecology of a variety of waterbirds, shorebirds, songbirds, and marshbirds, as well as proven experience using statistical techniques for analyzing bird data (e.g., distance sampling, capture-mark-recapture, other demographic modeling approaches, spatial and movement analyses, etc.).
  • Experience and working knowledge of Louisiana’s diversity of habitats, especially coastal wetlands, bottomland hardwood forests, and/or estuaries is a plus.
  • At least one year experience developing and providing environmental education programs to a variety of audiences and/or working with volunteers is strongly preferred.
  • Excellent work ethic, a team-focused attitude, and the ability to work well independently in the field.
  • Ability to maintain and repair mechanical equipment such as trucks and boats desirable.
  • Willingness to work long hours in sub-tropical wetland, coastal, and forest environments exposed to harsh Louisiana field conditions (sun, heat, biting insects, alligators, venomous snakes, wading in water or mud), sometimes alone.
  • Ability to walk long distances (at least two miles) while carrying field equipment (e.g., tripod and spotting scope) and/or other materials. Ability to lift and carry over short distances at least 40 pounds, with or without accomodation.
  • Regularly travel within the state of the Louisiana to field sites, often for several days at a time. Some work on weekends is necessary.
  • Valid driver’s license required, experience with small boats, and operating ATVs strongly preferred.

To apply, please visit:

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Job Opening: Senior Policy Specialist, Gulf Coast Restoration, National Wildlife Federation

December 15, 2014 | Posted by Elizabeth Van Cleve in Job openings

The National Wildlife Federation is seeking a Senior Policy Specialist for Gulf Coast Restoration to join our staff in Washington, DC. In this role you will advocate on behalf of NWF's Gulf Coast Restoration and Mississippi Delta Restoration (MRD) programs to protect and restore the Gulf of Mexico coastal area to greater resiliency in the face of storms, floods, sea level rise, human-caused erosion, oil spills, and other threats to wildlife and to coastal communities.

This includes leading the national portion of the National Wildlife Federation's campaigns to secure authorization and federal funding for restoring Coastal Louisiana and to direct funds from the BP oil spill to the restoration of coastal areas Gulf-wide. This position will also work, to a lesser extent, on the broader goals of Everglades restoration as it relates to the Gulf of Mexico. The Senior Policy Specialist will work in concert with NWF's team in Louisiana, with the Gulf Team in the other Gulf states, with NWF's partner organizations in both campaigns and with NWF's national restoration team. This position will be NWF's key voice advocating to the federal government and members of Congress on behalf of NWF's Gulf restoration and MRD priorities, and in particular for the use of all post-BP oil spill funds to advance those priorities.

In this role you will:

  • Advocate for NWF's and MRD campaign priorities to Congress and the Administration. This includes campaign's priorities with Congress and the Administration on RESTORE implementation and authorizations through WRDA and appropriations. Work includes policy analysis, materials production, and participation in relevant meetings.
  • Advocate for NWF's Gulf restoration priorities, particularly regarding the use of post-BP oil-spill funds, to Congress and the Administration. Work with the Gulf Restoration Director to identify NWF's restoration priorities. Work includes policy analysis, materials production, and participation in relevant meetings.
  • Integrate coastal Louisiana and Gulf campaigns with other NWF national programs and interests, engaging in National Advocacy Center meetings, supporting overlapping institutional priorities and collaborating with on-line, communications, lobby team and other key staff to advance agenda. Advocate for and otherwise support key policy reforms that will better protect people, communities, and wildlife, as assigned.


  • Bachelor's degree required, advanced degree preferred.
  • Candidates must have at least 7 years progressively responsible experience required in helping develop and implement advocacy campaigns, grassroots organizing, media, and environmental advocacy. Congressional experience and/or pertinent federal agency experience preferred.
  • Must be knowledgeable of how Federal agencies and Congress work.
  • Must know how to use water restoration laws, programs and policies as a tool to protect wildlife and wild places.
  • Must be a strategic thinker, well organized, strong communicator, and have a demonstrated ability to set goals and meet deadlines.
  • Must possess ability to work collaboratively with others.

There will be travel involved in this role – approx. six trips per year and some weekend work may be required.

The National Wildlife Federation is America's largest conservation organization, passionate about protecting wildlife for our children's future. NWF is an equal opportunity employer committed to workplace diversity.

To apply, please visit:

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