NOAA's Response and Restoration Blog

An inside look at the science of cleaning up and fixing the mess of marine pollution


Leave a comment

10 Years after Being Hit by Hurricane Katrina, Seeing an Oiled Marsh at the Center of an Experiment in Oil Cleanup

This is a post by Vicki Loe and Amy Merten of NOAA’s Office of Response and Restoration.

Oil tank damaged during Hurricane Katrina.

During Hurricane Katrina in 2005, one of the Chevron oil terminal’s storage tanks was severely damaged on top, possibly after being hit by something extremely large carried by the storm waters. (NOAA)

On August 29, 2005, not far from Chevron Pipe Line Company’s oil terminal in Buras, Louisiana, Hurricane Katrina made landfall. Knowing the storm was approaching, residents left the area, and Chevron shut down the crude oil terminal, evacuating all personnel.

The massive storm’s 144 mile per hour winds, 18 foot storm tide, and waves likely twice the height of the surge put the terminal under water. At some point during the storm, one of the terminal’s storage tanks was severely damaged on top, possibly after being hit by something extremely large carried by the storm waters. The tank released crude oil into an adjacent retention pond designed to catch leaking oil, which it did successfully.

However, just a few short weeks later, Hurricane Rita hit the same part of the Gulf and the same oil terminal. Much of the spilled oil was still being contained on the retention pond’s surface, and this second hurricane washed the oil into a nearby marsh.

A Double Impact

Built in 1963, Chevron’s facility in Buras is one of the largest crude oil distribution centers in the world and is located on a natural levee on the east bank of the Mississippi River. These back-to-back hurricanes destroyed infrastructure at the terminal as well as in the communities surrounding it. Helicopter was the only way to access the area in the weeks that followed.

Chevron wildlife biologist and environmental engineer Jim Myers witnessed the storms’ aftermath at the terminal. He described trees stripped of leaves, and mud and debris strewn everywhere, including power lines. Dead livestock were found lying on the terminal’s dock. And black oil was trapped in the marsh’s thick mesh of sedge and grass. This particular marsh is part of a large and valuable ecosystem where saltwater from the Gulf of Mexico and freshwater from the Mississippi River come together.

Even after using boom and skimmers to remove some oil, an estimated 4,000 gallons of oil remained in the 50 acre marsh on the back side of the terminal. Delicate and unstable, marshes are notoriously difficult places to deal with oil. The chaos of two hurricanes only complicated the situation.

Decision Time

Once the terminal’s substantial cleanup and repair activities began, an environmental team was assembled to consider options for dealing with the oiled marsh. Dr. Amy Merten and others from NOAA’s Office of Response and Restoration, Jim Myers and others from Chevron, and personnel from the U.S. Coast Guard, Louisiana Department of Wildlife and Fisheries, and U.S. Fish and Wildlife Service rounded out this team.

The team considered several options for treating the marsh, but one leapt to the top of the list: burning off the oil, a procedure known as in situ burn. In situ burning was the best option for several reasons: the density and amount of remaining oil, remote location, weather conditions, absence of normal wildlife populations after the storms, and the fact that the marsh was bound on three sides by canals, creating barriers for the fire. Also, for hundreds of years, the area had seen both natural burns (due to lightning strikes) and prescribed burns, with good results.

Yet this recommendation met some initial resistance. In situ burning was a more familiar practice for removing oil from the open ocean than from marshes, though its use in marshes had been well-reviewed in scientific studies. Still, in the midst of a hectic and widespread response following two hurricanes, burning oil out of marshes seemed like a potentially risky move at the time.

Furthermore, some responders working elsewhere followed conventional wisdom that the oil had been exposed to weathering processes for too long to burn successfully. However, the oil was so thick on the water’s surface and so protected from the elements by vegetation that the month-old oil behaved like freshly spilled oil, meaning it still contained enough of the right compounds to burn. The environmental team tested the oil to demonstrate it would burn before bringing the idea to those in charge of the post-hurricane pollution cleanup, the Unified Command.

Burn Notice

Left: Burning marsh. Right: Same view of green marsh 10 years later.

Similar views of the same marsh where the 2005 oil spill and subsequent burn occurred after Hurricanes Katrina and Rita. The view on the right is from August of 2015. (NOAA)

Fortunately, the leader of the Unified Command approved the carefully crafted plan to burn the oiled marsh. The burns took place on October 12 and 13, 2005, a month and a half after the spill. After dividing and cutting the affected marsh into a grid of six plots, responders burned two areas each day, leaving two plots unburned since they were negligibly oiled and did not have the right conditions to burn.

Lit with propane torches, the fire on the first day was dramatic, generating dense black smoke and burning for three hours, the result of burning the part of the marsh closest to the terminal, where the oil was thickest. The second fire generated less smoke but burned longer, for about four and half hours. Afterward, you could see how the burn’s footprint matched where different levels of oil had been.

Observations after the fact assured the environmental team that most (more than 90 percent) of the oil had been burned in the four treated areas. Small pockets of unburned oil were collected with sorbent pads, and any residual oil was left to degrade naturally. Within 24 hours of burning, traces of regrowth were visible in the marsh, and in less than a month, sedge grasses had grown to a height of one to two feet, according to Myers.

A Marsh Reborn

Healthy lush marsh vegetation at water's edge.

The marsh that was oiled after Hurricanes Katrina and Rita in 2005, and subsequently burned to remove the oil. This is how it looked in August of 2015, showing an abundance of diverse vegetation. (NOAA)

Ten years later, in August of 2015, I was curious to see how the marsh had come back. I had seen many photos of during and after the burn, and subsequent reports were that the endeavor had been a great success.

Knowing I would be in the New Orleans area on vacation, I was pleased to learn that Jim Myers would be willing to give me a tour of this marsh. I met him at the ferry dock to cross to the east side of the Mississippi River and the Chevron terminal.

We looked out over the marsh from an elevated platform behind the giant oil storage tanks. All you could see were lush grasses, clumps of low trees, and birds, birds, birds. Their calls were nonstop. We saw cattails uprooted next to flattened paths leading to the water’s edge, evidence of alligators creating trails from the water to areas for basking in the sun and of cows, muskrats, and feral hogs feeding on the cattails’ roots.

The water level was high, so rather than hike through the marsh, we traveled the circumference in a flat-bottomed boat. We saw many species of birds, as well as dragonflies, freely roaming cows, fish, and an alligator.

Today, the marsh is flourishing. I could see no difference between the areas that were oiled and burned 10 years ago and nearby areas that were untouched. In fact, monitoring following the burn [PDF] found that the marsh showed recovery across a number of measures within nine months.

This marsh represents one small part of a system of wetlands that has historically provided a buffer against the high waters of past storms. Since the 1840s, when it was settled, Buras, Louisiana, has survived being hit by at least five major hurricanes. But Hurricane Katrina was different.

Gradually, marshes across the northern Gulf of Mexico have been disappearing, enabling Hurricane Katrina’s floodwaters to overwhelm areas that have weathered previous storms. Ensuring existing marshes remain healthy will be one part of a good defense strategy against the next big hurricane. Given the successful recovery of this marsh after both an oil spill and in situ burn, we know that this technique will help prevent the further degradation of marshes in the Gulf.

See more photos of the damaged tank, the controlled burn to remove the oil, and the recovered marsh 10 years later.

Find more information about the involvement of NOAA’s Office of Response and Restoration after Hurricanes Katrina and Rita.

Amy Merten with kids from Kivalina, Alaska.Amy Merten is the Spatial Data Branch Chief in NOAA’s Office of Response and Restoration. Amy developed the concept for the online mapping tool ERMA (Environmental Response Mapping Application). ERMA was developed in collaboration with the University of New Hampshire. She expanded the ERMA team at NOAA to fill response and natural resource trustee responsibilities during the 2010 Deepwater Horizon oil spill. Amy oversees data management of the resulting oil spill damage assessment. She received her doctorate and master’s degrees from the University of Maryland.


3 Comments

How to Restore a Damaged Coral Reef: Undersea Vacuums, Power Washers, and Winter Storms

NOAA Fisheries Biologist Matt Parry contributed to this story and this restoration work.

After a ship runs aground on a coral reef, the ocean bottom becomes a messy place: thickly carpeted with a layer of pulverized coral several feet deep. This was the scene underwater off the Hawaiian island of Oahu in February of 2010. On February 5, the cargo ship M/V VogeTrader ran aground and was later removed from a coral reef in the brilliant blue waters of Kalaeloa/Barber’s Point Harbor.

NOAA and our partners suited up in dive gear and got to work restoring this damaged reef, beginning work in October 2013 and wrapping up in April 2014. While a few young corals have begun to repopulate this area in the time since the grounding, even fast-growing corals grow less than half an inch per year. The ones there now are mostly smaller than a golf ball and the seafloor was still covered in crushed and dislodged corals. These broken corals could be swept up and knocked around by strong currents or waves, potentially causing further injury to the recovering reef. This risk was why we pursued emergency restoration activities for the reef.

What we didn’t expect was how a strong winter storm would actually help our restoration work in a way that perhaps has never before been done.

How Do You Start Fixing a Damaged Reef?

First, we had to get the lay of the (underwater) land, using acoustic technology to map exactly where the coral rubble was located and determine the size of the affected area. Next, our team of trained scuba divers gathered any live corals and coral fragments and transported them a short distance away from where they would be removing the rubble.

Then, we were ready to clean up the mess from the grounding and response activity and create a place on the seafloor where corals could thrive. Divers set up an undersea vacuum on the bottom of the ocean, which looks like a giant hose reaching 35 feet down from a boat to the seafloor. It gently lifted rubble up through the hose—gently, because we wanted to avoid ripping everything off of the seafloor. Eventually, our team would remove nearly 800 tons (more than 700 metric tons) of debris from the area hit by the ship.

Unexpected Gifts from a Powerful Storm

In the middle of this work, the area experienced a powerful winter storm, yielding 10-year high winter swells that reduced visibility underwater and temporarily halted the restoration work. When the divers returned after the storm subsided, they were greeted by a disappointing discovery: the cache of small coral remnants they had stockpiled to reattach to the sea bottom was gone. The swells had scoured the seafloor and scattered what they had gathered.

But looking around, the divers realized that the energetic storm had broken off and dislodged a number of large corals nearby. Corals that were bigger than those they lost and which otherwise would have died as a result of the storm. With permission from the State of Hawaii, they picked up some of these large, naturally detached corals, which were in good condition, and used them as donor corals to finish the restoration project.

Finding suitable donor corals is one of the most difficult aspects of coral restoration. This may have been the first time people have been able to take advantage of a naturally destructive event to restore corals damaged by a ship grounding.

A Reef Restored

Once our team transported the donor corals to the restoration site a few hundred yards away, they scraped the seafloor, at first by hand and then with a power washer, to prepare it for reattaching the corals. Using a cement mixer on a 70-foot-long boat, they mixed enough cement to secure 643 corals to the seafloor.

While originally planning to reattach 1,200 coral colonies, the storm-blown corals were so large (and therefore so much more valuable to the recovering habitat) that the divers ran out of space to reattach the corals. In the end, they didn’t replace these colonies in the exact same area that they removed the coral rubble. When the ship hit the reef, it displaced about three feet of reef, exposing a fragmented, crumbly surface below. They left this area open for young corals to repopulate but traveled a little higher up on the reef shelf to reattach the larger corals on a more secure surface, one only lightly scraped by the ship.

The results so far are encouraging. Very few corals were lost during the moving and cementing process, and the diversity of coral species in the reattachment area closely reflects what is seen in unaffected reefs nearby. These include the common coral species of the genus Montipora (rice coral), Porites lobata (lobe coral), and Pocillopora meandrina (cauliflower coral). As soon as the divers finished cleaning and cementing the corals to the ocean floor, reef fish started moving in, apparently pleased with the state of their new home.

But our work isn’t done yet. We’ll be keeping an eye on these corals as they recover, with plans to return for monitoring dives in six months and one year. In addition, we’ll be working with our partners to develop even more projects to help restore these beautiful and important parts of Hawaii’s undersea environment.

UPDATE: See this restoration work come to life in a video documenting the process and find out how transplanted corals have been recovering.


Leave a comment

Why Are Tropical Storms and Hurricanes Named?

This is a post by NOAA Office of Response and Restoration’s Katie Krushinski.

The 2013 Atlantic hurricane season's first named storm was Tropical Storm Andrea, pictured here on June 8 crossing over Florida and up the East Coast. (NASA)

The 2013 Atlantic hurricane season’s first named storm was Tropical Storm Andrea, pictured here on June 8 crossing over Florida and heading up the East Coast. (NASA)

Have you ever wondered why storms are named? Up until the early 1950s, tropical storms and hurricanes were tracked by year and the order in which each one occurred during that year.

In time, it was recognized that people remembered shorter names more easily. In 1953, a new approach was taken and storms were named in alphabetical order by female name. The process of naming storms helps differentiate between multiple storms that may be active at the same time.

By 1978, both male and female names were being used to identify Northern Pacific storms. This was adopted in 1979 for the Atlantic storms and is what we use today.

The World Meteorological Organization came up with the lists of names, male and female, which are used on a six-year rotation. In the event a hurricane causes a large amount of damage or numerous deaths, that name will be retired. Since the 1950s, when it became normal to name storms, there have been 77 names retired, including Fran (1996), Katrina (2005), Rita (2005), and Sandy (2012).

To find out this year’s storm names and for a complete list of retired names, visit the National Weather Service’s website. And if you haven’t started your own severe-weather preparations, don’t delay; the 2013 Atlantic hurricane season (predicted to be more active than usual) has already begun.

The Gulf of Mexico region, in particular, experiences frequent natural and human-caused disasters such as hurricanes, tornadoes, and oil spills.

NOAA’s Gulf of Mexico Disaster Response Center aims to reduce the resulting impacts by helping to prepare federal, state, and local decision makers for a variety of threats, creating more adaptive and resilient coastal communities. Learn more about this valuable resource and center of NOAA expertise on the Gulf Coast.

Katie Krushinski

Katie Krushinski

Katie Krushinski works at NOAA’s Gulf of Mexico Disaster Response Center in Mobile, Ala., where she is responsible for coordinating training events, producing external communications, and writing and editing. Katie has a background in emergency response and management. NOAA’s Disaster Response Center serves as a one-stop shop, streamlining the delivery of NOAA services that help the Gulf region prepare for and deal with disasters.