NOAA's Response and Restoration Blog

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

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Explore Oil Spill Data for Gulf of Mexico Marine Life With NOAA GIS Tools

In the wake of the Deepwater Horizon oil spill, the sheer amount of data scientists were gathering from the Gulf of Mexico was nearly overwhelming. Everything from water quality samples to the locations of oiled sea turtles to photos of dolphins swimming through oil—the list goes on for more than 13 million scientific records.

So, how would anyone even start to dig through all this scientific information? Fortunately, you don’t have to be a NOAA scientist to access, download, or even map it. We have been building tools to allow anyone to access this wealth of information on the Gulf of Mexico environment following the Deepwater Horizon oil spill.

We’re taking a look at two of our geographic information systems tools and how they help scientists, emergency responders, and the public navigate the oceans of environmental data collected since the 2010 Deepwater Horizon oil spill.

When it comes to mapping and understanding huge amounts of these data, we turn to our GIS-based tool, the Environmental Response Management Application, known as ERMA®. This online mapping tool is like a Swiss army knife for organizing data and information for planning and environmental emergencies, such as oil spills and hurricanes.

ERMA not only allows pollution responders to see real-time information, including weather information and ship locations, but also enables users to display years of data, revealing to us broader trends.

View of Environmental Response Management Application showing map of Gulf of Mexico with varying probabilities of oil presence and sea turtle oiling during the Deepwater Horizon oil spill with data source information.

In the “Layer” tab on the right side of the screen, you can choose which groups of data, or “layers,” to display in ERMA. Right click on a data layer, such as “Turtle Captures Probability of Oiling (NOAA) (PDARP),” and select “View metadata” to view more information about the data being shown. (NOAA)

For instance, say you want to know the likelihood of sea turtles being exposed to heavy oil during the Deepwater Horizon oil spill. ERMA enables you to see where sea turtles were spotted during aerial surveys or captured by researchers across the Gulf of Mexico between May and September 2010. At the same time, you can view data showing the probability that certain areas of the ocean surface were oiled (and for how long), all displayed on a single, interactive map.

View of Environmental Management Application map of Gulf of Mexico showing varying probabilities of oil presence and sea turtle exposure to oil during the Deepwater Horizon oil spill with map legend.

Clicking on the “Legend” tab on the right side of the screen shows you basic information about the data displayed in ERMA. Here, the red area represents portions of the Gulf of Mexico which had the highest likelihood of exposing marine life to oil. Triangles show sea turtle sightings and squares show sea turtle captures between May and September 2010. The color of the symbol indicates the likelihood of that sea turtle receiving heavy exposure to oil. (NOAA)

Perhaps you want to focus on where Atlantic bluefin tuna were traveling around the Gulf and where that overlaps with the oil spill’s footprint. Or compare coastal habitat restoration projects with the degree of oil different sections of shoreline experienced. ERMA gives you that access.

You can use ERMA Deepwater Gulf Response to find these data in a number of ways (including search) and choose which GIS “layers” of data to turn on and off in the map. To see the most recently added data, click on the “Recent Data” tab in the upper left of the map interface, or find data by browsing through the “Layers” tab on the right. Or look for data in special “bookmark views” on the lower right of the “Layers” tab to find data for a specific topic of interest.

Now, what if you not only want to see a map of the data, what if you also want to explore any trends in the data at a deeper level? Or download photos, videos, or scientific analyses of the data?

That’s where our data management tool DIVER comes in. This tool serves as a central repository for environmental impact data from the oil spill and was designed to help researchers share and find scientific information ranging from photos and field notes to sample data and analyses.

As Ocean Conservancy’s Elizabeth Fetherston put it:

Until recently, there was no real way to combine all of these disparate pixels of information into a coherent picture of, for instance, a day in the life of a sea turtle. DIVER, NOAA’s new website for Deepwater Horizon assessment data, gives us the tools to do just that.

Data information and integration systems like DIVER put all of that information in one place at one time, allowing you to look for causes and effects that you might not have ever known were there and then use that information to better manage species recovery. These data give us a new kind of power for protecting marine species.

One of the most important features of DIVER, called DIVER Explorer, is the powerful search function that allows you to narrow down the millions of data pieces to the precise set you’re seeking. You do it one step, or “filter,” at a time.

DIVER software dialog box showing how to build a query by workplan topic area for marine mammals studied during the Deepwater Horizon oil spill.

A view of the step-by-step process of building a “query,” or specialized search, in our DIVER tool for Deepwater Horizon oil spill environmental impact data. (NOAA)

For example, when you go to DIVER Explorer, click on “Guided Query” at the top and then “Start to Explore Data,” choose “By Workplan Topic Area,” hit “Next,” and finally select “Marine Mammals” before clicking “Run Query” to access information about scientific samples taken from marine mammals and turtles. You can view it on a map, in a table, or download the data to analyze yourself.

An even easier way to explore these data in DIVER, however, is by visiting and scrolling down to and clicking on #5 Preassessment/Assessment (§§ 990.40 – 990.45; 990.51). This will reveal a list of various types of environmental impacts—to birds, sea floor habitat, marine mammals, etc.—which the federal government studied as part of the Deepwater Horizon oil spill’s Natural Resource Damage Assessment.

Say you’re interested in marine mammals, so you click on 5.6 Marine Mammal Injury and then 5.6.3 Data sets. You can then download and open the document “NOAA Marine Mammal data related to the Deepwater Horizon incident, available through systems such as DIVER and ERMA, or as direct downloads. (September 23, 2015).”

Under the section “Data Links,” you can choose from a variety of stored searches (or “queries”) in DIVER that will show you where and when, for example, bottlenose dolphins with satellite tags traveled after the spill (tip: zoom in to view this data on the map)—along with photographs to go with it (tip: click on the “Photos” tab under the map to browse).

Map view of DIVER software map showing where tagged dolphins swam in the Gulf of Mexico after the Deepwater Horizon oil spill.

A map view of DIVER shows where tagged dolphins traveled along the Gulf Coast, showing two populations that stayed in their home bases of Barataria Bay and Mississippi Sound. (NOAA)

This can tell us key information, such as the fact that certain populations of dolphins stay in the same areas along the coast, meaning they don’t travel far from home. We can also look at data about whether those dolphin homes were exposed to a lot of oil, which would suggest that the dolphins that lived there likely were exposed to oil again and again.

Both of these tools allow us to work with incredible amounts of data and see their stories brought to life through the power of geographic information systems. So, go ahead and start exploring!

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Science of Oil Spills Training Now Accepting Applications for Spring 2016

Two people closely examining rocks and seaweed on a shoreline.

These classes help prepare responders to understand the environmental risks and scientific considerations when addressing oil spills, and also include a field trip to a local beach to apply newly learned skills. (NOAA)

NOAA‘s Office of Response and Restoration, a leader in providing scientific information in response to marine pollution, has scheduled Science of Oil Spills (SOS) classes in two locations in spring 2016:

  • Mobile, Alabama the week of March 28, 2016
  • Ann Arbor, Michigan the week of May 16, 2016

We will accept applications for these classes as follows:

For the Mobile class, the application period will be open until Friday, January 22. We will notify accepted participants by email no later than Friday, February 5.

For the Ann Arbor class, the application period will be open until Friday, March 11. We will notify accepted participants by email no later than Friday, March 25.

SOS classes help spill responders increase their understanding of oil spill science when analyzing spills and making risk-based decisions. They are designed for new and mid-level spill responders.

These trainings cover:

  • Fate and behavior of oil spilled in the environment.
  • An introduction to oil chemistry and toxicity.
  • A review of basic spill response options for open water and shorelines.
  • Spill case studies.
  • Principles of ecological risk assessment.
  • A field trip.
  • An introduction to damage assessment techniques.
  • Determining cleanup endpoints.

To view the topics for the next SOS class, download a sample agenda [PDF, 170 KB].

Please understand that classes are not filled on a first-come, first-served basis. We try to diversify the participant composition to ensure a variety of perspectives and experiences, to enrich the workshop for the benefit of all participants. Classes are generally limited to 40 participants.

For more information, and to learn how to apply for the class, visit the SOS Classes page.

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Births Down and Deaths Up in Gulf Dolphins Affected by Deepwater Horizon Oil Spill

A mother bottlenose dolphin pushes her dead newborn calf at the water's surface.

Dolphin Y01 pushes a dead calf through the waters of Barataria Bay, Louisiana, in March 2013. This behavior is sometimes observed in female dolphins when their newborn calf does not survive. Barataria Bay dolphins have seen a disturbingly low rate of reproductive success in the wake of the Deepwater Horizon oil spill. (Louisiana Department of Wildlife and Fisheries)

In August of 2011, a team of independent and government scientists evaluating the health of bottlenose dolphins in Louisiana’s Barataria Bay gave dolphin Y35 a good health outlook.

Based on the ultrasound, she was in the early stages of pregnancy, but unlike many of the other dolphins examined that summer day, Y35 was in pretty good shape. She wasn’t extremely underweight or suffering from moderate-to-severe lung disease, conditions connected to exposure to Deepwater Horizon oil in the heavily impacted Barataria Bay.

Veterinarians did note, however, that she had alarmingly low levels of important stress hormones responsible for behaviors such as the fight-or-flight response. Normal levels of these hormones help animals cope with stressful situations. This rare condition—known as hypoadrenocorticism—had never been reported before in dolphins, which is why it was not used for Y35 and the other dolphins’ health prognoses.

Less than six months later, researchers spotted Y35 for the last time. It was only 16 days before her expected due date. She and her calf are now both presumed dead, a disturbingly common trend among the bottlenose dolphins that call Barataria Bay their year-round home.

This trend of reproductive failure and death in Gulf dolphins over five years of monitoring after the 2010 Deepwater Horizon oil spill is outlined in a November 2015 study led by NOAA and published in the peer-reviewed journal Proceedings of the Royal Society.

Of the 10 Barataria Bay dolphins confirmed to be pregnant during the 2011 health assessment, only two successfully gave birth to calves that have survived. This unusually low rate of reproductive success—only 20%—stands in contrast to the 83% success rate in the generally healthier dolphins being studied in Florida’s Sarasota Bay, an area not affected by Deepwater Horizon oil.

Baby Bump in Failed Pregnancies

While hypoadrenocorticism had not been documented previously in dolphins, it has been found in humans. In human mothers with this condition, pregnancy and birth—stressful and risky enough conditions on their own—can be life-threatening for both mother and child when the condition is left untreated. Wild dolphins with this condition would be in a similar situation.

Mink exposed to oil in an experiment ended up exhibiting very low levels of stress hormones, while sea otters exposed to the Exxon Valdez oil spill experienced high rates of failed pregnancies and pup death. These cases are akin to what scientists have observed in the dolphins of Barataria Bay after the Deepwater Horizon oil spill.

Among the pregnant dolphins being monitored in this study, at least two lost their calves before giving birth. Veterinarians confirmed with ultrasound that one of these dolphins, Y31, was carrying a dead calf in utero during her 2011 exam. Another pregnant dolphin, Y01, did not successfully give birth in 2012, and was then seen pushing a dead newborn calf in 2013. Given that dolphins have a gestation of over 12 months, this means Y01 had two failed pregnancies in a row.

The other five dolphins to lose their calves after the Deepwater Horizon oil spill, excluding Y35, survived pregnancy themselves but were seen again and again in the months after their due dates without any young. Dolphin calves stick close to their mothers’ sides in the first two or three months after birth, indicating that these pregnant dolphins also had calves that did not survive.

At least half of the dolphins with failed pregnancies also suffered from moderate-to-severe lung disease, a symptom associated with exposure to petroleum products. The only two dolphins to give birth to healthy calves had relatively minor lung conditions.

Survival of the Least Oiled

Dolphin Y35 wasn’t the only one of the 32 dolphins being monitored in Barataria Bay to disappear in the months following her 2011 examination. Three others were never sighted again in the 15 straight surveys tracking these dolphins. Or rather, they were never seen again alive. One of them, Y12, was a 16-year-old adult male whose emaciated carcass washed up in Louisiana only a few weeks before the pregnant Y35 was last seen. In fact, the number of dolphins washing up dead in Barataria Bay from August 2010 through 2011 was the highest ever recorded for that area.

Survival rate in this group of dolphins was estimated at only 86%, down from the 95-96% survival seen in dolphin populations not in contact with Deepwater Horizon oil. The marshy maze of Barataria Bay falls squarely inside the footprint of the Deepwater Horizon oil spill, and its dolphins and others along the northern Gulf Coast have repeatedly been found to be sick and dying in historically high numbers. Considering how deadly this oil spill has been for Gulf bottlenose dolphins and their young, researchers expect recovery for these marine mammals to be a long time coming.

Watch an updated video of the researchers as they temporarily catch and give health exams to some of the dolphins in Barataria Bay, Louisiana, in August of 2011 and read a 2013 Q&A with two of the NOAA researchers involved in these studies:

This study was conducted under the Natural Resource Damage Assessment for the Deepwater Horizon oil spill. These results are included in the injury assessment documented in the Draft Programmatic Assessment and Restoration Plan that is currently out for public comment. We will accept comments on the plan through December 4, 2015.

This research was conducted under the authority of Scientific Research Permit nos. 779-1633 and 932-1905/MA-009526 issued by NOAA’s National Marine Fisheries Service pursuant to the U.S. Marine Mammal Protection Act.

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Deepwater Horizon Oil Spill Tied to Further Impacts in Shallower Water Corals, New Study Reports

Sick sea fan with discolored branches and hydroids covering it.

After the Deepwater Horizon oil spill, researchers found significant injuries in at least four species of sea fans along the Gulf’s continental shelf. Damage primarily took the form of overgrowth by hydroids (fuzzy marine invertebrates characteristic of unhealthy corals) and broken or bare branches of coral. (Credit: Ian MacDonald/Florida State University)

In the months and years after the 2010 Deepwater Horizon oil spill, damage and poor health were found in a swath of deep-sea coral reefs and related marine life at the bottom of the Gulf of Mexico.

Within roughly 16 miles of the leaking wellhead, researchers discovered sickened and damaged deep-sea corals, often coated in a clumpy brown material containing petroleum, and the sediments showed evidence of out-of-balance communities of tiny invertebrates inhabiting the seafloor sediments, whose diversity took a nose dive after the spill.

Now, a study published in October 2015 in the journal Coral Reefs reveals that this footprint of damage also extends to coral communities in shallower Gulf waters, up to 67 miles from the wellhead. In this latest study, researchers from NOAA, Florida State University, and JHT Inc. used video and images from remotely operated vehicles (ROV) to compare the health of corals on hard-bottom reefs in the “mesophotic zone” before and after the oil spill.

The mesophotic zone of the ocean receives low levels of light but supports abundant fish, corals, and sponges. The reefs in this study are important sources of habitat, food, and shelter for various marine life. These vibrant reefs also support recreational and commercial fishing for species such as snapper and grouper. Located in a region called the “Pinnacle Trend,” they are at the edge of the continental shelf off Louisiana, Mississippi, and Alabama, roughly 200-300 feet below the surface.

Previous oil spill studies focused on deep-sea coral communities 4,000 feet under the ocean, located near the leaking wellhead. While the Pinnacle Trend reefs are shallower and more remote, they were below the surface oil slick that persisted for several weeks.

What Lies Beneath

Three of the largest reefs at Pinnacle Trend—bearing the colorful names Alabama Alps Reef, Roughtongue Reef, and Yellowtail Reef—were located beneath the surface slick of Deepwater Horizon oil for three to five weeks in the summer of 2010. Located between 35 and 67 miles from the leaking well, corals on the reefs were likely to have been exposed to oil and dispersant that sank from the surface down toward the seafloor. These reefs were measured against two other reef sites more than 120 miles beyond the leaking well and below the Deepwater Horizon oil slick less than three days.

Graphic showing a profile of the Gulf of Mexico's seafloor habitats from shore out to the leaking wellhead.

A profile of the Gulf of Mexico seafloor habitats extending from the shore to depths around the Macondo wellhead. The mesophotic coral reefs in this study were located at the edge of the continental shelf. (NOAA/Kate Sweeney)

Because researchers had access to ROV footage of these coral reefs dating back as far as 1989, they could directly measure what level of injury could be considered “normal” for each reef. After all, this area of the Gulf is known to be susceptible to impacts from fishing methods that contact the sea bottom. Researchers suspect that fishing was the cause of injuries observed at the two sites far from the spill because lines were wrapped around many of the coral colonies.

Not a (Sea) Fan of Damaged Corals

The three reefs closer to the wellhead had less evidence of fishing but showed major declines in health after the oil spill in 2010. More than half of the coral colonies at these sites showed signs of damage by 2011, compared with less than 10% before the spill. In comparison, the sites further from the wellhead had no significant change before and after the Deepwater Horizon oil spill.

In addition, injured corals the scientists noted in 2011 continued to deteriorate in the years that followed, “suggesting recovery of injured corals is unlikely,” said lead author Dr. Peter Etnoyer of NOAA. Healthy corals noted after the incident in 2011 remained healthy through the end of the study in 2014, suggesting the injured corals would have been healthy but for the spill.

The researchers in this most recent study noted significant injuries among at least four species of large gorgonian octocorals (sea fans) in the three impacted reefs. Injuries took the form of overgrowth by hydroids (fuzzy marine invertebrates characteristic of unhealthy corals) and broken or bare branches of coral. To a lesser extent, corals also appeared severely discolored, with eroded polyps, had lost limbs, or toppled over entirely.

An earlier study of these mesophotic reefs by some of the same scientists in the journal Deep Sea Research detected low levels of a petroleum compound known as polycyclic aromatic hydrocarbons (PAHs) in coral tissues and nearby seafloor sediments. The levels were low compared to sites near the wellhead, but at this point, no one yet has established what constitutes a toxic level of these compounds to marine life in mesophotic coral communities.

“The corals of the Pinnacle Trend require decades to reach maturity,” said Florida State University scientist Ian MacDonald, who also contributed to the study. “Recovery will require years and it may not be immediately apparent whether the injured colonies are being replaced with new settlements. Our task is to study the process—to learn as much as we can and to ensure that nothing impedes this vital natural process.”

“The results presented here may vastly underestimate the extent of impacts to mesophotic reefs in the northern Gulf of Mexico,”  the researchers commented, since the reefs in this study represent less than 3 percent of the mesophotic reef habitat that was known to occur beneath the oil slick. “The reefs have some prospects for recovery since many healthy colonies remain,” said Etnoyer. NOAA and its partners on this study recommend efforts to protect and restore the Pinnacles Trend reefs in order to conserve the corals and fish along this part of the ocean floor.

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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.

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Melting Permafrost and Camping with Muskoxen: Planning for Oil Spills on Arctic Coasts

 Muskoxen near the scientists' field camp on Alaska's Espenberg River.

Muskoxen near the scientists’ field camp on Alaska’s Espenberg River. (NOAA)

This is a post by Dr. Sarah Allan, Alaska Regional Coordinator for NOAA’s Office of Response and Restoration, Assessment and Restoration Division.

Alaska’s high Arctic coastline is anything but a monotonous stretch of beach. Over the course of more than 6,500 miles, this shoreline at the top of the world shows dramatic transformations, featuring everything from peat and permafrost to rocky shores, sandy beaches, and wetlands. It starts at the Canadian border in the east, wraps around the northernmost point in the United States, and follows the numerous inlets, bays, and peninsulas of northwest Alaska before coming to the Bering Strait.

Planning for potential oil spills along such a lengthy and varied coastline leaves a lot for NOAA’s Office of Response and Restoration to consider. We have to take into account a wide variety of shorelines, habitats, and other dynamics specific to the Arctic region.

This is why fellow NOAA Office of Response and Restoration scientist Catherine Berg and I, normally based in Anchorage, jumped at the opportunity to join a National Park Service–led effort supporting oil spill response planning in the state’s Northwest Arctic region.

Our goal was to gain on-the-ground familiarity with its diverse shorelines, nearshore habitats, and the basics of working out there. That way, we would be better prepared to support an emergency pollution response and carry out the ensuing environmental impact assessments.

Arctic Endeavors

Man inflating boat next to ATV and woman kneeling on beach.

At right, NOAA Regional Resource Coordinator Dr. Sarah Allan collects sediment samples while National Park Service scientist Paul Burger inflates the boat near the mouth of the Kitluk River in northwest Alaska. (National Park Service)

Many oil spill planning efforts have focused on oil drilling sites on Alaska’s North Slope, especially in Prudhoe Bay and the offshore drilling areas in the Chukchi Sea. However, with increased oil exploration and a longer ice-free season in the Arctic, more ship traffic—and a heightened risk of oil spills—extends to the transit routes throughout Arctic waters.

This risk is especially apparent in the Northwest Arctic around the Bering Strait, where vessel traffic is squeezed between Alaska’s mainland and two small islands. On top of the growing risk, the Northwest Arctic coast, like much of Alaska, presents daunting logistical challenges for spill response due to its remoteness and limited infrastructure and support services.

To help get a handle on the challenges along this region’s coast, Catherine Berg and I traveled to northwest Alaska in July 2015 and, in tag-team fashion, visited the shorelines of the Chukchi Sea in coordination with the National Park Service. Berg is the NOAA Scientific Support Coordinator for emergency response and I’m the Regional Resource Coordinator for environmental assessment and restoration.

The National Park Service is collecting data to improve Geographic Response Strategies in the Bering Land Bridge National Preserve and the Cape Krusenstern National Monument, both flanking Kotzebue Sound in northwest Alaska. These strategies, a series of which have been developed for the Northwest Arctic, are plans meant to protect specific sensitive coastal environments from an oil spill, outlining recommendations for containment boom and other response tools.

Because our office is interested in understanding the potential effects of oil on Arctic shorelines, we worked with the Park Service on this trip to collect information related to oil spill response and environmental assessment planning in northwest Alaska’s Bering Land Bridge National Preserve.

The Wild Life

From the village of Kotzebue, two National Park Service scientists and I—along with our all-terrain vehicle (ATV), trailer, and all of our personal, camping, and scientific gear—were taken by boat to a field camp on the Espenberg River. After arriving, we could see signs of bear, wolf, and wolverine activity near where this meandering river empties into the Bering Sea. Herds of muskoxen passed near camp.

Considering most of the Northwest Arctic’s shorelines are just as wild and hard-to-reach, we should expect to be set up in a similar field camp, with similarly complex planning and logistics, in order to collect environmental impact data after an oil spill. As I saw firsthand, things only got more complicated as weather, mechanics, shallow water, and low visibility forced us to constantly adapt our plans.

Heading west, we used ATVs to get to the mouth of the Kitluk River, where the Park Service collected data for the Geographic Response Strategies, while I collected sediment samples from the intertidal area for chemical analysis. These samples would serve as set of baseline comparisons should there be an oil spill in a similar area.

Traveling there, we saw dramatic signs of coastal erosion, a reminder of the many changes the Arctic is experiencing.

The next day, the boat took us around Espendberg Point into Kotzebue Sound to the Goodhope River estuary. There, we used a small inflatable boat with a motor to check out the different sites identified for special protection in the Geographic Response Strategy. I also took the opportunity to field test the “Vegetated Habitats” sampling guideline I helped develop for collecting time-sensitive data in the Arctic. Unfortunately, the very shallow coastal water presented a challenge for both our vessels; the water was only a few feet deep even three miles offshore.

After an unplanned overnight in Kotzebue (more improvising!), I returned to the field camp via float plane and got an amazing aerial view of the coastline. The Arctic’s permafrost and tundra shorelines are unique among U.S. coastlines and will require special oil spill response, cleanup, and impact assessment considerations.

Sound Lessons

After I returned to the metropolitan comforts of Anchorage, my colleague Catherine Berg swapped places, joining the Northwest Arctic field team.

As the lead NOAA scientific adviser to the U.S. Coast Guard during oil spill response in Alaska, her objective was to evaluate Arctic shoreline types not previously encountered during oil spills. Using our Shoreline Cleanup and Assessment Technique method, she targeted shorelines within Kupik Lagoon on the Chukchi Sea coast and in the Nugnugaluktuk River in Kotzebue Sound. She surveyed the profile of these shorelines and recorded other information that will inform and improve Arctic-specific protocols and considerations for surveying oiled shorelines.

Though we only saw a small part of the Northwest Arctic coastline, it was an excellent opportunity to gauge how its coastal characteristics would influence the transport and fate of spilled oil, to improve how we would survey oiled Arctic shorelines, to gather critical baseline data for this environment, and to field test our guidelines for collecting time-sensitive data after an oil spill.

One of the greatest challenges for responding to and evaluating the impacts of an Arctic oil spill is dealing with the logistics of safety, access, transportation, and personnel support. Collaborating with the Park Service and local community in Kotzebue and gaining experience in the field camp gave us invaluable insight into what we would need to do to work effectively in the event of a spill in this remote area.

First, be prepared. Then, be flexible.

Thank you to the National Park Service, especially Tahzay Jones and Paul Burger, for the opportunity to join their field team in the Bering Land Bridge National Preserve.

Dr. Sarah Allan.

Dr. Sarah Allan has been working with NOAA’s Office of Response and Restoration Emergency Response Division and as the Alaska Regional Coordinator for the Assessment and Restoration Division, based in Anchorage, Alaska, since February of 2012. Her work focuses on planning for natural resource damage assessment and restoration in the event of an oil spill in the Arctic.

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How Is an Oil Spill in a River Different Than One in the Ocean?

Boat with boom next to oil mixed with river bank vegetation.

The often complex, vegetated banks of rivers can complicate cleaning up oil spills. (NOAA)

Liquid asphalt in the Ohio River. Slurry oil in the Gulf of Mexico. Diesel in an Alaskan stream. Each of these oil spills was very different from each other, partly because they involved very different types of oils.

But even if the same type of oil were spilled in each case, the results would be just as distinct because of where they occurred—one in a large inland river, one in the open ocean, and one in a small coastal creek.

In many cases, oil tends to float. But just because an oil floats in the saltwater of the Atlantic Ocean doesn’t mean it will float in the constantly moving freshwater of the Mississippi River.

But why does that happen? And what else can we expect to be different when oil spills into a river and not the ocean?

Don’t Be Dense … Blame Density

To answer the first question: When oil floats, it is generally because the oil is less dense than the water it was spilled into. The more salt is dissolved in water, the greater the water’s density. This means that saltwater is denser than freshwater. Very light oils, such as diesel, have low densities and would float in both the salty ocean and freshwater rivers.

However, very heavy oils may sink in a river (but perhaps not on the ocean), which is what happened when an Enbridge pipeline carrying a diluted form of oil from oil sands (tar sands) leaked into Michigan’s flooded Kalamazoo River in 2010. The lighter components of the oil quickly evaporated into the air, leaving the heavier components to drift in the water column and sink to the river bottom. That created a whole slew of new challenges as responders tried new methods of first finding and then cleaning up the difficult-to-access oil.

Going with the Flow

In rivers, going with the flow usually means going downstream. Except when it doesn’t. When might a river’s currents carry spilled oil upstream?

At the mouth of a river, where it meets the ocean, a large incoming tide can enter the river and overwhelm the normal downstream currents. That could potentially carry oil floating on the surface back upstream.

In open areas, such as on the ocean surface, both winds and currents have the potential to direct where spilled oil goes. And along most coasts, wind is what brings spilled oil onto shore.

In rivers, however, the downstream currents usually dominate the overall movement of oil while wind direction often determines which side of the river oil ends up on.

Locks and Other Blocks

Unlike the ocean, rivers sometimes feature structures such as dams, locks, and other barriers that block or slow down the free flow of water. During an oil spill on a river, these structures can also slow down the movement of oil.

That’s a helpful feature for responders who are trying to catch up to and clean up that oil. Frequently, dams and locks cause oil to pool up on the surface next to them. Some of the tools responders use to collect oil from these areas include skimmers, which are devices that remove thin layers of oil from the surface, and sorbent pads and booms, which are large squares and long tubes of special material that absorb oil but not water.

In fact, the banks of the river can constrain spilled oil as well. Because the oil can’t spread as far or thin as in open water, oil slicks can be thicker on rivers, and recovery efforts can be more effective.

One exception is the case of flow-over dams, known as weirs. The water passing over weirs can be very turbulent, causing oil to disperse into the water column. If it is very light oil and there’s not very much, that oil tends not to resurface and form another slick. But sheens may resurface with heavier oils that might be broken up going over a weir but later resurface as the water it is traveling in becomes calmer downstream.

Vegging Out

Oil rings on trees next to a river with boom.

Flooding on the Kalamazoo River in Michigan during the Enbridge pipeline oil spill left a ring of oil around trees and other vegetation after the river returned to its normal level. (NOAA)

Often, plants grow in rivers and line their banks, whereas many parts of the coast are open sandy or rocky beaches, which tend to be easier to clean oil off of than vegetation. (Salt marshes and mangroves being notable oceanic exceptions.) If oil gets past booms, the long floating barriers responders use to prevent the spread of oil, and leaves a coating on plants, then plant cleanup options generally include cutting, burning, treating with chemical shoreline cleaners, or flushing vegetation with low-pressure water.

Plant life actually became an issue during the oil sands spill in Michigan’s Kalamazoo River. Because this river was flooded at the time of the spill and later returned to its normal level, oil on the river surface actually became stranded in tree branches along the riverbanks.

Muddying the Waters

Another issue for oil spills in rivers is sediment. Rivers often carry a lot of sediment in their currents. (How do you think the Mississippi got its nickname “Big Muddy”?) That means when oil droplets drift into the water column of a river, the sediment has the potential to stick to the oil droplets. Eventually (depending on how strong-flowing and full of sediment a river is) some of the oil-sediment combination may settle out to the bottom of the river, usually near the river mouth as the water slows down and reaches the ocean.

One notable example is related to an oil spill that happened on the Mississippi River in New Orleans in 2008. The tanker Tintomara collided with Barge DM932, ripping it in half and releasing all of the heavy fuel oil it was carrying. Downstream of where the responders were cleaning up oil, the Army Corps of Engineers was dredging the sediments that build up at the mouth of the Mississippi and an oily sheen appeared in the collected sediment.

Responders suspected the oil from Barge DM932 had mixed with the river sediment and fell to the bottom further downstream as the river neared the Gulf of Mexico.

Learn more about oil spills in rivers at


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