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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.


NOAA Joins Response to Pipeline Oil Spill at Refugio State Beach Near Santa Barbara, California

POSTED May 20, 2015 | UPDATED May 21, 2015: On May 19, 2015, NOAA was notified of a 24-inch pipeline rupture that occurred earlier in the day near Refugio State Beach in Santa Barbara County, California.

A reported 500 barrels (21,000 gallons) of crude oil flowed from the shore side of Highway 101 into the Pacific Ocean. The source has since been secured.

As of May 21, Office of Response and Restoration oceanographers estimate that forecasted winds and currents in the affected area of the oil spill will move the slick eastward parallel to the shore Thursday night and Friday. The oil consists of patches and streaks of various sizes and thicknesses, broken up and spread over approximately 20 miles of coast and up to 5 miles offshore. The percent of oil floating on the surface in the slicks is low, estimated to be less than 10 percent in the affected area.

Cleanup measures include skimmers, vacuum trucks, absorbent pads, and absorbent boomShoreline Cleanup and Assessment Technique (SCAT) teams are documenting the level of oil and impacts to the shoreline. 7,777 gallons of an oil and water mixture have been collected from the ocean. Several oiled birds, including pelicans, and an oiled California sea lion were found stranded and are being taken care of by official wildlife rehabilitation teams.

According to the U.S. Coast Guard, a commercial oil spill response company is conducting cleanup operations. Boats are collecting oil offshore. California Department of Fish and Wildlife has ordered beach closures. The U.S. Coast Guard has organized the Incident Management Team and is conducting overflights. The U.S. Environmental Protection Agency is also responding and is focusing on the site of the pipeline break and inland cleanup.

Spilled oIl flowing next to rocks

Overflight photo shows oil flowing towards the ocean following a pipeline break. (U.S. Coast Guard)

The Office of Response and Restoration’s Jordan Stout is on-scene as the NOAA Scientific Support Coordinator as well as an OR&R overflight observation specialist.  OR&R has been providing information on fate and effects of the crude oil and potential environmental impacts both in the water and on the shore.

In this preassessment phase scientists are researching what natural resources may have been exposed to the oil and whether to proceed with a Natural Resource Damage Assessment. Additional scientists will be deployed to the area in the coming days. Also from NOAA, the National Weather Service, the National Marine Fisheries Service, the Restoration Center, and the Office of National Marine Sanctuaries are providing support.

In 1969, a major oil spill occurred in the Santa Barbara area as a result of a well blowout. One of the largest environmental disasters in U.S. waters at that time, the legacy of that incident includes the creation of the National Environmental Policy Act, U.S. Environmental Protection Agency, and National Marine Sanctuaries system (which soon encompassed California’s nearby Channel Islands, which were affected by the 1969 Santa Barbara spill).

For further information, see the Joint Information Center website: Refugio Response Information.


Attempting to Answer One Question Over and Over Again: Where Will the Oil Go?

The Deepwater Horizon Oil Spill: Five Years Later

This is the first in a series of stories over the coming weeks looking at various topics related to the response, the Natural Resource Damage Assessment science, restoration efforts, and the future of the Gulf of Mexico.

Oil spills raise all sorts of scientific questions, and NOAA’s job is to help answer them.

We have a saying that each oil spill is unique, but there is one question we get after almost every spill: Where will the oil go? One of our primary scientific products during a spill is a trajectory forecast, which often takes the form of a map showing where the oil is likely to travel and which shorelines and other environmentally or culturally sensitive areas might be at risk.

Oil spill responders need to know this information to know which shorelines to protect with containment boom, or where to stage cleanup equipment, or which areas should be closed to fishing or boating during a spill.

To help predict the movement of oil, we developed the computer model GNOME to forecast the complex interactions among currents, winds, and other physical processes affecting oil’s movement in the ocean. We update this model daily with information gathered from field observations, such as those from trained observers tasked with flying over a spill to verify its often-changing location, and new forecasts for ocean currents and winds.

Modeling a Moving Target

One of the biggest challenges we’ve faced in trying to answer this question was, not surprisingly, the 2010 Deepwater Horizon oil spill. Because of the continual release of oil—tens of thousands of barrels of oil each day—over nearly three months, we had to prepare hundreds of forecasts as more oil entered the Gulf of Mexico each day, was moved by ocean currents and winds, and was weathered, or physically, biologically, or chemically changed, by the environment and response efforts. A typical forecast includes modeling the outlook of the oil’s spread over the next 24, 48, and 72 hours. This task began with the first trajectory our oceanographers issued early in the morning April 21, 2010 after being notified of the accident, and continued for the next 107 days in a row. (You can access all of the forecasts from this spill online.)

Once spilled into the marine environment, oil begins to move and spread surprisingly quickly but not necessarily in a straight line. In the open ocean, winds and currents can easily move oil 20 miles or more per day, and in the presence of strong ocean currents such as the Gulf Stream, oil and other drifting materials can travel more than 100 miles per day. Closer to the coast, tidal currents also can move and spread oil across coastal waters.

While the Deepwater Horizon drilling rig and wellhead were located only 50 miles offshore of Louisiana, it took several weeks for the slick to reach shore as shifting winds and meandering currents slowly moved the oil.

A Spill Playing on Loop

Over the duration of a typical spill, we’ll revise and reissue our forecast maps on a daily basis. These maps include our best prediction of where the oil might go and the regions of highest oil coverage, as well as what is known as a “confidence boundary.” This is a line encircling not just our best predictions for oil coverage but also a broader area on the map reflecting the full possible range in our forecasts [PDF].

Our oceanographers include this confidence boundary on the forecast maps to indicate that there is a chance that oil could be located anywhere inside its borders, depending on actual conditions for wind, weather, and currents. Why is there a range of possible locations in the oil forecasts? Well, the movement of oil is very sensitive to ocean currents and wind, and predictions of oil movement rely on accurate predictions of the currents and wind at the spill site.

In addition, sometimes the information we put into the model is based on an incomplete picture of a spill. Much of the time, the immense size of the Deepwater Horizon spill on the ocean surface meant that observations from specialists flying over the spill and even satellites couldn’t capture the full picture of where all the oil was each day.

Our inevitably inexact knowledge of the many factors informing the trajectory model introduces a certain level of expected variation in its predictions, which is the situation with many models. Forecasters attempt to assess all the possible outcomes for a given scenario, estimate the likelihood of the different possibilities, and ultimately communicate risks to the decision makers.

In the case of the Deepwater Horizon oil spill, we had the added complexity of a spill that spanned many different regions—from the deep Gulf of Mexico, where ocean circulation is dominated by the swift Loop Current, to the continental shelf and nearshore area where ocean circulation is influenced by freshwater flowing from the Mississippi River. And let’s not forget that several tropical storms and hurricanes crossed the Gulf that summer [PDF].

A big concern was that if oil got into the main loop current, it could be transported to the Florida Keys, Cuba, the Bahamas, or up the eastern coast of the United States. Fortunately (for the Florida Keys) a giant eddy formed in the Gulf of Mexico in June 2010 (nicknamed Eddy Franklin after Benjamin Franklin, who did some of the early research on the Gulf Stream). This “Eddy Franklin” created a giant circular water current that kept the oil largely contained in the Gulf of Mexico.

Some of the NOAA forecast team likened our efforts that spring and summer to the movie Groundhog Day, in which the main character is forced to relive the same day over and over again. For our team, every day involved modeling the same oil spill again and again, but with constantly changing results.  Thinking back on that intense forecasting effort brings back memories packed with emotion—and exhaustion. But mostly, we recall with pride the important role our forecast team in Seattle played in answering the question “where will the oil go?”


NOAA Prepares for Bakken Oil Spills as Seattle Dodges Oil Train Explosion

As federal leaders in oil spill response science, NOAA’s Office of Response and Restoration is grateful for each oil spill which does not take place, which was fortunately the case on July 24, 2014 in Seattle, Washington, near our west coast office. A train passing through the city ran off the tracks, derailing three of its 100 tank cars carrying Bakken crude oil from North Dakota to a refinery in the port town of Anacortes, Washington. No oil spilled or ignited in the accident.

However, that was not the case in five high-profile oil train derailments and explosions in the last year, occurring in places such as Casselton, North Dakota, when a train carrying grain derailed into an oil train, causing several oil tank cars to explode in December 2013.

Oil production continues to grow in North America, in large part due to new extraction technologies such as hydraulic fracturing (fracking) opening up massive new oil fields in the Bakken region of North Dakota and Montana. The Bakken region lacks the capacity to transport this increased oil production by the most common methods: pipeline or tanker. Instead, railroads are filling this gap, with the number of tank cars carrying crude oil in the United States rising more than 4,000 percent between 2009 (9,500 carloads) and 2013 (407,761).

Just a day before this derailment, Seattle City Council signed a letter to the U.S. Secretary of Transportation, urging him to issue an emergency stop to shipping Bakken crude oil in older model tank train cars (DOT-111), which are considered less safe for shipping flammable materials. (However, some of the proposed safer tank car models have also been involved in oil train explosions.) According to the Council’s press release, “BNSF Railway reports moving 8-13 oil trains per week through Seattle, all containing 1,000,000 or more gallons of Bakken crude.” The same day as the Council’s letter, the Department of Transportation proposed rules to phase out the older DOT-111 model train cars for carrying flammable materials, including Bakken crude, over a two-year period.

NOAA’s Office of Response and Restoration is examining these changing dynamics in the way oil is moved around the country, and we recently partnered with the University of Washington to research this issue. These changes have implications for how we prepare our scientific toolbox for responding to oil spills, in order to protect responders, the public, and the environment.

The fireball that followed the derailment and explosion of two trains, one carrying Bakken crude oil, on December 30, 2013, outside Casselton, N.D.

The fireball that followed the derailment and explosion of two trains, one carrying Bakken crude oil, on December 30, 2013, outside Casselton, N.D. (U.S. Pipeline and Hazardous Materials Safety Administration)

For example, based on our knowledge of oil chemistry, we make recommendations to responders about potential risks during spill cleanup along coasts and waterways. We need to know whether a particular type of oil, such as Bakken crude, will easily ignite and pose a danger of fire or explosion, and whether chemical components of the oil will dissolve into the water, potentially damaging sensitive fish populations.

Our office responded to a spill of Bakken crude oil earlier this year on the Mississippi River. On February 22, 2014, the barge E2MS 303 carrying 25,000 barrels of Bakken crude collided with a towboat 154 miles north of the river’s mouth. A tank of oil broke open, spilling approximately 31,500 gallons (750 barrels) of its contents into this busy waterway, closing it down for several days. NOAA provided scientific support to the response, for example, by having our modeling team estimate the projected path of the spilled oil.

Barge leaking oil on a river.

Barge E2MS 303 leaking 750 barrels of Bakken crude oil into the lower Mississippi River on February 22, 2014. (U.S. Coast Guard)

We also worked with our partners at Louisiana State University to analyze samples of the Bakken crude oil. We found the oil to have a low viscosity (flows easily) and to be highly volatile, meaning it readily changes from liquid to gas at moderate temperatures. It also contains a high concentration of the toxic components known as polycyclic aromatic hydrocarbons (PAHs) that easily dissolve into the water column. For more information about NOAA’s involvement in this incident, visit IncidentNews.


Detecting Change in a Changing World: 25 Years After the Exxon Valdez Oil Spill

Life between high and low tide along the Alaskan coast is literally rough and tumble.

The marine animals and plants living there have to deal with both crashing sea waves at high tide and the drying heat of the sun at low tide. Such a life can be up and down, boom and bust, as favorable conditions come and go quickly and marine animals and plants are forced to react and repopulate just as quickly.

But what happens when oil from the tanker Exxon Valdez enters this dynamic picture—and 25 years later, still hasn’t completely left? What happens when bigger changes to the ocean and global climate begin arriving in these waters already in flux?

Telling the Difference

Two people wearing chest waders sift for marine life in shallow rocky waters.

In 2011 NOAA marine biologist Gary Shigenaka (right) sifts through the sediments of Alaska’s Lower Herring Bay, looking for the tiny marine life that live there. (Photo by Gerry Sanger/Sound Ecosystem Adventures)

In the 25 years since the Exxon Valdez oil spill hit Alaska’s Prince William Sound, NOAA scientists, including marine biologist Gary Shigenaka and ecologist Alan Mearns, have been studying the impacts of the spill and cleanup measures on these animals and plants in rocky tidal waters.

Their experiments and monitoring over the long term revealed a high degree of natural variability in these communities that was unrelated to the oil spill. They saw large changes in, for example, numbers of mussels, seaweeds, and barnacles from year to year even in areas known to be unaffected by the oil spill.

This translated into a major challenge. How do scientists tell the difference between shifts in marine communities due to natural variability and those changes caused by the oil spill?

Several key themes emerged from NOAA’s long-term monitoring and subsequent experimental research:

  • impact. How do we measure it?
  • recovery. How do we define it?
  • variability. How do we account for it?
  • subtle connection to large-scale oceanic influences. How do we recognize it?

What NOAA has learned from these themes informs our understanding of oil spill response and cleanup, as well as of ecosystems on a larger scale. None of this, however, would have been apparent without the long-term monitoring effort. This is an important lesson learned from the Exxon Valdez experience: that monitoring and research, often viewed as an unnecessary luxury in the context of a large oil spill response, are useful, even essential, for framing the scientific and practical lessons learned.

Remote Possibilities

As NOAA looks ahead to the future—and with the Gulf of Mexico’s Deepwater Horizon oil spill in our recent past—we can incorporate and apply lessons of the Exxon Valdez long-term program into how we will support response decisions and define impact and recovery.

The Arctic is a region of intense interest and scrutiny. Climate change is opening previously inaccessible waters and dramatically shifting what scientists previously considered “normal” environmental conditions. This is allowing new oil production and increased maritime traffic through Arctic waters, increasing the risk of oil spills in remote and changing environments.

If and when something bad happens in the Arctic, how do scientists determine the impact and what recovery means, if our reference point is a rapidly moving target? What is our model habitat for restoring one area impacted by oil when the “unimpacted” reference areas are undergoing their own major changes?

Illustrated infographic showing timeline of ecological recovery after the Exxon Valdez oil spill.

Tracking the progress of recovery for marine life and habitats following the Exxon Valdez oil spill is no easy task. Even today, not all of the species have recovered or we don’t have enough information to know. (NOAA) Click to enlarge.

Listening in

NOAA marine biologist Gary Shigenaka explores these questions as he reflects on the 25 years since the Exxon Valdez oil spill in the following Making Waves podcast from the National Ocean Service:

[NARRATOR] This all points back at what Gary says is the main take-away lesson after 25 years of studying the aftermath of this spill: the natural environment in Alaska and in the Arctic are rapidly changing. If we don’t understand that background change, then it’s really hard to say if an area has recovered or not after a big oil spill.

[GARY SHIGENAKA] “I think we need to really keep in mind that maybe our prior notions of recovery as returning to some pre-spill or absolute control condition may be outmoded. We need to really overlay that with the dynamic changes that are occurring for whatever reason and adjust our assessments and definitions accordingly. I don’t have the answers for the best way to do that. We’ve gotten some ideas from the work that we’ve done, but I think that as those changes begin to accelerate and become much more marked, then it’s going to be harder to do.”


Read a report by Gary Shigenaka summarizing information about the Exxon Valdez oil spill and response along with NOAA’s role and research on its recovery over the past 25 years.

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Protecting the Great Lakes After a Coal Ship Hits Ground in Lake Erie

The coal ship CSL Niagara got stuck in Lake Erie's soft, muddy bottom at the entrance to Sandusky Bay in November 2013.

The coal ship CSL Niagara got stuck in Lake Erie’s soft, muddy bottom at the entrance to Sandusky Bay in November 2013. (U.S. Coast Guard)

In the course of a year, from October 2012 to October 2013, the Emergency Response Division of NOAA’s Office of Response and Restoration responded to 138 oil spills, chemical accidents, and various other threats to coastal environments and communities. Many of these responses required considerable time from the scientific team to estimate where spills might spread, analyze chemical hazards, and assess whether natural resources are at risk. Sometimes, however, we’re called into some incidents that end well, with minimum help needed on our part and no oil spilled.

Last November, LCDR John Lomnicky received a call from the U.S. Coast Guard with an example of an accident that had the potential to be much worse. LCDR Lomnicky is our Scientific Support Coordinator for the Great Lakes region and is based in Cleveland, Ohio.

When Staying Grounded Is a Bad Thing

On November 17, just after 10:00 in the morning, the vessel master of the CSL Niagara reported to the U.S. Coast Guard that his ship had run aground while leaving Sandusky Bay through Moseley Channel to Lake Erie. Aboard the ship were 33,000 metric tons (36,376 U.S. tons) of coal, headed to Hamilton, Ontario, and about 193 metric tons of intermediate fuel oil (a blend of gasoil and heavy fuel oil) and marine diesel. The concern in a situation like this would be that the grounded ship might leak oil. Its stern was stuck in the soft mud at the bottom of Lake Erie. At the time, the vessel master reported there were no injuries, flooding, or visible pollution.

This ship, the CSL Niagara, has a long history of transporting coal in Lake Erie. Launched in April of 1972 for Canada Steamship Lines, Ltd., the new ship was 730 feet long and even then was carrying coal to Hamilton, Ontario. During over 40 years of sailing in the Great Lakes, the Niagara has also carried cargos of grain, coke, stone, and iron ore.

NOAA chart of Lake Erie.

Lake Erie has an average depth of 62 feet, but its western basin, where the CSL Niagara grounded, averages only 24 feet deep. (NOAA Chart)

Even though the vessel hadn’t released any oil, the Coast Guard Marine Safety Unit, who had responders at the scene very shortly after the accident, put in a call to the Office of Response and Restoration’s LCDR Lomnicky for scientific support. As a precaution, they requested that we model the trajectory of oil in a worst case scenario if 145 metric tons of intermediate fuel oil and 48 metric tons of diesel fuel were released all at once into the water. We also provided a prediction of when the lake’s lower-than-usual water level would return to normal so a salvage team could refloat the stuck vessel. After gathering all of this information for the Coast Guard, LCDR Lomnicky continued to stand by for further requests.

In the hours that followed the ship’s grounding, the winds grew stronger, hampering efforts to free the vessel. The wind was causing the water level in the lake to drop and NOAA’s National Weather Service in Detroit predicted a 7.5 foot drop in levels for western Lake Erie. By 8:30 p.m., with 30 knot winds in two-to-three foot seas, the three tugboats contracted by the ship’s owner to dislodge the Niagara were making some progress. By midnight, however, with weather conditions worsening, salvage operations were suspended and scheduled to resume at first light.

But the next morning, November 18, the water level had dropped another two feet, and the three tugs still had had no luck freeing the stern of the Niagara from the lake bottom. The ship’s owner was now working on plans for lightering (removing the fuel) and containing any potentially spilled oil. Fortunately, there were still no reports of damage to the vessel or oil discharged into the water. The ship was just stuck.

By 4:00 that afternoon the water conditions had improved and another attempt to free the vessel was planned. Also, a combined tug-barge was en route should lightering become necessary.

Later that evening, shortly after 10:00, the ship was pulled free by two of the tugs and was back on its way early the next morning.

The location where the CSL Niagara grounded in Lake Erie is indicated with a red diamond, along with a window of information and photo of the grounded ship. It is mapped in Great Lakes ERMA, NOAA's online mapping tool for coastal pollution cleanup, restoration, and response.

The location where the CSL Niagara grounded in Lake Erie is indicated with a red diamond, along with a window of information and photo of the grounded ship. It is mapped in Great Lakes ERMA, NOAA’s online mapping tool for coastal pollution cleanup, restoration, and response. (NOAA)

Keeping the Great Lakes Great

Lake Erie is the shallowest of the five Great Lakes, with an average depth of 62 feet. Yet its western basin, where this ship grounding occurred, has an average depth of only 24 feet. The lake is an important source of commerce for both the U.S and Canada, who depend on it for shipping, fishing, and hydroelectric power. These industries place environmental pressure on the lake’s ecosystems, which  are also threatened by urban and agricultural runoff.

Happily, quick responders, sound information, and a break in the weather may have prevented this incident from becoming something much worse. A spill into Lake Erie could be devastating, especially considering its shallow waters, but this time, like many other times along the nation’s coasts, an oil spill was avoided.

Didn’t know that NOAA works in the Great Lakes? Nicknamed “the third coast,” the Great Lakes are a major U.S. water body, with a shoreline that stretches longer than the East Coast and Gulf Coast combined. Learn more about the Great Lakes and NOAA’s efforts there in this Great Lakes regional snapshot.

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Study Shows Gulf Dolphins in Poor Health following Deepwater Horizon Oil Spill

A dolphin is observed with oil on its skin on August 5, 2010, in Barataria Bay, La.

A dolphin is observed with oil on its skin on August 5, 2010, in Barataria Bay, La. (Louisiana Department of Wildlife and Fisheries/Mandy Tumlin)

Barataria Bay, located in the northern Gulf of Mexico, received heavy and prolonged oiling after the 2010 Deepwater Horizon oil spill. This area is also home to many bottlenose dolphins. In the wake of the spill, how healthy are dolphins living in this area? And how do they compare to dolphins living elsewhere?

As part of the Natural Resource Damage Assessment for the Deepwater Horizon oil spill, a team of more than 50 government, academic, and non-governmental researchers assessed the health of bottlenose dolphins living in Louisiana’s Barataria Bay, which received heavy oiling following the Deepwater Horizon spill, and in Florida’s Sarasota Bay, which was not oiled following the spill.

The team of scientists and veterinarians temporarily captured live dolphins, performed comprehensive health examinations on them at the site, and then released them. The health exam included measuring each dolphin’s length and weight; doing a physical exam; sampling skin, blood, and blubber; and performing an ultrasound to evaluate their internal organs, particularly their lung condition and pregnancy status. The team has published the results of this study in the peer-reviewed journal Environmental Science & Technology.

We spoke with two of the NOAA scientists involved, Dr. Lori Schwacke and Dr. Teri Rowles, to learn more about the research and what their findings mean for dolphins in the Gulf of Mexico.

Q: When did you conduct the dolphin health assessments and what did you observe?

Aug 2011: A veterinarian performs an ultrasound to assess a Barataria Bay dolphin’s health.

Aug 2011: A veterinarian performs an ultrasound to assess a Barataria Bay dolphin’s health. (NOAA)

The first health assessments were conducted in the summer of 2011 in Barataria Bay, La., and in Sarasota Bay, Fla. We found that the dolphins in Barataria Bay were in very poor health. Many of them were underweight and their blood tests showed a number of abnormal conditions such as anemia, elevated markers of inflammation, and increased liver enzymes.

Also, one rather unusual condition that we noted in many of the Barataria Bay dolphins was that they had very low levels of some hormones (specifically, cortisol) that are produced by the adrenal gland and are important for a normal stress response. Under a stressful condition, such as being chased by a predator, the adrenal gland produces cortisol, which then triggers a number of physiological responses including an increased heart rate and increased blood sugar. This gives an animal the energy burst that it needs to respond appropriately. In the Barataria Bay dolphins, cortisol levels were unusually low. The concern is that their adrenal glands were incapable of producing appropriate levels of cortisol, and this could ultimately lead to a number of complications and in some situations even death.

We also found significant lung disease. We looked for several different abnormalities based on studies that have been done on captive animals, and what we saw was most consistent with pneumonia. In some of the animals, the lung disease was so severe that we considered it life-threatening for that individual.

Q: How serious were the conditions observed in dolphins from Barataria Bay?

Some of the conditions observed in these dolphins were very serious. Some of the animals had multiple health issues going on, such as lung disease, very high liver enzymes, and indications of chronic inflammation. The veterinarians assigned a prognosis for each animal and nearly half of the Barataria Bay dolphins were given a guarded (uncertain outcome) or worse prognosis. In fact, 17 percent of them were given a poor or grave prognosis, indicating that they weren’t expected to live.

In comparison, in Sarasota we had only one guarded prognosis and the rest were in good or fair condition. Sarasota dolphins were much healthier than Barataria Bay dolphins.

Q: Have you been able to follow up on the status of any of the dolphins examined during these assessments?

We know one of them died. Y12 was a 16-year-old male that we examined in August 2011. He was underweight and many of his blood parameters were out of the expected range. The veterinary team assigned him a grave prognosis. His carcass was recovered by the Louisiana Department of Wildlife and Fisheries in January of 2012. So we know that he only survived a little over five months  after the health assessment was conducted. . But often carcasses aren’t recovered, and there were other dolphins that we examined that we didn’t expect to live for very long.

We’re also conducting photographic monitoring studies to monitor the survival and reproductive success or failure of the dolphins we sampled. Several of the females we sampled in Barataria Bay were pregnant so we’ve been monitoring them around and past their due date to see whether or not we see them with a calf. The gestation period for a dolphin is around 12 months, so these monitoring studies take a little bit longer. We hope to report those results soon.

Q: Are the disease conditions observed in Barataria Bay dolphins—lung disease, compromised stress hormone response—consistent with those expected from exposure to oil?

The decreased cortisol response is something fairly unusual but has been reported from experimental studies of mink exposed to fuel oil. The respiratory issues are also consistent with experimental studies in animals and clinical reports of people exposed to petroleum hydrocarbons.

Q: How do you know these health impacts weren’t caused by other lingering pollutants in the Gulf?

We analyzed the dolphins’ blubber to evaluate the levels of contaminants that have been previously reported in marine mammal tissues and then also linked with health effects. This covered a fairly broad suite of contaminants and included polychlorinated biphenyls (PCBs) as well as a suite of persistent pesticides that we know accumulate in dolphins over their lifetime, leaving a record of their exposure. We found that the levels of these pollutants in Barataria Bay dolphins were actually lower than the levels in Sarasota Bay dolphins. The levels from Barataria Bay dolphins were also low compared to previously reported levels in dolphins from a number of other coastal sites in the southeastern U.S. Therefore, we don’t think that the health effects we saw can be attributed to these other pollutants that we looked at.

Q: Are there more dolphin health assessments currently taking place or planned for the future?

Yes, in the summer of 2013 we repeated the studies in Sarasota Bay and Barataria Bay and expanded the studies to Mississippi Sound, where we assessed dolphins both in Mississippi and in Alabama waters. Those samples and data are still being analyzed.

Q: Was there anything about this study that you found surprising?

The magnitude of the health effects that we saw was surprising. We’ve done these health assessments in a number of locations across the southeast U.S. coast and we’ve never seen animals that were in this poor of condition.

Q: How does this study relate to or inform the investigation of the high number of marine mammal strandings observed along the Gulf Coast since February 2010 (the Unusual Mortality Event), which pre-dates the Deepwater Horizon oil spill?

Following the Deepwater Horizon oil spill, numerous dolphins were documented encountering oil, such as those in this photo from July 2010.

Following the Deepwater Horizon oil spill, numerous dolphins were documented encountering oil, such as those in this photo from July 2010. (NOAA)

The Unusual Mortality Event that’s underway is in the same general geographic area as the Deepwater Horizon oil spill response and overlaps with the Natural Resource Damage Assessment. These findings overlap with the high number of strandings, particularly in the Barataria Bay or central Louisiana area.

When you have a significant event like an oil spill or an Unusual Mortality Event, being able to study both live and dead animals provides more information about what might be going on as animals get ill and then die. Having access to findings from both of these studies enables us to look for commonalities between what we’re finding in the sick animals and what we’re finding in the dead animals to better evaluate causes and contributing factors.

Q: Outside of NOAA, who else did you work with to perform the health assessment?

This work was part of the Deepwater Horizon Natural Resource Damage Assessment being conducted cooperatively among NOAA, other federal and state trustees, and BP. This wouldn’t have been possible without the help of a number of our partners, including the National Marine Mammal Foundation, Chicago Zoological Society, and Louisiana Department of Wildlife and Fisheries. Also, Seaworld and the Georgia Aquarium provided personnel to support our studies. Their expertise and experience were key to getting these studies done.

We greatly appreciate the efforts of researchers from the Sarasota Dolphin Research Program, which led the dolphin health assessments in Sarasota.

Watch a video of the researchers as they temporarily catch and give health exams to some of the dolphins in Barataria Bay, La., in August of 2011: