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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What Have We Learned About Using Dispersants During the Next Big Oil Spill?

The Deepwater Horizon Oil Spill: Five Years Later

This is the eighth 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.

A U.S. Air Force plane drops an oil-dispersing chemical onto an oil slick on the Gulf of Mexico

A U.S. Air Force plane drops an oil-dispersing chemical onto an oil slick on the Gulf of Mexico May 5, 2010, as part of the Deepwater Horizon response effort. (NOAA)

Five years ago, in the middle of the response to the Deepwater Horizon oil spill, I was thrown into a scientific debate about the role of chemical dispersants in response to the spill. Dispersants are one of those things that are talked about a lot in the context of oil spills, but in reality used pretty rarely. Over my more than 20 years in spill response, I’ve only been involved with a handful of oil spills that used dispersants.

But the unprecedented use of chemical dispersants on and below the ocean’s surface during the Deepwater Horizon oil spill raised all sorts of scientific, public, and political questions. Questions about both their effectiveness in minimizing impacts from oil as well as their potential consequences for marine life in the Gulf of Mexico.

Did we understand how the ingredients and components of the dispersants behave? How toxic are they? What are the potential risks of dispersants and do they outweigh the benefits?

We knew the flood of questions wouldn’t end when the gushing oil well was capped; they would only intensify the next time there was a significant oil spill in U.S. waters. NOAA, as the primary scientific adviser to the U.S. Coast Guard, would need to keep abreast of the surge of new information and be prepared to answer those questions. Five years later, we know a lot more, but many of the scientific, public, and policy questions remain open to debate.

What Are Dispersants?

Dispersants are a class of chemicals specifically designed to remove oil from the water surface. One commonly used brand name is Corexit, but there are dozens of different dispersant mixtures (see this list of all the products available for use during an oil spill).

They work by breaking up oil slicks into lots of small droplets, similar to how dish detergent breaks up the greasy mess on a lasagna pan. These tiny droplets have a high surface area-to-volume ratio, making them easier for oil-eating microbes to break them down (through the process of biodegradation). Their small size also makes the oil droplets less buoyant, allowing them to scatter throughout the water column more easily.

Why Does Getting Oil off the Ocean Surface Matter?

Oil slicks on the water surface are particularly dangerous to seabirds, sea turtles, marine mammals, sensitive early life stages of fish (e.g., fish eggs and embryos), and intertidal resources (such as marshes and beaches and all of the plants and animals that live in those habitats). Oil, in addition to being toxic when inhaled or ingested, interferes with birds’ and mammals’ ability to stay waterproof and maintain a normal body temperature, often resulting in death from hypothermia. Floating oil can drift long distances and then strand on shorelines, creating a bigger cleanup challenge.

However, applying dispersants to an oil slick instead shifts the possibility of oil exposure to animals living in the water column beneath the ocean surface and on the sea floor. We talk about making a choice between either protecting shorelines and surface-dwelling animals or protecting organisms in the water column.

But during a large spill like the Deepwater Horizon, this is a false choice. No response technology is 100 percent effective, so it’s not either this or that; it’s how much of each? If responders do use dispersants, some oil will still remain on the surface (or reach the surface in the case of subsurface dispersants), and if they don’t use dispersants, some oil will still naturally mix into or remain in the water column.

Why Don’t We Just Clean up Oil with Booms and Skimmers?

Cleaning up oil with mechanical response methods like skimmers is preferable because these vessels actually remove the mess from the environment by skimming and collecting oil off the water surface. And in most spills, that is all we use. There are thousands of small and medium-sized spills annually, and mechanical cleanup is the norm for these incidents.

But these methods, known as “mechanical recovery,” can only remove some of the oil. Under ideal (rather than normal) circumstances, skimmers can recover—at best—only around 40 percent of an oil spill. During the Deepwater Horizon oil spill response, skimmers only managed to recover approximately 3 percent of the oil released.

Dispersants generally are only considered when mechanical cleanup would be swamped or is considered infeasible. During a big spill, mechanical recovery may only account for a small percentage of the oil. Booms (long floating barriers used to contain or soak up oil) and skimmers don’t work well in rough seas and take more time to deploy. Booms also require constant maintenance or they can become moved around by wind and waves away from their targeted areas. If they get washed onto shore, booms can cause significant damage, particularly in sensitive areas such as marshes and wetlands.

Aircraft spraying dispersant are able to treat huge areas of water quickly while a skimmer moves very slowly, only one to two miles per hour. In the open ocean spilled oil can spread as fast, or faster, than the equipment trying to corral it.

Isn’t There Something Better?

Chemical product label for Corexit dispersant.

Dispersants, such as Corexit, are a class of chemicals specifically designed to remove oil from the water surface by breaking up oil slicks into lots of small droplets. (NOAA)

Well, researchers are trying to develop more effective response tools, including safer dispersants. And the questions surrounding the potential benefits and risks of using dispersants in the Gulf of Mexico have led to substantial research in the Gulf and other waters at risk from spills, including the Arctic. That research is ongoing, and answering one question usually leads to several more.

Unfortunately, however, once an oil spill occurs, we don’t have the luxury of waiting for more research to address lingering scientific and technical concerns. A decision will have to be made quickly and with incomplete information, applied to the situation at the moment. And if, during a large spill, mechanical methods become overwhelmed, the question may be: Is doing nothing else better than using dispersants?

That summer of 2010, in between trips to the Gulf and to hearings in DC, we began to evaluate the observations and science conducted during the spill to build a foundation for planning and decision making in future spills. In 2011, NOAA and our partners held a national workshop of federal, state, industry, and academic scientists to discuss what was known about dispersants and considerations for their use in future spills. You can read the reports and background materials from that workshop.

That was not the only symposium focused on dispersant science and knowledge. Almost every major marine science conference over the past five years has devoted time to the issue. I’ve been involved in workshops and conferences from Florida to Alaska, all wrestling with this issue.

What Have We Learned?

Freshly spilled crude oil in the Ohmsett saltwater test tank starts turning brown after dispersants applied.

The Deepwater Horizon oil spill spawned a larger interest in researching dispersants. Here, you can see freshly spilled crude oil in the Ohmsett saltwater test tank in New Jersey, where the oil starts changing a few minutes after dispersants were applied. Note that some of the oil is still black, but some is turning brown. (NOAA)

Now, five years later, many questions remain and more research is coming out almost daily, including possible impacts from these chemicals on humans—both those active in the response as well as residents near the sites of oiling. Keeping up with this research is a major challenge, but we are working closely with our state and federal partners, including the U.S. Environmental Protection Agency and Coast Guard, as well as those in the academic community to digest the flow of information.

The biggest lesson learned is one we already knew. Once oil is spilled there are no good outcomes and every response technology involves trade-offs.

Dispersants don’t remove oil from the environment, but they do help reduce the concentration of the oil by spreading it out in the water (which ocean currents and other processes do naturally), while also increasing degradation rates of oil. They reduce the amount of floating oil, which reduces the risk for some organisms and environments, but increases the risk for others. We also know that some marine species are even more sensitive to oil than we previously thought, especially for some developmental stages of offshore fish including tuna and mahi mahi.

But we also know, from the Exxon Valdez and other spills, that oil on the shore can persist for decades and create a chronic source of oil exposure for birds, mammals, fish, and shellfish that live near shore. We don’t want oil in the water column, and we don’t want oil in our bays and shorelines. Basically, we don’t want oil spills at all. That sounds like something everyone can agree with.

But until we stop using, storing and transporting oil, we have the risk of spills. The decision to use dispersants or not use dispersants will never be clear cut. Nor will it be done without a lot of discussion of the trade-offs. The many real and heart-felt concerns about potential consequences aren’t dismissed lightly by the responders who have to make tough choices during a spill.

I am reminded of President Harry Truman who reportedly said he wanted a one-handed economist, since his economic advisers would always say, “on the one hand…on the other.”


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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?”


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What Does It Take to Clean up the Cleanup From an Oil Spill?

Bags of oiled waste on a beach next to a No Smoking sign.

Bags and bags of oiled waste on the beach of Prince William Sound, Alaska, following the Exxon Valdez oil spill in March 1989. (NOAA)

Imagine spilling a can of paint on your basement floor (note: I have done this more than once.). Luckily, you have some paper towels nearby, and maybe some rags or an old towel you can use to mop up the mess. When you’re finished, all of those items probably will end up in the garbage. Maybe along with some of the old clothes you had on.

You might not think much about the amount of waste you generated, but it was probably a lot more than the volume of paint you spilled—maybe even 10 times as much. That number is actually a rule of thumb for oil spill cleanup. The amount of waste generated is typically about 10 times the volume of oil spilled.

Our colleagues at the International Tanker Owners Pollution Federation (ITOPF) did a study on this very topic, looking at the oil-to-waste ratio for nearly 20 spills [PDF]. (A messy job, for sure.) ITOPF found that the general rule for estimating waste at oil spills still held true at about 10 times the amount spilled.

The Mess of a Cleanup

Cleanup workers collect oily debris in bags on the banks of the Mississippi River.

Responders collect oily debris during the M/V Westchester oil spill in the Mississippi River near Empire, Louisiana, in November 2000. (NOAA)

What kinds of wastes are we talking about? Well, there is the oil recovered itself. In many cases, this can be recycled. Then there are oily liquids. These are the result of skimming oil off of the water surface, which tends to recover a lot of water too, and this has to be processed before it can be properly disposed. Shoreline cleanup is even messier, due to the large amounts of oily sands and gravel, along with seaweed, driftwood, and other debris that can end up getting oiled and need to be removed from beaches.

Some response equipment such as hard containment booms can be cleaned and reused, but that cleaning generates oily wastes too. Then there are the many sorbent materials used to mop up oil; these sorbent pads and soft booms may not be reusable and would be sent to a landfill. Finally, don’t forget about the oil-contaminated protective clothing, plastic bags, and all of the domestic garbage generated by an army of cleanup workers at the site of a spill response.

Aiming for Less Mess

A large U.S. oil spill response will have an entire section of personnel devoted to waste management. Their job is to provide the necessary storage and waste processing facilities, figure out what can be recycled, what will need to be taken to a proper landfill or incineration facility, and how to get it all there. That includes ensuring everything is in compliance with the necessary shipping, tracking, and disposal paperwork.

The amount of waste generated is a serious matter, particularly because oil spills often can occur in remote areas. In far-off locales, proper handling and transport of wastes is often as big a challenge as cleaning up the oil. Dealing with oily wastes is even more difficult in the Arctic and remote Pacific Islands such as Samoa because of the lack of adequate landfill space. One of the common goals of a spill response is to minimize wastes and segregate materials as much as possible to reduce disposal costs.

In a 2008 article [PDF], the U.S. Coast Guard explores in more detail the various sources of waste during an oil spill response and includes suggestions for incentivizing waste reduction during a response.


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When Oil Spills Take You to Hawaii and the Yellowstone River in Two Days

Overview of the Yellowstone River at the site of the pipeline spill.

Overview of the Yellowstone River at the site of the pipeline spill on Jan. 19, 2015. (U.S. Environmental Protection Agency)

We get called for scientific support between 100 and 150 times a year for oil spills, chemical releases, and other marine pollution events around the nation. That averages to two or three calls per week from the U.S. Coast Guard or U.S. Environmental Protection Agency, but those calls aren’t nicely scheduled out during the week, or spread out regionally among staff in different parts of the country.

The date of an oil spill is just the starting point. Many of these pollution incidents are resolved in a day or two, but some can lead to years of work for our part of NOAA. Some oil spills make the national and regional news while others might only be a local story for the small coastal town where the spill took place.

To give you an idea, some of the incidents we worked on just last week took us from Hawaii one day to eastern Montana the next day—and we were already working on two others elsewhere. These incidents included a pipeline break and oil spill in the Yellowstone River in Montana; a mystery spill of an unknown, non-oil substance that resulted in birds stranded in San Francisco Bay, California; a tug boat sinking and releasing diesel fuel off of Oahu, Hawaii; and a fishing vessel grounded near Sitka, Alaska.

Aerial view of oil spilled along the edge of Yellowstone River.

View from an aerial survey of the spill site on the Yellowstone River, taken about six miles upstream from Glendive, Montana. (Montana Department of Environmental Quality)

The Yellowstone River spill involved a pipeline releasing oil as it ran under a frozen river. The source of the leaking oil has been secured, which means no more oil is leaking, but response operations are continuing. It is an interesting spill for several reasons. One is because the oil type, Bakken crude, is an oil that has been in the news a lot recently. More Bakken crude oil is being transported by train these days because the location of the oil fields is far from ports or existing pipelines. Several rail car accidents involving this oil have ended in explosions. Another reason the Yellowstone River spill is of particular interest is because the response has to deal with ice and snow conditions along with the usual challenges of dealing with an oil spill.

Watch footage of an aerial survey over the Yellowstone River and spilled oil:

The mystery spill in the San Francisco Bay Area is still a mystery at this point (both what it is and where it came from), but hundreds of birds are being cleaned in the meantime. The response is coordinating sampling and chemical analysis to figure out the source of the “mystery goo” coating these seabirds.

Marine diesel fuel dyed red in the ocean.

Marine diesel fuel, dyed red, is shown approximately seven miles south of Honolulu Airport on January 23, 2015. The spill came from a tugboat that sank off Barbers Point Harbor, Oahu, on January 22. (U.S. Coast Guard)

Meanwhile, the tugboat accident in Hawaii involved about 75,000 gallons of fuel oil leaking from a tugboat that sank in over 2,000 feet of water. All 11 crewmembers of the tugboat were safely rescued. We were helping forecast what was happening to the spilled oil and where it might be drifting. In addition, there was a lot of concern about endangered Hawaiian monk seals and sea turtles in the area, but no oiled wildlife have been reported.

And that brings us to the fishing vessel grounded in Alaska. At this time the vessel is still intact and hasn’t spilled any of the 700 gallons of fuel believed to be onboard. Salvors are working to refloat the vessel. Fortunately, the crew had time to cap some of the fuel tank vents before abandoning ship, which may be helping prevent oil from being released. All four crew were safely rescued.

That makes four very different spills in four very different areas … and we have to be ready to respond with oil spill models and environmental expertise for all of them at the same time. But that’s just all in a day’s work at NOAA.


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Information about Oil Spills Is at Your Fingertips

Where and when was the biggest oil spill? How many oil spills happen each year? Is the frequency of oil spills going up or down? Where can I get information about oil spills?

We at NOAA’s Office of Response and Restoration hear these questions often, frequently from high school students looking for help writing their research papers …

We have a lot of information on our website about oil spills in general, as well as those cases in which we have provided scientific expertise during the response. In addition, we maintain IncidentNews.noaa.gov, which has information on thousands of selected historical incidents spanning 30 years of our experience responding to spills.

But NOAA only becomes involved with larger, more complex incidents in which scientific expertise is required to track or clean up spilled oil or cases with a significant threat to marine and coastal resources. Sometimes we get involved before any oil has actually spilled, such as when a ship runs aground on a coral reef and the fuel tanks have not been breached—yet. We typically respond to more than a hundred oil and chemical incidents annually, but there are thousands of smaller spills happening as well, many in marinas and urban and industrial waterways.

So what are some good sources of information on oil spills? For general statistics on oil spills in U.S. waters, I recommend that researchers go to the National Response Center website at http://www.nrc.uscg.mil.

The National Response Center (NRC) receives all reports of releases involving hazardous substances, including oil spills. Reports to the NRC activate the National Contingency Plan and the federal government’s response capabilities. The NRC maintains reports of all releases and spills in a national database going back to 1990 that you can download and search.

If you are interested in a specific pollution incident in the United States, the U.S. Coast Guard has a lot of information in their Marine Casualty and Pollution Data files. This database goes back to 1973 and captures details about marine casualty and pollution incidents that were investigated by the Coast Guard.

On the international level, the International Tanker Owners Pollution Federation (ITOPF) does a good job of providing data on oil spills from tankers and barges transporting oil. The ITOPF database goes back to 1970, and includes data from a variety of sources including maritime insurers and shipping publications.

One of the interesting trends that ITOPF data shows is that while tanker traffic has increased over the past 30 years, there has been a downward trend in oil spills originating from tankers.  In their list of the top 20 tanker accidents, 19 occurred before 1990, or pre-Exxon Valdez. Since then, many oil pollution prevention rules have been put in place and ship navigation tools have been improved. One notable example being the phase out of single-hull tankers.

Another good source of international data is CEDRE, the Centre of Documentation, Research and Experimentation on Accidental Water Pollution, based in Brittany, France. The CEDRE website has a good map and database featuring major oil spills around the world, dating back to 1917.

Speaking of oil spill data, we crunched the numbers on the locations of all of our oil spill-related responses from 2014 and came up with the following infographic:

Map of United States with numbers of oil spill responses in various coastal regions.

NOAA oil spill responses in 2014, by region. Includes actual and potential oil spills. The Gulf of Mexico, a region which produces and refines a lot of oil, also experiences the most oil spill responses NOAA is involved with of any other region. The U.S. Coast Guard in different regions takes advantage of NOAA support services in different ways, which may account for some of the very low or very high numbers of NOAA responses in various regions. (NOAA)


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A Final Farewell to Oil Tankers with Single Hulls

January 1, 2015 marks a major milestone in preventing oil spills. That date is the deadline which the landmark Oil Pollution Act of 1990 (OPA-90) specifies for phasing out single-hull tankers in U.S. waters. That act, passed after the 1989 Exxon Valdez oil spill in Prince William Sound, Alaska, required that all new tankers and tank-barges be built with double hulls.

Recently constructed single-hull tankers were allowed to operate, but 25 years after the Exxon Valdez, those vessels are now at the end of their operational life and will no longer be able to carry oil as cargo. The requirement was phased in gradually because of the difficultly of converting existing single-hull tankers to double hulls, and retiring the single-hull tankers more rapidly would have been a major disruption to world shipping.

Counting Down to a New Era

There won’t be a dramatic change-over on New Year’s Eve; most of the tankers calling on U.S. ports have had double hulls years before this deadline. However, one ship which was not switched over to a double hull soon enough was the tanker Athos I. This ship, carrying 13.6 million gallons of heavy crude oil, struck a submerged anchor in the Delaware River and caused a relatively large, complicated oil spill near Philadelphia, Pennsylvania, 10 year ago.

In 1992, two years after the Oil Pollution Act, the International Convention for the Prevention of Pollution from Ships (the MARPOL Convention) was amended to require all newly built tankers have double hulls. MARPOL has been ratified by 150 countries, representing over 99 percent of merchant tonnage shipped worldwide.

Stay out of Trouble by Going Double

So, what is the big issue around single vs. double-hull ships? Historically, tankers carrying oil were built with a single hull, or single shell.

While we measure oil in barrels, it is not actually shipped that way. Instead, oil is pumped into huge tanks that are part of the structure of tankers and barges. For vessels with a single hull, one plate of steel is all that separates the oil on board from the ocean. If the hull were punctured from a collision or grounding, an oil spill is pretty much guaranteed to follow. On the other hand, a ship with a double hull has two plates of steel with empty space in between them. The second hull creates a buffer zone between the ocean and the cargo of oil.

Naval architects have debated the merits of various hull designs in reducing oil spills, and using a double hull, essentially a hull within a hull, was selected as the preferred vessel design.

Close up of gash in hull on Cosco Busan cargo ship.

The cargo ship Cosco Busan lost 53,000 gallons of fuel oil when the single-hull ship hit the San Francisco-Oakland Bay Bridge in 2007. (U.S. Coast Guard)

However, the double hull requirements only apply to tankers and tank barges. Container ships, freighters, cruise ships, and other types of vessels are still built with single hulls. While these ships carry a lot less oil than a tanker, a large non-tank vessel can still carry a lot of fuel oil, and some have caused some pretty big spills, including the 2007 oil spill caused by the cargo ship Cosco Busan in San Francisco Bay.

Of course, double hulls don’t prevent all oil spills from tankers either, but the design has been credited with reducing the amount spilled, especially in the cases of low-speed groundings and collisions.

And some pretty spectacular collisions have resulted in double-hull tankers not spilling a drop.

Twenty years after the Exxon Valdez oil spill, the Norwegian tanker SKS Satilla collided with a submerged oil rig in the Gulf of Mexico. The collision tore a huge hole in the side of the oil tanker, but, thankfully, none of the 41 million gallons of crude oil it had on board was spilled.


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A Major Spill in Tampa Bay—21 Years Ago this Month

Two barges next to one another; one with oil spilled on its deck.

An oil soaked barge, after the 1993 Tampa Bay spill. (NOAA)

 

OR&R’s Doug Helton recalls his experience responding to a major spill in 1993.

August 10 is an anniversary of sorts.  21 years ago, I spent much of the month of August on the beaches of Pinellas County, Florida.  But not fishing and sunbathing. On August 10, 1993, three vessels, the freighter Balsa 37, the barge Ocean 255, and the barge Bouchard 155, collided near the entrance of Tampa Bay, Florida.

A barge on fire, with smoke coming form the deck.

The collision resulted in a fire on one of the barges and caused a major spill. (NOAA)

The collision resulted in a fire on one of the barges and caused a major oil spill. Over 32,000 gallons of jet fuel, diesel, and gasoline and about 330,000 gallons of heavy fuel oil spilled from the barges. Despite emergency cleanup efforts, the oil fouled 13 miles of beaches and caused injury to birds, sea turtles, mangrove habitat, seagrasses, salt marshes, shellfish beds,  as well as closing many of the waterways to fishing and boating.

The prior year I had been hired by NOAA and tasked with developing a Rapid Assessment Program (RAP) to provide a quick response capability for oil and chemical spill damage assessments, focusing on the collection of perishable data and information, photographs, and videotape in a timely manner to determine the need for a natural resource damage assessment. The emergency nature of spills requires that this type of information be collected within hours after the release. Time-sensitive data, photographs, and videotape are often critical when designing future assessment studies and initiating restoration planning—and are also used later as evidence in support of  Natural Resource Damage Assessment (NRDA) claims. The Tampa Bay spill was one of the first major responses for the RAP team.

The case was settled long ago and restoration projects have all been implemented to address the ecological and socioeconomic impacts of the spill. But some of the damage assessment approaches developed during that incident are still used today, and some of the then innovative restoration approaches are now more commonplace.

Sunset behind a bridge over a bay.

Tampa Bay, Skyway Bridge sunset, August 3, 2013. (Jeff Krause/Creative Commons)

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