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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Surveying What Hurricane Katrina Swept out to Sea

This is a post by Nir Barnea of NOAA’s Marine Debris Program.

Sunken boat next to a house in Louisiana.

Hurricane Katrina’s storm surge, over 25 feet high in places, destroyed houses, boats, and infrastructure along the Gulf Coast, and when it receded, it washed out to sea massive amounts of what became marine debris. (U.S. Coast Guard)

Hurricane Katrina was a powerful storm, one which brings a variety of powerful images to people’s minds: The satellite image of the huge storm moving toward the Gulf Coast, the flooded neighborhoods of New Orleans, damaged boats strewn all over like discarded toys.

But for me, the image I remember most vividly is one of stairways leading to homes no longer there. Driving along Mississippi’s Route 90 from Biloxi to Pass Christian on a hot August day in 2006, I saw dozens of them. They were the only remnants left of the beautiful beachfront houses that once lined that road, an area devastated by Hurricane Katrina’s overwhelming storm surge.

Swept Away

The same massive storm surge that demolished these houses was the reason I was in the region a year after Hurricane Katrina struck the Gulf Coast. The storm surge, over 25 feet high in places, destroyed houses and infrastructure, and when it receded, it washed out to sea massive amounts of what became marine debris.

In the wake of Hurricane Katrina and less than a month later, Hurricane Rita, the marine debris in ports and navigation channels was cleared quickly. However, the remaining debris, outside of navigation channels and in fishing and boating areas, posed a safety hazard to people, damaged boats and fishing gear, and hampered recreation and commercial activities.

To help deal with this debris, Congress appropriated funding in 2006 and again in 2007 to NOAA’s Office of Coast Survey and Office of Response and Restoration to survey traditional fishing grounds, map items found, disseminate survey information to assist with removal, and inform the public.

The project took three years. During the first phase, areas off the coast of Alabama, Mississippi, and eastern Louisiana were surveyed with side scan sonar. The survey teams generated maps of suspected underwater debris items (called “targets”) and placed them on the Gulf of Mexico Marine Debris Project website. We also shared with the public the locations of debris items determined to be a danger to navigation.

In the second phase of the project, our survey covered nearshore areas along the central and western Louisiana coastline. In addition to side scan sonar, survey teams used multi-beam survey technology for major targets, which is a powerful tool that provided us with vivid images of the objects detected.

NOAA, Federal Emergency Management Agency (FEMA), U.S. Coast Guard, and the State of Louisiana collaborated closely to determine which targets were the result of Hurricanes Katrina or Rita and therefore eligible for removal. Many of the targets we detected were actually not the result of these two major storms.

Dealing with Disaster Debris

Overturned boat in water awaiting salvage with another boat salvaged in background.

To help deal with the debris not yet cleared after Hurricanes Katrina and Rita, Congress appropriated funding to NOAA to survey traditional fishing grounds, map items found, and share that information to assist with removal and public notification. (NOAA)

On September 2, 2009, the project partners met in Baton Rouge, Louisiana, for a workshop summarizing the project. Participants provided insights and suggestions for improving the process, which were later gathered into the workshop proceedings [PDF]. We learned many lessons from this project, which should be put to good use in the future.

One of the things I liked most about the project was its collaborative nature. Project partners included two NOAA offices and eight contractors, Coast Guard, FEMA, a host of state agencies from the three impacted states, NOAA Sea Grant, and of course, the general public in the Gulf of Mexico. This collaborative effort did not go unnoticed, and the project received the Gulf Guardian Award for Partnership.

Hurricane Katrina was the first severe marine debris event for the young NOAA Marine Debris Program, established in 2005. It was not the last.

Over the last 10 years, our program, along with other parts of NOAA, have dealt with marine debris from Hurricane Sandy, a tsunami in American Samoa, and most recently, the influx of debris from the Japan tsunami of 2011.

Sadly, this trend suggests more such events in the future. NOAA and other agencies have learned a lot over the past 10 years, and we are better prepared for the next disaster which might sweep debris out to sea or bring large amounts of it onto shore (what we call “severe marine debris events”). Learn more at gulfofmexico.marinedebris.noaa.gov and marinedebris.noaa.gov/current-efforts/emergency-response.


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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 http://response.restoration.noaa.gov/oil-and-chemical-spills/oil-spills/resources/oil-spills-rivers.html.


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From Board Games to Cookbooks, How the Exxon Valdez Oil Spill Infiltrated Pop Culture

Big oil spills, those of the magnitude which happen only once every few decades, often leave a legacy of sorts.

In the case of the 1989 Exxon Valdez oil spill, which dumped roughly 11 million gallons of crude oil into Alaska’s Prince William Sound, that legacy took many forms. Legislative, ecological, and even cultural—yes, that extends to pop culture too.

In short order, the Exxon Valdez oil spill prompted monumental changes in the laws governing maritime shipping and oil spill response. In 1990, Congress passed the Oil Pollution Act, empowering NOAA and the U.S. Environmental Protection Agency to better respond to and plan for spills and setting up a trust fund (paid for by an oil tax) to help with cleanup operations.

Furthermore, this important legislation mandated that oil tankers with single hulls (like the easily punctured Exxon Valdez) would no longer be permitted to operate in U.S. waters, instead requiring double-hull vessels to carry oil. (However, the full phaseout of single-hull tankers would take decades.)

More than 25 years later, researchers are still uncovering this spill’s ecological legacy, its stamp on the natural world, and learning what happens when oil interacts with that world. The spill affected some two dozen species and habitats, some of which have not yet recovered.

Of course, the Exxon Valdez oil spill also left a complicated cultural legacy, imparting health, social, psychological, and economic impacts on the people living and working in the area, particularly those whose livelihoods are closely tied to the ocean. Commercial fishers, the recreation and tourism industry, and more than a dozen predominantly Alaskan Native communities relying on fish, waterfowl, and other natural resources for subsistence were dramatically affected by the oil spill.

Yet the cultural echoes of this environmental disaster spread beyond Alaska. It inspired a second grader to write an impassioned letter about the plight of otters threatened by the spill to the Alaska director of the Fish and Wildlife Service. After working at this spill, it inspired one NOAA marine biologist to begin collecting some of the strange pieces of memorabilia related to the incident, from a piece of the ill-fated tanker to an Exxon safety calendar featuring the ship in the very month it would run aground.

These echoes even managed to permeate the ranks of pop culture. Take a look at these five ways that the Exxon Valdez oil spill has shown up in places most oil spills just don’t go:

A view of part of the board game “On the Rocks: The Great Alaska Oil Spill” with a map of Prince William Sound.

The game “On the Rocks: The Great Alaska Oil Spill” challenges players to clean all 200 miles of shoreline oiled by the Exxon Valdez — and do so with limits on time and money. (Credit: Alaska Resources Library and Information Services, ARLIS)

  1. A board game. Local bartender Richard Lynn of Valdez, Alaska, created the game “On the Rocks: The Great Alaska Oil Spill” after working part-time to clean up the spill. Each player navigates through the game using an authentic bit of rock from Prince William Sound. The goal was to be the first player to scrub all 200 miles of oily shore. The catch was that you only had about 6 months and $250 million in play money to accomplish this. You could pick up your own copy of the game for $16.69, which was the hourly rate Exxon’s contracted workers earned while cleaning up the spill.
  2. A movie. Dead Ahead: the Exxon Valdez Disaster was the 1992 made-for-TV movie that dramatized the events of the oil spill and ensuing cleanup. This film even featured some well-known actors, including John Heard as Alaska inspector Dan Lawn and Christopher Lloyd as Exxon Shipping Company President Frank Iarossi.
  3. A cookbook. Fortunately, the recipes in The Two Billion Dollar Cookbook don’t feature dishes like “oiled herring” or “otter on the rocks.” Instead, this 300 page cookbook compiled by Exxon Valdez cleanup workers and their friends and families highlights meals more along the lines of barbeque sandwich mix and steak tartare, in addition to being peppered with personal stories from its contributors. Proceeds from the sale of this cookbook benefit a homeless shelter and food bank based in Anchorage, Alaska. Why two billion dollars? That was how much Exxon had shelled out for responding to the spill when the cookbook hit the presses.
  4. A play. Two plays, in fact. Dick Reichman, resident of Valdez, Alaska, during the momentous spill, has twice written and directed plays that examined this disaster—and the high emotions that came with it—through the theatrical lens. His first play, written in 1992 and dubbed “The official Valdez oil spill melodrama,” was Tanker on the Rocks: or the Great Alaskan Bad Friday Fish-Spill of ’89. His second, The Big One: a Chronicle of the Exxon Valdez Oil Spill, was received with some acclaim during its 2009 run in Anchorage. You can watch a short video of the actors and director preparing for the 2009 performance (warning: some explicit language).
  5. Children’s books, novels, and poetry. From a children’s book about a young girl rescuing an oiled baby seal to a novel written by the tugboat captain who towed the Exxon Valdez out of Prince William Sound, there exists a bounty of literature exploring the many human and environmental themes of this oil spill. As you peruse them, keep in mind this NOAA scientist’s recommendations for evaluating what you’re reading about oil spills, especially when doing so with kids.

Have you seen other examples of the Exxon Valdez or perhaps, more recently, the Deepwater Horizon oil spill showing up in pop culture?

A special thanks to the Alaska Resources Library and Information Services (ARLIS) for compiling an excellent list of Exxon Valdez related information [PDF] and for helping procure an image of the rare “On the Rocks” board game.


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To Bring Back Healthy California Ocean Ecosystems, NOAA and Partners Are “Planting” Long-Lost Abalone in the Sea

This is a post by Gabrielle Dorr, NOAA/Montrose Settlements Restoration Program Outreach Coordinator.

Diver placing PVC tube with small sea snails on the rocky seafloor.

A diver places a PVC tube filled with young green abalone — sea snails raised in a lab — on the seafloor off the southern California coast. (NOAA)

They weren’t vegetables but an excited group of scuba divers was carefully “planting” green abalone in an undersea garden off the southern California coast all the same. Green abalone are a single-shelled species of sea snail whose population has dropped dramatically in recent decades.

On a Wednesday in mid-June, these oceanic “gardeners”—NOAA biologist David Witting and divers from The Bay Foundation—released over 700 young green abalone into newly restored kelp forest areas near Palos Verdes, California. This was the first time in over a decade that juvenile abalone have been “outplanted,” or transplanted from nursery facilities, to the wild in southern California. This ongoing project is a partnership between NOAA, The Bay Foundation, Redondo SEA Lab, The Nature Conservancy, and the California Department of Fish and Wildlife.

Spawned and reared at The SEA Lab in Redondo Beach, California, all of the juvenile abalone were between two and four years old and were between a quarter inch and 3 inches in size. Biologists painstakingly tagged each abalone with tiny identifying tags several weeks prior to their release into the wild.

Leading up to outplanting day, microbiologists from the California Department of Fish and Wildlife had to run rigorous tests on a sample of the juvenile abalone to certify them as disease-free before they were placed into the ocean. Several days before transferring them, biologists placed the abalone in PVC tubes with netting on either end for easy transport.

“This was just a pilot outplanting with many more larger-scale efforts to come in the near future,” stated David Witting from NOAA’s Restoration Center. “We wanted to go through all of the steps necessary to successfully outplant abalone so that it would be second nature next time.”

Marine biologists from The Bay Foundation, along with Witting and other NOAA biologists, will be going out over the next six to twelve months to monitor the abalone—checking for survival rates and movement of the abalone. “We expect to find some abalone that didn’t survive the transfer to the wild but probably a good number of them will move into the cracks and crevices of rocky reef outcroppings immediately,” according to Witting.

Why Abalone?

PVC tube filled with green abalone lodged into the rocky seafloor.

After testing and refining the techniques to boost the population of green abalone in the wild, scientists then will apply them to help endangered white and black abalone species recover. (NOAA)

All seven abalone species found along the U.S. West Coast have declined and some have all but disappeared. White and black abalone, in particular, are listed as endangered through the Endangered Species Act (ESA). Three abalone species (green, pinto, and pink) are listed as Species of Concern by NOAA Fisheries, a designation meant to protect the populations from declining further and which could result in an ESA listing. The two remaining abalone species, reds and flats, are protected and managed by states along the U.S. West Coast.

Historically, the main cause of abalone’s demise was a combination of overfishing and disease. Today, many other threats, such as poaching, climate change, oil spills, and habitat degradation, contribute to the decline of abalone and could impact the health of future populations.

The recent green abalone outplanting was one of the many steps needed to advance the recovery of all abalone species. Methods for rearing and outplanting are first being tested using green abalone because this species is more abundant in the wild. Once the methods are refined, they then will be employed to recover endangered white and black abalone—both species which are currently living on the brink of extinction.

What the Future Holds

A small green abalone eats red algae stuck to a plastic rack.

A young green abalone, reared in a lab in southern California, grazes on red algae. Raising these sea snails in a lab requires a lot of resources, prompting scientists to explore other approaches for boosting wild abalone populations. (Credit: Brenda Rees, with permission)

In particular, biologists are hoping to refine a technique they are coining “deck-spawning” as a way to outplant abalone in the future. Maintaining abalone broodstock and rearing them in a lab requires a lot of resources, funding, and time. This monumental effort has spurred biologists to develop an initially successful, alternate approach, which involves inducing mature, wild abalone to spawn on the deck of a boat.

The scientists then take the viable abalone larvae that develop and release them in a habitat where the young abalone are likely to settle and thrive. Immediately after spawning, the parent abalone can then be returned to the wild where they can continue to be a component of the functioning ocean ecosystem.

The green abalone outplanting project is part of a broader effort to restore abalone but is also playing an important role in work being led by The Bay Foundation with NOAA’s Montrose Settlements Restoration Program to restore southern California’s kelp forests. In southern California, fish habitat has been harmed by decades of toxic pollution dumped into the marine environment. After clearing areas that would be prime kelp habitat if not for the unnaturally high densities of sick and stressed sea urchins, NOAA, The Bay Foundation, and our partners have seen kelp bounce back once given relief from those overly hungry urchins.

While abalone also eat seaweed, including kelp, they are a natural competitor of urchins in this environment and will help keep urchin populations in check, ultimately allowing a healthy kelp forest community to return.

Watch as divers transport the young abalone using PVC tubes and release them on the rocky seafloor off California’s coast:

Gabrielle Dorr

Gabrielle Dorr.

Gabrielle Dorr is the Outreach Coordinator for the Montrose Settlements Restoration Program as part of NOAA’s Restoration Center. She lives and works in Long Beach, California, where she is always interacting with the local community through outreach events, public meetings, and fishing education programs.


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This Is How We Help Make the Ocean a Better Place for Coral

Large corals on the seafloor.

The ocean on its own is an amazing place. Which is why we humans like to explore it, from its warm, sandy beaches to its dark, mysterious depths. But when humans are involved, things can and often do go wrong.

That’s where we come in. Our corner of NOAA helps figure out what impacts have happened and what restoration is needed to make up for them when humans create a mess of the ocean, from oil spills to ship groundings.

In honor of World Ocean Day, here are a few ways we at NOAA make the ocean a better place for corals when ships accidentally turn them into undersea roadkill.

First, we literally vacuum up broken coral and rubble from the seafloor after ships run into and get stuck on coral reefs. The ships end up crushing corals’ calcium carbonate homes, often carpeting the seafloor with rubble that needs to be removed for three reasons.

  1. To prevent it from smashing into healthy coral nearby.
  2. To clear space for re-attaching coral during restoration.
  3. To allow for tiny, free-floating coral babies to settle in the cleared area and start growing.

Check it out:A SCUBA diver using a suction tube to vacuum coral rubble from the seafloor during coral restoration after the VogeTrader ship grounding.Sometimes, however, the broken bits get stuck in the suction tube, and you have to give it a good shake to get things moving. SCUBA divers shaking a suction tube to clear it on the seafloor.Next, we save as many dislodged and knocked over corals as we can. In this case, popping them into a giant underwater basket that a boat pulls to the final restoration site.

SCUBA diver placing coral piece into a large wire basket on the seafloor during coral restoration after the VogeTrader ship grounding.Sometimes we use “coral nurseries” to regrow corals to replace the ones that were damaged. This is what that can look like:

Staghorn coral fragments hanging on an underwater tree structure of PVC pipes.Then, we cement healthy corals to the seafloor, but first we have to prepare the area, which includes scrubbing a spot for the cement and coral to stick to.

SCUBA diver scrubbing a spot on the seafloor for the cement and coral to stick to.(And if that doesn’t work very well, we’ll bring out a power washer to get the job done.)

SCUBA diver using a power washer to clear a spot on the seafloor for the cement and coral to stick to during coral restoration after the VogeTrader ship grounding.Finally, we’re ready for the bucket of cement and the healthy coral.

SCUBA diver turning over a bucket of cement on the seafloor during coral restoration after the VogeTrader ship grounding.

Instead of cement, we may also use epoxy, nails, or cable ties to secure corals to the ocean floor.

After all that work, the seafloor goes from looking like this:

View of seafloor devoid of coral before restoration.To this:

View of seafloor covered with healthy young coral and fish after restoration due to the VogeTrader grounding.

Ta-da! Good as new, or at least, on its way back to being good-as-new.

When that’s not enough to make up for all the harm done to coral reefs hit by ships, we look for other restoration projects to help corals in the area, like this project to vacuum invasive algae off of coral reefs in Oahu.

Watch how this device, dubbed the “Super Sucker,” works to efficiently remove the yellow-brown algae that is smothering the corals:

Or, as another example of a coral restoration project, we set sail each year to the remote Papahānaumokuākea Marine National Monument in the Northwestern Hawaiian Islands to pull more than 50 tons of giant, abandoned fishing nets off of the pristine coral reefs.

In 2014, that included removing an 11 ton “monster net” from a reef:

For the most part, the coral restoration you’ve seen here was completed by NOAA and our partners, beginning in October 2013 and wrapping up in April 2014.

These corals were damaged off the Hawaiian island of Oahu in February of 2010 when the cargo ship M/V VogeTrader ran aground and was later removed from a coral reef in Kalaeloa/Barber’s Point Harbor.


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Who Thinks Crude Oil Is Delicious? These Ocean Microbes Do

This is a post by Dalina Thrift-Viveros, a chemist with NOAA’s Office of Response and Restoration.

Edge of oil slick at ocean surface.

There are at least seven species of ocean bacteria that can survive by eating oil and nothing else. However, usually only a small number of oil-eating bacteria live in any given part of the ocean, and it takes a few days for their population to increase to take advantage of their abundant new food source during an oil spill. (NOAA)

Would you look at crude oil and think, “Mmm, tasty…”? Probably not.

But if you were a microbe living in the ocean you might have a different answer. There are species of marine bacteria in several families, including Marinobacter, Oceanospiralles, Pseudomonas, and Alkanivorax, that can eat compounds from petroleum as part of their diet. In fact, there are at least seven species of bacteria that can survive solely on oil [1].

These bacteria are nature’s way of removing oil that ends up in the ocean, whether the oil is there because of oil spills or natural oil seeps. Those of us in the oil spill response community call this biological process of removing oil “biodegradation.”

What Whets Their Oily Appetites?

Communities of oil-eating bacteria are naturally present throughout the world’s oceans, in places as different as the warm waters of the Persian Gulf [2] and the Arctic conditions of the Chukchi Sea north of Alaska [3].

Each community of bacteria is specially adapted for the environment where it is living, and studies have found that bacteria consume oil most quickly when they are kept in conditions similar to their natural environments [4]. So that means that if you took Arctic bacteria and brought them to an oil spill in the Gulf of Mexico, they would not eat the oil as quickly as the bacteria that are already living in the Gulf. You would get the same result in the reverse case, with the Arctic bacteria beating out the Gulf bacteria at an oil spill in Alaska.

Other factors that affect how quickly bacteria degrade oil include the amount of oxygen and nutrients in the water, the temperature of the water, the surface area of the oil, and the kind of oil that they are eating [4][5][6]. That means the bacteria that live in a given area will consume the oil from a spill in the summer more quickly than a spill in the winter, and will eat light petroleum products such as gasoline or diesel much more quickly than heavy petroleum products like fuel oil or heavy crude oil.

Oil-eating microbes fluorescing in a petri dish.

This bacteria, fluorescing under ultraviolet light in a petri dish, is Pseudomonas aeruginosa. It has been used during oil spills to break down the components of oil. (Credit: Wikimedia user Sun14916/Creative Commons Attribution-ShareAlike 3.0 Unported license)

Asphalt, the very heaviest component of crude oil, is actually so difficult for bacteria to eat that we can use it to pave our roads without worrying about the road rotting away.

What About During Oil Spills?

People are often interested in the possibility of using bacteria to help clean up oil spills, and most oil left in the ocean long enough is consumed by bacteria.

However, most oil spills last only a few days, and during that time other natural “weathering” processes, such as evaporation and wave-induced breakup of the oil, have a much bigger effect on the appearance and location of the oil than bacteria do. This is because there are usually only a small number of oil-eating bacteria in any given part of the ocean, and it takes a few days for their population to increase to take advantage of their abundant new food source.

Because of this lag time, biodegradation was not originally included in NOAA’s oil weathering software ADIOS. ADIOS is a computer model designed to help oil spill responders by predicting how much of the oil will stay in the ocean during the first five days of a spill.

However, oil spills like the 2010 Deepwater Horizon well blowout, which released oil for about three months, demonstrate that there is a need for a model that can tell us what would happen to the oil over longer periods of time. My team in the Emergency Response Division at NOAA’s Office of Response and Restoration has recognized that. As a result, version 3 of ADIOS, due to be released later in 2015, will take into account biodegradation.

My team and I used data published in scientific journals on the speed of oil biodegradation under different conditions to develop an equation that can predict how fast the components of oil will be consumed, and how the speed of this process can change based on the surface area-to-mass ratio of the oil and the climate it is in. A report describing the technical details of the model will be published in the upcoming Proceedings of the Arctic and Marine Oilspill Program Technical Seminar, which will be released after the June conference.

Including oil biodegradation in our ADIOS software will provide oil spill responders with an even better tool to help them make decisions about their options during a response. As part of the team working on this project, it has provided me with a much greater appreciation for the important role that oil-eating bacteria play in the long-term effort to keep our oceans free of oil.

I know I’m certainly glad they think oil is delicious.

Dalina Thrift-ViverosDalina Thrift-Viveros is a Seattle-based chemist who has been providing chemistry expertise for Emergency Response Division software projects and spill responders since 2011, when she first started working with NOAA and Genwest. When she is not involved in chemistry-related activities, Dalina sings with the rock band Whiskey River and plays sax with her jazz group, The Paul Engstrom Trio.

Literature cited

[1] Yakimov, M.M., K.N. Timmis, and P.N. Golyshin. “Obligate oil-degrading marine bacteria,” Current Opinion in Biotechnology, 2007, 18(3), pp. 257-266.

[2] Hassanshahian, M., G. Emtiazi, and S.Cappello. “Isolation and characterization of crude-oil-degrading bacteria from the Persian Gulf and the Caspian Sea,” Marine Pollution Bulletin, 2012, 64, pp. 7–12.

[3] McFarlin, K.M., R.C. Prince, R. Perkins, and M.B. Leigh. “Biodegradation of Dispersed Oil in Arctic Seawater at -1°C,” PLoS ONE, 2014, 9:e84297, pp. 1-8.

[4] Atlas, R.M. “Petroleum Biodegradation and Oil Spill Bioremediation,” Marine Pollution Bulletin, 1995, 31, pp. 178-182.

[5] Atlas, R.M. and T.C. Hazen. “Oil Biodegradation and Bioremediation: A Tale of the Two Worst Spills in U.S. History,” Environmental Science & Technology, 2011, 45, pp. 6709-6715.

[6] Head, I.M., D.M. Jones, and W.F.M. Röling, “Marine microorganisms make a meal of oil,” Nature Reviews Microbiology, 2006, 4, pp. 173-182.


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NOAA and Partners Work Quickly to Save Corals Hit by Catamaran in Puerto Rico

Experts estimate that thousands of corals were broken, dislodged, buried, or destroyed when the 49-foot-long catamaran M/V Aubi ran aground along the north coast of Puerto Rico the night of May 14, 2015.

Traveling from the Dominican Republic to San Juan, Puerto Rico, the recreational boat became grounded on a coral reef, causing significant damage to the reef. As the vessel was being moved, the vessel’s two hulls slowly ground further into the reef, forming mounds of coral and leaving rubble on the ocean bottom. UPDATED 5/27/2015: The area of the vessel’s direct impact is 366 square meters (not quite 4,000 square feet), while partial impact covers more than 1,000 square meters (roughly 10,764 square feet).

On the night of the grounding, responders were immediately concerned about preventing a spill of the fuel on board the Aubi. The fuel had to be removed from the fuel tanks in the aluminum hulls of the catamaran before it was moved off of the coral reefs. By the evening of May 15, approximately 1,500 gallons of fuel had been removed successfully, readying the vessel to be towed from the reef. It was pulled free during high tide the next morning.

The location of the grounding is in a Puerto Rico Marine Reserve, overseen by the Puerto Rico Department of Natural and Environmental Resources.

Crushing News and Rubble Rousers

The species of coral affected by the accident are mostly Diploria, or brain coral, and Acropora palmata, or elkhorn coral. Listed as threatened under the Endangered Species Act, elkhorn coral is one of the most important reef-building corals in the Caribbean. Brain coral, found in the West Atlantic Ocean and the Caribbean, is also an important reef-building coral and is known for its stony, brain-like appearance.

Although there was significant damage to the coral, an oil spill fortunately was prevented. While exposure to oil may kill corals, it more frequently reduces their ability to perform photosynthesis and causes growth or reproductive problems.

A multi-organizational team, which included NOAA, was able to salvage over 800 coral colonies (or fragments of colonies), moving them into deeper water nearby for temporary holding.  About 75 very large colonies of brain coral were righted but unable to be moved because of their size.

Broken brain coral on seafloor.

Brain coral (Diploria) and elkhorn coral (Acropora palmata) represent the majority of the coral species affected by this vessel grounding. (NOAA)

With buckets and by hand, the team filled 50 loads of rubble (approximately nine cubic yards) into open kayaks and small boats to transport them to a deeper underwater site that Puerto Rico Department of Natural Resources had approved for dumping.  All that material, moved in one day, would otherwise likely have washed into the healthy reef adjacent to the damaged one and potentially caused even more harm.

While poor weather has been preventing further work at the grounding site this past week, the team expects to restart work soon. Once that happens, initial estimates are that it will take 10-15 days to reattach the salvaged corals and to secure the rubble most at risk of moving. Stabilizing or removing the remaining rubble and rebuilding the topographic complexity of the flattened seafloor, accomplished using large pieces of rubble, would likely take an additional 10 days.

Both the location and nature of the corals dominating the area make it a very viable location for complete restoration using nursery-grown corals, but the scope and scale would still need to be determined.

Small Boat, Big Impact?

Healthy brain coral on seafloor.

An area of healthy corals near the site of the grounded M/V Aubi. Divers acted quickly to protect these corals from being damaged by the large amounts of rubble loose on the seafloor after the accident. (NOAA)

Even though the vessel involved in this grounding was relatively small, an unofficial, anecdotal report from the team working on the site noted that the amount of damage appeared comparable to that caused by the groundings of much larger vessels, such as tankers.

If not for the quick work of the U.S. Coast Guard, Puerto Rico Department of Natural Resources, NOAA, support contractors, volunteers from non-governmental organizations, and members of the local community, the damage could have been much worse.

Healthy coral reefs are among the most biologically and economically valuable ecosystems on earth.

According to NOAA’s Coral Reef Conservation Program, a little-known fact is that corals are in fact animals, even though they may exhibit some of the characteristics of plants and are often mistaken for rocks.

Learn more about how NOAA dives to the rescue of corals in the Caribbean when they become damaged by grounded ships.

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