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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Sea Grant Reports: Dolphins, Sea Turtles and the Impacts from Deepwater Horizon

photo of a bottlenose dolphin calf. Image credit: NOAA.

A bottlenose dolphin calf in the Gulf of Mexico. Image credit: NOAA

Two popular marine animals—dolphins and sea turtles—are the focus of new publications from the Sea Grant Oil Spill Science Outreach Team. In the aftermath of the largest oil spill in history, many expressed concern about its impact on these long-lived, slow-to-mature creatures. Now, almost seven years after the spill, scientists have a better understanding of how they fared. The team examined this research, synthesizing peer-reviewed findings into two easy-to-understand outreach bulletins.

Starting in 2010 a month before the Macondo blowout, scientists documented more than 1,000 stranded dolphins and whales along the northern Gulf of Mexico. From 2010 until 2014, they examined the health and stranding patterns of dolphins along the coasts of Louisiana, Mississippi, Alabama, and Florida, discovering that oiled areas had more sick and dead dolphins.

Scientists also found many sick and stranded pre-term and newborn dolphins. Overall, young dolphins in the study area were eight times more likely to have pneumonia or inflamed lungs and 18 times more likely to show signs of fetal distress than those from areas outside the Gulf. The Deepwater Horizon’s impact on bottlenose dolphins report examines all of the factors, including oil that scientists think contributed to dolphin populations’ drop in numbers during this time.

The Sea turtles and the Deepwater Horizon oil spill report details the impacts on threatened or endangered sea turtles species in the Gulf. In total, scientists estimate that the oil spill and related response activities killed between 95,000 and 200,000 sea turtles. Lasting impacts of these losses may take time to become clear. For example, scientists do not fully understand how oil exposure affects sea turtles’ ongoing reproductive abilities. They continue to monitor sea turtle populations by counting numbers of nests, hatchlings, and adult females on beaches.

Sea turtle in water. Image credit: Texas Sea Grant/Pam Plotkin

A healthy green sea turtle swims in the Gulf of Mexico. Image credit: Texas Sea Grant/Pam Plotkin

More articles about the impacts of Deepwater Horizon on marine mammals:

 

Tara Skelton is the Oil Spill Science Outreach Team Communicator for the Mississippi-Alabama Sea Grant Consortium. The Sea Grant Oil Spill Science Outreach Program is a joint project of the four Gulf of Mexico Sea Grant College Programs, with funding from partner Gulf of Mexico Research Initiative. The team’s mission is to collect and translate the latest peer-reviewed research for those who rely on a healthy Gulf for work or recreation. To learn more about the team’s products and presentations, visit gulfseagrant.org/oilspillscience.


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How to Test for Toxicity

Oil washes onto a beach.

Oil washes onto the beach on the day of the spill at Refugio State Beach, May 19, 2015. Image credit: NOAA

What is toxicity? Most definitions would explain it as the degree to which a substance is poisonous.

Knowing a substance’s toxic levels is particularly important to federal agencies that use the information to test potential risks posed to people’s health and to the environment.

So how do scientists know how toxic something is and whether or not that substance—be it oil, chemical treating agents or toxic metals—will be toxic when introduced into marine or coastal waters?

The basic tool for determining toxicity of substances to marine and aquatic organisms is the toxicity test.

In its simplest form, toxicity testing is taking healthy organisms from a container of clean water and placing into one containing the same water with a known concentration of a pollutant. The observer then watches to see if, and when, it appears to become lethargic, sick or dies, and comparing those results to the organisms left in the clean water.

Complexities of toxicity testing

The testing process for determining toxicity in marine environments is detailed, rigorous, and time consuming.

There must be containers of both the uncontaminated (clean) water (called a control) and the pollutant-treated water; a bare minimum is five containers of each. The reason for the replications is the concept of variability. Given five test organisms, such as a fish species, there will be a range of sensitivity among them.

Having multiple testing samples allows scientists to determine the level toxic to the average organism and the level toxic to the most sensitive organism. Having more than one of the same organism in each test container is required; ten is standard.

It’s easy to see how a toxicity test grows in complexity: 50 specimens for the controls (10 in each of five replicate containers) and 50 more in the five treated containers (10 in each of five replicate treatment containers). That’s 100 organisms.

But then, to find out what concentrations of the toxicant are safe and which are not, there needs to be at least five different treatment concentrations, each with five containers and each container with 10 test organisms. Now we’re dealing with 600 test organisms and 60 test containers.

Observations over time

The next step in a toxicity test is recording the changes in the organisms over time. A standard observation period is daily, every 24 hours for at least 4 days (96 hours). For each interval of time, observations must be recorded for:

  • Each of the treatment and control containers
  • The numbers of organisms that are alive and normal
  • The number not doing well
  • The number dead

Then apply a statistical procedure to estimate the median concentration of the toxin that maimed or killed half the organisms and write up the results. The key is to write it up with enough information so that someone else can exactly duplicate the test.

Quality control against bias

Added to all this, the design of a toxicity test must include a number of features to insure there is no bias in the results.

  • The containers must be lined up randomly and given codes so that the researcher doesn’t know until the experiment is over which containers had which concentrations.
  • Water quality must be monitored to ensure that temperatures and oxygen remain the same in all containers.
  • Once the data is collected, the researcher must calculate the median lethal concentration, meaning the concentration of toxin that would kill half the test population.
  • Further, it is important not to rely only on one experiment. The whole thing should be repeated once or twice more to be convinced that the first effort was not a fluke.

Finally, the researcher must write a report that not only describes the experiment and results, but also puts them in context with similar data from other studies reported in the scientific literature.

Using toxicity data

These are the steps scientists go through to determine if a substance is toxic and at what concentration levels.

In reality, today, toxicity testing is even more complicated and detailed. There are now many measures of toxicity other than death or sickness: for example, many tests done today look at “endpoints” such as effects on enzyme systems, or changes in animal behavior or decreases in egg production.

The final use of toxicity data is comparison with concentrations measured or expected in the field. If the concentrations of a pollutant in the field are below any of the concentrations deemed “toxic” in the laboratory, it may well be that the pollutant is not a problem. If concentrations in the field are higher, then there is cause for concern.

 

By Alan Mearns, Ph.D. Mearns is an ecologist and senior staff scientist with the Emergency Response Division.


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Closing Down Damage Assessment After Deepwater Horizon

Shelves filled with jars.

The plankton archive contains over 130,000 samples from 19 different surveys conducted as part of the natural resources damage assessment. Plankton archive located at the Stennis Space Center in Mississippi. Image credit: NOAA

The environmental toll from the 2010 Deepwater Horizon oil spill disaster was enormous, demanding a massive deployment of people and materials to measure the adverse effects.

Federal and state agencies worked quickly to scale up the emergency response, clean up the spill, mount a large-scale effort to assess the injuries to wildlife and other natural resources, and record how these lost resources adversely affected the public.

When the cleanup was finished, and the injuries were determined, another challenge came: NOAA and other agencies had to close down the largest damage assessment field operation in the nation’s history.

During five years of field studies assessing the injuries to natural resources, more than one hundred thousand samples were collected.

Instead of discarding the samples once the assessment was over, and the BP settlement was completed, it made more sense to find other uses for the samples, and the valuable laboratory, field, and office equipment attained during the assessment work. In many cases, the cost of finding new homes for samples and equipment was cheaper than disposal.

Repurposing samples and equipment: the work goes on

Shutting down the assessment operations involved clearing out laboratories and warehouses filled with samples, field equipment, and supplies.

In most instances, only a portion of each sample was needed for analysis and by the end of 2015, NOAA had an extensive trove of environmental samples.

Recognizing that many research scientists might put these samples to good use, NOAA made the materials available by publishing announcements in professional society newsletters. After receiving about one hundred inquiries, staff and contractors began distributing more than 5,000 samples.

Additionally, some sample collections were archived in publicly available repositories, with other historical and scientifically valuable collections. Thousands of samples of plankton, fish, and other organisms collected during post-spill trawls in Gulf waters went to a NOAA archive in Stennis, Mississippi.

The Smithsonian Institution in Washington, D.C. received rare deep-sea corals. Later this year the National Marine Mammal Tissue Bank will host thousands of samples from species of dolphins and other marine mammals found dead after the oil spill.

Universities across the United States received samples for research. Sediment samples sent to Florida State University in Tallahassee are supporting studies on the long-term fate of Deepwater Horizon oil deposited on Gulf beaches and in nearshore environments.

Researchers at Jacksonville University in Florida are using samples to compare the weathering of tar balls found submerged to tar balls those stranded on land. Additionally, researchers at Texas A&M University obtained samples of the spilled oil for studies of bacteria that biodegrade oil.

Graphic with gloved hands pouring liquid from sample jar into beaker and numbers of samples, results, and studies resulting from NOAA efforts.

Finding new homes for scientific instruments and other equipment

Field samples were not the only items distributed to advance oil spill science. NOAA shipped hundreds of large and small pieces of equipment to universities and other research partners to aid ongoing investigations about the effects of oil spills on the environment, and the ongoing monitoring of the Gulf environment.

Repurposed supplies and equipment found a second life at many institutions including the:

  • University of Miami
  • NOVA Southeastern University
  • Dauphin Island Sea Lab
  • University of Southern Mississippi
  • University of South Florida
  • Louisiana State University
  • Texas A & M
  • Smithsonian Institution

In addition to laboratory equipment, some university researchers received practical items such as anchors, battery packs, buoys, forceps, freezer packs, glassware, preservatives such as alcohol and formalin, and thermometers.

NOAA coordinated with BP to recover and repurpose thousands of items BP purchased for the assessment. While clearing out office buildings and trailers, NOAA staff identified and requested valuable pieces of laboratory and field equipment, and other supplies. Some of these items, such as microscopes, initially cost tens of thousands of dollars.

First responders from NOAA and the U.S. Coast Guard also received field safety equipment including:

  • Personal floatation devices
  • Safety goggles
  • Pallets of nitrile gloves
  • Lightning detectors
  • Sorbent boom

All of which support preparedness for future incidents.

Countless NOAA staff rose to the enormous challenges of responding to, assessing impacts from, and restoring the natural resources injured by the Deepwater Horizon incident. This work continues, assisted by the creative reuse and repurposing of materials across the country to support ongoing efforts to advance oil spill science and improve preparedness for future spills.

Read more about and the work of NOAA’s Office of Response and Restoration and partners in responding to the spill, documenting the environmental damage, and holding BP accountable for restoring injured resources:

 

Greg Baker, Rob Ricker, and Kathleen Goggin of NOAA’s Office of Response and Restoration contributed to this article.


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Assessing the Impacts from Deepwater Horizon

Beach with grass.

Beach habitat was part of the Deepwater Horizon oil spill settlement. Image Credit: NOAA

The 2010 Deepwater Horizon disaster spread spilled oil deep into the ocean’s depths and along the shores of the Gulf of Mexico, compromising the complex ecosystem and local economies. The response and the natural resources damage assessment were the largest in the nation’s history.

Ecosystems are comprised of biological, physical, and chemical components, interconnected to form a community. What happens in one location has serious, cascading effects on organisms in other parts of the ecosystem. The Gulf’s coastal wetlands and estuaries support the entire Gulf ecosystem, providing food, shelter, and nursery grounds for a variety of animals. The open waters of the Gulf also provides habitat for fish, shrimp, shellfish, sea turtles, birds, and mammals.

Evaluating impacts from the spill

Considering these interdependencies during the assessment process was important. At the same time, it was impossible to test or examine every injured bird, every sickened dolphin, or every area contaminated with oil. That was cost prohibitive and scientifically impossible.

Instead, NOAA scientists evaluated representative samples of natural resources, habitats, ecological communities, ecosystem processes and linkages.

To do that, scientists made 20,000 trips to the field, to obtain 100,000 environmental samples that yielded 15 million records. This data collection and subsequent series of scientific studies formed the basis for the natural resources damage assessment that led to the largest civil settlement in federal history.

A short summary of the natural resource injuries:

Marshes injured

  • Plant cover and vegetation mass reduced along 350 to 720 miles of shoreline
  • Amphipods, periwinkles, shrimp, forage fish, red drum, fiddler crabs, insects killed

Harvestable oysters lost

  • 4 – 8.3 billion harvestable oysters lost

Birds, fish, shellfish, sea turtles, and dolphins killed

  • Between 51,000 to 84,000 birds killed
  • Between 56,000 to 166,000 small juvenile sea turtles killed
  • Up to 51% decrease in Barataria Bay dolphin population
  • An estimated 2 – 5 trillion newly hatched fish were killed

Rare corals and red crabs impacted

  • Throughout an area about 400 to 700 square miles around the wellhead

Recreational opportunities lost

  • About $527 – $859 million in lost recreation such as boating, fishing, and beach going
Top fish shows no oil bottom fish shows oil.

The top picture is a red drum control fish that was not exposed to oil, while the bottom red drum fish was exposed to Deepwater Horizon oil for 36 hours. The bottom fish developed excess fluid around the heart and other developmental deformities. This is an example of the many scientific studies conducted for the natural resources damage assessment. Image Credit: NOAA/Abt

What we shared

Those studies not only documented the injuries, but also helped the entire scientific community understand the effects of oil spills on nature and our communities. All of the scientific studies, including over 70 peer-reviewed journal articles, as well as all the data collected for the studies, are available to the public and the scientific community. Additionally, our environmental response management software allows anyone to download the data from a scientific study, and then see that data on a map.

We will be publishing new guidance documents regarding sea turtles and marine mammals by the end of 2017. These guides compile best practices and lessons learned and will expedite natural resources damage assessment procedures in the future.

Read more about Deepwater Horizon and the work of NOAA’s Office of Response and Restoration and partners in responding to the spill, documenting the environmental damage, and holding BP accountable for restoring injured resources:

 

Tom Brosnan, Lisa DiPinto, and Kathleen Goggin of NOAA’s Office of Response and Restoration contributed to this article.


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Deepwater Horizon: Response in the Midst of an Historic Crisis

Tractor with trailers on beach.

Cleanup crews in Pensacola Beach, Florida, try to remove oil from the sand in November 2010. The Deepwater Horizon oil spill that severely injured the environment also directly affected the seafood trade and tourism economies of five Gulf states. Image Credit: NOAA

The Deepwater Horizon oil spill began on April 20, 2010, with a blowout of BP’s Macondo drilling platform in the Gulf of Mexico. In addition to the death of 11 men, the spill resulted in the largest mobilization of resources addressing an environmental emergency in the history of the United States.

The size of the spill required the Emergency Response Division to refine tracking subsurface oil, flowrate calculations, and long-term oil transport modeling. Data and information management became a paramount issue. NOAA’s web-based environmental management mapping tool proved invaluable in tracking and sharing data across the many teams and command posts.

With only 12 full time responders and about 120 NOAA staff nationally, the size and complexity of the incident taxed the spill team’s capacity to respond. NOAA recruited retired staff and contractors to provide additional emergency support, along with scientists from across the nation and internationally.

Other NOAA programs provided critical services in the field, on ships, aircraft, and in regional laboratories, weather forecast offices, and regional command posts. As the response grew, staffing the various missions required extraordinary interagency coordination.

Overall, several thousand NOAA staff worked on spill response and damage assessment activities. Seven NOAA ships—39 percent of the NOAA fleet—conducted cruises with missions as diverse as seafood safety monitoring, wellhead monitoring, and detecting subsurface oil. Five NOAA aircraft flew over 773 flight hours to track the oil spill and to measure air quality impacts.

Challenges faced with Deepwater Horizon

Forecasting the oil’s movement: How would the Loop Current effect the oil’s potential to spread to the Florida Keys and beyond? To answer that staff worked 24-7 modeling where the oil might spread in an effort to help defuse the public’s concern that oil would rapidly travel around Florida and oil shorelines along the Atlantic seaboard. After more than a month of daily mapping, overflights, and satellite analyses, our data showed no recoverable oil in the area, and the threat of oil spreading by the Loop Current diminished.

Calculating how much oil spilled and where it went:

Estimating the size of an oil spill is difficult, and determining the volume spilled from this leaking wellhead over a mile deep was even more challenging. Federal scientists and engineers worked with experts from universities on interagency teams to calculate the flow rate and total volume of oil spilled.

Another interagency team, led by the U. S. Geological Survey, NOAA, and the National Institute of Standards and Technology developed a tool called the Oil Budget Calculator to determine what happened to the oil. Working with these experts and agencies, NOAA was able to estimate the amount spilled, and how much oil was chemically dispersed, burned, and recovered by skimmers.

NOAA scientists also studied how much oil naturally evaporated and dispersed, sank to the sea floor, or trapped in shoreline sediments. Other studies determined how long it took the oil to degrade in those different environments.

While dispersant use reduced the amount of surface and shoreline oiling, and reduced marsh impacts, dispersants likely did increase impacts to some species during sensitive life stages that live in the water column and the deep ocean. The use of dispersants is under review.

Infographic about Deepwater Horizon.

Statistical information about Deepwater Horizon. Image Credit: NOAA

Quickly communicating the science of the situation including:

The public demanded answers fast, and social media rapidly took over as a primary tool to voice their concerns. We responded with continual updates through social media and on our website and blog. Still, keeping ahead of misconceptions and misinformation about the spill proved challenging. The lesson learned is that we can’t underestimate social media interest.

In addition to responding to the public’s need for accurate information, NOAA had to coordinate with universities and other academics to and quickly leverage existing research on an active oil spill. The size and multi-month aspect of the spill generated huge academic interest, but also meant that scientists were mobilizing and conducting field activities in the middle of an active response.

Lessons Learned

The list of lessons learned during the response continues to grow and those lessons are not limited to science. Organizational, administrative, policy, and outreach challenges were also significant considering the size, scope, and complexity of the response.

After nearly 30 years, the Exxon Valdez spill studies continue in an effort to understand the impacts and recovery in Prince William Sound. Given that timeline as a guide, NOAA expects Deepwater Horizon studies to continue for decades.

It will take that research and the perspective of time to understand the overall effects of the spill and response actions on the Gulf ecosystem and the communities that depend on a healthy coast.

 

Read more about Deepwater Horizon and the work of NOAA’s Office of Response and Restoration and partners in responding to the spill, documenting the environmental damage, and holding BP accountable for restoring injured resources:

Doug Helton and Kathleen Goggin of NOAA’s Office of Response and Restoration contributed to this article.


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High Water and Sunken Oil on the Great Mississippi

Man in orange uniform inspecting wrecked barge.

U.S. Coast Guard conducting initial damage survey of barge from the UTV Amy Frances. Credit: U.S. Coast Guard

If you can’t see spilled oil, how do you find it and clean it up?

That’s the situation emergency responders faced in two oil spills on the Mississippi River that challenged their understanding of how to approach evaluating oil spill conditions.

The first incident was Sept. 3, 2015 when two tow barges collided on the Lower Mississippi River near Columbus, Kentucky. The second was Jan. 21, 2016 when a barge towed by the UTV Amy Frances struck the Natchez Bridge on the Lower Mississippi River. The Lower Mississippi is the most traveled and commercially important portion of the river’s system.

In both instances, the U.S. Coast Guard requested assistance from the National Oceanic and Atmospheric Administration. NOAA’s Office of Response and Restoration has scientific support coordinators stationed throughout the country to respond to spill emergencies.

The two incidents also spilled slurry oil—a byproduct of the oil refining process, which is denser than water and so, sinks instead of floating on the water’s surface. Despite understanding the scientific attributes of the oil, the responders needed to know where it was and how it would react to the river’s high water conditions.

“Just because you know the physical properties doesn’t tell you it will stay in one piece or get torn to bits and scattered all over the river bottom,” said Adam Davis, NOAA scientific support coordinator in the Gulf of Mexico who responded to both spills. “What we didn’t know was how it would interact with the river bottom and whether the best practice assessment tools would work given the river conditions at the time.”

In other words, would the oil sink and go straight to the bottom as one coherent mass or, would the currents tear it into pieces and take it downstream over a larger area? Or, would the oil be rapidly buried and evade the ability to locate and recover it?

Damaged barge.

A view of the damaged barge Apex 3508, whose tug boat collided with another on Sept. 2, 2015, causing an oil spill on the Mississippi River near Columbus, Kentucky. The rest of the oil on board the barge was removed. Credit: U.S. Coast Guard

Locating sunken oil in a large, dynamic river like the Lower Mississippi can be daunting. Fortunately, In the case of the Apex 3508 barge collision in Kentucky, the response team was able to use sophisticated side scan sonar and multibeam sonar to locate the oil and map the river bottom. Additionally, a novel dredging technique using an environmental clamshell-dredging device proved effective in recovery.

By the time of the Natchez Bridge incident, the river had moved from its low water condition typical of late summer to the extreme high water associated with seasonal spring flooding. Measurements showed the river raged from 8-13 knots (9-14 miles per hour) and was discharging about 1.8 million cubic feet of water per second. The response team again used side scan and multibeam sonar, but in this instance more to understand how the high flow conditions would affect what was going on along the river bottom. The multibeam imagery showed 30-50 foot tall sand waves were moving along the river bottom at a rate of about 30 feet in about two hours.

“Given the immense amount of sediment being transported rapidly downstream as evidenced by the multibeam imagery, we immediately knew that any oil that had found its way to the bottom near mid channel had been rapidly buried by the next massive sand wave and was unlikely to be recovered any time soon,” Davis said.

When the river is moving swiftly, the safest place for a damaged barge that can’t be transported to a fixed facility is often along the riverbank. The problem with a leaking barge pushed in along a flooded riverbank is that it is hard and often dangerous to assess the leakage. This was certainly the case in the Natchez incident.

“We knew the side scan and multibeam tools simply wouldn’t work well up close to the barge, Davis said. “There was just too much interference caused by the barge and the flooded trees along the bank to be able to see what was going on.”

The typical snare drag or probing for oil would not work in the high water conditions either. The equipment would snag on debris and vegetation below the water’s surface, and operating a vessel in a flooded tree line was unsafe.

“In order to probe we needed an object that could be easily and quickly fabricated from items on-hand,” Davis said. “The right tool didn’t exist, the solution called for a little ingenuity and quick action.”

Pole with oil dripping from the end onto a white pad.

The makeshift “cotton swab” tool created to collect oil samples from the submerged trees along the flooded riverbank during the response to the Amy Frances incident. Credit: NOAA

With the barge pushed in to the bank, securely tied off, and under the control of the tow, it offered a stable and safe enough platform for the response team to take a long pole with its ends wrapped in sorbent material and probe along the shore side. The new tool looked like a giant cotton swab and proved effective in quickly confirming the presence of sunken oil along the bank.

“Often I find that people are quite surprised that oil spill response strategies can be pretty low-tech sometimes and still be effective,” Davis said. “In the ‘NCIS’ age of ‘isn’t there a high tech gadget that can just easily fix your complex and dynamic problem’? Sometimes it is hard to convey that to people.”

Despite standards for evaluating oil spills, every spill has its unique challenges that require a deep understanding of science and an ability to think creatively.


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Showcasing Our Partnership with Coast Guard on Instagram

Ship's upper deck with rainbow.

A NOAA research team journeyed to the icy Arctic north of Alaska in 2014 on board the USCG Cutter Healy. A rain shower through Unimak Pass in the Aleutian Islands provided a rainbow, visible from an Arctic survey boat accompanying the Healy. (Credit NOAA)

This week the National Oceanic and Atmospheric Administration Office of Response and Restoration will be taking over U.S. Coast Guard’s Instagram to showcase our long partnership.

Coming up at the end of this week, March 24, is the anniversary of Exxon Valdez – one of the largest oils spills in the nation’s history. However, our history actually goes back prior to Exxon Valdez to the grounding of the tanker Argo Merchant in 1976.

During the week, we’ll post photos of our work with the Coast Guard from our beginning to the present spotlighting our  work together in the Arctic, during hurricanes, Deepwater Horizon, and other incidents.

Head on over to USCG Instagram and view how we partner to keep the nation’s coasts and waterways safe for maritime commerce, recreational activities, and wildlife.

Read these recent articles about our partnership:

5 Ways the Coast Guard and NOAA Partner

Below Zero: Partnership between the Coast Guard and NOAA