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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In the Wake of the Deepwater Horizon Oil Spill, Gulf Dolphins Found Sick and Dying in Larger Numbers Than Ever Before

The Deepwater Horizon Oil Spill: Five Years Later

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

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

Dolphins washing up dead in the northern Gulf of Mexico are not an uncommon phenomenon. What has been uncommon, however, is how many more dead bottlenose dolphins have been observed in coastal waters affected by the Deepwater Horizon oil spill in the five years since. In addition to these alarmingly high numbers, researchers have found that bottlenose dolphins living in those areas are in poor health, plagued by chronic lung disease and failed pregnancies.

Independent and government scientists have undertaken a number of studies to understand how this oil spill may have affected dolphins, observed swimming through oil and with oil on their skin, living in waters along the Gulf Coast. These ongoing efforts have included examining and analyzing dead dolphins stranded on beaches, using photography to monitor living populations, and performing comprehensive health examinations on live dolphins in areas both affected and unaffected by Deepwater Horizon oil.

The results of these rigorous studies, which recently have been and continue to be published in peer-reviewed scientific journals, show that, in the wake of the 2010 Deepwater Horizon oil spill and in the areas hardest hit, the dolphin populations of the northern Gulf of Mexico have been in crisis.

Troubled Waters

Due south of New Orleans, Louisiana, and northwest of the Macondo oil well that gushed millions of barrels of oil for 87 days, lies Barataria Bay. Its boundaries are a complex tangle of inlets and islands, part of the marshy delta where the Mississippi River meets the Gulf of Mexico and year-round home to a group of bottlenose dolphins.

During the Deepwater Horizon oil spill, this area was one of the most heavily oiled along the coast. Beginning the summer after the spill, record numbers of dolphins started stranding, or coming ashore, often dead, in Barataria Bay (Venn-Watson et al. 2015). One period of extremely high numbers of dolphin deaths in Barataria Bay, part of the ongoing, largest and longest-lasting dolphin die-off recorded in the Gulf of Mexico, persisted from August 2010 until December 2011.

In the summer of 2011, researchers also measured the health of dolphins living in Barataria Bay, comparing them with dolphins in Sarasota Bay, Florida, an area untouched by the Deepwater Horizon oil spill. Differences between the two populations were stark. Many Barataria Bay dolphins were in very poor health, some of them significantly underweight and five times more likely to have moderate-to-severe lung disease. Notably, the dolphins of Barataria Bay also were suffering from disturbingly low levels of key stress hormones which could prevent their bodies from responding appropriately to stressful situations. (Schwacke et al. 2014)

“The magnitude of the health effects that we saw was surprising,” said NOAA scientist Dr. Lori Schwacke, who helped lead this study. “We’ve done these health assessments in a number of locations across the southeast U.S. coast and we’ve never seen animals that were in this poor of condition.”

The types of illnesses observed in live Barataria Bay dolphins, which had sufficient opportunities to inhale or ingest oil following the 2010 spill, match those found in people and other animals also exposed to oil. In addition, the levels of other pollutants, such as DDT and PCBs, which previously have been linked to adverse health effects in marine mammals, were much lower in Barataria Bay dolphins than those from the west coast of Florida.

Dead in the Water

Based on findings from the 2011 study, the outlook for dolphins living in one of the most heavily oiled areas of the Gulf was grim. Nearly 20 percent of the Barataria Bay dolphins examined that year were not expected to live, and in fact, the carcass of one of them was found dead less than six months later (Schwacke et al. 2014). Scientists have continued to monitor the dolphins of Barataria Bay to document their health, survival, and success giving birth.

Considering these health conditions, it should come as little surprise that record high numbers of dolphins have been dying along the coasts of Louisiana (especially Barataria Bay), Alabama, and Mississippi. This ongoing, higher-than-usual marine mammal die-off, known as an unusual mortality event, has lasted over four years and claimed more than a thousand marine mammals, mostly bottlenose dolphins. For comparison, the next longest lasting Gulf die-off (in 2005–2006) ended after roughly a year and a half (Litz et al. 2014 [PDF]).

Researchers studying this exceptionally long unusual mortality event, which began in February 2010, identified within it multiple distinct groupings of dolphin deaths. All but one of them occurred after the Deepwater Horizon oil spill, which released oil from April to July 2010, and corresponded with areas exposed heavily to the oil, particularly Barataria Bay (Venn-Watson et al. 2015). In early 2011, the spring following the oil spill, Mississippi and Alabama saw a marked increase in dead dolphin calves, which either died late in pregnancy or soon after birth, and which would have been exposed to oil as they were developing.

The Gulf coasts of Florida and Texas, which received comparatively little oiling from the Deepwater Horizon spill, did not see the same significant annual increases in dead dolphins as the other Gulf states (Venn-Watson et al. 2015). For example, Louisiana sees an average of 20 dead whales and dolphins wash up each year, but in 2011 alone, this state recorded 163 (Litz et al. 2014 [PDF]).

The one grouping of dolphin deaths starting before the spill, from March to May 2010, took place in Louisiana’s Lake Pontchartrain (a brackish lagoon) and western Mississippi. Researchers observed both low salinity levels in this lake and tell-tale skin lesions thought to be associated with low salinity levels on this group of dolphins. This combined evidence supports that short-term, freshwater exposure in addition to cold weather early in 2010 may have been key contributors to those dolphin deaths prior to the Deepwater Horizon spill.

Legacy of a Spill?

A bottlenose dolphin swims in the shallow waters along a sandy beach with orange oil boom.

A bottlenose dolphin swims in the shallow waters along the beach in Grand Isle, Louisiana, near oil containment boom that was deployed on May 28, 2010. Oil from the Deepwater Horizon oil spill began washing up on beaches here one month after the drilling unit exploded. (U.S. Coast Guard)

In the past, large dolphin die-offs in the Gulf of Mexico could usually be tied to short-lived, discrete events, such as morbillivirus and marine biotoxins (resulting from harmful algal blooms). While studies are ongoing, the current evidence does not support that these past causes are responsible for the current increases in dolphin deaths in the northern Gulf since 2010 (Litz et al. 2014).

However, the Deepwater Horizon oil spill—its timing, location, and nature—offers the strongest evidence for explaining why so many dolphins have been sick and dying in the Gulf since 2010. Ongoing studies are assessing disease among dolphins that have died and potential changes in dolphin health over the years since the spill.

As is the case for deep-sea corals, the full effects of this oil spill on the long-lived and slow-to-mature bottlenose dolphins and other dolphins and whales in the Gulf may not appear for years. Find more information related to dolphin health in the Gulf of Mexico on NOAA’s Unusual Mortality Event and Gulf Spill Restoration websites.


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At the Bottom of the Gulf of Mexico, Corals and Diversity Suffered After Deepwater Horizon Oil Spill

The Deepwater Horizon Oil Spill: Five Years Later

This is the second 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.

Very little, if any, light from the sun successfully travels to the extreme bottom of the Gulf of Mexico. At these dark depths, the water is cold and the inescapable pressure of thousands of feet of ocean bears down on everything.

Yet life in the deep ocean is incredibly diverse. Here, delicate branches of soft coral are embraced by the curling arms of brittlestars. Slender sea fans, tinged with pink, reach for tiny morsels of food drifting down like snow from above. From minute marine worms to elongated fish, the diversity of the deep ocean is also a hallmark of its health and stability.

However, this picture of health was disrupted on April 20, 2010. Beginning that day and for almost three months after, the Macondo wellhead unleashed an unprecedented amount of oil and natural gas nearly a mile beneath the ocean. In addition, the response to this oil spill released large amounts of chemical dispersant, both at the source of the leaking oil and on the ocean surface. These actions were meant to break down oil that might have threatened life at the sea surface and on Gulf shores. Nevertheless, the implications for the ocean floor were largely unknown at the time.

In the five years since the Deepwater Horizon oil spill, a number of academic and independent scientists along with state and federal agencies, including NOAA and the Bureau of Ocean Energy Management, have been collaborating to study just how this oil spill and response affected the deep ocean and seafloor of the Gulf. What they found was the footprint of the oil spill on the seafloor, stamped on sickened deep-sea corals and out-of-balance communities of tiny marine invertebrates.

A Sickened Seafloor

A part of the world difficult to reach—and therefore difficult to know—the depths of the Gulf of Mexico required a huge collaborative and technological effort to study its inhabitants. Beginning in the fall of 2010, teams of scientists set out on multiple research cruises to collect deep-sea data, armed with specialized equipment, including remotely operated vehicles (ROVs), cameras capable of withstanding the crushing pressure of the deep ocean, and devices that could bore into the ocean bottom and scoop up multiple samples of sediments at a time.

Through these efforts, researchers have uncovered large areas of the Gulf of Mexico seafloor that contain most of the oil spill’s notable deep-sea impacts. One area in particular surrounds the damaged wellhead and stretches to the southwest, following the path of the massive underwater plume of Deepwater Horizon oil. At times, up to 650 feet thick and over a mile wide, the oil plume drifted at depths more than 3,500 feet beneath the ocean surface, leaving traces of its presence on the bottom as it went (Camilli et al. 2010).

The Macondo wellhead sits at the center of a bull’s-eye–shaped pattern of harm on the seafloor, with oil-related impacts lessening in intensity farther from the oil’s source. Further tying this pattern of injury to the Deepwater Horizon spill, a conservative chemical tracer of petroleum turned up in surface seafloor sediments extending 15 miles from the wellhead (Valentine et al. 2014).

Diversity Takes a Nose Dive

Few people ever see the bottom of the deep ocean. So what do these impacted areas actually look like? Starting several months after the leaking well was capped, researchers used ROVs and special cameras to dive down roughly 4,500 feet. They found multiple deep-sea coral colonies showing recent signs of poor health, stress, and tissue damage. On these corals, the polyps, which normally extend frilly tentacles from the corals’ branching arms, were pulled back, and excessive mucus hung from the corals’ skeletons, which also revealed patches of dead tissue. All of these symptoms have been observed in corals experimentally exposed to crude oil (White et al. 2012 PDF).

Five photos of deep-sea coral showing the progression of impacts over several years.

A time series of coral showing the progression of typical impacts at a site of coral colonies located less than seven miles from the source of Deepwater Horizon oil. You can see the brown “floc” material present in November 2010 disappears by March 2011 and afterward, is replaced by fuzzy gray hydroids and the coral loses its brittlestar companion. (Credit: Hsing et al. 2013)

Many of these coral colonies were partly or entirely coated in a clumpy brown material, which researchers referred to as “floc.” Chemical analysis of this material revealed the presence of petroleum droplets with similar chemical markers to Deepwater Horizon oil. The brittlestars usually associated with these corals also appeared in strange colors and positions. Some entire coral colonies were dead.

Research teams noted these observations only at corals within roughly 16 miles of the wellhead (White et al. 2012 PDF, Fisher et al. 2014). However, many similar coral colonies located further from the spill site showed no poor health effects.

Even one and two years later, deep-sea corals within the footprint of the spill still had not recovered. Hydroids took the place of the brown floc material on affected corals. Relatives of jellies, hydroids are fuzzy, grayish marine invertebrates that are known to encrust unhealthy coral.

Life on and under the sediment at the bottom of the Gulf also suffered, with the diversity of a wide range of marine life dropping across an area roughly three times the size of Manhattan (Montagna et al. 2013). Notably, numbers of tiny, pollution-tolerant nematodes increased in areas of moderate impact but at the expense of the number and types of other species, particularly copepods, small crustaceans at the base of the food chain. These effects were related to the concentration of oil compounds in sediments and to the distance from the Deepwater Horizon spill but not to natural oil seeps.

Top row, from left,  two types of crustaceans and a mollusk. Bottom row shows three types of marine worms known as polychaetes.

Examples of some of the common but very small marine invertebrates found living on and under the Gulf of Mexico seafloor. The top row shows, from left, two types of crustaceans and a mollusk, which are more sensitive to pollution. The bottom row shows three types of marine worms known as polychaetes, which tended to dominate ocean sediments with higher oil contamination found near corals. (Courtesy of Paul Montagna, Texas A&M University)

More sensitive to pollution, fewer types and numbers of crustaceans and mollusks were found in sediments around coral colonies showing impacts. Instead, a few types of segmented marine worms known as polychaetes tended to dominate ocean sediments with higher oil contamination near these corals (Fisher et al. 2014).

A Long Time Coming

Life on the bottom of the ocean moves slowly. Deep-sea corals live for hundreds to thousands of years, and their deaths are rare events. Some of the corals coated in oily brown floc are about 600 years old (Prouty et al. 2014). The observed impacts to life in the deep ocean are tied closely to the Deepwater Horizon oil spill, but the full extent of the harm and the eventual recovery may take years, even decades, to manifest (Fisher and Demopoulos, et al. 2014).

Learn more about the studies supported by the federal government’s Natural Resource Damage Assessment for the Deepwater Horizon oil spill, which determines the environmental harm due to the oil spill and response and seeks compensation from those responsible in order to restore the affected resources.


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Three and a Half Things You Didn’t Know About the History of Oil Spills

Lakeview oil gusher surrounded by sandbags.

The largest oil spill in the United States actually took place in 1910 in Kern county, California. The Lakeview #1 gusher is seen here, bordered by sandbags and derrick removed, after the well’s release had started to subside. (U.S. Geological Survey)

Like human-caused climate change and garbage in the ocean, oil spills seem to be another environmental plague of modern times. Or are they?

The human relationship with oil may be older than you think. In California’s San Joaquin Valley, that relationship may date back more than 13,000 years. Archaeologists have discovered a long history of Native Americans using oil from the area’s natural seeps, including the Yokut Indians creating dice-like game pieces out of walnut shells, asphalt, and abalone shells. At an archaeological site in Syria, the timeline extends back even further: bitumen oil was used to affix handles onto Middle Paleolithic flint tools dating to around 40,000 BC.

As history has a tendency to repeat itself, we can benefit from occasional glimpses back in time to place what is happening today into a context beyond our own fast-moving lives. When it comes to oil spills, you may be surprised to learn that this history goes far beyond—and is much more complicated than—simply the 2010 Deepwater Horizon and 1989 Exxon Valdez oil spills.

Based on the research of NOAA oil spill biologist Gary Shigenaka, here we present three and a half things you probably didn’t know about the history of oil spills.

1. Oil spills have been happening for more than 150 years, but society has only recently started considering them “disasters.”

If you look back in time for historical accounts of oil spills, you may have a hard time finding early reports. When the first oil prospectors in Pennsylvania would hit oil and it almost inevitably gushed into the nearby soil and streams, people at the time saw this not as “environmental degradation” but as a natural consequence of the good fortune of finding oil. In an 1866 account of Pennsylvania’s oil-producing Venango County, this attitude of acceptance becomes apparent:

When the first wells were opened…there was little or no tankage ready to receive it, and the oil ran into the creek and flooded the land around the wells until it lay in small ponds.  Pits were dug in the ground to receive it, and dams constructed to secure it, yet withal the loss was very great…the river was flooded with oil, and hundreds of barrels were gathered from the surface as low down as Franklin, and prepared as lubricating oil.  Even below this point oil could be gathered in the eddies and still water along the shore, and was distinctly perceptible as far down as Pittsburgh, one hundred and forty miles below.

2. The largest oil spill in the United States didn’t take place in the Gulf of Mexico in 2010 but in the California desert a hundred years earlier.

But similar to the Deepwater Horizon, this oil spill also stemmed from a runaway oil well. In Maricopa, California, the people drilling Lakeview Well No. 1 lost control of the well, which would eventually spew approximately 378 million gallons of oil into the sandy soil around it. The spill lasted more than a year, from March 14, 1910 until September 10, 1911, and only ceased after the well collapsed on itself, leaving a crater in the desert surrounded by layers of oil the consistency of asphalt.

3. The Alaskan Arctic is not untouched by oil spills; the first one happened in 1944.

The Naval ship S.S. Jonathan Harrington surrounded by Arctic sea ice.

The Naval ship S.S. Jonathan Harrington surrounded by Arctic sea ice. This ship likely caused the first major oil spill in Alaskan Arctic waters in August 1944. (U.S. Navy)

NOAA and many others are doing a lot of planning in case of an oil spill in the Alaskan Arctic. But whatever may happen in the future, in August of 1944, Alaska Native Thomas P. Brower, Sr. witnessed what was likely the first oil spill in the Alaskan Arctic. The U.S. Navy cargo ship S.S. Jonathan Harrington grounded on a sandbar near Barrow, Alaska. To lighten the ship enough to get off the sandbar, the crew apparently chose to release some of the oil it was carrying. In a 1978 interview, Brower describes the scene and its impacts on Arctic wildlife:

About 25,000 gallons of oil were deliberately spilled into the Beaufort Sea…the oil formed a mass several inches thick on top of the water. Both sides of the barrier islands in that area…became covered with oil.  That first year, I saw a solid mass of oil six to ten inches thick surrounding the islands.

…I observed how seals and birds who swam in the water would be blinded and suffocated by contact with the oil.  It took approximately four years for the oil to finally disappear. I have observed that the bowhead whale normally migrates close to these islands in the fall migration … But I observed that for four years after that oil spill, the whales made a wide detour out to sea from these islands.

And because the last point refers more to oil than oil spills, we’re counting it as item three and a half:

3½. The oil industry probably saved the whales.

Cartoon of whales throwing a ball with banners.

On April 20, 1861, this cartoon appeared in an issue of Vanity Fair in the United Kingdom. It hails the “Grand ball given by the whales in honor of the discovery of the oil wells in Pennsylvania.” (Public Domain)

The drilling of the first oil well in Pennsylvania in 1859 touched off the modern oil industry in the United States and beyond—and likely saved the populations of whales, particularly sperm whales, being hunted to near-extinction for their own oil, which was used for lighting and lubrication. The resulting boom in producing kerosene from petroleum delivered what would eventually be a lethal blow to the whaling industry, much to the whales’ delight.


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How Do You Keep Invasive Species out of America’s Largest Marine Reserve?

A young monk seal and birds on the beach of French Frigate Shoals in the Northwestern Hawaiian Islands.

The coral reefs of Papahānaumokuākea Marine National Monument are the foundation of an ecosystem that hosts more than 7,000 species, including marine mammals, fishes, sea turtles, birds, and invertebrates. Many are rare, threatened, or endangered, including the endangered Hawaiian monk seal. At least one quarter are found nowhere else on Earth. (NOAA)

From Honolulu, it takes a day and a half to get there by boat. But Scott Godwin, an expert in the ways “alien” marine life can travel and take hold in new places, knows what is at risk. He understands perfectly well what might happen if a new species manages to make that journey to the remote and incredible area under his watch.

Godwin works for the Resource Protection Program in NOAA’s Office of National Marine Sanctuaries. Along with the U.S. Fish and Wildlife Service and State of Hawaii, he is charged with protecting Papahānaumokuākea Marine National Monument, a tall order considering that it is one of the largest marine conservation areas in the world. This monument includes an isolated chain of tropical islands, atolls, and reefs hundreds of miles northwest of the main Hawaiian Islands—appropriately known as the Northwestern Hawaiian Islands—as well as nearly 140,000 square miles of surrounding waters. The monument is home to a host of rare and unique species, some found exclusively within its borders, as well as some of the healthiest and least disturbed coral reefs on Earth.

Map of main and Northwestern Hawaiian Islands

Papahānaumokuākea Marine National Monument is the single largest fully protected conservation area under the U.S. flag, and one of the largest marine conservation areas in the world. It encompasses 139,797 square miles of the Pacific Ocean — an area larger than all the country’s national parks combined. (NOAA)

And it is Godwin’s job to keep it that way. Along with climate change and marine debris, invasive species have been identified as one of the top three threats to this very special place, which, in addition to being a national monument, is also a national wildlife refuge and United Nations World Heritage Site. Fortunately, invasive species also happen to be Godwin’s area of expertise.

If new species were to break into the monument’s borders—and in some cases, they already have—the risk is of them exhibiting “invasive” behavior. In other words, outcompeting the native marine life among the coral reefs and taking the lion’s share of the most valuable resources: food and space.

But considering how remote and expansive the area is—the Northwestern Hawaiian Islands stretch across 1,200 nautical miles and are closed to the general public—how would anything find its way there in the first place?

Yet help from humans is how many species arrive in new environments, including the main Hawaiian Islands, where more than 400 non-native marine species are established. That means ships and other human activity coming from Hawaii represent the greatest potential for bringing invasive species into the monument.

Packing List: Bleach, Deep Freezer, and Quarantine Clothes

Dianna Parker of the NOAA Marine Debris Program learned this lesson firsthand. In October 2014, she and colleague Kyle Koyanagi joined a team of NOAA divers from the Pacific Islands Fisheries Science Center (PIFSC) on a mission to Papahānaumokuākea Marine National Monument to remove the tons of old fishing nets that wash up on its coral reefs each year.

In the months leading up to her departure from Honolulu, Parker learned she would need something called “quarantine clothes.” In essence, they were a brand-new set of clothes set aside for each time she would step on dry land in the Northwestern Hawaiian Islands. Furthermore, these new clothes had to be sealed in plastic bags and stored in a walk-in freezer for 48 hours before she could wear them. That made for a chilly start to the day, as Parker recalled.

The quarantine clothes were part of a U.S. Fish and Wildlife Service protocol for limiting both the introduction of foreign species into the monument and the spread of species between islands within it. “Something that’s native to one tiny island could be alien to the next one down the chain,” said Parker. The transmission could happen via a spore on your shoe or a seed stuck to your shirt.

In addition, all of the gear and equipment they were using, such as wet suits, fins, and life vests, had to be soaked in a dilute bleach solution before being used in a new location, a protocol developed by NOAA.

For the roughly month-long mission, Parker brought six full outfits to wear on the six islands the ship planned to visit. In the end, she only visited five islands and was able to turn a t-shirt from the sixth outfit into a makeshift hat to keep the hot sun at bay.

“Having to go through that level of precaution to not bring invasive species into the monument makes you realize just how delicate things are up there,” reflected Parker.

Stowaways Not Welcome

But before Parker and the rest of her team left on their mission, the vessel that would carry them, the NOAA Ship Oscar Elton Sette, first had to undergo a thorough cleaning and inspection before being granted a permit to enter the monument. The hull was scrubbed and checked by specially trained divers for even as much as a rogue barnacle. Ballast water, the water held in tanks on a ship to provide stability, was inspected closely as well because numerous creatures worldwide have been documented hitching a secret ride this way. And, of course, the ship was examined for rats, the perennial stowaways.

However, rats arrived in the monument years ago via the U.S. military activity previously based on Midway Atoll, a strategic naval base during World War II and the Cold War, and French Frigate Shoals, a runway and refueling stop for planes headed to Midway during World War II. While efforts to eradicate rats at these former military bases were successful, attempting a similar project for underwater species would be much more challenging. Marine species spread very quickly and human activities are necessarily limited by the finite amount of time we can spend underwater.

Currently, Godwin has documented about 60 non-native marine species in the Papahānaumokuākea Marine National Monument, mainly at Midway, but these species—the majority of which are marine invertebrates such as tube worms and sea squirts—are not recent arrivals. Most likely harken back to the area’s military days, which ended in 1994. Today the easiest way for a new marine species to get a foothold on these reefs is by colonizing “disturbed habitat,” or areas humans have altered, such as seawalls or docks, as is the case at Midway and French Frigate Shoals.

“Competition with native species is pretty stiff,” admits Godwin. While marine life from outside the monument can become established, they often don’t have the opportunity to become invasive, he said. “But we never say never,” which is why he helps train NOAA divers going to the monument to recognize the aggressive behaviors of marine invasive species.

Marine Debris and Surprises from Japan

Person pulling bio-fouled net out of water into boat with diver's help.

NOAA divers examining the abandoned fishing nets for potentially invasive species, as they were removing them from the Northwestern Hawaiian Islands in October 2014. (NOAA)

Godwin was on high-alert, however, when debris washed away from Japan during the 2011 tsunami began showing up in Hawaii. Most marine debris in the Northwestern Hawaiian Islands comes in the form of fishing nets typically lost in the open ocean—the kind the NOAA PIFSC team was clearing from reefs. Many of the species colonizing these nets are native to the open ocean and generally do not survive in the monument’s coastal environment.

But the boats and other debris from Japan came from the coast, bringing with them the hardy and flexible marine life capable of surviving the transoceanic journey until they found another coastal home. Fortunately, Godwin found that none of the non-native Japanese species showing up on tsunami debris became established in either Hawaii or the monument.

“Marine debris is a vector [for invasive species],” said Godwin, “but we have very little control,” which is why dealing with it in the monument focuses more on response than prevention. Yet with invasive species, prevention is always the goal. And when you get a glimpse of the unique place that is Papahānaumokuākea Marine National Monument, it is not hard to understand the lengths being taken to protect it.


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To Save Corals in an Oahu Bay, First Vacuum up Invasive Algae, Then Apply Sea Urchins

Diver placing algae into Super Sucker vacuum hose.

With the help of a gentle vacuum hose attached to a barge — a device known as the “Super Sucker” — divers can now remove invasive algae from coral reefs in Kaneohe Bay in much less time. (Credit: State of Hawaii Division of Aquatic Resources)

Progress used to be painfully slow. On average, it would take a diver two strenuous hours to remove one square meter (roughly 10.5 square feet) of the exotic red algae carpeting coral reefs in Kaneohe Bay, Hawaii. In addition to ripping away thick mats of algae, divers also had to pluck off any remaining algae stuck to the reef and use a hand net to capture bits floating in the surrounding water. Even then, these invasive algae were quick to regrow from the tiniest remnants left behind.

Today, however, divers can clear the same area in roughly half the time, or even less, depending on how densely the algae are growing. How? With the help of a device called the “Super Sucker.”

This underwater vacuum is not much more than a barge equipped with a 40 horsepower pump and long hose that gets lowered into the water. Divers still pull off chunks of algae from the reef, but they then stuff it into the device’s hose. The steady, gentle suction of the Super Sucker pulls the algae—including any tiny drifting remnants—through the hose up to a mesh table on the barge. There, seawater drains out and any critters accidentally caught by the algae-vacuuming can be returned to the ocean. People on the barge can then pack the algae into mesh bags to be taken back to shore. (Watch a video of the Super Sucker at work.)

Super sucker barge with green collection hose in a tropical bay.

The Super Sucker barge at left in Kaneohe Bay. The green collection hose used to vacuum up invasive algae from the reefs below is visible on the water surface. (Credit: State of Hawaii Division of Aquatic Resources)

The success of the Super Sucker stands to be augmented with help from small, spiny sea creatures—sea urchins—as well as a new, dedicated infusion of funding from NOAA which will expand the device’s reach in Oahu’s Kaneohe Bay. But the question remains: How did exotic algae come to cause so much trouble for corals in the first place?

A Welcome Introduction, an Unintended Stay

The problematic marine algae, or seaweed, in Oahu’s Kaneohe Bay actually is a complex of two types of algae originally from Southeast Asia: Kappaphycus and Eucheuma. Both algae were brought to this area on the eastern side of Oahu in the 1970s in an attempt to cultivate them as a source of carrageenan, a thickening agent used in processed foods. While the agricultural endeavor never took off in Oahu, these algae did. Unfortunately, this was somewhat of a surprise. Two years after the algae’s introduction, several studies found a low likelihood of their escaping from experimental pens and threatening coral habitat in the bay.

In the decades since, Kappaphycus and Eucheuma have proven that prediction very wrong, as these algae are now comfortably established in Kaneohe Bay. Because these algae spread aggressively once they arrived in this new environment, they have earned the label “invasive.” The algae have been overgrowing the coral reefs, smothering and killing corals by blocking the sunlight these organisms need to survive. These days, some areas of Kaneohe Bay are no longer dominated by corals but instead by invasive algae.

Tumbleweed-like clumps of invasive algae on a coral reef.

Meet the complex of invasive algae plaguing coral reefs in Oahu’s Kaneohe Bay: Kappaphycus and Eucheuma. These thick, warty, plastic-like, and irregularly branching algae grow in tumbleweed-like clumps, often smothering coral beneath them. (Credit: State of Hawaii Division of Aquatic Resources)

Delivering a Double-Whammy to Invasive Algae

Around 2005, NOAA helped fund the development of the Super Sucker as part of a joint project between the State of Hawaii and the Nature Conservancy. The project was aimed at containing these invasive algae in Kaneohe Bay, a partnership that continues to the present day.

Today, NOAA is becoming involved once more by expanding this project and bringing the Super Sucker into new parts of Kaneohe Bay. NOAA will accomplish this by using part of the nearly $6 million available for restoration after the 2005 grounding of the ship M/V Cape Flattery. When the ship became lodged on coral reefs south of Oahu, efforts to refloat the vessel and avoid an oil spill caused extensive harm to coral habitat across approximately 20 acres, an area now recovering well on its own.

Sea urchins grazing on seaweed on a coral reef.

The native sea urchins eat away at any invasive algae left on the coral, keeping the algae’s growth in check. The State of Hawaii Division of Aquatic Resources is raising these urchins in captivity and releasing them into Kaneohe Bay. (Credit: State of Hawaii Division of Aquatic Resources)

This restoration project will not just involve the Super Sucker, however. Another key component in controlling invasive algae in Kaneohe Bay is reintroducing a native predator. While most plant-eating fish there prefer to graze on other, tastier algae, native sea urchins have shown they are happy to munch away at the tiniest scraps of Kappaphycus and Eucheuma found on reefs. But the number of sea urchins in Kaneohe Bay is unusually low.

Currently, the State of Hawaii Division of Aquatic Resources is raising native sea urchins and experimentally releasing them back into the bay. NOAA’s restoration project for the Cape Flattery coral grounding would greatly expand the combined use of the Super Sucker and reintroduced sea urchins to control the invasive algae.

Together, mechanically removing the algae with the Super Sucker and reintroducing sea urchins in the same area should be effective at curbing the regrowth and spread of invasive algae in the northern part of Kaneohe Bay. Making sure invasive algae do not spread outside the bay is an important part of this coral restoration project. This northern portion, near a major entrance to the bay, is a critical area for containing the algae and making sure it doesn’t escape from the bay to other near shore reefs.

Saving Corals and Creating Fertilizer

Top, coral reef with invasive algae. Bottom, same reef after algae was removed.

Top, coral reef before Super Sucker operations, and bottom, the same reef after the Super Sucker has cleared away the invasive algae. (Credit: State of Hawaii Division of Aquatic Resources)

Ultimately, the goal is to move toward natural controls (i.e., the sea urchins) taking over the containment of Kappaphycus and Eucheuma algae in Kaneohe Bay.

The benefits of removing the algae from the area’s coral reefs are two-fold. First, clearing away the carpets of algae saves the corals that are being smothered beneath them. Second, opening up other areas of the seafloor previously covered by algae creates space for young corals to settle and establish themselves, growing new reef habitat.

Another benefit of clearing the invasive algae in this project is that it provides a source of free fertilizer for local farmers. Not only does it offer a sustainable source of nutrients on agricultural fields but the algae breaks down more slowly and is therefore less susceptible than commercial fertilizer to leaching into nearby waterways.

Even so, a 2004 study confirmed that these algae do not survive in waters with low salt levels, meaning that any algae that do run off from farms into nearby streams will not eventually re-infect the marine environment. Another win.


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Why Are Seabirds so Vulnerable to Oil Spills?

Out of the squawking thousands of black and white birds crowding the cliff, a single male sidled up to the rocky edge. After arranging a few out-of-place feathers with his sleek beak, the bird plunged like a bullet into the ocean below. These penguin look-alikes (no relation) are Common Murres. Found along the U.S. coast from Alaska to California, this abundant species of seabird dives underwater, using its wings to pursue a seafood dinner, namely small fish.

During an oil spill, however, these classic characteristics of murres and other seabirds work to their disadvantage, upping the chance they will encounter oil—and in more ways than one. To understand why seabirds are so vulnerable to oil spills, let’s return to our lone male murre and a hypothetical oil spill near his colony in the Gulf of Alaska.

Preening in an Oil Sheen

After diving hundreds of feet beneath the cold waters of the North Pacific Ocean, the male murre pops back to the surface with a belly full of fish—and feathers laminated in oil. This bird has surfaced from his dinner dive into an oil slick, a common problem for diving birds during oil spills. His coat of feathers, once warm and waterproof, is now matted. The oil is breaking up his interlocking layer of feathers, usually maintained by the bird’s constant arranging and rearranging, known as preening.

With his sensitive skin suddenly exposed not just to the irritating influence of oil but also to the cold, the male murre becomes chilled. If he does not repair the alignment of his feathers soon, hypothermia could set in. This same insulating structure also traps air and helps the bird float on the water’s surface, but without it, the bird would struggle to stay afloat.

Quickly, the freshly oiled seabird begins preening. But with each peck of his pointed beak into the plumage, he gulps down small amounts of oil. If the murre ingests enough oil, it could have serious effects on his internal organs. Impacts range from disrupted digestion and diarrhea to liver and kidney damage and destruction of red blood cells (anemia).

But oil can find yet another way of entering the bird: via the lungs. When oil is spilled, it begins interacting with the wind, water, and waves and changing its physical and chemical properties through the process of weathering. Some components of the oil may evaporate, and the murre, bobbing on the water’s surface, could breathe in the resulting toxic fumes, leading to potential lung problems.

Birds’-Eye View

Colony of murres on a rocky outcropping on the California coast.

Murres are very social birds, living in large colonies on rocky cliffs and shores along the U.S. West Coast. If disturbed by an oil spill, many of these birds may set off temporarily to find a more suitable home. (Creative Commons: Donna Pomeroy, Attribution-NonCommercial 3.0 Unported License)

This single male murre is likely not the only one in his colony to experience a run-in with the oil spill. Even those seabirds not encountering the oil directly can be affected. With oil spread across areas where the birds normally search for food and with some of their prey potentially contaminated or killed by the oil, the colony may have to travel farther away to find enough to eat. On the other hand, large numbers of these seabirds may decide to up and move to another home for the time being.

At the same time that good food is becoming scarcer, these birds will need even more food to keep up their energy levels to stay warm, find food, and ward off disease. One source of stress—the oil spill—can exacerbate many other stresses that the birds often can handle under usual circumstances.

If the oil spill happens during mating and nesting time, the impacts can be even more severe. Reproducing requires a lot of energy, and on top of that, exposure to oil can hinder birds’ ability to reproduce. Eggs and very young birds are particularly sensitive to the toxic and potentially deadly properties of oil. Murres lay only one egg at a time, meaning they are slower to replace themselves.

The glossy-eyed male murre we are following, even if he manages to escape most of the immediate impacts of being oiled, would soon face the daunting responsibility of taking care of his fledgling chick. As young as three weeks old, his one, still-developing chick plops off the steep cliff face where the colony resides and tumbles into the ocean, perhaps a thousand feet to its waiting father below. There, the father murre is the chick’s constant caregiver as they travel out to sea, an energy-intensive role even without having to deal with the potential fallout from an oil spill.

Birds of a Feather Get Oiled Together

Like a bathtub filled with rubber ducks, murres form giant floating congregations on the water, known as “rafts,” which can include up to 250,000 birds. In fact, murres spend all but three or four months of the year out at sea. Depending on where the oil travels after a spill, a raft of murres could float right into it, a scenario which may be especially likely considering murre habitat often overlaps with major shipping channels.

After the 1989 Exxon Valdez oil spill in Prince William Sound, responders collected some 30,000 dead, oil-covered birds. Nearly three-quarters of them were murres, but the total included other birds which dive or feed on the ocean surface as well. Because most bird carcasses never make it to shore intact where researchers can count them, they have to make estimations of the total number of birds killed. The best approximation from the Exxon Valdez spill is that 250,000 birds died, with 185,000 of them murres.

While this population of seabirds certainly suffered from this oil spill (perhaps losing up to 40 percent of the population), murres began recovering within a few years of the Exxon Valdez oil spill. Surprisingly resilient, this species is nonetheless one of the most studied seabirds [PDF] precisely because it is so often the victim of oil spills.


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When the Dynamics of an Oil Spill Shut Down a Nuclear Power Plant

Yellow containment boom floats on a river next to a nuclear power plant.

Precautionary containment boom is visible around the water intake system at the Salem Nuclear Generating Station in New Jersey on December 6, 2004. The nuclear plant was shut down for 11 days to prevent the heavy, submerged oil from the Athos spill from clogging the water intakes. (NOAA)

“I’ve never reopened a nuclear power plant,” thought NOAA’s Ed Levine. Despite that, Levine knew it was his job to get the right information to the people who ultimately would make that decision. This was his role as a NOAA Scientific Support Coordinator during oil spills. However, most major oil spills do not affect nuclear power plants. This wintry day in 2004 was an exception.

Forty miles north of the Salem Nuclear Generating Station in New Jersey, an oil tanker called the Athos I had struck an object hidden beneath the Delaware River. As it was preparing to dock at the CITGO refinery near Philadelphia on November 26, the ship began tilting to one side, the engine shut down, and oil started gushing out.

“Not your typical oil spill,” later reflected Jonathan Sarubbi, who served as U.S. Coast Guard Captain of the Port and led the federal response during this incident. Not only did no one immediately know what the ship had hit—or where that object was located in the river channel—but the Athos, now sitting too low in the water to reach the dock, was stuck where it was. And it was still leaking its cargo of heavy Venezuelan crude oil.

Capt. Sarubbi ordered vessel traffic through this busy East Coast shipping channel to stop until the object the Athos hit could be found. Little did Capt. Sarubbi, Levine, and the other responders know that even more challenges would be in store beneath the water and down the river.

Getting Mixed up

Most oils, most of the time, float on the surface of water. This was precisely what responders expected the oil coming out of the Athos to do. But within a couple days of the spill, they realized that was not the case. This oil was a little on the heavier side. As it shot out of the ship’s punctured bottom, some of the oil mixed with sediment from the river bottom. It didn’t have far to go; thanks to an extremely low tide pulling the river out to sea, the Athos was passing a mere 18 inches above the bottom of the river when it sprung a leak.

Now mixed with sediment, some of the spilled oil became as dense as or denser than water. Instead of rising to the river surface, it sank to the bottom or drifted in the water column. Even some of the oil that floated became mixed with sediment along the shoreline, later sinking below the surface. For the oil suspended in the water, the turbulence of the Delaware River kept it moving with the currents increasingly toward the Salem nuclear plant, perched on the river’s edge.

NOAA’s oil spill trajectory model GNOME forecasts the spread of oil by assuming the oil is floating on the water’s surface. Normally, our oceanographers can verify how well the forecasts are doing by calibrating the model against twice-a-day aerial surveys of the oil’s movement. The trouble with oil that does not float is that it is harder to see, especially in the murky waters of the Delaware River.

Responders were forced to improvise. To track oil underwater, they created new sampling methods, one of which involved dropping weighted ropes into the water column at various points along the river. The ropes were lined with what looked like cheerleader pom-poms made of oil-attracting plastic strips that would pick up oil as it passed by.

Nuclear Ambitions

Nuclear plants like the Salem facility rely on a steady flow of freshwater to cool their reactors. A thin layer of floating oil was nearing the plant by December 1, 2004, with predictions that the heavier, submerged oil would not be far behind. By December 3, small, sticky bits of oil began showing up in the screens on the plant’s cooling water intakes. To keep them from becoming clogged, the plant decided to shut down its two nuclear reactors the next day. That was when NOAA’s Ed Levine was tasked with figuring out when the significant threats due to the oil had passed.

Eleven days later, the Salem nuclear plant operators, the State of New Jersey, and the Nuclear Regulatory Commission allowed the plant to restart. A combination of our modeling and new sampling methods for detecting underwater oil had shown a clear and significant drop in the amount of oil around the plant. Closing this major electric generating facility cost $33.1 million out of more than $162 million in claims paid to parties affected by the Athos spill. But through our innovative modeling and sampling, we were able to reduce the time the plant was offline, minimizing the disruption to the power grid and reducing the economic loss.

Levine recalled this as an “eye-opening” experience, one yielding a number of lessons for working with nuclear power plants should an oil spill threaten one in the future. To learn more about the Athos oil spill, from response to restoration, visit response.restoration.noaa.gov/athos.

A special thanks to NOAA’s Ed Levine and Chris Barker, former U.S. Coast Guard Captain Jonathan Sarubbi, and Henry Font, Donna Hellberg, and Thomas Morrison of the Coast Guard National Pollution Funds Center for sharing information and data which contributed to this post.

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