Archive for Science
By Alisha Renfro, Coastal Scientist, National Wildlife Federation
The blow out of the Macondo well claimed 11 lives and began the largest marine oil spill in U.S. history. It took 87 days to finally cap the well and by then at least 134 million gallons of crude oil had been expelled into the Gulf of Mexico.
With the source of the oil nearly a mile below the surface of the water and at four times the size of the Exxon Valdez, the BP oil disaster presented many new challenges. The experience and response methods used in previous oil spills was often found to be impossible to apply or ineffective. As a result, scientists began scrambling to measure how much oil was leaking from the well, tracking and predicting where it would go and trying to understand what this spill would mean for the people, wildlife and habitat of the Gulf.
While large amounts of scientific data have been collected and published in peer-reviewed journals in the five years since the oil spill, more scientific research is still ongoing. The science related to the spill has been largely funded through a few different sources, including:
The NSF has scientific funding available to address pressing research needs during unanticipated events, like the BP oil spill. The availability and flexibility of this funding source allowed scientists receiving this grant to quickly mobilize and collect important data that may have otherwise been missed in the confusion in the days after the spill when oil was still gushing out of the wellhead.
In May-2010, BP dedicated $500 million over 10 years to independent scientific research to investigate the oil spill impacts on the Gulf of Mexico and Gulf coast states. This initiative funded research projects and research consortia that range from the deep Gulf to the shoreline. Hundreds of peer-reviewed publications have resulted from this initiative and a searchable list of this research can be found here.
The Oil Pollution Act of 1990 authorizes natural resource trustees – specific federal agencies, affected states and the party responsible, in this case BP – to evaluate the impacts of this oil spill on the natural resources of the region and to implement projects that restore or replace those resources. While the NRDA process related the BP oil spill is touted as the most transparent in its history, the many findings of the ongoing assessment are not available to the public.
The unprecedented size and complexity of the BP oil spill demands well-funded, intensive and wide-ranging scientific study. This research, particularly through NRDA, is crucial for the path forward towards restoration that will bolster and restore the health of the Gulf ecosystem and the people and wildlife that depend on it.
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This post has been cross-posted from an article originally published on the National Audubon Society’s website
By: Melanie Driscoll, Director of Bird Conservation, Gulf Coast Conservation/Mississippi Flyway, Erik Johnson, Director of Bird Conservation, Audubon Louisiana
A BP-authored report claiming that the Gulf has recovered is inaccurate and insulting—here’s why.
Nearly five years after the largest accidental marine oil spill in U.S. history, BP is doing its best to convince the public that the 4.9 million barrels of oil that leaked into the Gulf of Mexico have done no lasting damage. That’s the message found in The Gulf of Mexico Environmental Recovery and Restoration report the company released three weeks ago.
Based on what the report does present, it’s obvious that BP chose to ignore recent research that shows the ongoing impact of the oil spill, particularly on birds (pp 15-17 of report). That BP ignores peer-reviewed science is nothing new—they have been denying culpability and the validity of peer-reviewed, published research since the spill itself. Meanwhile, their own conclusions lack peer-review and they have not released their methodology. Because of this lack of transparency, BP has made claims that are impossible to refute or verify.
One of the government agencies responsible for monitoring the Gulf health following the oil spill—the NOAA Damage Assessment, Remediation, and Restoration Program—is expected to hold itself to a high standard of independent scientific peer-review as it completes its Natural Resource Damage Assessment (NRDA). While we await the NRDA studies to be completed and released, BP has flaunted such professional standards in its allusions to NRDA findings that cannot be verified at this stage. The trustees of NRDA themselves called BP’s recent report “inappropriate as well as premature.”
Along with others in the scientific community, the National Audubon Society rejects BP’s claims. While their report leaves much to criticize, here are its five main flaws:
- Their conclusions are not credible given lack of peer-review, questionable methodology and premature conclusions.
They claim “search teams likely found 97 percent of large birds and 78 percent of small birds.” These numbers are inconceivable to any researcher or birder who has looked for birds on a beach. It stands to reason that a detection rate of 97 percent as claimed by BP is unlikely, even for living and mobile birds; their estimate seems grossly optimistic compared to detection rates published widely in the scientific literature. In addition, BP compared their estimate of searcher efficiency for carcasses placed on beaches to the searcher efficiency across sandy beach, rocky beach, and marsh habitats. Detection rates are known to vary widely based on factors such as carcass coloration and habitat, and the actual searches in the Deepwater Horizon disaster occurred across marsh, mangrove, rocky beach, and sandy beach habitats. Attacking a single parameter from a complex study, and doing so using an apples-to-oranges comparison, is disingenuous and misleading.
- The Gulf of Mexico ecosystem has not returned to a pre-oil spill “baseline condition”.
First of all, the oil is not gone. Significant deposits (up to 230,000 barrels) of oil have been discovered in the sediment on the Gulf floor. This oil regularly washes ashore during storms, re-oiling marshes and beaches. In October 2014, researchers discovered a 1,250-square-mile “bathtub ring” of oil on the Gulf floor–equivalent to the size of Rhode Island. Indeed, as the BP report was released a 22,000-pound tar mat was being removed from East Grand Terre Island in Barataria Bay, LA.
BP’s conclusions are incredibly premature. With lagged effects, trophic cascades, food web effects, and repeated re-oiling of the coast, we could be seeing surprises and environmental effects for years to come on birds and on the entire ecosystem.
Erosion is forever. Land and crucial habitats have disappeared. It’s impossible to return to a “baseline” when the land that composed that baseline and is crucial to coastal bird populations has disappeared. Studies show that marsh that was heavily oiled was undercut and eroded back, creating ragged marsh edges that were unoiled or lightly oiled. The scientists have then seen a wave of erosion of these unoiled or lightly oiled marsh, as waves reshape the ragged marsh edge to create a new, smoother edge. Not only has much of the heavily oiled marsh eroded, but marsh that was less damaged has followed.
- Damage to birds from the BP oil spill is evident and has been well documented, contrary to what BP reports.
In the 95 days following the oil spill, conservative estimates are that hundreds of thousands to more than a million birds died.
This acute damage does not take into account the molecular, cellular, reproductive, and developmental damage that may accumulate in birds for years to come. That is significant, it is long-term, and it matters.
Birds exposed to oil during their early development may accumulate damage that causes failed reproduction. Additionally, many long-lived species like pelicans, terns, and egrets do not breed until their second, third, or fourth year of life, meaning the young exposed to oil early in their lives hadn’t started breeding in 2011, making BP’s conclusions based on 2011 information premature.
- More studies are needed to understand the ongoing and long-term effects on bird populations.
In other species, lagged and trophic level effects have resulted in increasing effects from oil being detected over time since the disaster. Very few studies on bird productivity have been published that looked beyond the 2010-2011 nesting season. More studies are needed to draw broad conclusions.
Scientifically, the most reliable way to study productivity is to compare productivity of birds exposed to oil and not exposed to oil within the same season. The only study of which we are aware that has used this reliable methodology is a study of the Seaside Sparrow, which showed reduced nest success for sparrows on oiled sites in 2012 and 2013.
- BP’s use of Audubon’s Christmas Bird Count (CBC) data is flawed and their summaries of other data are incomplete and misleading.
BP misused CBC data to obscure potential impacts. It’s likely they used data from well outside the impacted areas. Particularly, Sandwich Terns and Northern Gannets are not counted by CBC participants 10-100 times more than Piping Plovers in the impacted areas. The numbers they used for Red Knots appear to include the entire rufa subspecies, which mainly winters in the Tierra del Fuego region in southern Argentina and the Maranhão region of northeastern Brazil. It is difficult to tell how CBC data were used, but it is clear from the relative abundance of some species that data from outside the Gulf were included in analyses. Using broader data from other regions could mask any local and regional changes in populations due to the oil spill. Without describing their methods, it is apparent that BP’s report represents a misuse of Audubon’s publicly available data.
BP reported oiling rates from long after the oil well was capped, resulting in oiling rates that appear to be very low: In its report, BP cites data saying “researchers saw no visible oil in 99 percent of the roughly 500,000 live bird observations from May 2010 to March 2011.” A study following the Deepwater Horizon spill showed that 8.6 percent of captured shorebirds showed evidence of oiling, indicating that BP’s observational evidence may have underestimated exposure by as much as an order of magnitude.
BP selected a study that appeared to show no effects on birds to highlight a success that is likely just a lack of use of the oiled region: In BP’s reference to the Northern Gannet publication, researchers in this paper used light-level geolocators to determine wintering locations of Northern Gannets. Digging into the details of the paper, it is clear that only a small sample of the researcher’s birds wintered in the Gulf of Mexico (8 birds in their study) and that the Gulf birds foraged in areas primarily >100 miles away from the spill site, i.e., well outside of area of the most devastating impacts. Thus it may be no surprise that these few birds did not show elevated polycyclic aromatic hydrocarbon (harmful chemicals from oil) levels as they were not in the spill zone. The U.S. Fish and Wildlife Service’s published account of bird deaths following the spill paints a different picture—Northern Gannets were one of the most frequently encountered dead bird after the spill.
BP incorrectly concluded from a published study that researchers did not find evidence that variations in age classes of Brown Pelicans on Louisiana barrier islands were related to the oil spill. However, the paper specifically states “…additional research is required to evaluate potential long-term population trends.” Also, “Care should be taken in interpretation of our result as a lack of effect [of oil] on demography because there are combinations of spill-related reductions in fecundity and age-specific mortality that could result in no changes in age structure.” One scenario that’s easy to imagine is that all age classes were reduced similarly. In short, like the authors state, there are many possible scenarios that could influence their findings.
Despite BP’s claims, we may not know the full impact of the oil spill for decades to come. Even more, we will not achieve lasting, meaningful restoration in the Gulf Coast until BP quits stalling, quits the legal and publicity campaign and actually funds full restoration.
Sign this petition telling BP to stop their delay tactics and fully fund Gulf restoration.No Comments
By Estelle Robichaux, Restoration Project Analyst, Environmental Defense Fund
The BP oil spill has had devastating impacts on Gulf Coast ecosystems and communities, but coastal Louisiana’s land loss crisis began decades before the disaster. The Clean Water Act fines and other money paid through settlements relating to the spill offer an unprecedented opportunity to restore Gulf Coast habitats and natural resources.
Many of the early restoration projects funded in Louisiana are focused on barrier islands because of the important role they play in the coastal ecosystem and the severe impacts they experienced during the spill. Louisiana’s barrier islands were heavily oiled because they act as a “first line of defense” against disturbance, such as storm surge or, in this case, oil. In fact, Louisiana’s coastal islands continue to experience re-oiling even today.
Caminada Headland Beach & Dune Restoration
One very important barrier island restoration project currently underway is the Caminada Headland Beach & Dune restoration, which is part of our coalition’s priority project, Belle Pass to Caminada Pass Barrier Island Restoration. The Caminada Headland forms the western edge of the Barataria Basin barrier system and has experienced some of the highest rates of shoreline retreat and land loss along the Louisiana coast.
I recently had the opportunity to see the first constructed phase of the Caminada restoration project on a field trip hosted by our partner, Restore or Retreat, and the Greater Lafourche Port Commission. It was inspiring to see restoration at work! There were birds and crabs on the shoreline, small plants naturally re-vegetating and the different project components working together – breakwaters protecting the shore and the sand fence having created a substantial dune. More projects like this are exactly what coastal Louisiana needs.
Why is the Caminada Headland important?
The Caminada Headland is a significant feature along Louisiana’s coastline because it provides critical habitat for important neotropical migratory birds and threatened or endangered species, such as the piping plover and Kemp’s ridley sea turtle. It is also a buffer from storm surge and waves for valuable public and private infrastructure, including Port Fourchon and Highway 1, which provides the only evacuation route for coastal communities such as Grand Isle, La.
Port Fourchon is an important nexus in our national energy infrastructure system. Approximately 18 percent of the nation’s oil supply is transported through the port, and it is the land base for the Louisiana Offshore Oil Port (LOOP). The LOOP is connected to refineries across the country, which collectively make up half of the oil refining capacity in the U.S., and handles about 15 percent of our foreign oil imports. The activity, infrastructure and continuing growth of the port is truly impressive!
What makes this restoration project unique?
The first phase of the Caminada Headland restoration project created and enhanced more than 300 acres of beach and dune habitat. This project used a mix of sediment pumped from the Mississippi River and high-quality, beach-compatible sand from Ship Shoal, a large marine sand deposit just offshore of Isles Dernieres. Most of the other nearby sand sources have been exhausted, so this was the first time that sediment from Ship Shoal has been used for restoration.
The planning and design of the Caminada project was funded using the Coastal Impact Assistance Program and Louisiana state surplus funds, but they only had enough money (~$70 million) to restore a portion of the island. The success of this first phase, however, was leveraged when more funding became available, via the National Fish & Wildlife Foundation, to complete restoration of Caminada’s beach and dune habitat.
Construction on the first phase of the beach and dune habitat restoration is complete and soon the entire project area will be planted with native vegetation. The second phase of construction for the Caminada Headland restoration project – which at 489 acres, is the largest restoration project ever undertaken by Louisiana’s Coastal Protection and Restoration Authority – should begin within the next month. Design for restoration of the Caminada Headland back barrier marsh is also currently underway.
Check out my previous post in this series, Exploring Early Coastal Restoration Funding and Projects1 Comment
FOR IMMEDIATE RELEASE
Emily Guidry Schatzel, National Wildlife Federation, 225.253.9781, email@example.com
Jacques Hebert, National Audubon Society, 504.264.6849, firstname.lastname@example.org
Elizabeth Van Cleve, Environmental Defense Fund, 202.553.2543, email@example.com
Five Years Later: Gulf Oil Disaster’s Impacts to Habitat and Wildlife Still Evident
Leading Conservation Groups Highlight BP Spill’s Ongoing Effects, Continued Need for Restoration
(New Orleans, LA—March 31, 2015) Five years after the Deepwater Horizon rig exploded, killing 11 men and spewing at least 3.19 million barrels of oil into the Gulf of Mexico, leading national and local conservation organizations working on Mississippi River Delta and Gulf Coast restoration – Environmental Defense Fund, National Audubon Society, National Wildlife Federation and Lake Pontchartrain Basin Foundation – released the following statement:
“Despite BP’s claims that the Gulf oil disaster and its ecological impacts are over, ongoing research and present-day observations in areas that were heavily oiled tell a different story.
“New independent scientific studies provide evidence that the full consequences of the spill to wildlife and habitats are still unfolding. From dolphins to sea turtles to birds, we still are seeing the real and lasting environmental impacts of one of the worst oil spills in our nation’s history.
“BP claims the nearly 134 million gallons of oil spilled into the Gulf has not negatively affected the ecosystem. But continued surveillance of areas like Barataria Bay, where thick oil coated vital wildlife habitat, including marshes and barrier islands, reveals lasting effects of the spill. Cat Island, a mangrove island that was heavily oiled, was once a lush, thriving rookery for brown pelicans and other birds, but today it is gray, lifeless and has nearly disappeared. Other coastal areas damaged by the spill are also still in need of repair.
“To this day, oil is still being found, most recently in the form of a 25,000-pound tar mat located on a Louisiana barrier island, near where 40,000 pounds of BP-oiled material was unearthed two years ago. It’s time for BP to put the publicity campaign aside, stop shirking responsibility and finally ‘make it right’ for the people, wildlife and habitats of the Gulf Coast.
“The oil disaster wreaked incomparable damage to an already-stressed Gulf Coast ecosystem. In Louisiana, the oil spill dealt another blow to an area ravaged by land loss – since the 1930s, Louisiana has lost nearly 1,900 square miles of land, or an area the size of Delaware. Nowhere is restoration more needed than the Mississippi River Delta, which is the cornerstone of a healthy Gulf ecosystem.
“Restoration solutions are within reach and plans are in place, but implementation of restoration plans cannot fully begin until BP accepts responsibility and pays its fines. Thanks to vehicles like Louisiana’s Coastal Master Plan and the historic RESTORE Act of 2012, which ensures that the Clean Water Act fines BP pays will be used for restoration, the Gulf Coast can make headway on real restoration projects that can make a difference. We have a once-in-a-lifetime opportunity to restore the health of our wetlands, revive Gulf Coast economies that depend on them, and make the Gulf Coast better than it was before the spill, but we must begin restoration now. The Gulf Coast – and the people, wildlife and jobs that depend on it – cannot wait any longer.”
Since the BP oil disaster five years ago, ongoing findings deliver truths omitted by BP’s ads: the oil disaster’s negative effects are increasingly clear, present and far from resolved.
A new infographic depicts ongoing impacts of the Gulf oil disaster five years later. And over the past year alone, new scientific research has surfaced:
- A 2014 study found evidence of a 1,250-square-mile area of oil contamination on the ocean floor around the Macondo wellhead in deep Gulf sediments.
- A new NOAA study found a large number of dead dolphins in heavily oiled places, including Barataria Bay, La.
- Recent studies estimate 800,000 birds died as a result of being exposed to BP oil.
- Modeling for a recent stock assessment projected that between 20,000 and 60,000 Kemp’s ridley sea turtles died in 2010 as a result of the spill.
- A 2014 study found concentrations of PAH (polycyclic aromatic hydrocarbon) – which can cause harmful effects in many birds, fish and wildlife – in Barataria and Terrebonne marshes, which may persist for decades.
- A 2012 study found that oiled marshes in Barataria Bay eroded at double the rate of non-oiled marshes.
Straddling the border of Plaquemines and St. Bernard parishes in Southeastern Louisiana is the Caernarvon Freshwater Diversion built by the Army Corps of Engineers and operated since 1992 to balance water salinity by funneling river water into coastal marshes.
Lately, the diversion has had indirect effects that are raising eyebrows among scientists and those seeking to find solutions to address the crisis of Louisiana’s disappearing coast. The Caernarvon Freshwater Diversion is creating land at a rapid pace by delivering nutrient-rich river fresh water to bayous that have been starved of sediment and are eroding at an alarming rate.
In a new video, Coordinator of Lake Pontchartrain Basin Foundation’s Coastal Sustainability Program Dr. John Lopez outlines how approximately 1,000 acres of wetlands have been developed from the Caernarvon Diversion to create a new delta and within it a new bayou known as Bayou Bonjour. The new bayou is named in contrast to the book "Bayou Farewell," foretelling of the tragic loss of our wetlands and bayous. “Caernarvon was not designed or operated to build land,” Lopez notes, yet “Big Mar Pond has been filling up over the last twenty years due to sediment from Caernarvon.” How did this happen? Lopez explains how the diversion has provided an “ideal recipe for building a delta”: (river freshwater + sediments + nutrients = land growth).
Big Mar is located directly behind Braithwaite Park, a Plaquemines Parish community housed outside the federal levee system where devastation from Hurricanes Katrina, Rita, and Isaac occurred. Building land in Big Mar could provide a much-needed buffer for this community and an example for how to protect others like it. “As long as Caernarvon Diversion is flowing, this waterway and others like it will develop and this gives us hope in Louisiana that we can rebuild our coast,” says Lopez. In addition, recently planted cypress trees are thriving and will provide additional environmental and flood protection benefit as a new "line of defense."
Take a tour of Bayou Bonjour:
Want to learn more about the Caernarvon Diversion and other solutions for restoring the Mississippi River Delta? Visit mississippiriverdelta.org, like us on Facebook, and follow us on Twitter. You can also share the video with your network using the following tweet:
- Introducing Bayou Bonjour: Caernarvon Diversion has created an “ideal recipe for building a delta” #RestoreOurCoast http://youtu.be/5TExITZM2Wg
By Matthew Phillips, National Wildlife Federation
When trying to understand how ecosystems function, scientists often look at food webs–the complex relationships between animals, insects, plants, and bacteria that govern who eats whom.
Food webs in the Gulf of Mexico are as complex as they come. The different habitat types, from forests to wetlands to ocean, mean a diverse array of species. The Gulf food web would be nearly impossible to understand in its entirety, but we can simplify it into a chain to help us think about it. Plants form the base of this chain, as they convert sunlight into the energy that fuels the entire system. Plants are eaten by herbivores, who are then eaten by larger organisms. Scientists can learn a lot about how an ecosystem functions by studying the ends of the chain–the plants at the bottom and the animals that occupy the top. However, it’s the species in the middle that provide crucial linkages.
One recent study, “Disturbance and recovery of salt marsh arthropod communities following BP Deepwater Horizon oil spill” assessed how arthropods living in the Gulf wetlands responded to the BP oil spill. Arthropods are an enormous group of organisms, including insects, spiders, crabs, crustaceans, and just about anything else with a hard outer shell that lacks a vertebral column. The authors looked at the heart of the food chain: the huge number of arthropod species that provide links between fish, birds, and other animals. If the oil spill affected these populations, they reasoned, the effects would ripple through the rest of ecosystem, causing unpredictable damage.
They measured the density of arthropod populations in patches of Spartina alterniflora, a grass that dominates Gulf coast marshes, while oil was washing up on marsh shoreline in 2010 and again one year later. For comparison, they visited 12 marshes with oil and 10 with no oil. They ensured the vegetation and soil were similar in each location to negate any differences between habitat types.
Their results were both striking and hopeful. During 2010, they found half as many arthropods in the marshes that had oil as in those with no oil. Because birds, fish, and even plants depend on these organisms, losing half the population could potentially devastate the ecosystem. But by 2011 arthropods in the oiled marshes were back at the same densities as in the unoiled marshes. It seemed that arthropods were primarily susceptible to the direct effects of oil. Oil may remain in wetlands for decades after a spill, but it usually seeps into the soils under the marsh grass. The arthropods in this study lived in the grasses above the marsh surface. Once the oil disappeared into the soil, their populations returned to normal.
This study presents a more important conclusion than simply the resilience of arthropods to oil. Ecosystems are intricate webs of interactions between the living and non-living environment, and looking at one organism, relationship, or phenomenon may not reveal any significant truth about the ecosystem as a whole. Except for a thin sheen of oil, the marshes in this study appeared healthy. But, in fact, oil had wiped out half the arthropods. We should treat ecosystems as the fragile, profoundly complex systems they are. Protecting them should be the top priority. Any disturbance can have widespread and unpredictable consequences.
To learn more about our coalition and the plans to restore our marshes and wetlands, click here. More information about the ongoing effects of the BP oil spill can be found here: "Understanding effects of chemical dispersants on marine wildlife is critical to whale population" and "Five years later, scientists gather to assess ongoing impact of BP oil spill."No Comments
This was originally posted on the National Wildlife Federation's Wildlife Promise blog.
By Emily Guidry Schatzel, National Wildlife Federation
One day after BP released a report saying the Gulf is on the road to recovery, we took a trip to one of the most impacted areas from the BP oil spill—Barataria Bay, Louisiana. From a dead baby dolphin to devastation at a bird rookery to active clean-up crews removing tons of oil from barrier islands, we found a very different picture from what BP painted in its report.
We started the day off at Cat Island. Once a vibrant barrier island covered in brown pelicans, roseate spoonbills, terns and gulls, it was hit hard by the oil during the spill. Today, the island is unrecognizable. The thick mangrove forests are all dead and the island is essentially a small spit of mud with the skeletal remains of vegetation, hosting just a handful of birds. Coastal Louisiana is already losing a football field of land every hour, and studies show that the oil accelerated this erosion.
Next we went to East Grand Terre, a nearby barrier island. Roughly 20 workers were out there cleaning up oil. BP confirmed this latest clean-up was part of a process to remove a 25,000-pound tar mat found in late February 2015. Finding oil here is not a huge surprise–two years ago, a 40,000 pound tar mat was found in the same area.
Even worse, in that same area, we also saw a mother dolphin attempting to resuscitate her dead infant. She was surrounded by a group of dolphins–all of them visibly in distress. Such a tragic sight was difficult to witness.
On the same day, The Lens reported that two dead adult bottlenose dolphins washed up on nearby Queen Bess Island.
We don’t know why these particular dolphins died. But we do know that NOAA has determined bottlenose dolphins in this area of Barataria Bay are sick—very sick. They have symptoms of oil exposure—unusual lung masses, adrenal gland problems, even teeth that are falling out. Based on the study, NOAA concluded that “the health effects seen in the Barataria Bay dolphins are significant and likely will lead to reduced survival and ability to reproduce.”
We also know that dolphin deaths in Louisiana remain four times higher than average. And that high numbers of stillborn and premature dolphins have been found in the northern Gulf every spring since 2010.2 Comments
This was originally posted on the National Wildlife Federation's Wildlife Promise blog.
By Ryan Fikes, National Wildlife Federation
BP has just released a new report on the state of the Gulf, called Gulf of Mexico: Environmental Recovery and Restoration. The glossy report is filled with footnotes and citations, but leaves key pieces of science out.
Here are ten important things BP’s latest report strategically didn’t mention:
- Dolphins died before the spill – from freshwater
The report says: “An “unusual mortality event” (UME) involving an abnormally high number of dolphin deaths in the Gulf of Mexico began in February 2010, months before the Deepwater Horizon accident.”
What it leaves out: The deaths of a cluster of dolphins during the months before the Deepwater Horizon exploded were likely caused by extended exposure to fresh water and unusually cold weather. (Source: NOAA)
- Gulf dolphins are now very susceptible to an old disease
The report says: “NOAA has said that brucella, a bacterium that can infect animals, is “a common thread” in a number of the animals examined. Nearly one-third of the dolphins tested as of Nov. 25, 2014 were positive for brucella.”
What it leaves out: In 2011, Teri Rowles, the coordinator of NOAA’s National Marine Mammal Health and Stranding Response Program said, “Severe environmental stress, including from exposure to oil, could have reduced the animals’ ability to fight infection.”(Source: NOAA)
And in 2013, NOAA released a study showing that dolphins in heavily-oiled Barataria Bay had adrenal gland problems consistent with oil exposure that would in fact harm their ability to fight infections.(Source: Environmental Science & Technology)
- For the Kemp's ridley, anything less than an increase is a decrease
The report says: “For Kemp’s ridley sea turtles, nesting numbers the two years after the accident were above historical averages.”
What it leaves out: Up until 2009, Kemp’s ridley nests were increasing exponentially (15-19%) every year. In 2011 and 2012, the number of Kemp’s ridley nests—while essentially the same as the
numbers seen in 2009—were still below expectations. Even more troubling are the significant decreases in nests seen in 2010, 2013, and 2014. (Source: Gulf States Marine Fisheries Commission)
- Sperm whales in the Gulf have high levels of toxic metals
The report says: “While data analysis is ongoing, BP has not seen any evidence indicating that oil or dispersant compounds from the Deepwater Horizon accident have impacted the health of whales in the Gulf.”
What it leaves out: Researchers have found higher levels of DNA-damaging metals such as chromium and nickel in sperm whales in the Gulf of Mexico compared to sperm whales elsewhere in the world. (Source: Environmental Science & Technology)
And a recent study found that the two dispersants used in the Deepwater Horizon spill—Corexit 9500 and 9527—were both found to be damaging to sperm whale cells and DNA. (Source: Aquatic Toxicology)
- Oil exposure damages fish development – in many species
The report says: “A study by university and government researchers examined the overlap between spawning habitat and oiled waters and concluded that the spawning area for bluefin tuna extended much farther west than previously known and that “the proportion of spawning habitat impacted by oil was generally predicted to be small (<10%).”
What it leaves out: Estimates vary on how many larval bluefin tuna may have been exposed. One NOAA study estimated that the figure could be as high as 20 percent. (Source: NOAA)
And a recent comprehensive laboratory study found that a chemical in Deepwater Horizon oil can cause irregular heartbeats in bluefin and yellowfin tuna that can lead to heart attacks, or even death. The resulting heartbeat changes significantly altered the development of other organs. The researchers suggest that many other vertebrate species in the Gulf could have been similarly affected. (Source: Science)
- Right after the spill, red snapper and other fish had unusual lesions
The report says: “Researchers from the University of South Alabama and Dauphin Island Sea Lab in Alabama took samples of reef fish from the Alabama and western Florida Panhandle coasts from January 2010 to June 2011. They found no significant evidence of diseased fish in those populations.”
What it leaves out: In the aftermath of the spill, a number of fish caught in the Gulf between eastern Louisiana and western Florida had unusual lesions or rotting fins. Lesions were most common in bottom-dwelling species, including red snapper, and were particularly common north of the wellhead. (Source: Transactions of the American Fisheries Society)
- An unusual lack of young red snapper
The report says: “In an Auburn University study published in 2014, researchers found no evidence that the spill affected young red snapper populations on reefs off the Alabama coast.”
What it leaves out: Both 2010 and 2011 had the lowest numbers of juvenile red snapper seen in the eastern Gulf fishery since 1994. (Source: NOAA SEDAR)
- Seaside sparrows on oiled sites less likely to fledge
The report says: “Data from studies that BP conducted independently indicate that in 2011, the spill did not adversely impact bird productivity – how successful birds are at producing offspring. Brown pelicans, laughing gulls, great egrets, black skimmers, bald eagles and ospreys were studied.
What it leaves out: Preliminary data from 2012 and 2013 indicate that seaside sparrows from nests on unoiled sites were significantly more likely to fledge than those on oiled sites.. (Source: BioScience)
- Oil is still washing up on beaches
The report says: “Since some of the heavily oiled areas were last surveyed a year or two earlier, NRDA teams resurveyed the areas in 2014 and determined that a total of just one mile remained heavily oiled.”
What it leaves out: Recent studies of beach shoreline in Alabama suggest that tar balls are likely to continue washing up for years to come on Gulf Coast beaches, and could pose a risk to organisms living on or near those beaches. (Source: Science of the Total Environment)
- Oil remains in Louisiana's coastal marshes
The report says: “A 2012 University of Florida study that measured the rate of marsh erosion in a limited geographic area in Louisiana showed that erosion rates returned to normal 18 months after the spill and that its impact was generally limited to the edge of the marshes.”
What it leaves out: In May 2013, three years after the spill, more than 80 miles of marsh shoreline in Louisiana remained visibly oiled. The long-term effects of the oiling of Gulf marshes are still unclear and may take decades to unfold. (Source: International Oil Spill Conference)
By Matthew Phillips, National Wildlife Federation
During and after the 2010 BP oil spill, clean-up crews relied heavily on chemical dispersants to break up oil slicks in the Gulf of Mexico. In total, crews used more than 2 million gallons of dispersants, namely Corexit 9500 and 9527, applying them directly to the head of the leaking well and over the surface waters of the Gulf. Dispersants break down oil into small droplets that easily mix with water and, in theory, biodegrade quickly. The intention is to reduce the amount of oil in an area, dispersing it throughout the water column. While debate continues over the efficacy of dispersants in cleaning up spills, their use continues to rise, despite little data on their suspected toxicity. For this reason, scientists have begun looking into the effects of these powerful chemicals on marine wildlife.
In a recent study out of the University of Southern Maine, “Chemical dispersants used in the Gulf of Mexico oil crisis are cytotoxic and genotoxic to sperm whale skin cells,” researchers tested the effects of the chemical dispersants Corexit 9500 and Corexit 9527 to sperm whale skin cells. There is a small population, around 1600 sperm whales, residing in the Gulf. Since these whales inhabit part of the area inundated with oil after the BP spill, there is a high chance some of these whales came into contact with oil, and with the dispersants. With so few whales, the population is highly susceptible to disturbance: any chaotic or harmful event threatens its overall vitality. In addition, the most recent IUCN Red List of Threatened Species classified sperm whales as Vulnerable, meaning they are at risk of extinction. Therefore, understanding the effects of chemical dispersants on sperm whales is critical for ensuring the population’s health and stability.
To begin the process, researchers grew skin cells from samples obtained from Gulf whales before the spill. They applied varying concentrations of the two dispersants to the cultured cells, and measured the effects for one day. Since chemicals can be harmful in different ways, researchers studied the dispersants’ toxicity to the cells (called cytotoxicity) and to chromosomes (called genotoxicity). They found both dispersants to be poisonous to the cells, but only Corexit 9527 to be toxic to the cells’ genetic material.
Cytotoxicity and genotoxicity have different implications. A chemical that is cytotoxic –poisonous only at the cellular level—may cause fatal or non-fatal issues for individual organisms, such as skin lesions or respiratory complications. A chemical that is genotoxic, that disrupts the functions of genes, can leave an imprint on the next generation. It may cause problems in mating, reproduction, or calf development. A sperm whale exposed to Corexit 9527 may be unable to reproduce. If she can reproduce, she may have mal-formed or non-reproductive offspring.
Genotoxicity can have lingering detrimental effects on the population as a whole, endangering its future. While it would be valuable to know which dispersant is more toxic, researchers caution it is difficult to compare them because the effects are very different. Corexit 9500 was slightly more cytotoxic, but Corexit 9527 was significantly more genotoxic. Ultimately, the choice of which to use may depend on which outcome is more, or perhaps less, desirable.
There is no way to determine how many whales were exposed to dispersants, nor the degree of exposure. But a 2014 study citing widespread health problems among Gulf marine mammals, including complications in fetus development, gives cause for concern. The population’s size, the toxicity of chemical dispersants, and reports of toxin-related health problems make clear that Gulf sperm whales are at risk. Researchers will continue monitoring the health of the population, and only time will illuminate the full effects. Until we know more, we’re left wondering: if dispersants harm wildlife, how useful are they?No Comments