Archive for Wildlife
By Ryan Fikes, Staff Scientist, National Wildlife Federation, Gulf Restoration Campaign
It’s been more than five years since the Deepwater Horizon oil rig exploded. Since that time, a council of federal and state Trustees have been extensively investigating the impacts of the disaster on wildlife and habitats, but that information has been kept under wraps—for use in litigation against BP. Now that the case has settled, this research has finally been made public in a draft Programmatic Damage Assessment and Restoration Plan.
The impacts to wildlife and their habitats are shocking and far reaching. Despite clean-up efforts and the natural weathering processes over the five years since the spill, oil persists in some habitats where it continues to expose resources in the northern Gulf of Mexico. In many cases, the damage to wildlife and habitats was more severe than previously understood. The ecological linkages of these habitats and communities and their connectivity to the larger Gulf of Mexico ecosystem can result in cascading impacts, influencing the overall health and productivity of the Gulf of Mexico ecosystem.
Together, the National Wildlife Federation and Ocean Conservancy scientists have worked to dig in to the massive report and digest its findings. Here is a snapshot of the types and severity of impacts outlined in the draft report.
While the Trustees acknowledge that this is a very conservative estimate, the total number of birds killed by the BP oil disaster is from 56,100 to 102,400 birds. At least 93 species of birds across all five Gulf Coast states were exposed to oil.
2. Beach & Dune Habitat
BP oil covered at least 1,300 miles of the Gulf coastline, including 600 miles of beach, dune and barrier island habitat.
3. Lost Human Use
The public lost 16,857,116 days of boating, fishing and beach-going experiences. The total loss of recreational use of the Gulf due to the disaster is worth $528 million to $859 million.
Between 4 and 8.3 billion oysters are estimated to have been lost. Over three generations (minimum recovery time), the dead oysters would have produced a total of 240 to 508 million pounds of fresh oyster meat.
5. Salt Marsh
Louisiana lost up to 53 percent of its salt marsh plants across 350-721 miles of shoreline. In Louisiana wetlands, erosion rates approximately doubled along at least 108 miles of shoreline. The effect lasted for at least 3 years.
Sargassum, a floating seaweed that provides habitat for young fish and sea turtles, was exposed to oil, which may have caused the loss of up to 23 percent of this important habitat.
7. Seagrass Habitat
Seagrass beds covering a total area roughly the size of 206 football fields (272 acres) were lost from the time of the disaster through 2012.
8. Larval Fish
The Trustees estimated that 2-5 trillion larval fish were killed. The loss of larval fish likely translated into millions to billions of fish that would have reached a year old had they not been killed by the BP oil disaster.
9. Sea Trout
Several of species of sea trout, including the spotted (or speckled) sea trout, were severely impacted by the disaster. An estimated 20-100 billion sea trout larvae were killed as a result of the disaster.
The growth of young white, pink and brown shrimp was dramatically affected by oil. The total loss of shrimp production over 2010 and 2011 due to oiling is estimated at more than 2,300 tons.
11. Red Drum
The growth of young red drum fell by up to 47 percent along marsh shorelines in Louisiana that were persistently oiled since 2010, and an estimated 700 tons of red drum were lost. Reduced red drum production persisted through 2013 and is expected to continue.
While nearly all of the species of whales in the footprint of the oil have demonstrable, quantifiable injuries, the most hard-hit was the Bryde’s whale. With only about 50 Bryde’s whales left in the Gulf, roughly half of these animals were exposed to oil—and nearly a quarter were killed. It is unclear if Bryde’s whales will be able to recover.
13. Bottlenose Dolphins
The number of bottlenose dolphins in Barataria Bay and Mississippi Sound—two areas particularly affected by the disaster—is projected to decline by half. The populations are expected to take 40-50 years to recover. In the 5 years after the oil disaster, more than 75 percent of pregnant dolphins observed within the oil footprint failed to give birth to a viable calf.
14. Coral Reefs
The footprint of injury to mid-depth coral reefs is just over 4 square miles. These areas along the continental shelf edge, known as the Pinnacles, showed extensive damage to both the coral colonies and the reef fish associated with them. The larger ecological functions of this habitat were very likely impaired.
15. Sea Turtles
All five of the Gulf’s sea turtles are either threatened or endangered. It is estimated that somewhere between 61,000 and 173,000 sea turtles—of all ages—were killed during the disaster. For the endangered Kemp’s ridley sea turtle, this equals 10-20 percent of the average number of nesting females each year, which would have laid approximately 65,000 – 95,000 additional hatchlings.
16. Deep Seafloor
The footprint of BP oil on the Gulf seafloor around the wellhead is an area more than 20 times the size of Manhattan (over 770 square miles). An additional 3,300 square miles may have been affected.No Comments
By Shannon Hood, Environmental Defense Fund
Today is National Oyster Day, and we’re celebrating the holiday with a post about these useful and tasty bivalves and the University of Maryland Center for Environmental Science’s (UMCES) Horn Point Laboratory, which is growing them by the billions.
Previous posts have discussed the ecological and economic importance of oysters, so we won’t spend time on this today. In preparation for a series of other posts on the (r)evolutionary oyster industry, this post will explain their life history and introduce some of the research being conducted to ensure their continued success.
Oysters grow in large colonies that make up reefs. Mature oysters begin to spawn when the water temperature reaches 74-86 degrees Fahrenheit. When the first male or female spawns, others sense it as they filter the water, thus triggering more to spawn.
The sperm and eggs join in the water column. The newly formed larvae will swim and feed for approximately two weeks until they reach what’s known as the pediveliger stage and are ready to attach to a substrate, a process known as “setting.” When an oyster sets, it secretes a glue-like substance and will not move from this location for the duration of its life. At this point, the oyster is known as a spat.
In the lab, this process is much the same as in the wild, however, it takes place in a controlled environment. In this environment, staff are able to control variables such as temperature, salinity and food availability – variables which have tremendous effects on oyster spawning and survival rates.
Aside from their work in growing oysters, the UMCES Horn Point Hatchery is a hotspot for research on all things oyster, including numerous graduate student researchers looking into how salinity affects setting and growth throughout oysters’ lives. Having a good understanding of optimal salinities and answering these questions, we remove yet another unknown in this industry, allowing greater understanding for how to ensure oysters are able to thrive now and into the future.
Oyster populations and harvests are on the rise in the Chesapeake Bay for the first time in decades. In 2004, just 26,000 bushels were harvested from Maryland’s waters. In 2014, Chesapeake Bay harvesters reported their best year in three decades, bringing in 900,000 bushels from traditional on-bottom leases.
What’s the cause of this rebounding industry? It’s no miracle cure, but rather a host of federal and state management practices, a booming aquaculture industry, successful hatcheries that provide a reliable source of larvae and new science that is allowing these bivalves to thrive once again.
What does this mean for Louisiana? Our coastal waters boast some of the best conditions for oyster growth in the nation. Using funds from the Natural Resources Damages Assessment (NRDA) Early Restoration Program, LSU Sea Grant is operating a new, state of the art hatchery on Grand Isle, a hatchery capable of producing up to one billion oyster larvae per year. This increased capacity can add significantly to the production potential of the state’s public and private oyster grounds. Additionally, off-bottom aquaculture and remote setting are looking more and more like realistic options to increase the industry’s success. Stay tuned for future posts about each of these new tools in the oyster industry’s toolbox.
By Matthew Phillips, Outreach Assistant, Mississippi River Delta Restoration Coalition, National Wildlife Federation
Last Thursday, the Mississippi River Delta Restoration Coalition team traveled south to Plaquemines Parish to tour some of Louisiana’s disappearing wetlands. Andy Buchsbaum, National Wildlife Federation’s Vice President of Conservation Action, was in town to see our work firsthand. We packed the cars and drove to Buras, La to meet Ryan Lambert, owner of Cajun Fishing Adventures. We piled into two bay boats and set off through the marshes of Fort St. Philip. He explained how this natural opening on the east side of the Mississippi River was loading sediment into the marshes, building ground for plants to grow on. He has seen how rich and diverse the vegetation has become, and how wildlife has returned in droves in the last few years.
At the end of the day the team gathered at Woodland Plantation for happy hour and an amazing meal. Everyone agreed that seeing the coast we are fighting to restore is a crucial part of our work. Our supporters in Plaquemines Parish, ground zero for Louisiana Coastal Restoration, are some of the most fervent advocates of restoration. Having passionate people explaining what the coast means to them while immersed in the environment they love was invigorating. We returned to New Orleans, Baton Rouge, and Washington, D.C., with a renewed sense of commitment to the Louisiana coast.
By Ashley Peters, Communications Associate, National Audubon Society
In May, a group of more than 30 volunteers gathered at the Grand Isle Community Center to learn about issues facing Louisiana’s beach-nesting birds and how people can help. Cute, fuzzy chicks of birds such as Least Terns and Wilson’s Plovers need our help during each spring and summer to protect them from human disturbance and other threats.
“There are many ways birds and people can share the beach, it’s just a matter of awareness,” says Erik Johnson, Audubon Louisiana’s Director of Bird Conservation. “We need help informing beach-goers about what beach-nesting birds need to successfully raise their little ones. These threatened birds need safe, open, sandy areas and we hope folks will respect the birds by keeping their distance.”
The volunteer training included information on how to identify shorebirds, how to interpret bird behavior, and ways to help beach-nesting birds succeed. The training was followed by a crawfish boil celebration to show appreciation for new and current volunteers, as well as program partners.
Least Tern and Wilson’s Plover chicks are camouflaged to avoid predation and nests are also hard to see because the birds lay their eggs in shallow depressions, or “scrapes,” in the sand. Audubon Louisiana marks sensitive beach areas with signs and symbolic fencing to prevent people from accidentally entering nesting sites. This reduces the chances of eggs and chicks being inadvertently trampled, run over, or harmed in other ways if parent birds are flushed (or chased away) from nests.
In addition to ensuring there is suitable habitat for birds through the implementation of Louisiana’s Coastal Master Plan and other initiatives, Audubon organizes the Coastal Bird Stewardship Program as well as the Coastal Bird Survey to monitor and encourage birds to successfully live and breed on beaches.
Next time you’re on the beach, remember the following:
- Keep your distance: Sensitive nesting areas are posted with signs. When an adult bird is flushed or chased away, chicks and eggs are vulnerable to predators and overheating.
- Keep pets leashed: Nesting birds are very sensitive – even good pets are perceived as predators and will disturb nesting activities.
- Take your trash with you and dispose of fishing line properly: Birds can become easily entangled in loose line, plastic bags, and other unsightly garbage.
- Please do not feed the wildlife: This will attract predators, like gulls, crows, and other animals that will eat bird eggs and chicks.
- Get involved: Volunteer stewards help teach beachgoers how to help protect these vulnerable birds. Join our mailing list to receive updates, news, and notifications about volunteer opportunities.
To learn more about how you can help birds, visit La.Audubon.org/coastalstewardship or email Louisiana@Audubon.org. To learn more about Audubon’s Coastal Stewardship Programs, watch this video: https://www.youtube.com/watch?v=D-7O2vfEIG8No Comments
In the wake of the worst marine oil spill in U.S. history, Audubon is working to protect bird populations and restore critical habitat across all five Gulf states.
By Chris Canfield, Vice President, National Audubon Society, Gulf Coast and Mississippi Flyway
This post has been cross-posted from an article originally published on the National Audubon Society’s website.
This Monday marks five years since the Deepwater Horizon rig exploded, claiming 11 lives and unleashing the worst marine oil spill in U.S. history. In that time, the National Audubon Society has built on its 100-year legacy of protecting bird populations throughout the Gulf Coast and has extended its footprint of stewardship across all five states.
The Gulf Coast is an important breeding ground and migratory rest stop for many coastal birds, including Brown Pelicans, Least Terns, Wilson’s Plovers, Sanderlings and other vulnerable species. BP oil reached the coastal habitats – on which these birds rely during shorebird migration – at the height of nesting season for breeding waterbirds, resulting in the death of an estimated 1 million birds.
In the immediate aftermath of the spill, Audubon staff and hundreds of volunteers were on the ground, facilitating transport of oiled birds for cleaning and care, protecting critical habitat and nesting grounds and being the voice for birds throughout the disaster. In the years that followed, Audubon engaged its network of volunteers to help pass the historic RESTORE Act—ensuring that a majority of funds from the Clean Water Act fines BP pays will be allocated towards restoration efforts. In order to understand the immediate and long-term effects on birds, Audubon scientists also developed the Audubon Coastal Bird Survey, a citizen-scientist effort to monitor the health of coastal populations and to provide a better accounting of these populations going forward. The program has been expanded to all five Gulf states.
Five years have come and gone since the oil spill, and as the ongoing effects continue to be felt, the National Audubon Society is focused on ramping up its important stewardship for birds at more than 200 sites across the Gulf Coast. We empower citizens and communities to protect terns and skimmers in nesting colonies, protect the access of plover chicks to their feeding grounds, and oversee critical waterbird colonies from Florida to Texas. We still await assessment of full fines to BP and others involved with the catastrophic spill, but we have been successful putting available funds to work on expanded coastal bird protections.
To all of our volunteers, supporters and friends who have been there for the Gulf and its bird populations, thank you for helping us make significant progress in confronting this terrible disaster. We have a long way to go before meaningful restoration is achieved, so please stay engaged and stay committed. In the meantime, I encourage you to share this video to inform others about the important work Audubon is doing throughout the Gulf Coast and sign this petition asking BP to stop its campaign of misinformation and pay for the damage done.No Comments
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
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.
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