Meanwhile, offshore drilling is only going deeper and getting more dangerous. The Deepwater Horizon reached a depth of 1, meters. Now, studies show that more than half of the oil produced in the Gulf is coming from wells even deeper than that. All of this despite a study , which found that for every feet or Such accidents have been on an upswing under the Trump administration. There were also nearly 50 fatalities over that time.
Lingering oil slick in the Mississippi Delta off the coast of Louisiana on May 24, Leaks are a constant state of affairs. One oil well off the southeastern coast of Louisiana, owned by Taylor Energy, has been leaking since , spilling between and barrels per day. That a new spill will one day meet gulf shores has become and article of faith. Unfortunately, efforts to control a new slick will likely look much as they did after the Deepwater Horizon, with armadas of local fishermen once again mustered onto the front lines and toiling in a haze of chemicals.
As the oil eventually receded, many who fought to clean it up became seriously ill. Many of them have died of respiratory complications, including cancer. In the days following the blowout, some 47, people, mostly newly jobless fisherman, were contracted by BP to pilot their boats into the slick pulling skimmers. Others worked in Mississippi, Alabama and Florida to siphon oil off the beaches.
Almost immediately, thousands of them broke out in rashes. They began to cough up blood and developed wheezes. Some were plagued with migraines. Many complained of burning eyes and memory loss.
Still others were struggled with new heart aliments, kidney problems, liver damage, and discharge from their ears. Some experienced cognitive decline and anxiety attacks. What all of them had in common is their exposure to Corexit, an oil dispersant that contains an array of toxic chemicals, but which BP assured the workers was as safe to use as dishwashing liquid.
From the first days of the spill through the eventual capping of the well that following July, BP oversaw the dumping of 7 million liters of the dispersant from airplanes flown over the Gulf. Ten years later, controversy still rages about the wisdom of carpet-bombing the Gulf with these chemicals, and documents released since reveal that government scientists expressed concern at the time about the health consequences of mixing such large quantities of dispersants with the millions of barrels of sweet crude.
Oil and dispersants are a toxic stew. When the two are combined, they unleash heavy metals and hydrocarbons like benzene, hexane, and toluene, which are known carcinogens. Dispersants like Corexit contain solvents meant to break oil down into tiny droplets that sink. But when ocean water evaporates, so do these chemicals. When they are carried inland by the wind, they can sicken those who inhale them. In their interviews, many of these patients who worked on spill cleanup said they were discouraged by BP contractors from using protective gear, even though, as study later showed , Corexit, when mixed with oil is 52 times more toxic than oil alone.
Those who complained were met with efforts to silence them. This was the largest oil spill ever reported in U. In comparison, the Exxon Valdez tanker spilled approximately , barrels 11 million gallons of crude oil into Prince William Sound, Alaska, in Oil spill response efforts at the national and state level were led by a Unified Command established by the U. The Unified Command structure was developed to ensure efficient and coordinated containment, dispersal, and removal of oil and hazardous substances while minimizing damage to the human and marine environment.
Under the direction of the Unified Command, responders used both traditional and novel approaches to contain and recover the spilled oil. In the end, recovery efforts brought the final estimate of oil spilled down to 3. Responding to stranded or debilitated marine wildlife, especially to those that may have been exposed to oil, was a high priority during the days and months immediately following the Deepwater Horizon oil spill.
The Unified Command Wildlife Branch relied heavily on the existing stranding network in the Gulf to respond to stranded, distressed, and injured marine mammals, as those organizations already were federally authorized to conduct marine mammal response activities under the Marine Mammal Protection Act. Aerial surveys to assess the extent of oil contamination also provided a platform for opportunistic sightings of injured and dead marine mammals.
It characterized research efforts, highlighted the overall need to improve assessment and monitoring of marine mammals in the Gulf, and outlined priorities for future research and restoration efforts, stressing the importance of long-term monitoring studies of both individual marine mammals and marine mammal populations. In April , the Commission and several federal agency, academic, and non-governmental organization partners convened the Gulf of Mexico Marine Mammal Research and Monitoring meeting in New Orleans.
The objectives of the meeting were to:. View the meeting summary and copies of presentations. In January , Commission staff facilitated a virtual workshop focused on enhancing conservation of bottlenose dolphins in Mississippi state waters.
Bottlenose dolphins in Mississippi and throughout the Northern Gulf were significantly impacted by the Deepwater Horizon oil spill, and tracking recovery will require long-term monitoring and an ability to identify and minimize ongoing threats. Workshop participants from the National Marine Fisheries Service NMFS , Mississippi-based marine mammal research and stranding network facilities, and Mississippi state agencies discussed current capabilities and research activities within the state and current knowledge regarding the status, stock structure, and major threats to bottlenose dolphins in Mississippi state waters.
Discussions focused on critical uncertainties and opportunities for enhancing collaborations and expanding partnerships within the state and beyond to advance conservation efforts. The Commission continues to work with scientists and managers across the Gulf to refine and promote recovery and restoration strategies for marine mammals. We have outlined our priorities for restoration and long-term monitoring, as well as concerns regarding potential impacts of some large-scale restoration projects on marine mammals, in letters see letters section below to the Deepwater Horizon Natural Resource Damage Assessment NRDA Trustees and the Gulf Coast Ecosystem Restoration Council.
We have also submitted restoration project ideas to the Trustee Implementation Groups through the various federal and state portals, and commented on draft restoration plans. The development and refinement of scientifically robust mitigation and monitoring measures to minimize impacts of offshore oil and gas and renewable energy activities on marine mammals, including impacts from oil spills, was identified as a Strategic Objective in our Strategic Plan.
NOAA regulations implementing the Oil Pollution Act specify three phases for conducting damage assessments: 1 pre-assessment, 2 injury assessment and restoration planning, and 3 restoration implementation for more information, see the diagram of phases involved in a Natural Resource Damage Assessment under the Oil Pollution Act of That determination initiated the next phase of the process: injury assessment and restoration planning.
Movements and numbers of sperm whales were tracked after the spill using satellite tags and passive acoustic monitoring. Photo taken under NOAA permit Injury assessments conducted under NRDA involved quantifying the impact on either a specific type of resource e. Marine mammal injury assessment studies were conducted from to and included:.
Assessing oil spill-related impacts to marine mammals was complicated by the occurrence of a cetacean unusual mortality event in the northern Gulf that began before the spill occurred, in March An analysis of bottlenose dolphin stranding patterns before and after the spill indicated that strandings from March to May were likely associated with exposure to cold and freshwater in and around Lake Pontchartrain, Louisiana.
However, the majority of increased marine mammal strandings in the northern Gulf from to overlapped in space and time with the oil spill footprint. In addition, NRDA-related studies documented a myriad of adverse health issues in stranded and live-captured dolphins found within the affected area, such as persistent reproductive failure, adrenal disease, lung disease, and poor body condition.
Many of those studies were compiled and published in a Special Issue of Endangered Species Research: Effects of the Deepwater Horizon oil spill on protected marine species Volume 33, A comprehensive bibliography of both NRDA and independent Deepwater Horizon oil spill-related marine mammal research and monitoring can be found here.
Related: Gallery: Exploring the Gulf of Mexico. Problems began during drilling. BP had to stop drilling into the seabed about 2, feet m higher than expected because the pressure was too high. Next, they had to line the hole with a casing — a concrete pipe that prevents the hole from caving in.
A shorter casing would be easier to cement into place and was deemed safer by computer models, but the company ultimately decided to use a longer casing, which would be less prone to leaks.
In order to hold the casing in place, concrete would be pumped into the space between the casing and the surrounding Earth. For this to work, the concrete must surround the casing evenly, otherwise it could be unstable and vulnerable to oil leaking in from the sides.
To ensure an even, snug fit, engineers fit the casing with centralizers, which are metal tubes with strips of metal sticking out on each side. Computer models recommended that the casing be fit with 21 centralizers, but BP engineers chose to insert only six centralizers because of a supply shortage.
This increased the risk that the cement would surround the casing unevenly. With the casing and centralizers in place, it was time to pour the concrete. BP engineers made several choices during this step that further increased the risk of error. First, they cut pre-cementing tests short, which prevented technicians from checking for leaked oil at the bottom of the well; they pumped the cement slower than recommended, further increasing the risk that the cement would not fill the space around the casing evenly; and they limited the amount of cement used, which can cut the risk of lost oil but increases the risk of contamination by leaving more casing exposed.
In the months leading up to the disaster, Halliburton had conducted several tests showing that the type of cement used wasn't stable, meaning that it might form pores that allow liquids and gasses to pass through it.
Halliburton shared some of these test results with BP, but the company decided to proceed. The crew, made of Transocean and Haliburton employees, finished cementing just after midnight on April At that point, BP and Halliburton representatives checked a valve to be sure that the pressure from the cement was not pushing too much liquid up out of it.
After a couple of hours, the BP and Halliburton representatives emailed members of their respective teams to confirm that the cementing job had been a success. The operation went awry during the final step, when the crew planned to follow a set of precarious procedures to detach Deepwater Horizon from the well to make room for a smaller rig, the report describes. During the process, crew members conducted positive and negative pressure tests to ensure no gas had leaked into the well.
The negative pressure test should have alerted them that there was a leak, but they misinterpreted the results. At p. But that was a mistake — gaseous hydrocarbons had leaked into the well. When gaseous hydrocarbons enter a well, they expand to fill up the space, shooting up the pipe in what is called a "kick," and this is what happened at Deepwater Horizon.
The crew closed the blowout preventer — a seal that is designed to stop the expanding molecules from climbing up the well to the rig — but it was too late. The molecules climbed with increasing speed up the pipe until, at around p. A few minutes later, the gaseous hydrocarbons enveloped large areas of the rig and met at least one ignition source could have been heat or sparks from on-board equipment , which then erupted in an explosion that could be seen from miles away.
Eleven workers went missing during the explosion and were presumed dead three days later. The entire Deepwater Horizon rig capsized 36 hours after the explosion, on the morning of April 22, which is coincidentally Earth Day, a globally recognized day promoting environmental protection.
As the rig sank, it damaged the pipe leading down to the well. Oil began spilling from the well and did not stop for 87 days. The Deepwater Horizon spill is considered the largest marine oil spill in history, according to the U.
Environmental Protection Agency. Court proceedings following the spill estimated that 3.
0コメント