When you have 3. Part of the difficulty is that no two spills are alike. The amount and type of oil whether crude or refined affects how it spreads, and a spill in seawater spreads differently than in freshwater. Local environmental conditions also play a huge role: currents, tides, weather, wind speed and direction, air temperature, water temperature, and presence of ice all affect how the oil spreads and how well cleanup workers can access the spill area.
This variability makes it difficult to plan for spills ahead of time. The most basic method of cleanup is to control the spread of the oil using physical barriers. When oil spills in water, it tends to float to the surface and spread out, forming a thin slick just a few millimeters thick. A very thin slick is called a sheen, which often looks like a rainbow and can be seen in parking lots after a rainstorm.
Cleanup workers first surround the slick with floating booms to keep it from spreading to harbors, beaches, or biologically important areas like marshes. Then they can use different tools to remove the collected oil. Often they will drive skimmers, boats that skim spilled oil from the water's surface, through the slick. Only about percent of the oil was recovered by using skimming. After as much oil as possible is removed by skimmers, workers use sorbents to mop up the trace amounts left behind.
Sorbents either absorb oil like a sponge or adsorb oil, which means that oil sticks to its surface. They come in three main types: natural organic materials like peat moss, straw, hay, and sawdust; natural inorganic materials like clay, volcanic ash, sand, or vermiculite; and synthetic sorbents made of materials similar to plastic like polyurethane, polypropylene, and polyethylene.
Which type is used will depend on the particular spill, as some types of sorbents work best on different types of oil and under different weather conditions. Another option is to burn the oil away. About 5 to 6 percent of the oil from the Deepwater Horizon oil spill was removed by controlled burning.
Removing spilled oil from the environment is a difficult task. Because oil is hydrophobic doesn't mix with water , it floats to the surface when it spills into the ocean and forms large slicks. These slicks can wreak havoc on coastal ecosystems and animals, so cleanup workers use dispersants —chemicals that break down the oil into smaller particles that mix with water more easily—to prevent them from forming.
Evaporation, sunlight, and bacteria can then degrade these tiny droplets more quickly than if they were in a large slick, or waves can wash them away from the spill site.
Dispersants are often used when workers want to stop the slick from spreading to a protected area like a harbor or marsh. But dispersants can also enter the food chain and potentially harm wildlife. In the case of the Deepwater Horizon oil spill, clean-up workers treated the oil with over 1.
Typically such large amounts are sprayed over the open ocean from an airplane or helicopter. But during the Deepwater Horizon oil spill, they were also injected straight into the Macondo wellhead, the source of the leak, in order to reduce the amount of oil that reached the ocean surface.
Five years after the spill, some scientists believe that injecting dispersants directly at the wellhead may not have done much to help reduce the size of the oil droplets. Just because the oil and dispersants are out of human sight and mind in the deep sea doesn't mean they're gone. It's possible that life in the deep sea was exposed to the dispersant-oil mixture.
Scientists have found that the dispersant-oil mixture was rapidly colonized and broken down by bacteria that sunk towards the bottom. Any bits of the mixture that didn't get broken down would then get buried in coastal and deep-sea sediments , where its breakdown slowed. While the dispersant helps expose more of the oil to bacteria and waves which help to break it down, it also makes the oil more available to wildlife. One study showed that the combination of oil and the dispersant Corexit is 3 to times more toxic to rotifers microscopic animals than oil by itself.
This isn't because of anything inherently dangerous in the mixture of the two; the rotifers are more able to ingest oil once it's made accessible by the dispersant. But overall, scientists have concluded that the amount of combined oil and dispersant determines if it is toxic or not, and the concentrations during the Deepwater Horizon oil spill were below those levels that would be more toxic to marine species than the oil alone.
Oil slicks in and of themselves are toxic to marine wildlife, and this must be taken into consideration when choosing to use dispersants.
There is still more research needed to understand the effects of dispersant. A modeling effort supported by the Gulf of Mexico Research Initiative offered evidence that the dispersants injected into the Macondo wellhead may not have helped to lessen the amount of oil reaching the surface after all.
A lot of research is still needed to fully understand the long-term effects of dispersants and oil on the region and its inhabitants—not to mention how they move through the food chain to impact larger predators, such as people.
Researchers are developing new dispersants that cause less environmental damage for the next spill. See "Human Health Impacts. There were some immediate impacts to the animals of the Gulf of Mexico that could be seen with the naked eye: pelicans black with oil, fish belly-up in brown sludge, smothered turtles washed up on beaches.
But many of the long-term effects from the spill cannot be seen with the naked eye. Many exposed animals initially weathered the spill but then were marred with health problems for years afterward. Strandings of both dolphins and sea turtles increased significantly in the years following the spill. From the time of the spill in to , over a thousand dolphins were found stranded along the shores of the Gulf. Many of the dolphins suffered from lung disease, increased stress, and a compromised immune system.
Those that did not survive became part of the largest and longest dolphin die-off in the recoded history of the Northern Gulf of Mexico.
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Subscriber Exclusive Content. Why are people so dang obsessed with Mars? Thousands were put out of work in fisheries, tourism and energy. In the end, it would prove to be 12 times bigger than the Exxon Valdez spill in , the previous record holder. The Deepwater Horizon disaster signaled the risks of drilling for oil in one of the most culturally significant, ecologically diverse places in the world.
Take, for instance, the fish — which researchers at the University of South Florida say are still contaminated with hydrocarbons. Take the size of the spill itself, which a recent study has found to be far more extensive than initially thought, reaching as far as the southernmost tip of Florida. Oil on Gulf waters after the Deepwater Horizon spill. Credit: Jonathan Henderson. Take, too, the continuing impact the spill had on human health. According to a government health study published seven years after the spill, tens of thousands of workers who first responded to the study are still wrestling with respiratory illnesses brought on by Corexit, the chemical used to disperse the spill.
And take that many of those who were affected by that chemical — mostly lower-income fisherman — are still ill, or have gone on to die. The more time that passes, the worse the spill seems to become, begging the question — could something like this happen again?
As oil drilling moves farther offshore and deeper at sea, they say, the risk only increases. Some 17 percent of the oil produced in the United States comes from the Gulf of Mexico. Over 1, platforms are connected to refineries along the shore through more than 41, kilometers of pipelines.
Leading up to the coronavirus pandemic, which has caused oil prices to plummet, Gulf production continued to be remarkably robust. In the wake of the Deepwater Horizon disaster, the US interior department restructured in a bid to allow a new division of the agency, the bureau of safety and environmental enforcement, or BSEE, to focus on safety. The move was meant to separate safety regulators from government officials who might be more motivated by the money coming in from taxes on drilling.
Crucially, the Obama administration also beefed up safety rules for the offshore oil industry, including checks on blowout preventers like the one that failed on the Deepwater Horizon. But those rules have been weakened under the Trump administration.
Checks by the BSEE have been reduced as well. According to a study by the Center for American Progress, a liberal policy institute, the number of safety inspections the agency has conducted on rigs, platforms, pipelines, and other facilities during the last three years of the Trump administration decreased by 13 percent. The same study showed that enforcement actions against offshore drillers had fallen by 38 percent. Meanwhile, offshore drilling is only going deeper and getting more dangerous.
Fish and Wildlife Service on the programmatic environmental impact statement PEIS to evaluate the environmental consequences of restoration projects and newly planned projects following the Deepwater Horizon oil spill. Letter to NMFS on recommendations and rationale to assist the Deepwater Horizon Natural Resource Damage Assessment Trustee Council in developing a restoration plan to address injuries from the oil spill, including those to marine mammals and their habitats.
The objectives of the meeting were to: Provide an overview of marine mammal stocks and human activities. Review marine mammal research and monitoring programs. Identify high priority, overarching marine mammal data needs for the next years. Discuss options for collaborations to facilitate long-term research planning, information sharing, and capacity building. Marine mammal injury assessment studies were conducted from to and included: Aerial surveys to track changes in abundance and shifts in spatial distribution relative to baseline pre-spill conditions.
Satellite and radio tracking of individual animals to assess movements, distribution, and preferred habitat. Analysis of samples from stranded animals and live-captured wild dolphins to determine potential exposure to oil or other contaminants and secondary effects of disease or contaminant exposure on health.
Passive acoustic monitoring to determine the presence and movements of vocalizing animals. Prey sampling albeit limited to assess distribution and abundance as well as potential exposure to oil or other contaminants. To date, GOMRI-funded projects that have focused on investigating the impacts of the oil spill on marine mammals include the following: Consortium for Advanced Research on Marine Mammal Health Assessment CARMMHA — a team of marine mammal health scientists conducting cross-discipline research that includes veterinary assessments of managed animals, field assessments with wild populations, and integrative statistical modeling.
Natalia Sidorovskaia, University of Louisiana, which uses expertise from marine acoustics, biology, physics, engineering, mathematics, and computational predictive modeling. Cynthia Smith, National Marine Mammal Foundation, to adapt and test cutting edge medical technologies for evaluating potential reproductive system disorders and then integrate those technologies for dolphin capture-release field studies in Barataria Bay. John Hildebrand and Dr. Kait Frasier, Scripps Institution of Oceanography.
Graham Worthy, University of Central Florida. Reducing injury and mortality of bottlenose dolphins from hook and line fishing gear. Increasing marine mammal survival through better understanding of causes of illness and death and early detection and intervention of anthropogenic and natural threats. Measuring noise to improve knowledge and reduce impacts of anthropogenic noise on marine mammals. Reducing injury, harm, and mortality to bottlenose dolphins by reducing illegal feeding and harassment activities.
Reducing injury and mortality of marine mammals from vessel collisions. Protecting and conserving marine, coastal, estuarine, and riparian habitats. To date, funding has been approved by the TIGs for the following marine mammal projects: Alabama Estuarine Bottlenose Dolphin Protection Alabama TIG — Objectives are to characterize dolphin interactions with commercial and recreational vessels, reduce lethal impacts to dolphins from feeding and fishing interactions, and enhancing state enforcement of the MMPA.
Enhancing Capacity for the Alabama Marine Mammal Stranding Network Alabama TIG — Objectives are to increased trained staff capacity, improve average reporting and response time of strandings, and collect additional data to increase understanding of marine mammal populations in Alabama.
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