Gulf of Mexico Oil Spill Milestones
A Deepwater Horizon Timeline
The Deepwater Horizon oil spill in the Gulf of Mexico was the largest marine oil spill in U.S. history. With millions of gallons of oil spilled in the sea, the response effort was large and has lasted for over a decade. For over 10 years, scientists and researchers have come a long way in restoring, recovering, and researching the Gulf environment. While substantial progress has already been made, there’s still a lot to learn about the lasting impacts of oil spills.
Flushing oil away with freshwater
In an attempt to keep oil from coming into shore, Mississippi releases a levee to flush the area with freshwater. This freshwater influx is later linked to the loss of 8.3 million oysters along the Gulf shores of Louisiana.
Taking immediate action
In the days and weeks following the start of the spill, government agencies and scientists begin taking steps to mitigate the spread and impact of the oil. These steps include creating physical barriers with floating booms, using skimmers to remove oil from the water’s surface and the use of dispersants on and below the surface of the water.
BP makes their pledge
BP commits $500 million towards researching the effects of the oil spill on environmental and human health. With this funding, an independent research organization called the Gulf of Mexico Research Initiative (GoMRI) is formed. GoMRI funding is split among research groups, also known as consortia, that tackle overarching topics or research questions.
Tiny critters reveal an ecosystem imbalance
Researchers studying tiny, hard-shelled, single-celled organisms known as foraminifera find that they’re on the decline following the oil spill. Also known as forams, these critters are an indicator species, meaning their community changes can signal an ecosystem imbalance.
Researchers report ecosystems are rebounding
Just two years later, researchers are pleasantly surprised with how quickly ecosystems are recovering. Less oil sticks around than scientists predicted, in part because of oil-eating microbes from the Gulf’s seafloor. Scientists also note marsh grasses are rebounding well.
Tracing the source of an oil sheen
An oil sheen appears near the site of the Deepwater Horizon disaster. Researchers studying the oil’s chemical makeup find this sheen is the result of oil from the 2010 spill, not from an active leak in the wellhead.
Drifters help to gather data
Researchers associated with GoMRI’s Consortium for Advanced Research on Transport of Hydrocarbon in the Environment, or CARTHE, deploy drifters to gather locational data. Collecting this data allows for researchers to accurately model surface and below-surface currents to predict how oil disperses once it’s spilled, helping to aid in future response efforts.
Impacts on sparrow reproductive success
Scientists find that sparrow populations in Gulf marshlands are experiencing changes in their reproductive success. Sparrows nesting on previously oiled marsh areas are successful in raising only five percent of their chicks to fledging.
Understanding impacts on Gulf marsh grasses
Scientists studying the impact of the oil spill on marsh grasses along the Gulf waterline find that grasses growing in the outer marsh protect the inner marsh, leaving them largely untouched by oil. However, these oiled outer marsh areas erode twice as fast as non-oiled areas.
Dolphin strandings are on the decline
Dolphin strandings in the Gulf region began to rise after the 2010 spill. Over the next four years, researchers discovered over a thousand dolphins stranded and distressed along the Gulf Shore. This four-year period is recognized as the largest dolphin die-off in the Northern Gulf, but beginning in 2014 the number of stranded dolphins begins to steadily decline.
Scientists estimate seabird losses
Scientists collecting data about the impact of the oil spill on seabirds determine that a total of 93 different species of birds were affected. They estimate that 800,000 coastal birds and 200,000 offshore birds died as a result.
Identifying dispersant alternatives
Researchers identify food-grade materials as an effective alternative for dispersants. These food materials include lecithin found in soybeans and Tween 80 found in ice cream.
Understanding the effects on fish
Researchers look at the effects of the oil spill on fish, finding that certain fish species have adverse heart effects after exposure to even low levels of oil. They find that the heart of Mahi Mahi stops working efficiently as soon as 24 hours after exposure. Researchers also find that juvenile fish experience heart problems and behavioral defects when exposed to crude oil.
Restoration Begins on the Gulf of Mexico Seafloor
Almost 10 years following the spill, some restoration efforts are just getting underway. Four restoration projects aimed at restoring deep sponge and coral habitats injured by the spill are announced. In total, $126 million in restoration funds are allotted to these projects to help restore marine resources in the Gulf of Mexico.
Scientists develop a fish vulnerability index
Researchers create a framework to assess different species' responses to their environment, helping to identify which fish will be most vulnerable after a spill. This will allow researchers to respond to the most at-risk species in the event of future spills.
Midwater species likely harmed by oil spill
A study indicates dramatic losses in midwater sea life, likely due to the oil spill. Compared to 2011, the shrimp population numbers during the 2015/2016 season decreased by about half, squid populations decreased two-thirds, and fishes were down about 75 percent. But the biggest decline came from two of the most important food sources for large marine animals. The “anchovies of the open sea,” a group called lanternfishes, decreased over 80 percent, and krill, the favorite food of large whales, decreased by over 90 percent.
Smithsonian Scientists Aid in Restoration
Smithsonian National Museum of Natural History joins forces with NOAA and the Department of the Interior to help restore deep sponge and coral communities injured by the spill. Invertebrate zoology curators and scientists help provide taxonomic and genomic expertise to better understand these communities before and after the spill and to inform restoration activities.
May 2023
About 200 fragments of octocorals were transplanted from larger colonies to the seafloor 230 feet (70 meters) below the surface to test what types of restoration techniques will be the most successful at replacing the corals that were lost due to injury from the spill. After two months in their new location, over 95% of the transplanted corals were still healthy and surviving in their new home.