Oil industry & the ENVIRONMENT

map of platforms in the Gulf of Mexico

Map of the oil and gas platforms in the Gulf of Mexico in 2006. Source: Office of Ocean Exploration and Research, National Oceanic and Atmospheric Administration

Platforms boost ecosystems

There are nearly 4,000 oil and gas platforms in the Gulf of Mexico. Most of the Gulf has a flat, sandy or muddy bottom. This leaves little to no hard surface for organisms such as coral and sponges to attach. Once in place, oil platforms are colonized by corals, sponges, fish and many organisms, thereby creating a new marine ecosystem.

But what is an oil platform?

Offshore oil platforms, also called offshore oil rigs, are used to discover and extract oil and/or natural gas from underwater sources. After processing, the materials are piped or shipped to shore. Not only do these platforms house machinery needed for drilling, but they serve as home for the men and women who work there as well. Pictured below are the many different types of platforms.

types of offshore platforms

Types of platforms from left to right: 1 and 2) conventional fixed platforms; 3) compliant tower; 4 and 5) vertically moored tension leg and mini-tension leg platform; 6) Spar; 7 and 8) Semi-submersibles; 9) Floating production, storage, and offloading facility; 10) sub-sea completion and tie-back to host facility.
Source: Office of Ocean Exploration and Research, National Oceanic and Atmospheric Administration

quizWhere are offshore oil platforms located in the U.S.? Can you explain why these locations have so many platforms?

What's in a platform ecosystem?


In a study commissioned by the Minerals Management Service, fish biomassthe total mass of organic matter in fish (in a particular habitat) and fish densitynumber of fish per unit area or volume was higher around oil platforms than natural or artificial reefs. The fish population around a standing platform is 10-1000 times greater than the same habitat (sandy bottom) without a platform. Important sport and commercial species such as amberjack, barracuda, red snapper, pompano, tarpon, and cobia frequent oil platforms.

sea turtle nesting in sand

Nesting sea turtle. Source: Padre Island National Seashore, U.S. National Park Service

Sea Turtles

Scientists have found that sea turtles are associated with platforms in some regions of the Gulf of Mexico. Five species of sea turtles are found in the Gulf: 1) green, 2) hawksbill, 3) Kemp’s ridley, 4) leatherback, and 5) loggerhead turtles. All five turtle species are protected by the Endangered Species Act.

dolphins swimming

Source: Southwest Fisheries Science Center, National Oceanic and Atmospheric Administration


CetaceansAquatic mammals with very little hair, but are insulated from the cooler waters in which they live by a thick layer of blubber., such as dolphins and whales, are also found around platforms. The bottlenose and Atlantic spotted dolphins are most often sighted, probably due to their preference for relatively shallow water. Other cetaceans may be spotted more frequently now that technology allows for drilling in deeper areas of the Gulf. Since most cetaceans eat fish, large number of fish in the area.

yellow warbler

Yellow warbler. Source: Wikipedia, Credit: Paruline Jaune

Bird & Butterflies

Many species of migratory birds have developed migratory pathways across the great expanse of the Gulf of Mexico. In fact, nearly a billion birds travel to their wintering grounds in Mexico, Central and South America every fall, and return to North America in spring. Birds have found oil platforms to be wonderful resting areas on their long and tiring migrations. Hear the sounds of a yellow warbler at Bird Jam.


The Rigs-to-Reefs (RTR) program was developed after the benefits of oil platforms to the environment were recognized. The program which is a partnership between oil companies and the states, converts unproductive, obsolete oil rigs into artificial reefs. The huge offshore platforms are toppled and then fall to the bottom of the ocean, where they provide several acres of living and feeding habitat for thousands of underwater species within a year’s time.

school of fish swimming

Source: Rigs-to-Reef, Gulf of Mexico Region, Minerals Management Service

Until this program and its precursors were created, federal law and regulation specified that all platforms must be completely removed within 1 year of a halt in production. It seemed unwise to remove the valuable habitat that had been created, particularly when endangered animals such as sea turtles were associated with the structures, and eventually the Rigs-to-Reefs program was started (1984).

Everyone Benefits!

Oil Companies: By the end of 1999, Louisiana had 94 of the 151 nationwide platform donations. Through the Rigs-to-Reefs program oil corporations, the partnering state, and the public all benefit. Oil corporations find it much less expensive to convert platforms to artificial reefs rather than completing removing them. They are also absolved of liability when the state takes control of the former platform.

The States: The partnering states benefit monetarily because oil corporations are required to donate, in cash, 50% of the savings they get when they convert a platform rather than remove it. This money is used for research, maintenance, administration, liability, and construction of new artificial reefs. States also benefit from increased tourism revenue.

Artificial reefs boost recreational diving and recreational and commercial fishing. Studies commissioned by the Minerals Management Service and the Environmental Protection Agency found that 70% of all offshore fishing trips in Louisiana were headed to at least one platform, and 30% of the fish caught recreationally in Louisiana and Texas were caught near a platform.

Recreation: A study commissioned by the Minerals Management Service found that 20.2% of private boats, 50.9% of party boats, and 93.6% of the divers interviewed visit oil platforms or artificial reefs made from old platforms. The study also found that 21.9% of the 4.5 million recreational fishing trips in the Gulf States (Alabama to Texas) included a trip to a platform or RTR site. This translates into $172.9 million dollars in trip-related costs. An additional $640 million is spent on equipment for these trips, resulting in a huge economic boost. Local newspapers and fishing maps frequently list or show locations of platforms and artificial reefs created from platforms due to their popularity with fishermen.

Everyone benefits from the additional habitat created. The platforms allow more species and more individuals of each species to inhabit the Gulf of Mexico. Number and abundance of individual species is important for the stability of the Gulf of Mexico ecosystems. In addition, observations of Florida artificial reefs indicate that those made of old platforms are extremely resistant to hurricane damage. The same cannot be said for other materials used in the construction of artificial reefs.

Oil spills & the environment

In previous discussions, we have explored how the oil industry benefits our economy and environment. There are times, however, when the oil industry can negatively impact the environment and economy: when there are oil spills. In the spring and summer of 2010, the Gulf Coast of the United States experienced one of the worst oil spills in history. You can track the Deepwater Horizon Oil Spill by visiting the New York Times website which tracks the source of the spill, how it spread over time, and the landfall locations.

Oil Spills Damage Ecosystems

The most dramatic and immediate effects of oil spills include fish kills, oil covered birds, oily beaches and contaminated water supplies. But the long-term effects can be even more devastating, as toxic materials persist in waterways and on land for many years and eventually find their way into the food chain. Once in the food chain, wildlife and plants may be affected for years to come.

What Is a Food Chain?

At the base of the marine food chain is phytoplanktonmicroscopic plant-like organisms that float in the water. They live near the surface of the water and get their nutrients from sunlight, water and carbon dioxide.

Through photosynthesis6CO2 + 6H2O --> C6H12O6 + 6O2, phytoplankton, transform these nutrients into sugars and oxygen, which the rest of the food chain needs. In addition, phytoplankton is food for microscopic animal-like creatures called zooplankton and many insects and fish which are higher on the food chain. Humans and birds then eat the fish. As outlined in the diagram, frogs and salamanders eat insects and then snakes may eat the frogs and salamanders. It is easy to see that it all starts with phytoplankton and other photosynthetic organisms, so if these are negatively affected by an oil spill, the entire food web (chain) will collapse.

Plants & Phytoplankton

Oil spills often kill plant and algae species in impacted areas. The oil coats the plant and is toxic to their systems. If plant and algae species are lost, the entire food chain could be affected. In Louisiana marshes, cord grass (Spartina) form the foundation of the food chain and are therefore critical to a healthy ecosystem. In addition to their importance in the food chain, marsh grasses keep the wetlands from eroding. When their root systems degrade, erosion of the wetlands accelerates.

microscopic images of phytoplankton

Source: NASA, Credit: Gene Carl Feldman

The death of phytoplankton is also a concern, as they are the base of aquatic food chains. These tiny, microscopic creatures absorb carbon dioxide, a greenhouse gasgases in the atmosphere that trap heat and warm the earth, and produce the oxygen that you and I breathe. Even if plants survive the initial spill, a decrease in reproduction and growth is frequently observed. Overall, plants and algae species seem to recover quickly after oil spills which is why most of the focus is on animals after a spill.

Oil Spills & Animals

oiled turtle

Dr. Brian Stacy, NOAA veterinarian, prepares to clean an oiled Kemp's Ridley turtle. Source: National Oceanic and Atmospheric Administration and Georgia Dept of Natural Resources

Oil spills are often mixtures of both light and heavy oil products. Light oil products such as gasoline are highly toxic to animals. They can cause burns, irritation to mucous membranes, and neurological issues. These highly flammable products are very dangerous and potentially explosive, in addition to being very toxic. On the other hand, they evaporate quickly from the surface of the water so the threat of environmental damage is somewhat minimized.

“Heavier” oil products such as crude oil persist in the environment for longer periods of time. In fact, over time some types of oil gets ‘stickier’ and sticks to the animals even more. The oil reduces waterproofing and buoyancy of animals exposed to the oil. Grooming and preeningwhen a bird straightens and smoothes its feathers with its beak result in ingestion of oil which causes physiological problems. The animals most at risk for damage are those that spend much of their time on the surface of the water, like sea birds and marine mammals such as otters.

fish larvae

Fish larvae. Source: National Oceanic and Atmospheric Administration, Credit: Matt Wilson and Jay Clark

Fish & Oil

There are times when mature fish can swim away from an oil spill, suffering little to no harm. But this is not always the case. Some fish swim into oil because it looks like food floating on the surface of the water. Adult fish may suffer greatly by taking in oil through their gills, directly ingesting oil or suffocating due to the lack of oxygen. The direct exposure to crude oil causes a coagulated mucous film to cover the body and gills.

Normally, their early stages of life are at greater risk. Larvae and eggs are very susceptible to the toxins in oil which cause a range of effects from mortality to abnormal development and deformities.

Birds & Oil

Brown pelicans are the State Bird of Louisiana and were only recently, in November 2009, removed from the endangered species list. They are the only species of pelican that dive into the water for fish and are therefore at greater risk for death by oiling. Heavily oiled birds die from exposure, by ingesting the toxic crude or by drowning. A wildlife biologist described oiling like ‘swimming while wearing a raincoat’, a difficult task. It takes about four trained specialists 45 minutes to clean one bird. The cleaning process often causes great stress, which can also kill wildlife.

Birds die from exposure: Birds use their feathers as insulation to their body temperature between 39.4 and 41.1oC. When oil covers their feathers, it creates open holes and allows water against their skin. Heat loss occurs and their body temperature falls, so they come ashore to warm up, but can not find food once on shore. So birds may suffer from hypothermiawhen the core body temperature drops below that needed for the body to function normally as well as starvation.

Birds die from drowning: Oil makes feathers heavier and lessens their ability to trap air. It becomes harder for the bird to float and they are more likely to drown.

Birds die from organ damage: While trying to clean themselves of the oil, birds ingest large amounts of hydrocarbons which can cause organ damage.

Impact of the Deepwater Horizon Oil Spill

By late July 2010, over 4500 sea turtles, dolphins, birds and fish had been found dead or injured in the Gulf or on coastal beaches and marshes near the Gulf of Mexico. This map, prepared by researchers at Louisiana State University, shows the source of the oil spill and the location of dead and injured sea turtles and dolphins. The exact causes of death were not always clearly determined.

map of dead or injured turtles and mammals

Map of dead or injured turtles and mammals. Source: Louisiana State University

coral reef


shipwreck captured on camera

Source: Deepwater Shipwrecks, Gulf of Mexico Region, U.S. Dept of the Interior

To ensure that the oil industry preserves sites of historical interest, like old shipwrecks, the National Historic Preservation Act of 1966 laid out rules for locating new rigs in the Gulf of Mexico. Learn more about this process.

the beginning

Rigs-to-Reefs started in 1984 under the National Fishing Enhancement Act. Learn more about these artificial reefs from an ichthyologist named Milton Love.

underwater pipes form an artificial reef

Source: Rigs-to-Reefs, Texas Parks and Wildlife

You can also find detailed reports of these converted platforms from the U.S. Minerals Management Service.

map it

Because artifical reefs created from old oil platforms are wonderful fishing sites, several states provide maps and GPS coordinates for locating specific reefs.

Over 245 platforms have been converted to artificial reefs. Check out the coordinates for Louisiana sites.

map of artificial reefs in Louisiana

Map of artificial reefs in Louisiana. Source: Louisiana Dept of Wildlife & Fisheries

festival time

Each year on labor day weekend, Morgan City hosts the Shrimp & Petroleum Festival. The festival started 70 years ago when the first boatload of jumbo shrimp came in from the deepest waters ever fished by a small boat.

In 1967, the festival was renamed Shrimp & Petroleum to recognize the interconnection of the two industries that sustain Morgan City, where the festival is held.

It is the oldest harvest festival in Louisiana, and it includes a blessing of the fleet along with parades and tons of food. Visit the festival website for more information.

oil & impact

The Office of Protected Resources, part of NOAA Fisheries, is keeping a record of the number of turtles, mammals, and birds found oiled from the Deepwater Horizon oil spill. For current numbers, visit their website.

chart showing number of oiled animals

Chart of oiled and stranded animals and fish. Source: National Oceanic and Atmospheric Administration

new bacteria

Wondering what happened to all the oil from the Deepwater Horizon spill, scientists studied not only the location of the oil but also the content of the water itself. What they found was shocking. They found a new type of bacteria that eats oil without taking up a lot of oxygen to do so.

This finding was key because it means the bacteria will reduce the amount of oil in the water while leaving a normal amount of oxygen in the water for fish and animals to use.

New microscopic bacteria found. Source: PBS

In the past, bacteria might eat some of the oil, but they would also use up a lot of oxygen, meaning fewer fish and underwater animals could survive. These areas lacking oxygen became "dead zones."

Learn more about the new bacteria by visiting the PBS blog or reading the full article in the journal of Science.

underwater plumes

The Deepwater Horizon incident changed the way scientists viewed oil spills. They knew millions of gallons of oil were present in the ocean, but they couldn't locate a lot of the oil. It was almost as if the oil had disappeared.

What they realized is that most of the oil never surfaced given the depth of the well leak. Most of the oil remained in large underwater plumes. This discovery was first made by divers with the

Oil seen in deepwater sediment under ultraviolet light. Credit: University of South Florida

Studying the impact of such plumes will take many years and will require new methods of analyzing and locating such effects. Read a summary of these studies on the PBS Blog. Learn more detail from the journal of Science.