It is great theater. A huge tanker is fetched up on the rocks, a spreading oil slick oozing from her hull. Or perhaps it is a flaming offshore platform spewing huge quantities of crude into the sea. Add images of cuddly creatures covered in oil, the helpless victims of the tragedy, and this becomes great fodder for the six o'clock news. Worldwide, more than 380-million gallons of petroleum are put into the sea annually by nature and mankind, yet marine operations are a relatively minor contributor.
The poster boys of tanker accidents were Torrey Canyon in 1967 (124,000 tons spilled), Amoco Cadiz m 1978 (221,000 tons), and Exxon Valdez in 1989 (36,000 tons). These incidents, the result of human error, forced creation of major international regulatory agreements for seaborne transport of petroleum. Hundreds of millions of dollars worth of damage was done, but nature, with some help from humans, eventually healed the affected ecosystems.
The long-term effect of natural restoration should not be underestimated. During World War II many tankers were torpedoed off the East and Gulf Coasts of North America. Though these ships were smaller than today's, the cumulative effect was certainly massive. Today, the residual effects of these events of the early 1940s are negligible.
Since the mid-1980s, global tanker traffic has increased by more than a third as demand for energy accelerated. Yet between the 1980s and 1990s, the number of spill incidents dropped by two-thirds. This trend continues.
Operational and technical safeguards, as well as the international regulatory frameworks now in place, have made the international shipping of petroleum relatively safe. On any given day thousands of tankers are at sea, yet their global operations are responsible for less than 22 percent of deliberate or accidental spills.
In addition to tankers, the term "marine operations" includes port and terminal activities as well as sea floor pipelines. While terminal safety has greatly improved over the past two decades, pipelines offer some interesting challenges. For example, in the Gulf of Mexico 20,000 miles of pipelines serve more than 4,000 offshore structures. Some lines are more than three decades old and require intensive condition inspections, repairs, replacement, or removal.
The other marine-based petroleum sector is offshore drilling and production. It was after World War II when the first platforms were put offshore and 1947 for those first out of sight of land. Today, there are tens of thousands worldwide, producing from depths as great as 7,000 feet.
For U.S. platforms, the big news story was the 1969 Santa Barbara Channel blowout of Union Oil's Platform A which spilled 200,000 gallons of crude. This accident was caused by improper drilling procedures that compromised the integrity of the well and set in motion a massive environmental movement that ultimately resulted in many restrictions to U.S. offshore development. Ultimately, Congress in 1981 passed an offshore drilling moratorium that prohibited operations in 85 percent of U.S. coastal waters. However, with current energy concerns, there is action in Congress to lift the ban.
Since 1969 there have been no major platform accidents in U.S. waters. Worldwide these operations account for only 5 percent of oil spilled in the sea. Safety of today's operations was most evident in 2005 after hurricanes Rita and Katrina. Damage was substantial: 111 platforms destroyed, 52 damaged, and 450 pipelines disrupted. Yet there were no major spills.
Regrettably, the general public associates such maritime events with all oil pollution in the World Ocean. The fact is that worldwide, marine operations only account for about 30 percent of it. The major anthropomorphic source is the land consumers' use of petroleum products. Accidental and deliberate dumping, aerosols, and land runoff account for 70 percent of man-made oil pollution. Land-based sources are where more technology fixes and greater regulatory enforcement are needed.
Remarkably, nature is the single worst polluter, accounting for 45 percent of all oil introduced into the World Ocean. These are natural seeps of crude oil and gas that percolate up through geologic formations beneath the seafloor. Many are thousands of years old, giving researchers an ongoing natural laboratory to study the long-term fate and effects of hydrocarbon spills.
Perhaps the best-known area is off Santa Barbara, California. Here seeps equal the infamous 1969 spill about every two years and an Exxon Valdez in six-and-a-half years. Some experts propose resumption of oil and gas production from the same formations as a means to reduce these natural flows. Reducing pressure in the reservoir would slow natural seepage. There is evidence that this remedy has worked in other seep areas.
Any accidental or deliberate dumping of oil into the sea is bad, especially along densely populated coastlines. However, next time you step on a tar ball at the beach, know that it most likely did not come from marine operations.