ships between humans and the environment; in addition, they will enable the public to inform policymakers about such relationships in the unique context of their own communities. One of the key facts central to this discussion is that communities depend on ecosystem goods and services to differing extents and in very different ways. Finally, success in developing workable models for measuring natural resource damage in terms of ecosystem services will facilitate efforts to make the public whole in the wake of future disasters.
On April 20, 2010, an explosion on the DWH platform, which was drilling the Macondo well in Mississippi Canyon Block 252 in the GoM, killed 11 oil workers and injured 17 others, resulted in the largest oil spill in U.S. history, and inevitably impacted the ecosystem services of the GoM. An estimated 4.9 million barrels (±10 percent), approximately 205.8 million gallons, of oil flowed from the wellhead following the explosion.2 For context, this amount of oil represents approximately one-third of the nation’s daily consumption of oil. The DWH oil spill was unprecedented in both its magnitude (see Figure S.1) and the ocean depth at which oil was released, and the event captured the fears and concerns of the nation during the spring and summer of 2010. Recognizing the complexity and potential impacts of the spill, members of the U.S. Congress requested a study by the National Academy of Sciences to evaluate the impacts of the DWH oil spill on natural resources and ecosystem services in the GoM. The complete statement of task is given in Chapter 1.
Ecosytems contribute to our well-being and enjoyment by, for example, supplying fish for markets, wild game to hunt in coastal marshes, and powdery white sand at which to marvel. Formally, ecosystem services are defined as “the benefits provided by ecosystems to humans that contribute to making human life both possible and worth living.” These services are the result of functioning ecosystems—the interactions of plants, animals, and microbes with the environment—and can be classified into four categories:
• Provisioning services (e.g., material goods such as food, feed, fuel, and fiber);
• Regulating services (e.g., climate regulation, flood control, and water purification);
• Cultural services (e.g., recreational, spiritual, and aesthetic services);
• Supporting services (e.g., nutrient cycling, primary production, and soil formation).
The GoM is a highly productive marine ecosystem that is surrounded by the United States, Mexico, and Cuba. It is the world’s seventh largest peripheral sea, with a surface area of 1.51 million km2 and a volume of 2.4 million km3. The great habitat complexity in the GoM supports the region’s high biodiversity, which consists of endemic and cosmopolitan species. The
2 According to McNutt et al. (2012), BP’s containment efforts captured approximately 800,000 barrels of oil before it reached the marine environment, making the total amount of oil to enter the water column closer to 4.2 million barrels.