Oil spill permeates the Gulf’s most productive environments
By John Talberth and Stephen Posner on July 7, 2010 The BP oil spill will degrade critical ecosystem services and their economic benefits for decades to come. BP’s massive oil spill jeopardizes the underpinning of economic wealth in the Gulf of Mexico region – the diverse coastal and marine ecosystems that generate a bounty of goods and services for communities from the Yucatan peninsula to Key West. Ecosystem services, or the benefits that humans receive from nature, form the backbone of the recreation, tourism, and fishing industries, enhance property values along the coast, sequester carbon dioxide and provide storm and hurricane protection. The Gulf’s ecosystems provide all of these services free of charge, but they are not without value, and the massive BP oil spill has now put many of those ecosystems in great jeopardy. A recently-released study by Earth Economics (PDF) estimates that the Mississippi Delta’s ecological communities currently generate up to $13,000 per acre in ecosystem services each year. Over the next hundred years, this estimate, for just the Mississippi Delta region, translates into a present value of $330 billion to $1.3 trillion, the wide range owing to uncertainties about the value of ecosystem services over that time period. Exposure to residual oil over the course of decades will diminish the value of ecosystem services generated by marshes, wetlands, and coastal waters in the spill’s path. The loss of ecosystem service values from the BP spill will be felt in both the short and long term, both onshore and offshore. In the short term, for example, the CoStar Group predicts that the spill may drive down shore-area property value in the Gulf by ten percent over at least three years– a $4.3 billion loss. The spill’s effects on other services will endure for much longer. According to the Exxon Valdez Oil Spill Trustee Council, ecosystem services affected by that disaster are still recovering twenty years later (PDF). Using Earth Economics figures, a twenty percent reduction in ecosystem service values along the Gulf coast from the Louisiana-Texas border to St. George Island, Florida would equate to $15 to $60 billion in economic damages over a similar, twenty-year period, not counting losses to those directly affected by spill related closures in the short term. Perhaps the most pernicious impact of the spill, according to Dr. Thomas Shirley of Texas A&M, may occur offshore, affecting what is known as primary production. In the Gulf and other ocean basins, primary production is the very basis for the marine food chain. It is the process by which organisms turn carbon dioxide into organic compounds, mostly through photosynthesis. Coral reefs, sea grasses and algae are the most visible primary producers in coastal zones, but most oceanic primary production comes from microscopic planktonic algae, or “phytoplankton.” The Millennium Ecosystem Assessment identified primary production as one of the most important “supporting” ecosystem services. In the Gulf, primary production—measured in milligrams carbon per square meter per day – ranges from near zero to 7,300 near the Mississippi Delta at its peak in June and July. The annual average is 417 for the Gulf marine ecosystem as a whole. Tragically, the oil spill, which currently covers over 38,000 square kilometers lies almost directly across the area of highest primary productivity at the time of its monthly maximum. …
