RobertTwilley

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Panel 1: Confronting the Scientific Realities of Coastal Land Loss

Robert R. TwilleyDepartment of Oceanography and Coastal ScienceLouisiana State University: 

Robert R. Twilley Department of Oceanography and Coastal Science Louisiana State University President’s Forum on Meeting Coastal Challenges Lod and Carole Cook Alumni Center Baton Rouge, January 25, 2005 A Century of Coastal Degradation and our Current Approach to Coastal Restoration

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ECOSYSTEM NEEDS

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“In a hundred years, Louisiana as a whole had decreased by a million acres.“ [1.2 million since 1900, USGS] Plaquemines Parish is coming to pieces like old rotted cloth. A hundred years hence, there will in all likelihood be no Plaquemines Parish, no Terrebonne Parish.” Taken from ‘The Control of Nature’ by John McPhee, 1989

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ECOSYSTEM REHABILITATION

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Federal Projects with purpose to Protect and Serve the Public Good; With Long-term Unintended Consequences Flood Control (1927 - 1965 - to present)

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Federal Projects with purpose to Protect and Serve the Public Good; With Long-term Unintended Consequences Coastal Oil and Gas Exploration (1930-1970)

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Federal Projects with purpose to Protect and Serve the Public Good; With Long-term Unintended Consequences Navigation (1850-1970)

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Federal Projects with purpose to Protect and Serve the Public Good; With Long-term Unintended Consequences Agriculture (1850-1960) 1850: Swamp Land Act - Conversion of wetlands to agriculture production - organized drainage and flood-control enterprises.

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ECOSYSTEM REHABILITATION

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TIME LCA Restoration Goals Land Area (million acres) 1.0 2.0 3.0

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“Until about 1900, the river and its distributaries were able to compensate for the subsidence with the amounts of fresh sediments they spread in flood. Across the centuries, distribution was uneven, as channels shifted and land would sink in one place and fill in somewhere else, but over all the land-building process was net positive. “ Taken from ‘The Control of Nature’ by John McPhee, 1989

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1900 4) No Action: continued degradation rate; 2) Maintain: no wetland loss; 3) Reduce Loss: decrease in degradation rate; 1) Enhance: increase wetland acreage. 2000 With CWRPPA Effects (17 mi2/yr) - No Action 50 yr delay in Restoration Response of Goal 3 (4) (2) (3) (1) 2050 3000 1950 Land Area (million acres) 1.0 2.0 3.0 LCA Restoration Goals (2) (3) (4)

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“…Is it even possible to contain so enormous a hemorrhage of coastal land against the forces of nature and man's environmental folly?” Taken from Coastal Louisiana Drowning in Gulf Encroaching Salt Water Is Threatening the State's Economy and Homes By Lee Hockstader Washington Post Staff Writer Sunday, July 13, 2003; Page A01 © 2003 The Washington Post Company

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“We’ve REVERSED mother nature” Quote from Oliver Houck; Taken from ‘The Control of Nature’ by John McPhee, 1989 “We must recognize that natural processes cannot be RESTORED.We can’t put it back the way it was.” “The best we can do is try to get it back in balance…” Quote from Sherwood Gagliano; Taken from ‘The Control of Nature’ by John McPhee, 1989 “And there will be no RETREAT, without a struggle” Taken from ‘The Control of Nature’ by John McPhee, 1989

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Conclusions Degradation of nearly one third of the deltaic and chenier plains of coastal Louisiana has occurred over last 70 yrs from impacts initiated in 1900; Timeliness of rehabilitation process is critical to degree of vulnerability and coastal challenges; Issue One: When will the rehabilitation process start commensurate with degree of degradation; Ecosystem Forecasting: Developing tools of Ecosystem Rehabilitation Issue Two: What will be the response of coastal ecosystem to degree of rehabilitation measures (effective use of available funds);