Economic Assessment of the Impacts of the Opening of Bonnet Carre Spillway on Mississippi Commercial Fishing


Source: http://www.dmr.state.ms.us/index.php/marine-fisheries/shellfish

Heavy rain in the Mississippi Valley and rising Mississippi River water stages and flow prompted the U.S. Army Corps of Engineers, New Orleans District, to operate both the Bonnet Carre Spillway and the Morganza Floodway in May 2011 (U.S. Geological Survey, 2012). The Bonnet Carre Spillway was partially opened on Monday, May 9, 2011 in order to keep the volume of the Mississippi River flows at New Orleans from exceeding 1.25 million cubic feet per second (cfs). It was fully closed 43 days later on Monday, June 20, 2011 (U.S. Army Corps of Engineers, 2012). 

The prolonged exposure of the Mississippi oyster growing areas to freshwater intrusion due to the opening of the Bonnet Carré Spillway (BCS) during the Mississippi River flooding event (MSFE) in spring of 2011 resulted to massive mortalities (86%) of the state oyster populations (MDMR, 2011a). These massive mortalities created economic hardships in the state’s oyster harvesting and other input and output linked sectors. The rapid economic recovery of the oyster sector required immediate restoration efforts to replenish the damaged resources and allow the resumption of oyster harvesting, processing, distribution and consumption of oyster products.

The economic impacts of the BCS opening in 2011 was assessed using the preliminary assessment method using the Hurricane Katrina model when landings data after 2010 were not yet available and the post assessment method using the economic recovery model when landings data after 2010 became available. The preliminary assessment of the economic impacts of the BCS opening in 2011 to the Mississippi oyster fishery was prepared by Posadas (2011) to support MS-DMR application for fishery disaster declaration.  A more rigorous assessment of the impacts of freshwater flooding is added as part of the overall assessment of the individual and joint impacts of natural and technological disasters since 2005.

Posadas, Benedict C. 2011.  Economic Impacts of the Freshwater Intrusion to the Mississippi Oyster Fishery. Report prepared for the Mississippi Department of Marine Resources for submission to NOAA Fisheries.