Overview of statewide geophysical surveys for ecosystem restoration in Louisiana

Abstract

The System Wide Assessment and Monitoring Program (SWAMP) was implemented by the Louisiana Coastal Protection and Restoration Authority (CPRA) to develop an Adaptive Management Implementation Plan (AMIP). SWAMP ensures that a comprehensive network of coastal data collection/monitoring activities is in place to support the development and implementation of Louisiana’s coastal protection and restoration program. Monitoring of physical terrain is an important parameter of SWAMP. For the first time a systematic approach was adopted to undertake a geophysical (bathymetric, side-scan sonar, sub-bottom profile, and magnetometer) survey along more than 5,000 nautical miles (nm) (excluding the 1,559 nm currently being surveyed from west of Terrebonne Bay to Sabine Lake) of track-line in almost all of the bays and lakes from Chandeleur Sound in the east to Terrebonne Bay in the west. This data collection effort complements the regional bathymetric survey undertaken under the Barrier Island Comprehensive Monitoring (BICM) Program in the adjacent offshore areas. This paper describes how a study of this magnitude was conceptualized, planned, and executed along the entire Louisiana coast. It is important to note that the initial intent was to collect bathymetric data only for numerical modelling for ecosystem restoration and storm surge prediction. Geophysical data were added for oyster identification and delineation. These first-order data also help comprehend the regional subsurface geology essential for sediment exploration to support Louisiana’s marsh and barrier island restoration projects.