The U.S. Geological Survey (USGS), in cooperation with the Coastal Research Laboratory in the Department of Geology and Geophysics at the University of New Orleans (UNO) and the Center for Coastal Energy and Environmental Resources at Louisiana State University (LSU), is investigating the processes of coastal erosion and wetland loss in Louisiana (Sallenger and others, 1987; Sallenger and Williams 1989; Penland and others, 1992). Building on the USGS Louisiana Barrier Island Study (Williams and others, 1992) and the USGS Hurricane Andrew impact assessment (Penland and others, 1998), this data layer depicts the shore-normal transects used to measure shoreline change. The Isles Dernieres are located about 120 km southwest of New Orleans. This barrier island shoreline is 32 km long and extends from Caillou Bayou east to Wine Island Pass. The Isles Dernieres represent a barrier island arc developed from the reworking and erosion of an abandoned distributary of the Lafourche delta complex within the Mississippi River delta plain (Penland and others, 1988). Previous work by McBride and others (1992) documented a long-term (1887-1988) gulfside erosion rate of -11.1 m/y and a short-term (1978-1988) gulfside erosion rate of -19.2 m/y. The long-term bayside (1906- 1988) erosion rate was measured at -0.6 m/y and the short-term (1978-1988) bayside erosion rate was measured at -5.2 m/y. The Isles Dernieres decreased in area at a rate of -28.2 ha/y between 1887 and 1988, suggesting the long-term date of disappearance would be 2015. The rate of area loss between 1978 and 1988 was measured at -42.7 ha/y suggesting a short-term disappearance date of 2004. In the 1992 Hurricane Andrew impact assessment by Penland and others (1998), the Isles Dernieres experienced a brief and intense period of increased erosion. The average gulfside erosion rate accelerated to -59.37 m/y and the average bayside erosion rate accelerated to -10.8 m/y during the year of the 1992 Hurricane Andrew impact. The Isles Dernieres rate of area change accelerated to -155.7 ha/y during the 1992 hurricane season. Hurricane Andrew accelerated the long-term area loss rate to -28.5 ha/y and the shortterm area loss rate to -49.54 ha/y. The Hurricane Andrew impact on the Isles Dernieres produced 3-5 years of erosion in a matter of days. After the Hurricane Andrew impact, the projected long-term disappearance date of the Isles Dernieres was reduced from 2015 to 2012 and the short term disappearance date was reduced from 2004 to 2003. In this shoreline change update, the authors used the methods and transects used by McBride and others (1992) to insure data compatibility of the new measurements and analysis. To evaluate change in the shoreline position, shore-normal transects were constructed at approximately 15-second intervals of longitude or latitude depending on shoreline orientation. Isles Dernieres, Bayou Lafourche and Plaquemines barrier systems (east-west shroelines) were analyzed using 15-second (about 404 m) intervals of longitude, while the Chandeleur Islands (north-south shorelines) were examined by using 15-second (about 462 m) intervals of latitude. Measurements of shoreline movement and change in island width were taken along transects perpendicular to the composite shoreline trend. Average rates of movement and area change were calculated by dividing absolute measurements by elapsed time (year, month, and day - where available.) Shoreline change maps were procuded to determine the spatial and temporal distribution of shoreline movement (magnitude, direction, and rate of change) and document geomorphologic evolution. (McBride and others, 1992).

The U.S. Geological Survey (USGS), in cooperation with the Coastal Research Laboratory in the Department of Geology and Geophysics at the University of New Orleans (UNO) and the Center for Coastal Energy and Environmental Resources at Louisiana State University (LSU), is investigating the processes of coastal erosion in Louisiana (Sallenger and others, 1987; Sallenger and Williams 1989; Penland and others, 1992). Building on the USGS Louisiana Barrier Island Study (Williams and others, 1992), this data layer depicts the shore-normal transects that were used to measure shoreline change. The methods and transects used by McBride and others (1992) were used to insure data compatibility of the new measurements and analysis. To evaluate change in the shoreline position, shore-normal transects were constructed at approximately 15-second intervals of longitude or latitude depending on shoreline orientation. Isles Dernieres, Bayou Lafourche and Plaquemines barrier systems (east-west shroelines) were analyzed using 15-second (about 404 m) intervals of longitude, while the Chandeleur Islands (north-south shorelines) were examined by using 15-second (about 462 m) intervals of latitude. Measurements of shoreline movement and change in island width were taken along transects perpendicular to the composite shoreline trend. Average rates of movement and area change were calculated by dividing absolute measurements by elapsed time (year, month, and day - where available.) Shoreline change maps were procuded to determine the spatial and temporal distribution of shoreline movement (magnitude, direction, and rate of change) and document geomorphologic evolution. (McBride and others, 1992).

The U.S. Geological Survey (USGS), in cooperation with the Coastal Research Laboratory in the Department of Geology and Geophysics at the University of New Orleans (UNO) and the Center for Coastal Energy and Environmental Resources at Louisiana State University (LSU), is investigating the processes of coastal erosion in Louisiana (Sallenger and others, 1987; Sallenger and Williams 1989; Penland and others, 1992). Building on the USGS Louisiana Barrier Island Study (Williams and others, 1992), this data layer depicts the shore-normal transects that were used to measure shoreline change. The methods and transects used by McBride and others (1992) were used to insure data compatibility of the new measurements and analysis. To evaluate change in the shoreline position, shore-normal transects were constructed at approximately 15-second intervals of longitude or latitude depending on shoreline orientation. Isles Dernieres, Bayou Lafourche and Plaquemines barrier systems (east-west shroelines) were analyzed using 15-second (about 404 m) intervals of longitude, while the Chandeleur Islands (north-south shorelines) were examined by using 15-second (about 462 m) intervals of latitude. Measurements of shoreline movement and change in island width were taken along transects perpendicular to the composite shoreline trend. Average rates of movement and area change were calculated by dividing absolute measurements by elapsed time (year, month, and day - where available.) Shoreline change maps were procuded to determine the spatial and temporal distribution of shoreline movement (magnitude, direction, and rate of change) and document geomorphologic evolution. (McBride and others, 1992).

The U.S. Geological Survey (USGS), in cooperation with the Coastal Research Laboratory in the Department of Geology and Geophysics at the University of New Orleans (UNO) and the Center for Coastal Energy and Environmental Resources at Louisiana State University (LSU), is investigating the processes of coastal erosion and wetland loss in Louisiana (Sallenger and others, 1987; Sallenger and Williams 1989; Penland and others, 1992). Building on the USGS Louisiana Barrier Island Study (Williams and others, 1992), this data layer depicts the shoreline as it stood in 1996, which provides an 8.9 year update of McBride and others (1992). The Timbalier Islands are located about 100 km south-southwest of New Orleans. This barrier island shoreline is 30 km long and extends east from Cat Island Pass to Raccoon Pass. The Timbalier Islands represent a flanking barrier island system developed from the reworking and erosion of an abandoned distributary of the Lafourche delta complex within the Mississippi River delta plain (Penland and others, 1988). Island evolution is driven by predominant longshore sediment transport and storm overwash, causing the island arc to migrate to the north and west. The present configuration of the Timbalier Islands consists of Timbalier Island to the west, Timbalier Shoal, and East Timbalier Island to the east. Timbalier Shoal, located between the two islands within Little Pass Timbalier, is a transient area of moving sand, which is subaerial for some periods of measurement. The Gulf shoreline of East Timbalier Island has been armored by a rock seawall with a second seawall constructed landward in an attempt to protect oil and gas facilities on the bayside. In order to quantify shoreline changes since January 21, 1988, new vertical aerial mapping photography was acquired on December 9, 1996 The methods and transects used by McBride and others (1992) were used to insure data compatibility of the new measurements and analysis

The U.S. Geological Survey (USGS), in cooperation with the Coastal Research Laboratory in the Department of Geology and Geophysics at the University of New Orleans (UNO) and the Center for Coastal Energy and Environmental Resources at Louisiana State University (LSU), is investigating the processes of coastal erosion and wetland loss in Louisiana (Sallenger and others, 1987; Sallenger and Williams 1989; Penland and others, 1992). Building on the USGS Louisiana Barrier Island Study (Williams and others, 1992), this data layer depicts the shoreline as it stood in 1887. The Timbalier Islands are located about 100 km south-southwest of New Orleans. This barrier island shoreline is 30 km long and extends east from Cat Island Pass to Raccoon Pass. The Timbalier Islands represent a flanking barrier island system developed from the reworking and erosion of an abandoned distributary of the Lafourche delta complex within the Mississippi River delta plain (Penland and others, 1988). Island evolution is driven by predominant longshore sediment transport and storm overwash, causing the island arc to migrate to the north and west. The present configuration of the Timbalier Islands consists of Timbalier Island to the west, Timbalier Shoal, and East Timbalier Island to the east. Timbalier Shoal, located between the two islands within Little Pass Timbalier, is a transient area of moving sand, which is subaerial for some periods of measurement. The Gulf shoreline of East Timbalier Island has been armored by a rock seawall with a second seawall constructed landward in an attempt to protect oil and gas facilities on the bayside. In order to quantify shoreline changes since January 21, 1988, new vertical aerial mapping photography was acquired on December 9, 1996 The methods and transects used by McBride and others (1992) were used to insure data compatibility of the new measurements and analysis

The U.S. Geological Survey (USGS), in cooperation with the Coastal Research Laboratory in the Department of Geology and Geophysics at the University of New Orleans (UNO) and the Center for Coastal Energy and Environmental Resources at Louisiana State University (LSU), is investigating the processes of coastal erosion in Louisiana (Sallenger and others, 1987; Sallenger and Williams 1989; Penland and others, 1992). Building on the USGS Louisiana Barrier Island Study (Williams and others, 1992), this data layer depicts the shore-normal transects that were used to measure shoreline change. The methods and transects used by McBride and others (1992) were used to insure data compatibility of the new measurements and analysis. To evaluate change in the shoreline position, shore-normal transects were constructed at approximately 15-second intervals of longitude or latitude depending on shoreline orientation. Isles Dernieres, Bayou Lafourche and Plaquemines barrier systems (east-west shroelines) were analyzed using 15-second (about 404 m) intervals of longitude, while the Chandeleur Islands (north-south shorelines) were examined by using 15-second (about 462 m) intervals of latitude. Measurements of shoreline movement and change in island width were taken along transects perpendicular to the composite shoreline trend. Average rates of movement and area change were calculated by dividing absolute measurements by elapsed time (year, month, and day - where available.) Shoreline change maps were procuded to determine the spatial and temporal distribution of shoreline movement (magnitude, direction, and rate of change) and document geomorphologic evolution. (McBride and others, 1992).

The U.S. Geological Survey (USGS), in cooperation with the Coastal Research Laboratory in the Department of Geology and Geophysics at the University of New Orleans (UNO) and the Center for Coastal Energy and Environmental Resources at Louisiana State University (LSU), is investigating the processes of coastal erosion and wetland loss in Louisiana (Sallenger and others, 1987; Sallenger and Williams 1989; Penland and others, 1992). Building on the USGS Louisiana Barrier Island Study (Williams and others, 1992) and the USGS Hurricane Andrew impact assessment (Penland and others, 1998), this data layer depicts the shoreline as it stood in 1996, which provides an 8 year update of McBride and others (1992). The Isles Dernieres are located about 120 km southwest of New Orleans. This barrier island shoreline is 32 km long and extends from Caillou Bayou east to Wine Island Pass. The Isles Dernieres represent a barrier island arc developed from the reworking and erosion of an abandoned distributary of the Lafourche delta complex within the Mississippi River delta plain (Penland and others, 1988). Previous work by McBride and others (1992) documented a long-term (1887-1988) gulfside erosion rate of -11.1 m/y and a short-term (1978-1988) gulfside erosion rate of -19.2 m/y. The long-term bayside (1906- 1988) erosion rate was measured at -0.6 m/y and the short-term (1978-1988) bayside erosion rate was measured at -5.2 m/y. The Isles Dernieres decreased in area at a rate of -28.2 ha/y between 1887 and 1988, suggesting the long-term date of disappearance would be 2015. The rate of area loss between 1978 and 1988 was measured at -42.7 ha/y suggesting a short-term disappearance date of 2004. In the 1992 Hurricane Andrew impact assessment by Penland and others (1998), the Isles Dernieres experienced a brief and intense period of increased erosion. The average gulfside erosion rate accelerated to -59.37 m/y and the average bayside erosion rate accelerated to -10.8 m/y during the year of the 1992 Hurricane Andrew impact. The Isles Dernieres rate of area change accelerated to -155.7 ha/y during the 1992 hurricane season. Hurricane Andrew accelerated the long-term area loss rate to -28.5 ha/y and the shortterm area loss rate to -49.54 ha/y. The Hurricane Andrew impact on the Isles Dernieres produced 3-5 years of erosion in a matter of days. After the Hurricane Andrew impact, the projected long-term disappearance date of the Isles Dernieres was reduced from 2015 to 2012 and the short term disappearance date was reduced from 2004 to 2003. In this shoreline change update, the authors used the methods and transects used by McBride and others (1992) to insure data compatibility of the new measurements and analysis.

The U.S. Geological Survey (USGS), in cooperation with the Coastal Research Laboratory in the Department of Geology and Geophysics at the University of New Orleans (UNO) and the Center for Coastal Energy and Environmental Resources at Louisiana State University (LSU), is investigating the processes of coastal erosion and wetland loss in Louisiana (Sallenger and others, 1987; Sallenger and Williams 1989; Penland and others, 1992). Building on the USGS Louisiana Barrier Island Study (Williams and others, 1992) and the USGS Hurricane Andrew impact assessment (Penland and others, 1998), this data layer depicts the shoreline as it stood in 1887. The Isles Dernieres are located about 120 km southwest of New Orleans. This barrier island shoreline is 32 km long and extends from Caillou Bayou east to Wine Island Pass. The Isles Dernieres represent a barrier island arc developed from the reworking and erosion of an abandoned distributary of the Lafourche delta complex within the Mississippi River delta plain (Penland and others, 1988). Previous work by McBride and others (1992) documented a long-term (1887-1988) gulfside erosion rate of -11.1 m/y and a short-term (1978-1988) gulfside erosion rate of -19.2 m/y. The long-term bayside (1906- 1988) erosion rate was measured at -0.6 m/y and the short-term (1978-1988) bayside erosion rate was measured at -5.2 m/y. The Isles Dernieres decreased in area at a rate of -28.2 ha/y between 1887 and 1988, suggesting the long-term date of disappearance would be 2015. The rate of area loss between 1978 and 1988 was measured at -42.7 ha/y suggesting a short-term disappearance date of 2004. In the 1992 Hurricane Andrew impact assessment by Penland and others (1998), the Isles Dernieres experienced a brief and intense period of increased erosion. The average gulfside erosion rate accelerated to -59.37 m/y and the average bayside erosion rate accelerated to -10.8 m/y during the year of the 1992 Hurricane Andrew impact. The Isles Dernieres rate of area change accelerated to -155.7 ha/y during the 1992 hurricane season. Hurricane Andrew accelerated the long-term area loss rate to -28.5 ha/y and the shortterm area loss rate to -49.54 ha/y. The Hurricane Andrew impact on the Isles Dernieres produced 3-5 years of erosion in a matter of days. After the Hurricane Andrew impact, the projected long-term disappearance date of the Isles Dernieres was reduced from 2015 to 2012 and the short term disappearance date was reduced from 2004 to 2003. In this shoreline change update, the authors used the methods and transects used by McBride and others (1992) to insure data compatibility of the new measurements and analysis.

The U.S. Geological Survey (USGS), in cooperation with the Coastal Research Laboratory in the Department of Geology and Geophysics at the University of New Orleans (UNO) and the Center for Coastal Energy and Environmental Resources at Louisiana State University (LSU), is investigating the processes of coastal erosion and wetland loss in Louisiana (Sallenger and others, 1987; Sallenger and Williams 1989; Penland and others, 1992). Building on the USGS Louisiana Barrier Island Study (Williams and others, 1992), this data layer depicts the South Chandeleur Island as is stood in 1855. In order to quantify shoreline changes since 1989, new vertical aerial mapping photography was acquired on December 9, 1996. The methods and transects used by McBride and others (1992) were used to insure data compatibility of the new measurements and analysis .

These data provide an accurate high-resolution shoreline compiled from imagery of GULF COAST, CAMINADA PASS TO GRAND TERRE ISLANDS, LA . This vector shoreline data is based on an office interpretation of imagery that may be suitable as a geographic information system (GIS) data layer. This metadata describes information for both the line and point shapefiles. The NGS attribution scheme 'Coastal Cartographic Object Attribute Source Table (C-COAST)' was developed to conform the attribution of various sources of shoreline data into one attribution catalog. C-COAST is not a recognized standard, but was influenced by the International Hydrographic Organization's S-57 Object-Attribute standard so the data would be more accurately translated into S-57. This resource is a member of https://www.fisheries.noaa.gov/inport/item/39808