Published – Tide Magazine
©2015 – All Rights Reserved – Troy Gilbert
For years, boaters in coastal Louisiana watched as their GPS units and charts identified them as cruising over land or marsh, when in reality they were in open water. Having already lost 1,800 square mile of land due to coastal erosion – an area the size of Rhode Island – NOAA embarked on an exhaustive re-mapping of the Louisiana coast in 2014 and discovered that entire barrier islands, bays and bayous had vanished into the Gulf of Mexico. Not limited to Louisiana alone, coastal land loss is occurring throughout the Northern Gulf Coast and is most pronounced on the barrier islands which are crucial to sustaining some of the most productive recreational and commercial fisheries in North America.
The barrier islands of Texas, Louisiana, Mississippi, Alabama and Florida help to form natural bays and protect estuaries crucial to the life cycle of fisheries and also act as an important first line of hurricane defense for the Gulf Coast. Often bearing the full force of these storms, these islands have been subjected to extreme weather events throughout their estimated 4,500 year history. These sandy, narrow spits of land paralleling the coast which are mostly undeveloped, act as speed bumps for storm surge and protect the populated coastline and infrastructure, but they also protect the breeding grounds and nurseries for the life cycle of fisheries. For centuries there were natural processes in place to replenish and repair storm damage to these islands, but in the last 50 years giant swaths have been carved out of some and erosion is now systemic with loss rates dramatically accelerating in the last few decades due to human activity.
In the 1960’s, Hurricane Betsy and then Camille pounded the Mississippi Coast and through massive erosion and overwash, split Ship Island in half and created what is now known as the Camille Cut, as well as East and West Ship Islands. Hurricane Katrina further enlarged the Camille Cut and also reopened a wide pass into the western side of Alabama’s Dauphin Island in 2005. This cut into Dauphin Island occurred during several other major storms – Petit Bois Island originally broke off of Dauphin Island in the 18th century. While federally protected to varying degrees since 1971, the issue hasn’t been development pressures on the barrier islands located in the Gulf Islands National Seashore, but the dredging and deepening of shipping channels from the relatively shallow nearshore waters into the deep waters of the Gulf of Mexico for shipping.
Constantly in a state of flux as they shift and move westward at up to 130 feet a year with the prevailing current and winds, their sands have historically and naturally eroded from the eastern islands and migrated to the west. This system tends to create shoaling and even periodic islands appearing where
before there were none. In 1917, a small island emerged in between Horn and Ship Islands off the Mississippi Coast and by the mid 1920’s had been developed into a resort and casino during prohibition. Due to natural erosion patterns, by 1932 it and all developments on the island had washed away.
With the dredging of these channels to increasingly greater depths to accommodate modern shipping, the natural repair mechanisms have failed. The replenishing sand in the water column is grabbed by these channels which act as sand sinks and have contributed to the dramatically increased speed of erosion. According to the USGS, Petit Bois Island has shrunk by 50% and Ship Island has lost nearly 65% of its landmass since 1917 and the loss has accelerated in direct proportion to the widening and deepening of these channels throughout the Gulf Coast.
While the growing frequency of intense hurricanes and the normal issue of cold fronts stirring up the shallow waters and pristine bays off the coast contribute to the erosion and narrowing of these islands, sometimes dramatically, the one manageable issue is the need for proper placement of beach quality dredge back into the water transport system or directly onto the islands themselves.
Placement of sand removed directly from dredging has occurred on Ship Island in Mississippi periodically, to protect the historic Fort Massachusetts. In 2009, the U.S. Army Corps of Engineers proposed a nearly $500M plan to re-nourish Petit Bois, Horn and the closure of the 3 mile wide Camille Cut in Ship Island. The first phase of this work was completed in 2011 with the reconstruction of nearly 300 feet of the northern beaches of West Ship Island. The second phase, which includes the massive project of closing the Camille Cut, is expected to begin in 2015.
In Texas, a $9.4M project to reopen Cedar Bayou northeast of Corpus Christi is attempting the exact opposite. While barrier island erosion is very prevalent, the extent and contiguous nature of these islands has led to hyper salinity levels in the Laguna Madre and the Aransas and Mesquite Bays. Originally sealed 35 years ago to protect against the offshore Ixtoc I oilspill in Mexican waters that threatened the Texas coast, Cedar Bayou was a natural breathing point for these nearly landlocked waters and home to an incredible fishing ground for redfish, speckled trout and flounder as well as a water exchange and breeding ground for fish, shrimp and crabs.
Understanding the role and importance of these barrier islands as speed bumps during hurricanes and as contributing to natural fisheries, Dan Brown, Park Superintendant for the Gulf Islands National Seashore states, “For decades, we had a limited understanding of barrier island systems. It wasn’t until researchers started documenting and correlating the deepening of these channels to their land loss that we began to understand what was happening.”
In Louisiana, the majority of the Army Corps spending to repair damage from Hurricane Katrina over nine years ago has been on extensive storm protection, including repairing and raising levees and building flood control storm locks. Federal dollars have been spent on barrier island restoration in Louisiana and more could come from civil penalties against BP for the Deepwater Horizon oilspill which could top $20B.
Currently being litigated in court, BP agreed in 2011 to a $1B upfront payment towards these certain fines, but only agreed to release the majority of the money last year. Of this, $320M was allocated for Louisiana barrier island restoration in October of 2014, including target projects on Whiskey Island, Cheniere Ronquille, Shell Island and Breton Island. The Chandeleur island chain will also be targeted for major projects in the next installment of BP fines.
These barrier islands throughout the Northern Gulf Coast are important ecosystems and breeding grounds for seabirds and turtles as well as incredibly bountiful shrimp and oyster harvesting waters. Couple these important issues with the natural protections against storm surge for the developed coastlines and there is a real intersection of development, recreational/commercial fishing and preservation interests occurring all along the coast. Neglected for far too long, these investments are a first step into the restoration of the islands and continuing to give sportsmen ample opportunities to reel in those red snappers and speckled trout, while nearby the surf rolls on the quiet sugar sand beaches and dunes of the Gulf Coast.