Raccoon Island Restoration
Story and Photos by Gabe Giffin
Ever head out to your beloved fishing or hunting spot and notice that your favorite island is no longer there? Or while running your outboard your boat prop turns up muddy evidence of an island that has slipped under the tide forever. One hears the talk of coastal restoration, but is anything actually being done? This is part one of a series on coastal restoration, particularly Louisiana Department of Wildlife and Fisheries (LDWF) Coastal Operations Program and its stewardship of 11 coastal WMAs and refuges. These areas encompass some 453,297 acres, which span a variety of habitats from cypress tupelo swamps, to barrier islands, to freshwater deltas, and the variety of ecosystems that have experience significant loss due to subsidence and erosion. We will focus on projects that the Coastal Operations staff has completed or are in the works, while exploring the true cost of coastal erosion to our state.
In August of 1856, a number of Louisiana’s wealthy families were enjoying themselves on the roughly 25 mile strip of continuous beachfront known as Isle Derniere. At the time, the land was called Last Island and was a place of 19th century paradise. There was a large hotel, several gambling houses, elegant beach houses and even a dance hall for social events. During the summer months, wealthy plantation owners and their families would escape to Last Island as a respite from their stifling domiciles. The island offered an almost constant Gulf breeze, calming surf and pristine golden sands, which couldn’t be found on the mainland or the marsh.
Unfortunately, the island sat only five feet above sea level, and on August 10th a category four hurricane came rumbling ashore leveling almost every standing structure, splitting the island in two and killing nearly 200 of the estimated 400 visitors to the resort. The Louisiana coastal paradise was lost, virtually wiped away by Mother Nature’s powerful hand. The valuable lesson was learned, barrier islands weren’t the place for humans to take vacation or refuge.
Now, over 150 years later, the Ilse Derniere Barrier Island (IDBI) is split into several islands. Raccoon, Trinity and Whiskey being the three largest, yet large gaps of gulf waters flow between this once continuous 25-mile stretch. If you visit these islands today, you’ll find no trace of the lost paradise, as countless storms have come and gone over the years, tossing anything that was left behind after that fateful August day. However, one will find a different type of paradise among the mangroves and the dunes that comprise the remnants of Ilse Derniere , a paradise that is home to one of the state’s largest pelican nesting grounds.
Relocating Pelicans to Isle Derniere
In June 1984, LDWF was 16 years into the pelican reintroduction project. Fifty young pelicans were transferred from Queen Bess Island in Barataria Bay to Raccoon Island. The idea was to introduce pelicans to a new nesting ground in hopes they would return to it. This would be the third nesting ground to be successful, following Queen Bess Island and the Chandeleur Islands.
The relocation stuck at Raccoon Island, but they aren’t always successful in habitually returning to an island. Rockefeller Refuge in southwest Louisiana was another location the department attempted to locate pelicans to. However the pelicans returned east, never able to establish a pelicans nesting ground at Rockefeller. Habitat and location are key factors as to whether or not pelicans will annually nest in an area. The mangrove trees and the marshy bayside of Raccoon Island have made this island ideal for pelicans to return each year.
Terns and laughing gulls screech loudly as we approached Raccoon Island and pelicans straightened up on their nests as we drew close to the shore. Rock breakwaters surround the southeastern side of the island. Sand gradually gathers behind these gapped barriers over a period of time. A yearly catalog of aerial shots displays just how much sand has gathered. The island looks as if a dozen bell curves reach their peak at the middle of each barrier before sloping back toward the island.
“We placed the first set of breakwaters out here in ‘97 and another set of eight in ’07,” said Loland Broussard, a civil engineer with the Natural Resources Conservation Service (NRCS). The initial ’97 project on Raccoon Island was a demonstration project between LDWF and NRCS, attempting to reduce erosion on the island. Breakwaters were constructed roughly 250 yards from the shoreline, to reduce the intensity of wave action hitting the shoreline. Today, there are 16 breakwaters and nearly all look identical, serving more than their original purpose. The breakwaters have functioned beyond expectations in protecting this critical barrier island.
The area between the breaker and the shoreline gradually forms as sediment washes inward toward the island and then cannot retreat due to the barrier trapping it. Over time, enough sediment deposits in this area that land begins to accrete. In the case of Raccoon Island, one can now stand at the base of many of the rock barriers. Looking toward the island from the barrier, sand or shallow water slopes into solid beach and flares out, getting wider toward the island until you reach the first dune with vegetation taking root.
Behind the dune ridge are thousands of pelicans nesting in mangroves; about two dozen pelicans take off, a dozen more land. This occurs constantly. The area is saturated with the bird, and while there are other islands nearby to nest, the pelicans primarily remain here. Pelicans are habitual in their nesting areas. If they’ve nested there before they will return to that same island again. When a pelican arrives at an island it has previously nested on and cannot find proper substrate to nest, it simply won’t nest. It doesn’t go looking for another area to nest; it may just skip that year.
A primary example of this is Wine Island, a northeastern island of the Ilse Dernieres chain. Pelicans attempted to nest on this island last year but were unsuccessful. Before visiting Raccoon Island we briefly stopped at Wine Island. A sand ridge forms out of the water and abruptly angles up to a foot and a half ledge of sand. The island looks like a plateau sitting only about two feet out of the water. Pelicans and sandwich terns sit on the island, bare with hardly any vegetation and not a single mangrove tree. The island at one time had a ring of barrier rocks around it, to aid the containment of dredging material dumped from the Houma Navigation Canal. The site was as big as 35 acres in the mid-nineties, but with no funds for management, the rocks began to sink and the island has eroded down to only a few acres.
Raccoon Island is an example of coastal restoration that has worked. Two sets of barriers placed nearly 10 years apart look the same because the practice of trapping the sediment maintains the land long enough for vegetation to take root. In fact, about 45 yards from the dunes new rows of marsh grass are forming. As the vegetation grows, they will trap sediments blown on shore and slowly a dune will begin to form. The south side of the island has seen land accumulate but the north side of the island continues to erode, however, LDWF has a plan to help build land here.
TE-48 Raccoon Island Back Barrier Marsh Creation Project
On April 25, 2012, representatives from US Fish and Wildlife Service (USFWS), the Governor’s Louisiana Oil Spill Coordinator Office (LOSCO), NRCS and LDWF all met to survey the island and discuss building up the backside of Raccoon Island. The project calls for a retention dyke, built on the north side of the area, connecting two peninsulas that will enclose a large open water cove area*(look into if they building a certain marsh habitat there). Then sediment, from an offshore source, will be filled in between the dyke and the mangrove shoreline, creating about 60 acres of habitat. Furthermore, marsh grasses and other herbaceous plant species will be planted to help hold this sediment and compliment existing island habitat.
This part of the project is actually Phase B, Phase A was the creation of the latter eight breakwaters on the gulf side. The barriers on the south side of the island give a good indication to the potential land growth this area has. Arial surveys show how quickly the land can grow with a barrier, and likewise how quickly it can disappear in the wake of a hurricane.
Trip participants also discussed future possibilities for restoration work such as additional marsh creation in the near vicinity of TE-48 Phase B. Past restoration proposals have included additional breakwaters to incorporate the spit, or western most end of the island. This area was once connected to Raccoon Island but is now separated by about a mile of shallow gulf water. Although the additional marsh proposal was not approved, LDWF will continue to propose such projects on Raccoon Island in order to attempt to restore it to near pre-hurricane Andrew conditions of 1992.