In Terrebonne Parish,
slabs of recycled
plastic are being used
to hold marsh-grass
plugs, which help the
plants develop root
systems, and restore
the natural marsh.
IF YOU FLOAT IT,
THEY WILL COME
TO ANYONE INTERESTED in coastal Louisiana, it’s no secret hat the state has lost thousands of acres of valuable marshland and critical wetlands habitat to erosion
over the years. Most attempts to restore the
marshes rely on labor-intensive marsh grass
planting that has proven only marginally effective, or expensive dredge-and-fill operations.
But a promising new technique is taking root
— literally — in Terrebonne Parish. There, volunteers are using a “floating islands” concept,
and it’s outperforming all expectations.
The project, started in September 2011
by the Louisiana Chapter of the Coastal
Conservation Association (CCA), uses lightweight slabs of recycled plastic to hold marsh-grass plugs, which is like a flat for starting
tomato plants. The slabs, or islands, are then
towed into place with a small boat and
anchored in shallow water, down current from
existing natural marsh. The 8- to 10-inch-thick
islands, roughly 5 by 8 feet, hold up to 60
plugs. Over time, the plugs grow root systems
down into the seafloor. The plants can then
begin to trap sediments and eventually this
buildup will tie the “island” back into the
remaining natural marsh.
CCA members and students from nearby
Pointe-aux-Chenes Elementary School joined
Shell Oil Company employees and members
of a local Native American tribe to plant thousands of marsh-grass plugs last fall at four sites
around Isle de Jean Charles, an area where just
slivers of natural marsh remain due to severe
erosion. That project created 195 islands or
about 1,560 linear feet of floating marsh.
Monitoring since then has found that plants in
the islands are healthier and greener than those
in the surrounding marsh. In many places the
plants, now 3 to 4 feet tall, completely cover
the islands and are spreading back toward the
adjacent natural marsh as hoped.
The project is one of four Gulf Coast
restoration projects undertaken by the CCA
Building Conservation Trust with seed money
from Shell matched by local dollars, with additional support from businesses and America’s
Wetland Foundation. — R.L.