BELLE CHASSE, La. (AP) — Towns along Louisiana's flatMississippi River delta and elsewhere along the Gulf Coast face anuncertain future as the sea level rises and wetlands that surround them disappear.

On Tuesday, an 18-month initiative was launched to study therisks the states from Alabama to Texas face, including the dangerto ports, oil refineries and the lifestyles of coastalresidents.

“If nothing is done, where we are today will be water,” saidKing Milling, chairman of America's Wetland Foundation, at a newsconference in Belle Chasse.

The foundation is a coalition of businesses, local and stateofficials seeking to gain the nation's attention by highlightingthe economic importance of the Gulf Coast. It especially wantsCongress and the White House to fund restoration of the erodingMississippi River delta.

Related:Regional Insurance Coverage for the Southeast/GulfCoast

Jeff Hingle, sheriff of Plaquemines Parish, a delta sliver justoutside New Orleans that's home to Belle Chasse and fishingcommunities, said the parish runs the risk of becoming “an islandin the Gulf” if action isn't taken.

This sliver of land wasformed only about 600 years ago when the Mississippi River changedcourse and began building up the present delta.

In many places, Plaquemines already looks like an island in theGulf.

During a tour Tuesday of the parish's badly eroded marsh,deputies pointed out places that have been lost to the open water.The Gulf has eaten away at the land here, taking with it ridges,forests and old fishing villages. It is common to see pilings wherea building or pier once stood in the marsh.

The most pressing threat right now for Plaquemines is what'shappened to the marshes since the April 20 BP oil spill. The parish was the hardest-hit areabecause the Deepwater Horizon exploded about 50 miles away from theparish's tip, where the Mississippi River empties into theGulf.

The worst of the spill can be found in Bay Jimmy, where the edgeof the marsh is black with oil and dying.

Parish officials are frustrated by the federal government'sdecision to leave damaged marsh like Bay Jimmy alone for fear ofdoing more damage by trying to clean it up. They say vital marsh isbeing lost because the oil is not being cleaned up.

“You can see that oil keeps being brought in closer and closerto the marsh,” said P.J. Hahn, the director of the parish's coastalzone management program. He kneeled down and grabbed a handful oftarry, smelly brown oil in his gloved hand. The gooey stuff droppedfrom his hand.

“You see the oil on top of this thing, it's killed the rootsystem, and slowly the earth is being removed,” he said. “Thesemarshes are very sensitive; there is a lot of life that forms andbegins in these marsh areas.”

After the catastrophes of the BP oil spill and Hurricane Katrina, the Gulf Coast hopes that the nation nowunderstands its importance.

Forums to discuss making the Gulf Coast “resilient” will be heldin Plaquemines Parish, Lake Charles, Houston, Biloxi, Galveston,Mobile, Ala., Orange Beach, Ala., St. Mary Parish and New Orleansbetween March and July 2012.

This work follows on a recent $4.5 million risk analysis byEntergy Corp. that found the Gulf Coast faces $350 billion indamage over the next 20 years unless steps are taken to offsetnatural processes well under way.

The analysis includes vulnerabilities to the offshore oil andgas industry, an economic linchpin for the central and westernGulf.

New Orleans-based Entergy is one of the nation's largest nuclearpower providers and an advocate of expanding nuclear power as analternative to fossil fuels that generate greenhouse gases.

Its study focused on climate change, hurricanes and subsidence,the gradual sinking of coastal lands, a phenomenon particularly badin Louisiana.

Since at least the 1930s, the Mississippi River delta has beeneroding. Chief culprits include levee construction, oil drillingand hurricane storm surge.

Louisiana has lost about 2,100 square miles of coast and losesabout 25 square miles a year, according to the U.S. GeologicalSurvey.

On average, the Gulf region suffers losses of about $14 billiona year, the Entergy study found. But over the next 20 years, lossesare expected to rise to between $18 billion and $23 billion ayear.

Of course, losses could be averted by spending tens of billionsof dollars to prepare for future hazards, the study said.

The Gulf Coast communities are being asked to look at how theymight adapt. They could adopt tougher building codes, build betterlevees, restore wetlands and beaches and change practices inoffshore drilling, such as higher standards for offshore platformsand replacing semi-submersible drilling rigs with drill ships, andstrengthening electric utility systems.