(WVUE) - The GPS device on the boat David Sylve piloted through Barataria Bay had trouble keeping pace with the land loss.
"My GPS is telling me we're at four feet of water," Sylve said. However, the screen showed a large area of brown where an island is supposed to sit on the map.
"All the brown spots you see on the GPS used to be land."
It tells him he is smack dab in the middle of an island in Cat Bay."
"Now, there's no more land," Sylve said, "just all open water."
The islands of Cat Bay were ground zero in the 2010 Gulf of Mexico oil spill, when crude coated their shorelines.
In the months and years that followed, the Plaquemines Parish government blamed the spill for killing mangrove trees, the glue that held the islands together.
Three of the islands measured about 3-5 acres on the day of the spill.
It is also true that the islands were in trouble long before the blowout on the Deepwater Horizon oil rig.
As more land disappears in Barataria Bay, scientists point out storms and everyday tides
move more and more water across the islands, each waving taking a bite out of shorelines.
"We were out here seven years ago when we first started following the island and it had lush, 8 foot mangroves covering the island," said P.J. Hahn, the parish's former coastal zone managment director.
A few miles away, dozens of brown pelicans cling to the last remaining island in Cat Bay, a mound of shells less than the size of a basketball court in mid tide.
All that remains are a few patches of marsh grass with no living mangroves.
"It's like getting punched in the gut when you come out here and you see how fast this land is disappearing," Hahn said.
He expects all of the land to be gone by next year.
The Louisiana delta was always in transition.
As the Mississipp River changed course over thousands of year, belching mountains of sediment, new land formed.
However, land eroded in other places deprived of sediment and remnant shorelines converted to island.
As they became more isolated, the islands served as ideal nesting spots for pelicans and other birds.
"The island needs to be isolated enough that it doesn't have predators visiting all the time," said Davied Muth, Director of Gulf Restoration for the National Wildlife Federation.
Muth said the island "needs to be small enough that it can't support predators," such as racoons and coyotes principally."
Cat Bay made for a pelican paradise precisely because it became isolated as land disappeared.
The problem, Muth said, is that the river now contained within its levees no longer builds new land.
"Where we had hundreds and hundreds of potentially suitable islands, the number is just decreasing all the time."
As what used to be 30 different bays in Barataria Bay becomes one giant bay, Muth said the opportunity for those birds to find the ideal nesting spot also decreases.
"It's an open question," Muth said. "Are we going to have nothing in the end but man-made islands or man-maintained islands in order for them to nest?"