San Francisco Chronicle
NEW ORLEANS (AP) — A new federal study says Louisiana's devastating wetlands loss has slowed slightly since 2010, but cautions that the main reason is probably that no major hurricanes have hit the state since 2008.
"It's been a period of relative calm in hurricane activity, so it has reduced the stress on coastal wetlands," said Brady Couvillion, lead author of the U.S. Geological Service study, speaking in an interview. He added that the lack of destructive hurricanes allows plants to settle in.
The report released Wednesday describes wetlands loss from 1932 to 2016 but is not a study of its causes, he said.
"It's really good to see this data analysis done so thoroughly and so rigorously," said Denise Reed of The Water Institute of the Gulf, a coastal preservation research group.
"I think one of the things we see in this is that it just takes a bad storm year to get another dip down," said Reed, the group's vice president for strategic research initiatives.
The report said another factor in the relative slower rate may be that the most vulnerable wetlands already are gone.
"Eventually you come to a place where more robust land is left," said Reed, calling that an extremely important point.
Robert Twilley, director of the Louisiana Sea Grant at Louisiana State University, said hurricanes seem to do much more damage to wetlands than they used to, because there's so much more open water than there once was.
Other possible reasons for the slower rate include a decline in oil and gas work in the coastal area, recovery from four hurricanes that hit in 2005 and 2008, and coastal restoration work, according to the report.
It said wetlands loss was highest in the 1970s, averaging out to a football field's worth of land lost every 34 minutes. Now, according to the report, it takes an average of 1 hour and 40 minutes to lose that much land.
"We're still losing an estimated 28 square kilometers (11 square miles) per year," he said. "Granted, that's one-third of the highest annual loss." But, he said, "I sort of liken it to someone was stealing $3,000 a year from your bank account, and now it's $1,000 a year. It's still a big deal — something you've got to do something about."
Reed and Twilley said much the same thing.
"We can't celebrate the per-year rates too much because we have to watch the total loss," said Twilley.