Dam it: Fishers frustrated by closing of MRGO, but some catches increase

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Photo by U.S. Army Corps of Engineers

Some fishers claim the rock dam built across the MRGO in 2008 to block storm surge has hurt fishing

Some fishers claim the rock dam built across the MRGO in 2008 to block storm surge has hurt fishing

Robert Campo was born 46 years ago to a family of famous Shell Beach fishermen. Over the course of his life, he has seen the rapid erosion of the surrounding wetlands that sustain his community, industry and unique culture. Further, that loss has created a rising threat from hurricane storm surge and portends an eventual end to one of the nation’s most productive fisheries.

Much of that loss was caused by the Mississippi River-Gulf Outlet, a 70-mile shipping channel sliced through the heart of the eastern St. Bernard Parish wetlands from New Orleans to the Gulf. Long considered one of the worst environmental and economic disasters in state history, a cheer went up from coastal advocates in 2009 when that big canal was plugged with a rock dam near its southern end, and multi-billion dollar restoration plans were announced to rebuild the marshes with sediment and fresh water from the river.

But Campo and other fishers in the area didn’t celebrate. They are no fans of this particular  restoration effort.

“I knew when they plugged the channel things could get worse, and they have,” said Campo, who helps run his family’s marina and live-bait business.

“Restoration is suppose to help us, but this is just hurting us. Eventually it could kill us.”

It’s conventional wisdom that everyone wants to restore Louisiana’s crumbling, sinking coast.

But when “restore” actually means returning things to the way they once were, support can drop.

To people whose lives have been tied to the state’s coastal wetlands neighborhood the way it has devolved over the past 70 years, restoration is like gentrification. They fear the newcomers are pushing them out.

Fishers prospered as the delta became saltier

Seven decades ago the MRGO opened an expressway for salty Gulf waters and stronger tides into the Lake Pontchartrain-Borgne basin. After that, fishers enjoyed record catches of  speckled trout, redfish, shrimp and crab. Naturally, they worried about what would happen when the channel was closed and those conditions changed.

Six years later, some of them think they know the answer. Campo said fishing success has fallen since the repairs have begun.

He blames the dam on the MRGO for blocking saltwater and important tidal currents from the Gulf, and the diversion of freshwater from the river into area wetlands through the Violet Canal.

“The combination of that dam and the Violet siphon have changed everything,” he said. “The water’s just too fresh. Trout fishing is down, shrimping is down, and crabbing is way, way down.

“And trying to keep bait alive is twice, three time as hard. The water is so fresh in the canal and bayou, we got to put salt in our tanks to keep croakers alive.”

George Ricks, the charter-boat captain heading the Save Louisiana Coalition which opposes some of the state’s restoration plans, said the MRGO efforts have only made things worse for fishers.

“It’s killed salinity and increased the dead zones,” he said.  “Restoration is supposed to help things, not hurt them.”

Recent scientific reports support some of the fishers’ contentions.

A scientific look

Research on post-dam conditions by U.S. Geological Survey and the University of New Orleans found substantially fresher conditions north of the rock barrier while the Gulf side has saltier water and an expansion of areas with low oxygen in the summer. The research also pointed to less saltwater intrusion and fewer low-oxygen areas in Lake Pontchartrain.

But six years may be too short a time span to predict lasting changes, said John Lopez of the Lake Pontchartrain Basin Foundation.

“You generally need a longer time period to account for significant, unrelated events that can affect those factors,” he said.

For example, two dramatic events lowering salinities occurred in two of those six years.

During the BP oil spill in 2010, Gov. Jindal ordered all siphons and diversions connected to the river opened in an effort to keep oil from invading the marshes. And in May and June of 2011, the Bonnet Carre Spillway was opened, allowing some of the  Mississippi River to flow into Lake Pontchartrain to reduce the flood threat to New Orleans. The USGS data showed a dramatic plunge in salinities during those periods.

Conversely, the USGS records show a spike in salinity in August 2012 – the period when Hurricane Isaac’s salty Gulf storm tides stayed in the basin for several days.

State records on commercial shrimp and crab catches in the basin actually show improved results overall after the changes were put in place.

Average annual catches before and after MRGO dam
Before dam After dam
Crabs 9.4 million pounds 12.3 million pounds
White shrimp 2.7 million pounds 3.6 million pounds
Brown shrimp 4.5 million pounds 2.5 million pounds

The figures represent the average catches in six years before the dam, not including 2005, which saw fishing come almost to a standstill after Hurricane Katrina, and six years after the dam, not including 2010, when the state closed the commercial fishing for several months.

Campo, however, says the long-term impact of the changes is easy to forecast: Fresher water and fewer trout, shrimp and crabs.

“I’ve lived here my whole life – 46 years – and we always had salinities in the lake (Borgne) 15 to 20 parts per thousand,” he said. “Now you go out even to the rigs in the middle of the lake, and you’re going to see 5 or 6 parts per thousand. Trout can’t live in that. They move.

“Heck, right now I can go out any day and catch a limit of green trout [largemouth bass, a freshwater species] off the MRGO.

“That isn’t normal.”

But Campo’s memories don’t match the historical record. Research published before the MRGO was completed in 1963 classified the Lake Pontchartrain Basin as primarily a freshwater system, with salinities averaging between 3 and 8 parts per thousand.

In fact Campo concedes his grandfather, Frank “Blackie” Campo, a legendary figure among local fishers, often talked about fishing for green trout and sac-a-lait (crappie) in local waters, as well as hunting duck species such as mallards that thrived in the freshwater swamps that dominated the area.

After the MRGO opened, that habitat began a slow but steady drift to saltier conditions, with studies showing increases of 4 to 6 parts per thousand. Eventually  that resulted in a dramatic change in habitat.

Moreover, the saltwater intrusion caused by the channel led to the loss of at least 55,000 acres of wetlands. This included some 22,000 acres of cypress swamps along the MRGO corridor. Another 10,000 acres of cypress died along the Lake Maurepas shorelines on the far western end of the basin.

Reports show the loss of those wetlands significantly increased storm surge against local levees and floodwalls. A paper published in 2007 in the Journal of Coastal Research referenced a modeling study indicating the wetlands that were lost to MRGO impacts could have reduced storm surge from Hurricane Katrina by 80 percent.

Indeed, it was the impact of Katrina putting St. Bernard communities under 12 feet of water that provided the impetus for beginning the long-discussed closure of the MRGO, and restoring the wetlands that were lost.

Yet stopping this basin’s destruction by the Gulf of Mexico may not be in the fishers’ immediate economic self-interest. Coastal researchers say the forces that made anglers homes more vulnerable to flooding are likely responsible for the steady increase in their fishing fortunes over the past few decades.

Habitat gets better as the system dies

That irony it is part of the natural cycle of coastal deltas, and that the area is most bountiful before it dies.

Large rivers such as the Mississippi carry so much sediment that a delta it builds eventually grows so large it becomes an obstruction to the river’s path to the ocean. As pressure builds against its flow, the river will cut a new course to the ocean, creating a new mouth where it begins building a new delta.

Without new layers of sediment from the river, the abandoned delta begins sinking under its own weight. Once solid shorelines become fragmented, what once was a largely freshwater system turns brackish to salty.

But research shows coastal deltas are at their most productive for fisheries during these last stages of life. The mixture of salt and fresh water, the growing acres of shallow ponds and lagoons and the increasing miles of shoreline all are conducive to the food chain supporting valued species such as shrimp, crabs, speckled trout and redfish.

However if the sinking continues, eventually the amount of marshes left will be overwhelmed by the expanse of open Gulf water, and fishery production will plummet.

Fishermen such as Campo say they are not opposed to increasing flood protection by rebuilding the sinking deltas. They just prefer to see the rebuilding done by pumping river sand into the wetlands, a process that would not dramatically reduce salinity levels. They would also like to see culverts placed in the rock dam to allow some salt water and current to flow back into the wetlands north of the structure.

“We know they ain’t gonna tear down that thing,” Campo said. “But if they put culverts, which they could close when a storm is coming, we could have the best of both worlds.

“We gotta get that salinity back up, or this fishing will never be like it was.”

Yet UNO researcher Martin O’Connell* said that outside the immediate area of the MRGO, salinity levels in the basin have always fluctuated between fresh and salty. It’s the nature of a coastal estuary, he said.

“This type of estuary is supposed to have plenty of (salinity) changes because of all the factors that can influence it,” he said. “You get a lot of rain and the rivers leading into the basin that can drop the salinity. You get a tropical storm that can push it much higher. And you have regular tides cycles.”

O’Donnell thinks the tales of outstanding fishing passed down by anglers over the decades took place in those pre-MRGO says when salinities were swinging in that natural rotation.

“This system will always be changing, in a state of flux,” he said, “but that’s the beauty of it.”

*Correction: An earlier version of this story misspelled his name.

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