Federal judge throws out case over Mississippi Sound dolphin deaths. Here's why

A federal judge has dismissed a lawsuit Coast governments and groups filed against the U.S. Army Corps of Engineers over dolphin deaths after the corps opened the Bonnet Carré Spillway, releasing Mississippi River water that found its way into the Mississippi Sound.

U.S. District Judge Louis Guirola ruled that the Coast entities don't have standing to sue over the dolphin deaths. The lawsuit was filed by the cities of Biloxi, D'Iberville and Pass Christian, Harrison County, the Mississippi Hotel and Lodging Association and Mississippi Commercial Fisheries United Inc.

The localities and groups had hoped Guirola would require the corps to seek a federal permit for "taking" dolphins before opening the spillway, and require the Corps to avoid harming or killing the Mississippi Sound's dolphin population.

Guirola's opinion noted that the National Marine Fisheries Service would have the right to require a permit and otherwise regulate the taking of dolphins for spillway openings.

The corps opens the spillway when the Mississippi River threatens to flood New Orleans. Prolonged spillway openings in 2011 and 2019 exposed dolphins to more polluted river water than they could tolerate, causing the animals to die, the Coast entities maintained in their lawsuit. Many of the dolphins washed up covered in skin lesions.

Standing to sue would require the entities to show an actual injury, a connection between the injury and the corps' conduct and the court's ability to provide relief, Guirola noted in his opinion.

While the Coast entities alleged dolphins were harmed in 2011 and 2019, they didn't make claims that less prolonged spillway openings in recent years harmed dolphins, the judge noted, adding that "the frequency and length of spillway openings is unpredictable."

"As a result," he wrote, "the harm that spillway openings poses to dolphins is also unpredictable."

The number of dolphins in the Mississippi Sound was estimated at 1,265 in 2018. In 2019, 166 dolphins washed up on Mississippi shores, either dead or unable to return to the water, the lawsuit said. It was the highest number ever recorded, with the second-highest number recorded in 2011, when 147 dolphins were stranded during another flood year with high levels of river water.

"We're obviously disappointed in the ruling and will be evaluating our options for appeal," said Ocean Springs attorney Robert Wiygul, who represents the Coast governments and groups. "What this decision does not change is that operation of the Bonnet Carré Spillway in 2011 and 2019 caused massive dolphin deaths in the Mississippi Sound."