BILOXI (AP) — State marine officials expect the oyster industry can expect extreme losses when record amounts of freshwater heading down the Mississippi River reach the Mississippi Sound.
Oysters will be hit hard because they’re a stationary species; shrimp, finfish and crabs, which are mobile, are expected to be able to move ahead of freshwater entering the salty waters of the Sound, and the effect on the adults should be minimal, said Scott Gordon, director of the Shellfish Bureau, Office of Marine Fisheries in the Department of Marine Resources.
Gordon and other officials spoke Tuesday at a meeting in Biloxi.
“I fully expect to have 100 percent mortalities of the oysters in the western Mississippi Sound,” Gordon said.
Gordon said increased nutrient levels in the Sound will likely lead to algae blooms and lowered oxygen levels, which can kill fish.
“Many of the mobile species, shrimp, finfish, crabs should be able to move ahead of the diverted floodwaters,” he said.
Gordon expects much of the Sound will experience lower salinity levels and warmer water temperatures as the result of fresh water flowing from Lake Pontchartrain in Louisiana.
Another outcome of the fresh water will be the threat of invasive species such as Asian carp, silver carp, grass carp, apple snails, zebra mussels, hydrilla and salvina making their way into coast streams, he said.
The fresh water is coming from the Bonnot Carre Spillway opening on May 9 with near record flows, he said.
The last time the spillway was in 2008 when 160 of the 350 bays were opened, Gordon said. This year, 330 of the bays are open and he expects all 350 to be opened.
Officials are looking at 1983, when all 350 bays of the Bonnet Carre Spillway were opened for floodwaters, as a benchmark for predicting what will happen in the next few days and weeks.
“I was here in 1983 for the spillway opening,” Gordon said. “There was freshwater all the way to the Gulfport Ship Channel.”
Salinity levels were so low people were catching channel catfish and largemouth bass off the beach in Waveland, he said.
“I feel we’ll have at least that effect this time,” he said.
The soonest oysters could be re-established could be in August, for a 2013 harvest, Gordon said.
“It takes about 18 to 24 months for them to get from larva to the legal size,” he said.
Oyster reefs can be restored with cultch plants, which can be a mix of clean oyster shells, crushed limestone and crushed concrete.
Gordon and Tracy Floyd, the shrimp and crab bureau director, said the shrimp look in good condition to survive an influx of fresh water.
Floyd said the brown shrimp have been exposed to very conducive growth conditions of warm water and healthy salinity levels this year.
“We continue to see good abundance in our samples,” she said.