Member of the University of Florida’s Fisheries and Aquatic Sciences Program view LSU Sea Grants Voisin Oyster Hatchery’s off-bottom oyster bed while attending a meeting of the Gulf Coast Oyster Growers and Producers held at the facility. Photo: Ed Lallo/Newsroom Ink
by Ed Lallo/Gulf Seafood News Editor
For more than 20-years, the old Grand Isle Sea Grant oyster hatchery and lab faced exposure to every known element the Gulf of Mexico could throw at it. The recently opened Mike Voisin Oyster Hatchery, whose namesake served as a Louisiana Wildlife and Fisheries commissioner and chairman of the Louisiana Oyster Task Force, may not face that same exposure to the elements, but instead face new challenges both manmade and natural.
Louisiana Sea Grant oyster specialist John Supan explains to members of the Gulf Coast oyster community how the new hatchery is mobil so important equipment can be moved when hurricanes approach. Photo: Ed Lallo/Newsroom Ink
Water quality will be a continuing challenge for the new $3 million dollar hatchery according to John Supan, an oyster specialist with Louisiana Sea Grant, who designed and oversees the facility. “The building’s water system is designed to go into recirculating mode during times when water quality is not optimal. It is one thing to have the system, but making it work will be a big challenge,” he explained.
According to the oyster researcher, periods of low salinity from wind-driven plumes of Mississippi River water, or local heavy rainfall from tropical waves, affects larval production in a hatchery environment.
All About Water Quality
LDWF biologist Sarah Wooley spends her days in a lab looking more like a set from the Starship Enterprise. Photo: Ed Lallo/Newsroom Ink
Water quality has plagued the Grand Isle operation since inception. With more than 27 years in the making, the new oyster hatchery is shielded from the elements of the Gulf’s uncertain weather and Supan is confident he has found the solution for the fluctuation of water quality.
An advanced water circulation system and temperature-controlled system allows larvae and spat to be produced year-round. This will be instrumental in meeting the hatchery’s billion oyster larvae a year contract with the Louisiana Department of Wildlife and Fisheries (LDWF). Larvae produced at the facility will be used for the restoration of public reefs that were damaged after the Deepwater Horizon oil spill in 2010 and specifically for corrective action towards the state’s Natural Resource Damage Assessment funded cultch plants.
“On the top row are tetraploid oysters, which have four sets of chromosomes, and the bottom two row are diploid oysters, which have two sets,” explained Callam. “When you breed a tetraploid and a diploid, it results in a triploid, or an oyster that has a set of three chromosomes.” Photo: Ed Lallo/Newsroom Ink
“Sea Grant is under contract to direct the production of a billion larvae during the 10 month hatchery season,” said Supan. “That has us producing about a 130 million larvae a month, and I don’t see a problem with that. The main thing is to have the right brood stock, which we do in our nearshore oyster research farm.”
The first of its kind facility in the Gulf produces it own specialized food. LDWF biologist Sarah Wooley spends her days in a lab looking more like a set from the Starship Enterprise. White, red and blue lights illuminate the room giving off a surrealistic glow.
“We have 144 bags to grow algae to feed the oyster larvae,” she told Gulf Seafood News. “We produce more than 450 gallons of food each day, with any extra being used to feed the brood stock. The color light system is specific for algae growth. The white gives an overall spectrum, while the blue and red lights are designed for rapid growth.”
Next door, Brian Callam, a LSU Graduate Ph.D. Assistant, oversees egg spawning from the brood stock.
Once the eggs are fertilized -creamy looking liqud on strainer – they are placed in large tanks that fill the room. Photo: Ed Lallo/Newsroom Ink
“On the top row are tetraploid oysters, which have four sets of chromosomes, and the bottom two row are diploid oysters, which have two sets,” explained Callam. “When you breed a tetraploid and a diploid, it results in a triploid, or an oyster that has a set of three chromosomes. Triploids will not spawn in the summer, meaning they have nice fat meat, allowing for harvesting year round.”
Once the eggs are fertilized they are placed in large tanks that fill the room. They are then fed with Wooley’s special algae mix.
Twelve to fifteen days later, larvae are ready to spat, or cement themselves, onto a surface. The larvae can either be stored by being placed in a coffee filter, wrapped in a moist paper towel and sent to refrigeration; or allowed to spat on a micro cultch of ground-up oyster shells where each attaches itself a piece of fine sand-like cultch that will grow into a single oyster.
The first spawn for the hatchery was early in June of this year. The hatchery faced a couple of initial setbacks with brood failures caused by startup pains.
Projects and Challenges
The spat-on-shell project for the state is set to begin next year after a facility currently under construction in Buras. Spat on shell tank at the Voisin Hatchery. Photo: Ed Lallo/Newsrooom ink
Supan says that one unique project for the hatchery will be test planting triploids on the public grounds to be used as oyster generic markers indicating whether oysters from the hatchery are growing and surviving.
“Usually you wouldn’t plant triploids on the public grounds because they cannot reproduce,” he explained. “To ensure the planted spat has come from the hatchery, instead of from the wild, LDWF will plant triploids in a small research scale so the department can provide proof the project is actually working in the wild.”
The spat-on-shell project for the state is set to begin next year after a facility currently under construction in Buras, on the other side of Barateria Bay, is completed. There, larvae produced in the Voisin Hatchery will be added to whole shell to create the spat-on-shell to be planted in the public grounds.
“With Buris currently under construction, about all the Department can do now is throw larvae overboard like they have in years past. Definitely no the ideal way to do it,” said Supan.
“For the first time in more than 100 years, I have closed my oyster plant, all because of the fresh water diversion,” said oysterman Wilbert Collins. Photo: Ed Lallo/Newsroom Ink
Supan’s and the Louisiana Wildlife and Fishery project are also facings manmade challenges driven from Baton Rouge and Washington, D.C. In an effort to rebuild the rapidly disappearing Louisiana coastline, freshwater diversion projects are being discussed both in the state capital and on Capitol Hill. The projects could irreparably damage historic public and private oyster growing grounds and derail the intended mission of the hatchery.
Freshwater diversions into various bays have already started to ruin many public and private beds, affecting production of long-time harvesters.
“For the first time in more than 100 years, I have closed my oyster plant, all because of the fresh water diversion,” said oysterman Wilbert Collins. Collins, who has operated the family’s historic Collins Oyster Company in Golden Meadow for more than 60 years, told Gulf Seafood News that he could no longer afford to send his boats out to harvest oysters on his Caminada Bay lease.
Off-Bottom Oysters Expand
With the success of public and private leases lying in murky waters, Supan sees growth in the oyster industry laying in off-bottom caged grown oysters.
With the success of public and private leases lying in murky waters, Supan sees growth in the oyster industry laying in off-bottom caged grown oysters and has a working lab at the hatchery. Photo: Ed Lallo/Newsroom Ink
According to him, the hatchery has been filling orders coming from the Louisiana Oyster Dealers and Growers Association. “We have three off-bottom growers on Grand Isle currently, with a fourth on the way. They have been placing their orders for seed and we are filling them,” he said.
One solution to the nursery problem might lay with bait dealers. Supan would like to find a local dealer who is already using his pumps to run the water flow from his bait tanks back into the Bay.
Off-bottom growers take the small window screen spat produced in the hatchery and grow it large enough to be placed in mesh bags. Gulf-wide, off-bottom growers are gearing up to double their production, but even that is not nearly enough to meet the current demand by just New Orleans restaurants alone.
“Our Sea Grant marketing effort has created a demand for off-bottom oysters in New Orleans,” he said. “The chefs are clamoring for them.” Photo: Ed Lallo/Newsroom Ink
“We can produce the seed off-bottom growers need, but I don’t want to be in the seed business. Our job is to create business, not go into business,” he explained. According to the oyster expert, what is needed is a growth spurt in the off-bottom nursery business.
“Our Sea Grant marketing effort has created a demand for off-bottom oysters in New Orleans,” he said. “The chefs are clamoring for them. Overnight we are two years behind because we don’t have enough production. To get that production you have to have seed oysters, to get seed oysters we have to have more nurseries.”
“We can easily retrofit that system to grow seed oysters at the same time, so when water leaves his live bait tanks, it goes right into the seed oyster silos before going back into the bay,” Supan explained. “This will let the oysters filter their food out of the water. We have one local bait dealer that is starting to warm up to the idea.”
According to Supan, Grand Isle is ideally suited for seed nurseries because the salinity is almost perfect. He sees the challenge as getting local people and businesses interested in the idea.
“Right now we are in kind of in a Catch 22,” he said. “What we need is to create the product and the demand for the product in concert with one another. The challenge now is to start producing these oysters in a greater quantity.”
‘”Magnífico”