Grand Isle's Cutting-Edge Oyster Hatchery

The Michael C. Voisin Oyster Hatchery, one of Jefferson Parish's most cutting-edge and state-of-the-art facilities, is located someplace you might not expect!

When natural production of oyster seed was reduced due to drought and low Mississippi River discharge, the idea of an oyster hatchery was established as a commercial operation in 1990 in Grand Isle to help oysters grow using modern techniques through science and research while providing oysters to Louisiana consumers in a sustainable manner.

By 1993, naturally occurring seed production had recovered in most of the state, and the need for a commercial hatchery was no longer necessary, but the Louisiana Sea Grant bought the Grand Isle hatchery and converted it into a research facility.

Thanks to this newly developed initiative, the state now has a way to produce baby oysters that aren't attached to a shell. To supplement natural seeding, these tiny oysters can be released on public oyster grounds to grow and flourish. Unfortunately, Hurricane Katrina destroyed the original facility, forcing Louisiana Sea Grant to relocate to the Louisiana Department of Wildlife and Fisheries marine research lab, which is located next to the new building.

Construction on a brand-new, state-of-the-art facility began in April 2013 - one that would be indoors and fully climate protected, as the previous hatchery was outdoors and could only produce half the amount of oyster larvae, due in large part to a lack of indoor insulation and a way to keep seawater warm throughout the year. The new facility is elevated 15 feet over sea level, fully temperature controlled, and built to withstand winds of up to 140 mph.

The hatchery produces traditional two-chromosome oysters, in addition to a three-chromosome variety called triploid oysters. This variety cannot reproduce, allowing it to not waste the same energy needed to spawn during the summer months as 2 chromosome oysters. That means triploid oysters remain meaty and sweet in the "non-R months" allowing them to focus on growth instead of reproduction. However, these types of oysters require seeds to grow.

The hatchery can produce approximately 1 billion oyster seeds and larvae per year, in addition to growing their own microalgae, which is the primary food source for oyster larvae, and provides a process called remote settings.

The large-scale algae production included growing different species in a continuous culture system utilizing special LED filtered lighting rooms (too much direct sunlight or heat can kill the algae production) & produces up to 2000 liters (530 gallons) of algae per day to help the oysters grow.

Once the oysters have found their primary food source, hatchery-produced seeded oysters are raised in nursery tanks with a constant flow of raw water. Adult male and female oysters are fed algae to prepare them for spawning. For four weeks, the oysters are kept in shallow cold-water tanks at around 10 degrees C. The temperature is then raised two degrees per week to 24 degrees C to simulate a springtime temperature increase.

When the oysters are "ripe," they can be placed in a holding tank until they are needed or sold to oyster farmers as part of the Louisiana Department of Wildlife and Fisheries oyster sales program.

The hatchery also performs remote setting, which is the process of placing larvae in a set location away from the hatchery to make seeds (reproduce). To produce single oysters, larvae are collected on a 225-micron screen. After that, the larvae are wrapped in a paper material to keep them moist and cool. Larval oysters can then be shipped overnight to an oyster farmer. This process enables hatcheries to specialize in larval growth and oyster farmers to specialize in oyster growth - increasing production volume of oysters while decreasing production costs.

This oyster hatchery is a critical tool for rehabilitating the state's valuable oyster resources after oil spills, hurricanes, and natural erosion. The hatchery's annual production of 1 billion baby oyster larvae is insufficient to reseed the entire coast in the event of a disaster. However, it will help jump-start a troubled area. The advanced water circulation system and temperature-controlled features of the facility allow oysters to be produced all year, not just during the summer months.

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