Ban Affects Louisiana Oyster Industry
May 6, 2003
A California ban on
raw oysters harvested from the Gulf of Mexico in the spring and
summer months is affecting Louisiana's oyster industry. Louisiana
supplies about 70 percent of its harvested oysters to California,
and industry leaders say this ban could mean a loss of about $20
going to stop shipment of some product right now - which is the
slow time of the year for oysters, but we do ship a lot in the
summer time," said Mark Schexnayder, Sea Grant Extension
Agent in the LSU Agricultural Center. "If other states adopt
the ban, or if other people hear about it and stop eating oysters
because of what happened, it could have a huge effect."
California health officials
have banned the sale of raw oysters from the Gulf of Mexico from
April to October, citing six deaths from raw oyster consumption
last year, as well as deaths in previous years, among the reasons
for the ban.
primary concern is with a certain pathogenic bacteria, Vibrio
vulnificus, which is usually present in the Gulf and other ocean
waters where oysters are grown," said Jon Bell, Sea Grant
Extension Seafood Technology Specialist in the LSU Agricultural
Center. "The risk of illness increases with the increased
number of bacteria present in the water and oysters."
Although the amount
of Vibrio vulnificus in raw oysters can become quite high during
warmer summer months, the bacteria generally will not make people
with normal and healthy immune systems ill, Bell says. However,
individuals who have a compromised immunity can be affected. They
should not consume raw oysters at any time of the year.
"I want to point
out that the people who have become ill or who have actually died
in California from consuming raw oysters have been identified
as people at a high risk," Bell stressed.
California will accept
raw oysters that have been treated by approved methods to kill
bacteria. "Currently, two processing methods have been accepted
by the FDA and the state of California as post-harvest treatments
to reduce Vibrio vulnificus to non-detectable levels," Bell
said. "Oysters that have been processed by these methods
are acceptable to be imported and eaten raw year-round in California."
One method, low-temperature
pasteurization, involves placing the oysters in warm water, which
is below the temperature that would cook the oyster, and then
immediately placing the oysters in cooler water. "This combination
has been scientifically validated to destroy the V. vulnificus
bacteria, " Bell said.
Another validated method,
high-pressure processing, subjects the immersed oysters to very
high pressures that destroy the bacteria without affecting the
oyster, Bell explained. A third method, very low temperature freezing,
is currently under review for this designation.
Officials in Louisiana
believe more education is needed instead of outright bans on sales
like this one in California. But the ban is in effect, and Schexnayder
says the industry needs to look at other ways to add value to
their products, such as smoked oysters.
"I think we really
need to look at the Louisiana oyster industry as a whole and explore
possibilities to make more money from the raw product that we
produce instead of just shipping them out raw," Schexnayder
said. Louisiana harvests about 60 percent of the Gulf oysters
and produces about a third of the country's oysters. The state
has led the nation in developing ways to kill the bacteria in
raw oysters without actually cooking the oysters. Louisiana Sea
Grant currently supports research at LSU on this topic.
For more information,
contact Mark Schexnayder at (504) 838-1170 or email@example.com
or Jon Bell at (225) 578-5190 or firstname.lastname@example.org.
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