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School of Ocean Science and Engineering

Shellfish Sanitation Laboratory




The Interstate Shellfish Sanitation Conference (ISSC) was formed in 1982 to foster and promote shellfish sanitation through the cooperation of state and federal control agencies, the shellfish industry, and the academic community. The ISSC performs evaluations on the labs that perform these tests across the country to maintain continuity, consistency, quality control and good lab practices. There are mandatory evaluations performed every couple of years but the lab is subject to evaluation at any time. Testing must be performed in an exacting manner following every guideline to the letter. The analyses are done for a regulatory purpose, not for scientific research purposes.


Since 1985, GCRL's Microbiology Laboratory has performed all testing of Mississippi's oyster waters and product for the Mississippi Department of Marine Resources (MDMR). These tests are necessary to comply with federal regulations designed to protect public health. Without such tests, Mississippi shellfish could not be sold commercially or shipped across state lines. GCRL is the only conforming shellfish testing lab in the state of Mississippi.

The GCRL Microbiology Laboratory provides this vital service to the MDMR under guidelines set forth by the U.S. Food and Drug Administration under the National Shellfish Sanitation Program. These guidelines require that each state that harvests live shellfish must continuously monitor the growing waters for fecal coliform levels. Water quality testing focuses on fecal coliform bacteria, which serve as a good indicator of other potential biological contaminants.

MDMR personnel regularly collect seawater samples throughout the year from oyster harvest waters and deliver them to GCRL for analysis. GCRL Microbiology Laboratory personnel test the samples for fecal coliforms. Results are transmitted to MDMR immediately upon completion of testing, which requires approximately 24 hours. All data are reported to MDMR to support MDMR's management decisions regarding the oyster harvest. GCRL provides analytical support only; decisions on opening or closing of harvest areas are made by MDMR.

When there is a specific concern, MDMR also collects oyster meat samples for testing at GCRL. These tests require three to four days in the lab.

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Currently in the process of FDA verifying the post-harvest processing (PHP) protocol. PHP testing entails analyzing oysters after they have been processed and treated to reduce instances of Vibrio species (including Vibrio vulnificus and Vibrio parahaemolyticus). We are very excited about offering this testing to the private sector and scientific colleagues as well. GCRL Microbiology Laboratory will be the only FDA conformed laboratory for PHP testing in Mississippi. 

In 2019, we partnered with the Thad Cochran Marine Aquaculture Center's oyster and algae teams to do an ongoing bacteriological study on the bacteria loads in the oyster/algae aquaculture systems. The samples from the systems are analysis weekly for Vibrio sp., Aeromonas sp. and Pseudomonas sp. The data from these samples are used to look at the health of the systems.