With varying levels of red tide lingering off the coast of Southwest Florida – from Tampa Bay to Naples — some seafood eaters may wonder whether they can safely consume fish and shellfish caught in the Gulf. We talked to Razieh Farzad, a UF/IFAS assistant professor of food science and human nutrition and Florida Sea Grant affiliate researcher, to answer questions about red tide and seafood:
Q: To what extent is seafood safe to eat during a red tide?
A: In the United States, the seafood industry is highly regulated to ensure that commercially available seafood is safe. So, if you eat seafood from hotels, restaurants and grocery stores, you will be safe. Additionally, commercially available shellfish are often not locally harvested, and if harvested locally, they get tested for red tide neurotoxin before they get to market.
To minimize the risk that consumers will eat molluscan shellfish with natural toxins during a red tide, the Florida Department of Agriculture and Consumer Services manages harvesting, based partly on the presence of natural toxins in water and shellfish meat.
Q: What types of seafood are most impacted by red tide?
A: During a red tide event, we are primarily concerned with consuming mullsucan shellfish such as oysters, clams and mussels that are bivalves. Bivalves pump and filter a large amount of water through their bodies and can accumulate the toxin up to 100 times more of its concentration in the surrounding water. Therefore, consuming these products has the potential to be dangerous.
However, the red tide-related neurotoxin doesn’t accumulate in the edible part of crustacean shellfish such as crabs, shrimp and lobsters. The toxin also doesn’t accumulate in the fillet of the finfish, so finfish caught live can be eaten if filleted.
Q: How does the seafood industry monitor for safety issues associated with the red tide?
A: FDACS closes areas to harvesters and processors so they will not get any shellfish from potentially unsafe waters. This way, we comply with seafood safety regulations and protect public health.
Q: What do people who fish recreationally need to know about the fish they may catch when red tide is present?
A: Recreational harvesting of oysters, clams and mussels is banned by FDACS during red tide. However, edible parts of crustaceans — crabs, shrimp and lobsters – as well as finfish are not affected by the red tide-related neurotoxin, so they can be harvested recreationally. Sometimes, depending on the severity of the red tide, the Florida Fish and Wildlife Conservation Commission issues catch-and-release measures for a specific species of finfish, so I highly recommend checking for this kind of advisory during a red tide event before recreational harvesting.
Q: Is it safe to eat a fish that’s washed ashore during a red tide?
A: No, you should avoid eating the dead fish, whether it is during the red tide or not, because the reason for animal death cannot be absolutely known.
Q: Can cooking or freezing remove neurotoxin in red tide-contaminated seafood?
A: No, cooking and freezing will not remove the neurotoxin.
Q: What’s your best advice to consumers who are unsure if they should buy and eat fish or shellfish?
A: Red tide-related neurotoxin itself has no flavor, so you would not know if you were eating it. The only way to protect yourself is to know where your seafood comes from; only eat seafood that is harvested from open/approved water bodies or purchased commercially, do not harvest or eat shellfish from waterways where there’s a red tide bloom, do not eat the tomalley (the green stuff in crawfish and other shellfish), always avoid eating the dead fish on the shore and, never consume illegally harvested and unregulated shellfish.