Seafood Technology

Harmful Algal Blooms FAQ

Update 12/23/2015

HABs Mississippi December 2015 

Harmful Algal Blooms FAQ

Q. What is a HAB?
A. A harmful algal bloom is a higher-than-normal concentration of microscopic algae (plant-like organisms) in the water. These blooms are harmful because they produce a toxin that can affect fish, shellfish, marine mammals, birds and people. These blooms occur when colonies of algae (microscopic plants that live in the water) grow out of control. They can flourish when conditions such as wind, water currents and temperature are favorable. These blooms can produce toxic effects on fish, shellfish, marine mammals, birds and people.

Q. What are some of the effects of HABs?
A. The toxins associated with Karenia brevis, the species in the Mississippi Sound, can affect the central nervous system of fish, marine mammals and birds, potentially causing the animals to die. When the blooms are in high concentrations, wave and wind action can cause the toxins to be released in the air and cause eye and respiratory irritation (coughing, sneezing, tearing and itching) in humans and pets. Individuals with chronic respiratory problems, such as asthma or emphysema should be especially cautious as they may experience stronger reactions.

Q. Are HABs normal at this time of year?
A. Karenia brevis, the species that is in the Mississippi Sound now, is common in the Gulf of Mexico along the Gulf Coast of Florida, although blooms typically occur between August and October. Generally the blooms end between December and February. Mississippi is experiencing conditions that are more favorable for the blooms, given the warm water and air temperature and winds.

Q. How long can HABs last?
A. The duration of the blooms depends on physical and biological conditions, such as water temperature, wind direction, wind speeds, water currents, sunlight and salinity.

Q. Why were the beaches and oyster reefs closed?
A. MDMR closed the oyster reefs, and the Mississippi Department of Environmental Quality closed the beaches as a precautionary measure because of the potential of toxins in the water and close to the shore.

Q. Is it OK for me to catch and eat fish?
A. Yes. If you go fishing, it is safe to eat the fillets of finfish. The toxins accumulate in the guts of fish. However, do not harvest or eat dead or distressed fish.

Q. Is it OK for me to purchase and eat seafood at restaurants and seafood markets?
A. It is safe to consume seafood purchased in restaurants and from seafood dealers. Seafood products are monitored and tested regularly.

Q. Is it OK for me to eat oysters?
A. Mississippi oysters harvested before the reefs closed Friday, Dec. 11, are safe to eat. Additionally, oysters purchased in restaurants and by authorized dealers are monitored and tested.

Q. What if I need more information or see something unusual that should be reported?
A. Several agencies are working together to help with any questions about the red tide and its effects. To report a fish kill, call the MDMR at 228-374-5000. To report dead or distressed birds, call 601-321-1131. If you see a marine mammal in distress, call the Institute for Marine Mammal Studies at 1-888-767-3657. For questions about beach closures, call 228-432-3447.

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