Robotic Imaging System Provides Early Warning of Toxic Algal Bloom

Images of each cell in samples of seawater continuously pumped through the instrument are captured and sent over the Internet to Campbell’s laboratory, where the images are automatically classified into taxonomic groups. Dr. Campbell has been closely following the succession of algae species since last fall and recently noted elevated numbers of the dinoflagellate thought to be Dinophysis acuminata. This alga produces okadaic acid, which accumulates in shellfish and can cause diarrhetic shellfish poisoning (DSP).

After observing an increasing number of cells in mid-February, water collected from the site and oyster samples from the Port Aransas area were sent to an FDA laboratory for confirmation of toxin content. Within days, the Texas Department of State Health Services (DSHS) issued a recall of Texas oysters, clams, and mussels due to DSP. Aransas, Corpus Christi and Copano bays are now closed to shellfish harvesting, and DSHS is not aware of any illnesses resulting from this algae bloom (http://www.dshs.state.tx.us/news/releases/20080307.shtm).

Symptoms of DSP include vomiting, diarrhea, nausea and cramping which can begin from 30 minutes to 12 hours after eating shellfish containing the toxin. The DSHS reports “DSP usually is not life threatening and does not generally cause long-term effects.” Although Dinophysis species occur throughout the Gulf of Mexico, Dr. Campbell says “Dinophysis acuminata has never before been observed at such bloom levels in the Gulf.”

This test monitoring project is supported by the National Oceanographic and Atmospheric Administration’s Cooperative Institute for Coastal and Estuarine Environmental Technology.