Project: How Bacteria Influences the Production of Domoic Acid

Project summary from https://seagrant.gso.uri.edu/2018-2020-research/ (on 2021-01-29)

Pseudo-nitzschia, a genus of plankton that can produce domoic acid, a neurotoxin that, if ingested in dangerous amounts, can cause illnesses ranging from gastrointestinal problems and lethargy to short-term memory loss and seizures.

Although this type of plankton is always present in the bay and elsewhere, it is not always producing domoic acid.

Sea Grant-funded researchers are examining the specific species of phytoplankton that produce domoic acid, as production rates vary among species within the Pseudo-nitzschia genus, to determine whether a bloom has toxic potential. They are also looking at how partner bacteria that accompany the phytoplankton may have a role in influencing the amount of domoic acid the phytoplankton produces.

RESULTS:

Researchers found that multiple Pseudo-nitzschia (PN) strains are associated with domoic acid production at the long-term plankton time-series site near Fox Island and that domoic acid concentrations are generally highest at the passages mouths in Narragansett Bay. Researchers have observed distinct strains are prevalent during different times of the year with spikes of domoic acid in September/October in 2017 as well as June and September/October in 2018.

Findings also show that particulate domoic acid concentrations are greater than dissolved concentrations by examining phytoplankton cells and filtered water, indicating that domoic acid concentration is not correlated with cell count.