Institutions: Bigelow Laboratory for Ocean Sciences, U.S. Food and Drug Administration, Washington State Department of Health Public Health Laboratory, Maine Department of Marine Resources

Project Summary: Diarrhetic shellfish poisoning (DSP) toxins produced by the dinoflagellate Dinophysis can cause severe gastrointestinal illness in humans. The threat of Dinophysis blooms and associated DSP toxins in shellfish tissue may be increasing around the North American coast. Past Dinophysis blooms have caused the closure of shellfish beds and temporary pauses on harvesting to ensure shellfish safety, resulting in substantial economic losses. Routine, accurate quantification of DSP toxins in shellfish tissue, integrated into a comprehensive state monitoring and fishery management framework under the National Shellfish Sanitation Program (NSSP), is essential for public safety. However, adoption of the current NSSP-approved methodology has been limited due to challenges related to method implementation and transferability – approaches often need adjustment to accommodate different instrument manufacturers and their configurations. The overarching aim of the project is to increase the number of laboratories nationwide that are able to provide accurate analytical quantification of DSP toxins to regulatory decision makers at the state and federal level using NSSP-approved methodology. The primary objective is to generate a harmonized standard operating protocol for the quantification of DSP toxins in shellfish that allows a broader range of instrument configurations and analytical procedures than the current method, while maintaining sufficiently high quality control criteria to be adopted into the NSSP for broad regulatory use.

Institutions: Mote Marine Laboratory

Project Summary: Florida’s red tide, a harmful algal bloom caused by the dinoflagellate Karenia brevis, produces neurotoxins that can accumulate in shellfish and lead to neurotoxic shellfish poisoning (NSP) in humans. The increasing frequency and duration of Gulf of Mexico shellfish farm closures due to toxic red tides have severely damaged southwest Florida's shellfish industry and reduced the availability of shellfish for consumers. In order to thrive, the industry needs innovative technology for NSP toxin detection that would correlate with existing seafood safety regulatory protocols. Rapid, cost-effective biotoxin detection methods can mitigate the severe consequences of HABs on the shellfish industry and reduce the financial and administrative burdens of managing shellfish harvesting and distribution during red tide blooms. This project aims to advance new methods for NSP toxin measurement in seafood.

There are currently two National Shellfish Sanitation Program (NSSP) methods for NSP toxin detection in shellfish – the mouse bioassay (MBA), and an enzyme-linked immunosorbent assay (ELISA) – which are slow and labor-intensive, and limited in their application, respectively. This project will evaluate two recently developed prototypes – a fluorescence aptamer assay (FAA), and an enzyme-linked aptasorbent assay (ELASA) – to determine their viability as alternatives for detecting NSP toxins in shellfish.

Project Summary: Paralytic shellfish toxins (PSTs) are potent neurotoxins that cause paralytic shellfish poisoning (PSP) in fish, birds and mammals including humans. Commercial shellfish are routinely tested for PSTs using National Shellfish Sanitation Program (NSSP)-approved regulatory methods. The receptor binding assay (RBA) is a rapid, cost-effective test that is approved as an alternative method to the mouse bioassay for PSTs in mussels. Currently, the RBA is used by the Sitka Tribe of Alaska Environmental Research Laboratory (STAERL) for testing non-commercial shellfish. To extend the potential use of the RBA for shellfish regulatory applications, RBA method validation studies must be conducted for other shellfish species. The goal of this proposal is to expand the species of shellfish approved under this method. The Washington State Department of Health Public Health Laboratory and the National Centers for Coastal Ocean Science will partner with STAERL to conduct a series of shellfish matrix extension studies, and findings will be submitted to the Interstate Shellfish Sanitation Conference (ISSC) for evaluation.