Presentation Abstract
Preliminary results from a newly funded NOAA NCCOS MERHAB project developing new molecular methods for detecting Alexandrium catenella cyst concentrations in marine sediments will be presented. A. catenella is a dinoflagellate that produces saxitoxin, a powerful neurotoxin, that can be concentrated in filter feeding shellfish which, if ingested by humans, can lead to paralytic shellfish poisoning and potentially death. A. catenella overwinters as a cyst in the sediment and when environmental conditions are right, in the spring and summer, germinates into the water column as a vegetative cell. Previous studies have mapped the winter distribution of A. catenella cysts in Puget Sound sediments as a way of providing shellfish growers with an early warning system of potential hotspots for blooms of this harmful alga (HABs). The standard method for cyst detection in sediments depends on collecting sediment samples in winter, sieving, preserving, and staining the samples and manually enumerating the cysts using epifluorescence microscopy. This method is very labor intensive and requires extensive training to accurately identify the cysts. This new MERHAB project aims to develop new quantitative molecular assays (qPCR and FISH – fluorescent in situ hybridization) that will be compared with the existing standard microscopy protocol using surface sediment samples from Puget Sound, the Gulf of Maine, and Alaska to see if these new molecular techniques represent a viable alternative to the existing standard microscopy method. Preliminary maps of A. catenella surface sediment cyst distribution from winter 2020 in Puget Sound will be presented, as well as initial comparisons of cyst concentrations determined using both the molecular and microscopy methods.
Session Title
Track: Trophic Interactions - Zooplankton, Phytoplankton, Salmon, Forage Fish & Invasive Species – Posters
Conference Track
Trophic Interactions - Zooplankton, Phytoplankton, Salmon, Forage Fish & Invasive Species
Conference Name
Salish Sea Ecosystem Conference (2020 : Online)
Document Type
Event
SSEC Identifier
2020_abstractID_5455
Start Date
21-4-2020 9:00 AM
End Date
22-4-2020 4:45 PM
Genre/Form
posters
Subjects – Topical (LCSH)
Alexandrium catenella--Sampling--Salish Sea (B.C. and Wash.)
Geographic Coverage
Salish Sea (B.C. and Wash.)
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.
Type
Text
Language
English
Format
application/PDF
Included in
Fresh Water Studies Commons, Marine Biology Commons, Natural Resources and Conservation Commons, Terrestrial and Aquatic Ecology Commons
Mapping the cysts of Alexandrium catenella in the surface sediments of Puget Sound: A comparison of microscopy and molecular methods for enumeration
Preliminary results from a newly funded NOAA NCCOS MERHAB project developing new molecular methods for detecting Alexandrium catenella cyst concentrations in marine sediments will be presented. A. catenella is a dinoflagellate that produces saxitoxin, a powerful neurotoxin, that can be concentrated in filter feeding shellfish which, if ingested by humans, can lead to paralytic shellfish poisoning and potentially death. A. catenella overwinters as a cyst in the sediment and when environmental conditions are right, in the spring and summer, germinates into the water column as a vegetative cell. Previous studies have mapped the winter distribution of A. catenella cysts in Puget Sound sediments as a way of providing shellfish growers with an early warning system of potential hotspots for blooms of this harmful alga (HABs). The standard method for cyst detection in sediments depends on collecting sediment samples in winter, sieving, preserving, and staining the samples and manually enumerating the cysts using epifluorescence microscopy. This method is very labor intensive and requires extensive training to accurately identify the cysts. This new MERHAB project aims to develop new quantitative molecular assays (qPCR and FISH – fluorescent in situ hybridization) that will be compared with the existing standard microscopy protocol using surface sediment samples from Puget Sound, the Gulf of Maine, and Alaska to see if these new molecular techniques represent a viable alternative to the existing standard microscopy method. Preliminary maps of A. catenella surface sediment cyst distribution from winter 2020 in Puget Sound will be presented, as well as initial comparisons of cyst concentrations determined using both the molecular and microscopy methods.
