How viable are cysts of the harmful alga Alexandrium catenella from a “seed bed” in Puget Sound?
Presentation Abstract
Alexandrium catenella is a single-celled harmful alga that can produce a range of potent neurotoxins when it blooms. Shellfish concentrate these toxins from the water during filter feeding, and consumption of contaminated shellfish can impact wildlife and can also cause a severe illness in humans called paralytic shellfish poisoning (PSP). The life cycle of A. catenella involves a benthic overwintering cyst stage and a planktonic motile stage. Areas with high concentrations of resting cysts on the seafloor are called “seed beds” and are potential bloom initiation sites. To develop predictive bloom models for local forecasting, a better understanding of A. catenella life history characteristics is necessary; specifically, the processes governing cyst germination and bloom initiation. Using the Most Probable Number (MPN) method, the percentage of viable cysts and the rate of germination were each determined at 14°C and 20°C for the Quartermaster Harbor “seed bed” in Puget Sound. The number of viable cysts in the 0-1 cm layer was compared to the total number of cysts determined by primuline-stained counts of cysts in the same sample. All of the cysts in the sediment sample were capable of germinating at 20°C whereas 15% of cysts were capable of germinating at 14°C. The rates at which cysts germinate were also found to be temperature dependent, with a faster germination rate as temperature increases. These data suggest that temperature may affect both cyst germination capability and rate. Understanding the relationship between cyst germination and temperature can facilitate more accurate analysis of existing benthic cyst distribution data, as well as improving the sourcing of blooms from “seed beds.”
Session Title
Session S-08A: Harmful Algal Blooms, Climate, Shellfish, and Public Health - Emerging Issues in a Changing World
Conference Track
Harmful Algal Blooms and Shellfish
Conference Name
Salish Sea Ecosystem Conference (2014 : Seattle, Wash.)
Document Type
Event
Start Date
1-5-2014 5:00 PM
End Date
1-5-2014 6:30 PM
Location
Room 6C
Genre/Form
conference proceedings; presentations (communicative events)
Contributing Repository
Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.
Subjects – Topical (LCSH)
Alexandrium catenella--Dispersal--Washington (State)--Puget Sound; Alexandrium catenella--Growth--Climatic factors--Washington (State)--Puget Sound; Dinoflagellate cysts--Washington (State)--Puget Sound
Geographic Coverage
Salish Sea (B.C. and Wash.); Puget Sound (Wash.)
Rights
This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.
Type
Text
Language
English
Format
application/pdf
How viable are cysts of the harmful alga Alexandrium catenella from a “seed bed” in Puget Sound?
Room 6C
Alexandrium catenella is a single-celled harmful alga that can produce a range of potent neurotoxins when it blooms. Shellfish concentrate these toxins from the water during filter feeding, and consumption of contaminated shellfish can impact wildlife and can also cause a severe illness in humans called paralytic shellfish poisoning (PSP). The life cycle of A. catenella involves a benthic overwintering cyst stage and a planktonic motile stage. Areas with high concentrations of resting cysts on the seafloor are called “seed beds” and are potential bloom initiation sites. To develop predictive bloom models for local forecasting, a better understanding of A. catenella life history characteristics is necessary; specifically, the processes governing cyst germination and bloom initiation. Using the Most Probable Number (MPN) method, the percentage of viable cysts and the rate of germination were each determined at 14°C and 20°C for the Quartermaster Harbor “seed bed” in Puget Sound. The number of viable cysts in the 0-1 cm layer was compared to the total number of cysts determined by primuline-stained counts of cysts in the same sample. All of the cysts in the sediment sample were capable of germinating at 20°C whereas 15% of cysts were capable of germinating at 14°C. The rates at which cysts germinate were also found to be temperature dependent, with a faster germination rate as temperature increases. These data suggest that temperature may affect both cyst germination capability and rate. Understanding the relationship between cyst germination and temperature can facilitate more accurate analysis of existing benthic cyst distribution data, as well as improving the sourcing of blooms from “seed beds.”
