Molecular probes link
sea lion deaths
to toxic algal bloom
EMBARGOED FOR RELEASE:
Wednesday, 5 January 2000 at 11:00 U.S. Pacific Time
Debbie Meyer, Communications Coordinator
Monterey Bay Aquarium Research Institute
(831) 775-1807, firstname.lastname@example.org
MOSS LANDING, CaliforniaNew molecular probes used to identify toxic diatoms
allowed researchers to link a bloom of these algae to the deaths of more than 400
California sea lions in Monterey Bay during May and June 1998. Dr. Christopher
Scholin, a molecular biologist at the Monterey Bay Aquarium Research Institute
and colleagues report their research results in the 6 January issue of the journal
Harmful algal blooms in the ocean result from the rapid growth of some species of
microscopic algae that produce toxic by-products. These toxins can cause public health
threats and fisheries closures when transferred up the food chain, but the connection
between algal blooms and marine mammal mortality has been difficult to establish.
Traditional techniques used to identify the presence of potentially toxic algae work after
the bloom has occurred and may even miss the bloom. In this study, the bloom of the diatom
Pseudo-nitzschia australis and its associated neurotoxin domoic acid was first
noted in plankton samples using DNA probe tests developed by MBARI and a toxin test
developed by scientists at the National Oceanic and Atmospheric Administrations
Marine Biotoxin Research Program in Charleston, South Carolina.
"The DNA probes and toxin tests detected the short but significant bloom in Pseudo-nitzschia
australis," said Dr. Scholin. "Our early alert and collaboration with marine
mammal scientists and public health officials helped us collect the data needed to connect
the sea lion deaths with the bloom."
|A sample showing several species of the genus Pseudo-nitzschia
as seen under a light microscope.
||The toxic species Pseudo-nitzschia
australis identified in
the same sample by the glowing DNA probe.
These techniques, in which species-specific DNA probes bind to the RNA of the toxic
algae and glow when viewed under a microscope, could be applied using a robotic device in
the field. Dr. Scholin and colleagues at MBARI plan to deploy a prototype of such a device
in Monterey Bay this summer.
Note to media: Images and footage
available on request.
Additional research contacts:
Dr. Chris Scholin, Monterey Bay Aquarium Research Institute,
Dr. Frances Gulland, The Marine Mammal Center, 415-289-7370
Dr. Gregory J. Doucette, Marine Biotoxins Program, NOAA-NOS,