The historic 2005 “red tide” of the harmful algae
Alexandrium fundyense was the most widespread and
intense in New England since 1972. Concentrations of toxic
algae grew to 40 times the norm, and the tiny plants spread
to waters not usually affected by the species, which can cause
paralytic shellfish poisoning in humans.
Through a combination of good luck and good planning, WHOI
biologists were perfectly positioned to document the event
and to collect thousands of samples of algae-filled water
and sediment. Funded by the Woods Hole Center for Oceans and
Human Health (see Centers section),
a research team led by Dennis McGillicuddy, Deana Erdner,
and Bruce Keafer went to sea on R/V Oceanus in May
to examine the environmental conditions and biological phenomena
that distribute and disperse Alexandrium. After the
algae population exploded, NOAA funded the researchers to
go back to sea on CRV Tioga and other vessels a dozen
more times between May and December. Assisting him in sample
collection were summer students Theresa Black and Brenna Mahoney,
summer guest student Angie Moliter and research assistant
Kerry Norton.
On shore, Erdner, Linda McCauley, Norton, and a corps of students
and research assistants in Senior Scientist Don Anderson’s
laboratory isolated and cultured the cells that wrecked so
much havoc, analyzing the genetic and physiological makeup
of Alexandrium communities from various locations.
The study was founded on the idea that, as with humans, a
single population is actually composed of different “races”
or genotypes.
“We want to know who caused this bloom,” said
Erdner, research associate in the Biology Department. “Did
oceanographic and environmental conditions favor the bloom
of a certain genotype of Alexandrium? So far, it
appears that no single genotype dominated, but it’s
too early to say for sure. We know there was a lot of genetic
diversity at the beginning, middle, and end of the bloom.”
The investigative work will feed into computer models being
developed to understand—and eventually predict—the
conditions under which a bloom might develop and which type
of algae might show up.
—Mike Carlowicz
» View more
highlights for the Biology Department
|
