Environmental and Ecological Regulation of Differences and
Interactions between Solitary and Colonial forms of Phaeocystis antarctica
Click here to see our
Antarctic journey slide show (large powerpoint file; be patient when loading) Research Objectives: Phaeocystis antarctica (Prymnesiophyceae)
is widely distributed in the Southern Ocean and plays important roles in
polar ecology and biogeochemistry. It is a dominant primary producer, a main
component of organic matter vertical fluxes, and the principal producer of
volatile organic sulfur in the region. Yet P.
antarctica is also one of the lesser known species in terms of
its physiology, life history and trophic relationships with other organisms. P. antarctica occurs
mainly in two morphotypes: solitary cells and mucilaginous colonies, which
differ significantly in size, architecture and chemical composition. Relative
dominance between solitary cells and colonies determines not only the size
spectrum of the population, but also its carbon dynamics, nutrient uptake and
utilization. However, what regulates the differences between solitary and
colonial forms of P.
antarctica is not certain. The research objective of this project
was to address these over-arching questions:
Experiments
were conducted in the McMurdo station with natural P. antarctica
assemblages and co-occurring grazers. Laboratory experiments were conducted
to study size-specific growth and photosynthetic rates of P. antarctica,
size-specific grazing mortality due to microzooplankton and mesozooplankton,
the effects of macronutrients and micronutrients on the relative dominance of
solitary cells and colonies, and the effects of grazing-related chemical
signals on P. antarctica
colony development. We also developed educational materials to bring polar
science to K-12 students and the general public. |
Peer-reviewed Publications (please contact us for reprints):
from prolonged darkness and freezing. Proceedings of the Royal Society B 276:81-90
Elliott
DT, Tang KW, Shields AR (2008) Mesozooplankton beneath the summer sea ice in
McMurdo Sound, Antarctica:
abundance, species composition, and
DMSP content. Polar Biology 32:133-122
Tang
KW, Smith WO Jr, Elliott DT, Shields AR (2008) Colony size of Phaeocystis antarctica
(Prymnesiophyceae) as influenced
by zooplankton grazers. Journal of
Phycology 44:1372-1378
Shields
AR, Smith WO Jr (2008) An examination of the role of colonial Phaeocystis antarctica in the microbial
food web of the
Ross Sea. Polar Biology 31:1091-1099
review and future challenges. Biogeochemistry 83:147-172
Conference and
invited presentations:
Tang KW, Smith WO Jr, Elliott DT,
Shields AR (2008) It's good to be big--- Phaeocystis
antarctica colony size under the influence
of zooplankton grazers. Ocean Sciences Meeting, Orlando.
Tang KW (2008) Ecology of solitary and
colonial Phaeocystis antarctica.
IGB-Neuglobsow, Germany.
Tang KW, Shields AR, Smith WO Jr.
(2007) Dark and cold survival of Phaeocystis
antarctica. Workshops on Phaeocystis
blooms:
causes and consequences, France. [Abstract] [Powerpoint
presentation] (Data are not to be cited without permission from the
authors)
Nejstgaard JC, Artigas LF, Antajan
E, Sazhin AF, Tang KW, Steinke M, Dutz J, Koski M, Long JD, Guiselin N (2007)
Zooplankton
grazing on Phaeocystis:
a quantitative review and results from bottle incubation experiments and molecular
gut analysis in the
eastern English Channel. Workshop on Phaeocystis blooms: causes and
consequences, France.
Tang KW (2007) Why its sucks to be
single--- a lesson from the enigmatic haptophyte Phaeocystis. Crary Science Lecture, McMurdo
Station, Antarctica.
Tang KW (2006) Ecology of solitary
and colonial forms of Phaeocystis (invited
seminar). Polar Research Institute of China, China.
Tang KW (2006) Ecology of solitary
and colonial forms of Phaeocystis (invited
seminar). South China Normal University and Jinan
University (joint seminar), China.
Tang KW (2006) Ecology of solitary
and colonial forms of Phaeocystis (invited
seminar). HK University of Science and Technology,
Hong Kong.
Outreach Activities:
Invited talk: “ESCAP in
McMurdo: studying a unique phytoplankton species in Antarctica”,
Mentoring Young Scientists program,
Virginia Aquarium and Marine Science Center (November 2008)
“ESCAP from McMurdo: studying
a unique phytoplankton species in Antarctica” Hampton University DREAMS
seminar (October 2008)
Invited talk: “Into the
Cold--- a scientific journey” (presented to Marine Science Club), Booker
T. Washington Middle School, Newport
News, Virginia (November 2007)
Invited talk: “Into the
Cold--- a scientific journey” (presented to 7th graders), Booker T.
Washington Middle School, Newport News,
Virginia (November 2007)
Invited talk: “Into the
Cold--- a scientific journey” (presented to 7th graders), VIMS REU
program (June 2007)
“Into the Cold--- a scientific
journey”, Hampton University DREAMS seminar (February 2006)
Bringing polar
science to K-12 classroom:
In 2006/7 season we invited Jennifer
Gaydos (William & Mary School of Education) to join the ESCAP team.
Jennifer was a teacher-
in-training in Lafayette High School (Williamsburg, VA). In
addition to actively participating in the experiments, Jennifer established a
web diary for her LHS students to follow our research
activities in McMurdo. We also did a live web-cast to directly communicate with
Lafayette students and talked to them about living and
working in McMurdo.
Upon return, Jennifer produced a
digital “documentary” of the ESCAP project based on her own
experience. This documentary has
become a great tool for our outreach effort. We also have a
collection of photos and powerpoint presentations suitable for educational
use. If you would like to receive a copy of the documentary
or other educational materials related to our project, or to invite us to talk
to
K-12 students about polar research, please contact Kam Tang.