Mathematical Modeling of the Antarctic Ecosystem
Over the past few years, Veit and Sundaram have applied recent mathematical
developments in the description of spatio-temporal dynamics to modeling the
foraging habits of birds. One goal of this research is to learn how seabirds in
the Antarctic respond to changes in the abundance and distribution of their
principle prey, Antarctic Krill (Euphausia superba).
Krill abundance distribution is affected by physical oceanographic processes
such as shear fronts and current boundaries. Thus models of krill and its
predators involve the interplay of Eulerian and Lagrangian dynamics. One novel
approach we have been exploring is "agent-based" modeling, in which seabird and
krill dynamics are considered independently and "local" rules of engagement
constructed for their interplay. The rules themselves can be derived from
observational data, for example, by contrasting bird behavior in the vicinity of
krill swarms to that in areas lacking krill. In turn, the foraging models will
make predictions about the dispersion of birds under differing levels of krill
abundance. The long term goal is to forecast the impact of changes in krill
stocks on seabirds. Changes in krill stocks now seem inevitable, due both to
changing climate and to future commercial harvesting.
Recently, Veit was awarded an NSF CAREER Grant to support this activity. The
trip in December was the first of several, over the next few years, on which
groups of undergraduate and graduate students are taken to the Antarctic region.
In each season, the students help survey the insular shelf north of Elephant
Island, and record the abundance, distribution and behavior of seabirds. Krill
abundance is recorded using echosounders at the appropriate frequencies,
information which is corroborated by net hauls and visual sampling. Physical
oceanographic characteristics are recorded at the same time. Assessing the
correlation between these voluminous sets of spatio-temporal data takes
considerable effort, and we expect the job will take about four months. The
primary objective will be to quantify the linkage between prey abundance and
bird behavior, with the long term goal of using information on bird behavior to
index long-term changes in the prey base.
The teaching goal of this effort is twofold. First, the project will introduce
urban college students to a spectacular and economically important ecosystem.
Through their work on an oceanographic research vessel, students will be exposed
to a broad diversity of research topics and methodology, ranging from behavioral
ecology to physical oceanography. For example, on this last trip, a number of
our students assisted another research group, from the Woods Hole Oceanographic
Institute, with their experiments on plankton larvae.
Second, back at their campus, students will participate in the development of
the models to analyze and describe the data. This is facilitated by the
requirement that all students selected for the trips are required to take
courses in mathematical and statistical modeling prior to being selected.
The recent expedition to Antarctica is a culmination of several years of
collaboration in research and teaching. In particular, Veit and Sundaram
developed and team-teach a course in Mathematical Biology at the undergraduate
and graduate level. Recently, they have ported this course to the Graduate
Center as a Ph. D. course in the Biology Program. It will be offered there
during this fall semester.
For more information about these courses contact
Professor Richard Veit at veit@postbox.csi.cuny.edu
or Professor Sundaram at bas@math.csi.cuny.edu