Nancy Marcus
Research
Dormancy is an important phase in the life cycle of many species because it synchronizes
active periods of the life cycle with favorable conditions in the environment and enables
survival during periods of adversity. My research has primarily focused on the phenomenon
of dormancy in marine copepods. These studies have mostly considered the egg dormancy of
calanoid copepods, but we have also conducted some investigations of the CV dormancy
exemplified by Calanus. We have shown that photoperiod and
temperature are the primary factors affecting the induction of diapause egg production and
that accumulations of dormant eggs in the sea bed of coastal waters provide a seed bank for
recruitment of nauplii into the plankton. In some cases these eggs can survive for many years
in the sea bed. In recent years we have also turned our attention to evaluating the impact of
reduced oxygen concentrations on the population dynamics of copepods.
After more than 20 years of conducting "basic" research on the phenomenon of dormancy we are
now applying the knowledge we have acquired to the field of marine aquaculture. We are
particularly interested in developing copepods as a routine and reliable source of food for
rearing marine larval fish. Our approach is to use diapause eggs as a source of nauplii to
feed young larvae. Our research was highlighted in a past issue of Florida Aquaculture
(PDF Document), by
the Division of Aquaculture. Procedures for rearing Acartia tonsa for aquaculture are described
in the online manual,
"A Guide to the
Meso-Scale Production of the Copepod Acartia tonsa"
Collaborators in this effort have included the Harbor Branch Oceanographic Institution, the US Department of Agriculture, and the Mote Marine Laboratory.
We conduct work in our laboratory on the main campus at Florida State University and also at the FSU Marine Laboratory that is located about 1 hour south of Tallahassee.

