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My research interests focus on different
aspects of ecology and biology of the microbial food web (MFW) in aquatic
ecosystems. The MFW consists of a wide array of photosynthetic, heterotrophic, and
mixotrophic microorganisms. Less than two decades ago, scientists thought that most
of energy and nutrient transformations in the ocean were accomplished by relatively large
organisms (Classical Food Chain). Only with the development of modern methods did
the abundance, diversity, and activity of the ocean's smallest organisms become
apparent. The constantly fluctuating abundance and structure of the microbial food
web have profound effects on the flux of nutrients and energy throughout aquatic
systems. Understanding these flux patterns is a prerequisite for predicting how
marine and limnetic ecosystems might respond to global change or human impacts. Although
very complex, the MFW provides a researcher with a rare opportunity to simultaneously
examine organisms representing different steps of evolution from sub-cellular viruses to
metazoan invertebrates in their dynamic interactions with each other and their
environment. |
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The major objective of our collaborative
(with UT and NOAA) research program supported by the
National Science Foundation is to examine microbial food web dynamics and nutrient cycling
in Lake Michigan. This research is a part of a 5-year interdisciplinary research
program aimed at studying the Lake Michigan recurrent coastal plume (EEGLE). This physical event
may fundamentally affect food web dynamics in Lake Michigan by causing major changes,
during the winter-spring transition period, that, in turn, define the annual evolution of
the biotic community in the lake. We are comparing the temporal and spatial
structure and abundance of microbial food web and measuring nutrient cycling rates in
relation to community and species-specific grazing rates of and on microzooplankton. |
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Another research collaboration with UT
scientists focuses on microbial dynamics in Laguna Madre. Over the past nine
years, this coastal lagoon has experienced a persistent nuisance algal bloom also known as
the Texas Brown Tide (TBT). The bloom is mainly caused by the pelagophyte Aureoumbra lagunensis. Here, we are studying the
effects of the bloom on nitrogen dynamics as well as on trophic cascades, involving the
copepod Acartia tonsa and microzooplankton. |
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Peterl@uakron.edu |
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