Marine Sciences Program at Avery Point

I am a biological oceanographer. My research interests are in the biology, ecology and evolution of planktonic organisms, particularly pelagic copepods. Earlier in my career I investigated questions dealing with the role of planktonic organisms in biogeochemical cycles in the ocean, and the formation and fate of marine aggregates. Recently, my interests have broadened to deal with questions of the evolutionary ecology of plankton. My proudest professional achievement is training of some excellent graduate students. I encourage my students to become critical thinkers, to work on important questions in the field and to publish their work in a timely manner. These are the current projects (Sept. 2006) in my research group:

Interaction of grazers and toxic algae. Toxic algal blooms are proliferating worldwide, but we understand little of the consequences of such proliferation. We are currently interested in the evolution of grazer resistance to phytoplankton toxins. We have experimentally demonstrated that populations of grazers that experience frequent blooms of toxic algae have a fitness advantage over those populations, which do not frequently experience such blooms. Through grants from NOAA and EPA, We are now investigating the dynamics and transformations of toxins in grazers, and how toxin resistance affects them. ). We are also investigating the interaction of toxic algae, grazer resistance, and ecological stoichiometry on the expression of trophic cascades in the oceans.

Trophic cascades. There is considerable debate nowadays as to the existence and strength of trophic cascades in the ocean. Cascades occur when addition of a top predator effects changes down the food web. We are interested in experimentally examining the role of food web complexity and the stoichiometric imbalance between top predators and primary producers in modulating trophic cascades in pelagic ecosystems.

Long Island Sound Integrated Coastal Observing Sytem (LISICOS). I am in charge of the process studies of LISICOS (http://lisicos.uconn.edu/). Specifically, several faculty at UCONN are conducting studies dealing with the control of hypoxia in Long Island Sound (LIS). Our own contribution to LISICOS is the study of downward fluxes of organic matter and grazing in elemental cycling in LIS.

Water quality and planktonic resources in Long Island Sound. We are doing a historical analysis of water quality and plankton in LIS. With this analysis, we attempt to document if any changes have occurred in LIS in the last 50 years, and if so, what has driven these changes. This is a collaborative project with Dr. James O’Donnell, Dept. Mar. Sci.

Ecosystem simulation of Long Island Sound. The goal of this study is to establish the sensitivity of the LIS the System-Wide Eutrophication Model (SWEM) to model parameters, model formulation, and inter-annual variations in weather and river discharge. This is also a collaborative project with Dr. James O’Donnell, Dept. Mar. Sci.

Research Projects

Current Students

Publications

Hans G. Dam