Microbial Biogeochemistry

Rocky shoreline with waves

About Us

The Ziervogel Lab studies the role of heterotrophic microbes in elemental cycles in the ocean, and in the Great Lakes. A major focus of our work is the role of marine particles (marine snow) on microbially-mediated cycling of biologically important elements such as carbon, nitrogen, phosphorous, and oxygen. We use microbiological and geochemical tools to determine microbial metabolic rates and organic matter degradation, and laboratory incubations of microbial dynamics, particle formation and sinking, and sediment resuspension.

Kai Ziervogel

Research Expertise:
Biogeochemical cycling of organic matter in aquatic environments; carbon flux in and around sinking particles (marine snow); benthic-pelagic coupling; microbial oil degradation.

Graduate Students:
John Taylor
Jesse Ross

Undergraduate Student:
Madison Alstede. Madison conducts her Senior Capstone Research on microbially-mediated cycling of dissolved organic nitrogen and phosphorus in the South Atlantic Bight.    

Laboratory Assistant:
Rachel Morrison

Previous Lab Member:
Wilton Burns (Fall 2015 – Spring 2017, M.S. Oceanography); Wilton is currently a Ph.D. student in the Stockwell Lab at the University of Vermont. 

Organic matter aggregates (marine snow) and the fate of spilled oil in the ocean (funded by the Gulf of Mexico Research Initiative – GOMRI; 2010 – 2019).

The Ziervogel Lab is involved in two research consortia that study the fate of oil in the Gulf of Mexico, following the 2010 Deepwater Horizon oil spill. Within the two multi-institution efforts, we focus on (i) the fate of sedimented MOS in deep GOM environments following sediment resuspension, and (II) the effects of small-scale turbulence on MOS disaggregation and fragmentation, helping to predict the fate of MOS during sinking through the water column.

Combing single-cell genomics with microbially-mediated cycling of organic matter (funded by the National Science Foundation – NSF; 2018 – 2022).

This research is part of a multi-institution effort with Bigelow Laboratories, ME, and the Desert Research Institute, NV, that will develop and apply new tools on microbial degradation of biologically important polymers in diverse marine and continental environments to connect the functions of individual microbes to their genetic makeup.

Effect of water temperature on microbially mediated cycling of organic matter in the Gulf of Maine (funded by the School of Marine Sciences and Ocean Engineering, UNH; 2018 – 2019).

This collaborative project with two other UNH PIs (Drs. Letscher and Jones) aims to determine the effects of elevated water temperatures on rates of hydrolytic enzymes and turnover rates of particulate and dissolved organic matter in the Gulf of Maine at in-situ temperature and in situ +3ºC (i.e. the predicted temperature increase over the next 15 years).

Effects of sediment resuspension on internal nutrient loading and harmful cyanobacterial blooms in western Lake Erie (funded by the National Aeronautics and Space Administration - NASA; 2017-2019).

The major goal of this project is to determine cyanobacterial responses to storm-induced fluxes of dissolved and particulate phosphorous from the sediment in western Lake Erie. Our research program involves biogeochemical measurements in the water column and sediments at core sites in western Lake Erie, experimental work on sediment resuspension and microbial activities, and remote sensing of particle fluxes and cyanobacterial blooms in the investigation area. This project is a collaboration with NOAA Great Lakes Environmental Research Laboratory.