Environmental Biogeochemistry Staff

A photo of Timothy Maguire wearing a black suit with a dark blue undershirt.

Dr. Timothy J Maguire, Biogeochemistry Section Leader; The Academy of Natural Sciences of Drexel University

Dr. Timothy J. Maguire is the Biogeochemistry Section Lead at the Academy of Natural Sciences in Philadelphia. With a Ph.D. from Boston University, he has conducted influential research on the effects of human populations, urban infrastructure, and agriculture on biogeochemical cycles. Tim's expertise and postdoctoral work at the University of Michigan Collaborative Institute for Great Lakes Research, NOAA Great Lakes Environmental Research Laboratory, and University of Windsor Great Lakes Institute for Environmental Research have solidified his reputation in the field. As a Philadelphia researcher, he continues to explore how human activities impact the environment and shape the future of biogeochemistry.


Dr. David Velinsky, Professor and Senior Scientist, Dept. of Biodiversity, Earth and Environmental Science, Drexel University


David is a marine biogeochemist with over 20 years experience in marine and freshwater studies related to nutrient cycling, isotope biogeochemistry, and wetland nutrient and metal geochemistry. He started as an organic geochemist studying the transport of organic compounds in estuaries and from atmospheric transport, and shifted to studies of sulfur and selenium geochemistry. He has published studies related to many aspects of biogeochemistry and has a broad range in the cycling of bioactive elements. David has a B.S. in Oceanography from Florida Institute of Technology and a Ph.D. in Chemical Oceanography from Old Dominion University.


Dr. Michelle Gannon, Associate Chemistry Laboratory Manager, Assistant Teaching Professor, Dept. of Biodiversity, Earth, and Environmental Science, Drexel University

Michelle is a biogeochemist studying stable isotope and trace element chemistry ranging from single organisms (giant clam shells) to ecosystems. She manages the Stable Isotope Facility and performs trace element analysis in the LAVA lab at Drexel University. She has a B.S. in Geological Sciences from Temple University, M.S. in Geological Sciences from The University of Alabama, and Ph.D. from Drexel University.


Melissa Bross, Staff Scientist III

Melissa has a background in environmental science and geology, and thus excels at nutrient analyses and maintaining field electronics and instrumentation. She has over a decade of experience in environmental analysis. She has a B.S. in Environmental Science from Temple University and a M.S. in Environmental Science from Drexel University.


Tracey Curran, Staff Scientist II

Tracey coordinates the general lab facilities, manages various lab and field projects and assists with instrumentation. With degrees in molecular and cell biology and environmental science, she provides unmatched laboratory and field experience. She has a B.S. in Biology from Stockton University and a M.S. in Environmental Science from Drexel University.


Joseph Heiczinger, Staff Scientist I

Joey assists in all aspects of the Section’s activities, from field sampling to lab analysis. Joey has a M.S. in Management & Leadership from Western Governors U. and a B.S. in Biology from Lock Haven University.


Paul Kiry, Senior Staff Scientist IV

Paul has over 50 years of experience in all forms of environmental analysis of nutrients and trace metals. Paul, known as the chemistry guru, produces the lowest detection limits and is the point person for any chemistry related question. He has a B.S. in Biology from Delaware Valley College of Science and Agriculture and a M.S. in Environmental Science from Drexel University.

A headshot of Sophia Larson

Sophia Larson

Sophia is a Ph.D. candidate whose work focuses on forest carbon dynamics and related corresponding biogeochemical processes within the Green Mountain National Forest in Vermont, USA. She investigates how soil characteristics and stream water chemistry respond to diverse forest management practices and climate change. She has a B.S. in Earth Sciences from Dickinson College, an M.S. in Environmental Science from Drexel University, and has worked in the public and private environmental sectors.