Watershed Ecology Staff

Stefanie Kroll, Ph.D.

Assistant Research professor; Section leader Watershed Ecology;
Project Science Director for the Delaware River Watershed Initiative

Stefanie Kroll has a PhD in ecology from SUNY College of Environmental Science and Forestry in Syracuse, NY. She obtained a master’s-equivalent at the University of Castilla-La Mancha in Albacete, Spain, after working in interpretation and translation and teaching English for several years. Her focus on aquatic ecosystems is not surprising given that she grew up spending summers fishing and canoeing in the lakes and streams of New York State and surrounding areas. She volunteers with the Raritan Headwaters Association and Big Brothers Big Sisters of Southeastern Pennsylvania and works with ANS’ Women In Natural Sciences program. Previous work includes forest inventory, program support for a nonprofit environmental organization, community assessment of Onondaga Lake, and stream surveys throughout Spain.

Kathryn Christopher, M.S.

Staff Scientist II; Science Communication Specialist

Kathryn Christopher

Kathryn provides overall organizational support, conducts fieldwork and supports project communications for the Watershed Ecology section. Communications responsibilities include facilitating outreach to project partner organizations and producing data products such as reports and visual data representations. She also leads the Watershed Ecology section’s DRWI media efforts – editing the monthly “Stream Samples” e-newsletter, providing photos and written content for promotional and informational materials and managing the Academy’s DRWI team Twitter account (@ANSStreamTeam). Kathryn first started at the Academy in 2012 as a volunteer in the Botany Department. In 2013, she was hired as an Academy employee to work on the Delaware River Watershed Initiative. She has a master’s degree in environmental science from Drexel University and a bachelor’s degree in biology from Penn State University.

Hayley Oakland

Staff Scientist

Hayley Oakland

Hayley is a staff scientist in the watershed ecology section. She assists with data collection and analysis, report and grant writing, and project management. She has worked at the Academy of Natural Sciences of Drexel University since 2015, which has included managing the Growing Greener project under PI Stef Kroll, Ph.D. Hayley is pursuing a master’s of science in the Geography and Environmental Systems (GES) department at the University of Maryland, Baltimore County under the advisement of Matthew Baker, Ph.D. She holds a Coastal Resilience and Sustainability Fellowship from the Maryland Sea Grant, under which she will study the relationship between stream habitat and biota with Drs. Kroll and Baker. Hayley received her bachelor of science in 2014 from the University of Oregon in environmental science and a minor in biology.

Will Ryan, Ph.D.

Research Botanist; Restoration Ecologist

Will Ryan

Will Ryan is a restoration ecologist and field botanist with over fifteen years of experience in the management of ecologically significant natural areas in the Mid-Atlantic and New England regions. His work in the Patrick Center for Environmental Research focuses on scientific research in the fields of plant community ecology and restoration ecology, identifying best management practices for ecological restoration projects, and providing scientific support to over 50 organizations involved in the Delaware River Watershed Initiative. Will completed a Ph.D. in Entomology and Wildlife Ecology at the University of Delaware, under the advisement of acclaimed author and scientist, Dr. Douglas Tallamy, and a M.S. in Physical Geography, also at UD, working with well-known forest hydrologist, Dr. Delphis Levia.

Brendan Marencin

Lab Technician

Brendan Marencin

Brendan primarily works on the taxonomic identification and classification of aquatic macroinvertebrates to the family or genus level. He’s also responsible for preparing field samples for use in the lab and keeping the data organized. He performs fieldwork in wadeable streams to collect the samples using kick nets or Surber nets.

He is a recent graduate of Drexel University and received a Bachelor of Science with a concentration in Biological Sciences. During his junior year of his undergraduate program, he came to the Patrick Center during his cooperative opportunity internship. He has recently taken an interest in slide mounting and identifying the non-biting midge fly family, Chironomidae, to genus.


Research Assistant for Patrick Center of Environmental Research;
PhD Student, BEES Department, Drexel University


Boloroo is a PhD student within the department of Biodiversity, Earth and Environmental Sciences at Drexel University working as a Research Assistant for the Academy’s Patrick Center for Environmental Research. With a focus on central and Western Mongolian macroinvertebrate fauna, Boloroo brings her mayfly expertise to the lab with nearly a decade of taxonomic experience. Her doctoral work includes macroinvertebrate populations from western U. S. and eastern Pennsylvania utilizing Mongolian’s pristine aquatic ecosystems as reference conditions.