STREAM ECOLOGY
The conservation of freshwater ecosystems will become increasingly critical in the new century, and streams provide a model ecosystem for illustrating the operation of basic ecological processes and pressures imposed by human exploitation. Their relatively easy access and abundance in many landscapes make streams ideal places for instruction and research in ecology.
RESEARCH
My research has focused on the effects of 1) restoration strategies and 2) seasonal change on stream ecosystem processes . Both of these factors have the potential to alter rates of nutrient cycling, metabolism, microbial communities, organic matter dynamics, and fish communities via changes in light, leaf litter inputs, temperature, and stream substratum types. However, few studies have considered the interaction between seasonal dynamics and restoration projects in their evaluations.
STUDY SITES: RURAL & URBAN
To date, my work has centered on the influence of stream restoration on ecosystem function in northern Michigan. In future research projects, I will apply my experience studying stream restoration in a rural context towards understanding stream restoration initiatives in the New York City metro area.
Rural stream restoration: While the Upper Peninsula of Michigan was major center of logging industry in the late 19th and early 20th centuries, recreational activities such as hunting and fishing are now stronger economic drivers in the region. River restoration is an important goal of management agencies in order to increase production of native brook trout and attract visitors.
State, Shane, and Walton Creeks are forested headwater streams near Kenton, Michigan
Urban stream restoration: The ecosystem pressures in rural and urban environments are different (i.e., legacy of logging vs. human population and industrial pollution), but the tools and paradigms used in analyzes are identical. In addition, the study of urban restoration ecology provides unique opportunities to unite economic, social, and ecological perspectives regarding the relationship between urban culture and the natural environment. It's my view that an interdisciplinary collaboration will ensure resources are directed towards the implementation of projects that promote ongoing benefits for ecosystem and public health. I am currently seeking research partners and locations in the New York City region to carry out this work.
Urban streams have modified hydrology and a greater probability of having chemical and particulate pollution. (Photos courtesy of Dr. Laura Johnson for LINX II)
STREAM RESTORATION
Two types of restoration strategies commonly employed in streams in the Upper Midwest are the addition of large wood and the placement of gravel with sediment traps and reinforced banks. Large wood serves to increase organic matter retention and habitat complexity, and the gravel addition provides spawning areas for trout. Sally Entrekin and I have been the graduate students working on a large project funded by the USDA (Principal Investigators Drs. Jennifer Tank, Emma Rosi-Marshall, and Gary Lamberti) to experimentally determine the effects of large wood addition on ecosystem processes such as nutrient cycling, metabolism, secondary production, and fish community dynamics.
Stream restoration (manipulation) can effect biota directly through changes in habitat (geomorphology) or indirectly by fostering greater abundance of food resources
Map of log addition effects on depth in Shane Creek (created with GS+)
TEACHING
General Biology 1003: Baruch College
Undergraduate Teaching Assistant: Principles of Biology, Diversity and Function, Experimental Biology
Graduate Teaching Assistant: Aquatic Ecology
Teaching Apprentice: General Ecology
Guest Lecturer: Aquatic Ecology, General Ecology, Human Impacts and the Environment, Stream Ecology, and Stream Ecology: Methods, Loyola University of Chicago and University of Notre Dame
Certification of Teaching Excellence in Biological Sciences. University of Notre Dame 10/15/06
Hoellein, T.J., J.L. Tank, E.J. Rosi-Marshall, S.A. Entrekin, and G.A. Lamberti. 2007. Controls on spatial and temporal variation of nutrient uptake in three Michigan headwater streams. Limnology and Oceanography 52 (5) 1964-1977. Hoellein et al. 2007.pdf
Entrekin, S.A., E.J. Rosi-Marshall, J.L. Tank, T.J. Hoellein, and G.A. Lamberti. 2007. Macroinvertebrate secondary production in forested sand-bottom streams of the Upper Midwest. Journal of the North American Benthological Society. 26 (3): 472-490. Entrekin et al. 2007.pdf
Denaturing gradient gel electrophoresis (DGGE) illustrating fungal communities from cellulose substrata that were amended with different nutrient types and incubated in State Creek for three weeks
GOALS
As a new professor at Baruch College, my career vision is to combine environmental research with teaching and public service. My overarching goal is to influence public awareness and restoration of local freshwater ecosystems through research, education, and outreach. I am also keenly interested in collaborating with other instructors, researchers, and generally interested citizens to include ecological perspectives in subjects such as ethics, law, economics, and social justice.
