Congrats to Leslie Rieck, Ph.D.!

A big congratulations to Leslie Rieck, who successfully defended her dissertation: “Associations Between Hydrogeomorphic Characteristics and Biotic Community Dynamics in Urban Streams of Columbus, Ohio, USA” earlier today (June 27, 2019). Leslie’s research addresses urbanization of watersheds and how altered fluvial geomorphic processes and channel structure relate to macroinvertebrate drift, fish assemblages and stream-riparian food webs. Leslie will start a post-doc at Lycoming College in PA later this summer.

Society for Freshwater Science hosts special webinar on proposed WOTUS Rule

REMINDER: Please join us for the SFS-sponsored webinar:

Waters of the US (WOTUS) Proposed Rule: Overview and Action Steps

Efforts by the Trump administration are underway to roll back our nation’s Clean Water Act protections. The newly proposed rule revises the definition of Waters of the United States (WOTUS) and aims to exclude thousands of miles of streams and millions of acres of wetlands that are critical
to freshwater resources.

Join us for an informative and timely overview of the proposed WOTUS rule, the science that contradicts it, and how to submit an effective regulatory comment.

Dr. Mažeika Sullivan will lead this SFS-sponsored webinar open to the first 500 interested attendees at 2 P.M. ET on Monday, April 1st.

Click to Join the Webinar at 2 PM ET on April 1st
Dr. Mažeika Sullivan is an Associate Professor in the School of Environment and Natural Resources at The Ohio State University (OSU) and the Director of the Ramsar-designated Shiermeier Olentangy River Wetland Research Park. He received a B.A. in Anthropology from Dartmouth College, and earned his M.S. in Biology and Ph.D. in Natural Resources from the University of Vermont. Subsequently, he was a Postdoctoral Research Fellow at the University of Idaho before joining the OSU faculty in 2008. Dr. Sullivan’s research focuses on water quality and aquatic ecosystems, where his work integrates community and ecosystem ecology, fluvial geomorphology, and biogeochemistry. He is particularly interested in understanding natural and human drivers of biodiversity, community organization, and ecosystem function, and in using basic science to inform conservation and restoration efforts. Dr. Sullivan has published >50 peer-reviewed scientific publications. Dr. Sullivan also served as a member of the US EPA’s Science Advisory Board “Connectivity of Streams and Wetlands to Downstream Waters” Panel (2013-2014), has reviewed for over 30 ecological and environmental journals, and is an active member of the Society for Freshwater Science, American Fisheries Society, and the Ecological Society of America. Dr. Sullivan is a Distinguished University Teacher and served as a Fulbright Distinguished Chair of Biodiversity and Sustainable Development (Colombia, 2014-2015). His research has been funded by several sources, including the NSF, CDC, US Fish & Wildlife Service, Bureau of Land Management, US EPA, Ohio Department of Transportation, and the Ohio Division of Natural Resources.

Aquatic macroinvertebrate communities respond to riparian insect invader

Check out our new article about how a terrestrial invasive species shifts aquatic macroinvertebrate communities! You can read it here


Diesburg KM, SMP Sullivan, DWP Manning. 2018. Changes in benthic invertebrate communities of central Appalachian streams attributed to hemlock woolly adelgid invasion. Aquatic Sciences 81:11


Eastern hemlock trees (Tsuga canadensis [L.] Carr.) often dominate riparian vegetation of central Appalachian headwater streams, and the invasive hemlock woolly adelgid (Adelges tsugae Annand; HWA) has decimated hemlock stands in this region. Although research concerning HWA impacts on soil, hydrology, and forest structure is emerging, associated changes in stream structure and function are not as well documented. We quantified HWA-invasion effects on benthic macroinvertebrate communities in 21 headwater streams across Ohio, West Virginia, and Virginia (USA) representing unimpacted, moderate invasion, and severe invasion, respectively. We observed differences in benthic macroinvertebrate community composition; severely invaded sites exhibited the highest diversity, whereas moderate sites had the lowest diversity. The composition of macroinvertebrate functional feeding groups exhibited shifts as well. For example, the relative abundance of herbivorous invertebrates increased from 4% (± 3%) at unimpacted sites to 23% (± 14%) at severely impacted sites. Changes in macroinvertebrate density, diversity, and functional-group composition were associated with sediment grainsize distribution (proportion bedrock and D84), large-wood characteristics (volume and density), and nutrient concentrations (PO4 and NH4). Our results suggest that in-stream physical and chemical alterations associated with HWA-invasion and subsequent hemlock decline are associated with changes in stream invertebrate diversity and trophic relationships. We demonstrate how a pervasive terrestrial invader can influence in-stream biotic communities.

Joe Corra defends MSc thesis on aerial insectivorous birds, climate, and water quality in urbanizing landscapes

STRIVE Lab MSc candidate Joe Corra presented his research the relationships among water quality, climate, and aerial insectivorous birds, and how urbanization shapes those relationships. Aerial insectivorous birds – swallows, swifts, nightjars, and flycatchers – have experienced alarming declines in North America in recent decades. Declines have occurred across this diverse guild, suggesting that the availability and quality of insect prey is a common factor. Emergent aquatic insects constitute an important prey resource for many aerial insectivorous birds, and thereby connect riparian aerial insectivores to aquatic ecosystems. For his research, Joe used the Tree Swallow (Tachycineta bicolor) to investigate the associations between aerial insectivorous birds and urbanization, climate, and water quality. Building on the research launched by the STRIVE lab in 2014, he evaluated Tree Swallow reproductive success, body condition, and trophic dynamics at seven river-riparian sites representing urban and natural/protected land use in greater Columbus, Ohio over four consecutive breeding seasons (2014-2017).

Findings: Urban sites were associated with earlier clutch initiation in the spring – urban Tree Swallows laid their eggs one week earlier than their non-urban counterparts. In addition, urban-breeding swallows had greater fledging success, with urban nests producing 1.4 more fledglings, on average, than sites in natural/protected landscapes. Body burdens of mercury were higher among nestlings at urban sites but exhibited strong interannual variability. A gradient of stream urbanization was related to greater dietary reliance by Tree Swallows on aquatic insects and aquatically-derived energy; further, urban swallows fed at higher trophic levels than did swallows at natural/protected sites.

Investigation of potential drivers suggested that multiple features of the urban environment, including higher mean temperatures, increased availability of high-quality aquatic insect prey, and fewer days of extreme cold may contribute to fledging success and influence the timing of Tree Swallow breeding in urban areas. Further, stream urbanization was related to increased reliance on aquatic resources and higher trophic position, highlighting the role of aquatic-terrestrial connectivity in urban areas. However, the potential risk from elevated aquatic contaminants in urban areas represents a potentially adverse impact for urban-breeding aerial insectivores. Overall, this research underscores the importance of water quality for terrestrial wildlife, and the results draw attention to the potential role for cities in the conservation of aerial insectivorous birds.

Adult Tree Swallow.

Joe banding a Tree Swallow.

Relationship between Urban Stream Index and Tree Swallow Trophic Position (nestlings: p < 0.0001; adults: p = 0.001).

This research was funded by the Ohio Division of Wildlife through the Ohio Biodiversity Conservation Partnership, The Columbus Zoo & Aquarium, and the National Science Foundation.

STRIVE Lab and GrayFishLab Recruiting Post-doc, Grad Students for ALAN Research

With new funding from the Ohio Department of Transportation, we’re looking for a motivated post-doc, as well as MSc, and PhD students to join our research groups. See below for details! Post-docs applicants apply by Jan. 04, 2019; Grad Student applicants apply by Jan. 01, 2019.

Aquatic Ecology – Artificial Lighting at Night: Closing date: Jan. 04, 2019. Start date: by March 1st if possible. Salary: $48-50K/annually, plus benefits. The Stream and River Ecology Laboratory at The Ohio State University is seeking a Post-Doctoral Research Associate. The incumbent will be expected to contribute to research on the ecological effects of artificial lighting at night (ALAN) in aquatic and riparian ecosystems (from individuals to ecosystems), including field, experimental (e.g., mesocosms), and lab work. In addition, the s/he will be expected to assist with the analysis of data as well as the preparation of reports, articles, and associated project deliverables. The incumbent will be based at the Schiermeier Olentangy River Wetland Research Park and will be mentored by Dr. Mažeika Sullivan, with opportunities to work with project co-PI Dr. Suzanne Gray. Strong statistical and programming skills, preferably with R, are required. Interest in gaining teaching experience is highly desirable. Applicants must have completed and defended their Ph.D. by the start of the appointment. Interested applicants should submit the following: (1) Cover letter, C.V., and the names and contact information for three references; (2) Unofficial transcripts; and (3) Examples of published work. Funding is available for two years. For more information or to apply, contact Dr. Sullivan @

PhD position – ALAN 2018-final-ssfr2f

Also check out our previous and current work on ALAN under Projects.

Levon B. defends honor’s thesis on effects of urban stream temperatures on stream fish

After a couple years of hard field and lab work, STRIVE undergrad Levon Bajakian presented his honor’s research on the influences of urban stream temperatures on stream fish. Levon ran two lab trials to quantify the effects of both temperature variability (Trial 1) and consistently elevated temperatures (Trial 2) on Creek Chub, a common stream fish.

Creek Chub (Semotilus atromaculatus)
Photo: Brian Zimmerman

What did he find:
Creek Chub in the Trial 1 treatment group gained more weight and had lower blood plasma glucose concentrations (used as a measure of stress) than the control group, while Creek Chub in the Trial 2 treatment group showed no significant difference in weight compared to the control treatment, but the treatment group had significantly higher blood glucose concentrations. A stress response in a tolerant species like Creek Chub could potentially translate to severe impacts for more sensitive fish species as even minor increases in chronic stress caused by heat or other factors can have substantial consequences for wild fish. Altered temperature regimes are also likely to interact with other urban stressors on streams (e.g., pollution, altered hydrology and stream geomorphology, etc.), and will be an important area of future research.

Levon’s research complements ongoing research on the effects of urbanization on stream and wetland ecosystems. Here, Levon is working in the field filtering water samples, along with a little help from mi hijita Adela Lucía!

Levon shared a few thoughts on his research experience:
Completing my honors thesis has been one of the most challenging and rewarding experiences of my undergraduate career. I believe my time with Dr. Sullivan and the rest of STRIVE lab has helped me grow and develop both as a student and as a person, and I feel more prepared for life after graduation as a result. Needless to say, I am incredibly grateful to have been granted the opportunity to conduct research and explore my interests regarding urban stream temperatures and fish, and I would certainly recommend considering research to anyone else who might be interested!

Levon – thanks for all your great work and contributions to our research! Congrats on an excellent presentation, thesis, and your upcoming graduation. We all look forward to seeing where your talents take you in the coming years.

Navigating boundaries after dam removal

The theme for the 2018 Society for Freshwater Science meeting in Detroit, MI was “navigating boundaries in freshwater science”. A strong contingent of STRIVE lab members presented research that fit well within this theme, ranging from nutrient dynamics in linked reservoir-stream systems (K. Stefanik, R. Czaja), ecological networks (T. Kenly), upstream-downstream connections driven by aquatic insect drift (L. Rieck), urbanization effects on fish (L. Bajakian), cross-boundary effects of invasive species (K. Diesburg), and water quality and aerial insectivorous birds (J. Corra, D. Manning). Congrats to all for a successful and productive meeting! Check out the STRIVE lab twitter feed for action photos and more!

Speaking of navigating boundaries – we are continuing to learn more about the 5th Ave dam removal and how the Olentangy River ecosystem is responding to the removal of this conspicuous upstream-downstream boundary. Our work (and several other dam-removal studies) has previously focused on the importance of restoring upstream-downstream connections within the stream channel (see our blog post from last year, as well as recent article by Cook and Sullivan, below). But, we wanted to know more about how removing the dam could have effects that cross from the river to the riparian zones directly adjacent to the stream channel. To figure this out, we measured a few key responses: one was the number and biomass of aquatic insects that emerged from the river, and another was the spiders and birds (tree swallows) that live near the river and rely on aquatic insects for food. We also measured the chemical signatures (stable isotopes) of the algae and detritus in the river, the emergent insects, and spiders and swallows; these signatures allowed us to piece together the diets of spiders and swallows to understand how much of their food comes from the river, vs. terrestrial sources.

An orb-weaving spider of the family Tetragnathidae. These spiders often live in the margins of rivers, eating emerging aquatic insects. After dam removal, we observed a nearly 10-fold decline in their densities adjacent to the river. Photo: A. Kautza

So what happened to the river after dam removal that crossed aquatic-terrestrial boundaries? Well, mostly we found that the contraction of the river channel, and loss of vegetation at the edge of the river channel was bad news for the spiders (pictured left) – we saw close to a 10-fold decline in spider densities after the dam was removed, particularly where there was extensive floodplain restoration (pictured below).

The other responses we measured were less clear. By and large, spider and swallow diets were unchanged post-dam removal, and the variation we did observe was explained more by regional factors like annual temperatures, precipitation, and the river’s discharge. Nevertheless, we think that navigating across boundaries in this way could be an important aspect of future dam-removal monitoring and restoration efforts, particularly for larger dam-removal projects that prompt drastic changes to river morphology, and functioning.

Looking upstream toward Lane Avenue during extensive riparian restoration of the Olentangy River a few months after dam removal. Photo: SMP Sullivan

For more information, you can read the paper (open access) online:

Sullivan, S. M. P., D. W. P. Manning, and R. P. Davis. 2018. Do the ecological effects of dam removal extend across the aquatic-terrestrial boundary? Ecosphere 9(4):e02180 DOI:10.1002/ecs2.2180.

On the topic of dam removal, also check out another recent paper (also open access) from STRIVE on the ecological effects of dam removal:

Cook, D.R., and S.M.P. Sullivan. 2018. Associations between riffle development and benthic macroinvertebrate and fish assemblages following lowhead dam removal. Environmental Monitoring and Assessment 190: 339.


Looking for talented and motivated post-doctoral researcher – apply by April 27th:

Aquatic Ecology: Closing date: April 27th, 2018. Start date: by July 1st if possible. Salary: $46-48K/annually, plus benefits. The Stream and River Ecology Laboratory ( at The Ohio State University is seeking a Post-Doctoral Research Associate to contribute to an EPA-STAR-funded project on harmful algal blooms in the upper Ohio River Basin. The incumbent will be expected to contribute to studies of the ecological impacts of nutrient enrichment in streams, rivers, and reservoirs (from individuals to food webs to ecosystem functions), including field, experimental (e.g., mesocosms), and lab work. In addition, the incumbent will be expected to assist with the analysis of data as well as the preparation of reports, articles, and associated project deliverables. In addition to contributing to the project described above, the incumbent will be expected to pursue additional, complementary research. The incumbent will be based at the Schiermeier Olentangy River Wetland Research Park ( and will be mentored by Dr. Mažeika Sullivan, with opportunities to work with project co-PIs Dr. Lauren Pintor and Dr. Kaiguang Zhao. Strong statistical and programming skills, preferably with R, are required. Interest in teaching within the Aquatic Sciences curriculum is highly desirable. Applicants must have completed and defended their Ph.D. by the start of the appointment. Interested applicants should submit the following: (1) Cover letter, C.V., and the names and contact information for three references; (2) Unofficial transcripts; and (3) Examples of published work. Funding is available for two years. For more information or to apply, contact Dr. Sullivan @

Newly-funded Project Investigates HABs in the Upper Ohio River Basin

We’re eager to get started on a newly funded, 3-year, ~$700K grant by the U.S. Environmental Protection Agency (EPA), as part of its Science to Achieve Results (STAR) program. Our project focuses on nutrient enrichment and harmful algal blooms (HABs) in Ohio River catchments of Ohio, Kentucky, and Indiana, with a particular focus on non-agricultural freshwaters. This research is in collaboration with Drs. Lauren Pintor and Kai Zhao.

Specifically, we propose to develop a watershed classification system to diagnose and manage harmful algal blooms (HABs) in the upper Ohio River basin. The goal is a multi-scale, hierarchical tool that links climate and land-use with river physicochemical gradients and ecological condition to predict and prevent HABs. The resulting classification system will be presented in a framework that can be used by managers as a regular part of watershed planning and risk assessment efforts to prevent and predict HABs. This management tool represents a novel application of theoretical knowledge of hierarchical processes in watersheds and an innovative approach to predicting and managing HABs.

Conceptual model of relationships to be tested and used to develop multi-scale, hierarchical management tool.

CDC Funds Research on Antibiotic-resistant Bacteria in Rivers

We’re excited to collaborate with project leads Dr. Tom Wittum (OSU Vet Preventative Med) and Dr. Jiyoung Lee (OSU Environmental Health Sciences) on CDC-funded research investigating sources and fates of antibiotic-resistant bacteria in rivers.

In particular, our focus in on carbapenem drugs, which are often the antimicrobial therapy of choice to treat life-threatening invasive gram negative infections. The emergence of carbapenem-resistant Enterobacteriaceae (CRE) represents a critically important threat to public health. CRE are known to emerge in healthcare settings in response to frequent antimicrobial use and disseminate through environments that provide appropriate selection pressure. Our working hypothesis is that waste from metropolitan medical centers regularly transports CRE to wastewater treatment plants where they are maintained and ultimately discharged into surface waters, which may then serve as a reservoir for widespread dissemination of these highly resistant organisms. Study systems include the Scioto and Olentangy Rivers of central and southern Ohio.