76 University Drive
Hazleton, PA 18202
Research Interests
Fish and environmental health
Endocrine disruption
Fish population trends
Parasite-host ecology
Population genetics
Fish ecology
Publications
Factors Influencing the Prevalence of Hyperpigmented Melanistic Lesions in Smallmouth Bass Micropterus dolomieu in the Susquehanna River Basin, Pennsylvania, Journal of Fish Diseases - October 23, 2024
Collaborators: Geoffrey Smith, Co-Author; Vicki Blazer, Co-Author; Heather Walsh, Co-Author; Tyler Wagner, Co-Author
Temporal analysis of water chemistry and smallmouth bass (Micropterus dolomieu) health at two sites with divergent land use in the Susquehanna River watershed, Pennsylvania, USA, Environmental Monitoring and Assessment - September 11, 2024
Collaborators: Heather Walsh, Primary Author; Geoffrey Smith, Co-Author; Stephanie Gordon, Co-Author; Vicki Blazer, Co-Author
Feeding Habits and Ecological Implications of the Invasive Flathead Catfish, Pylodictis olivaris, in the Susquehanna River Basin, Pennsylvania, Transactions of the American Fisheries Society - August 22, 2024
Collaborators: Sydney Stark, Primary Author; Geoffrey Smith, Co-Author; Aaron Maloy, Co-Author; Jason Coombs, Co-Author; Tyler Wagner, Co-Author; Julian Avery, Co-Author
Population genetic structure and demographic history reconstruction of introduced flathead catfish (Pylodictis olivaris) in two US Mid-Atlantic rivers, Journal of Fish Biology
Collaborators: Justin Waraniak, Primary Author; Mike Eackles, Co-Author; Jason Keagy, Co-Author; Geoffry Smith, Co-Author; Sydney Stark, Co-Author; Shannon White, Co-Author; David Kayzak, Co-Author; Tyler Wagner, Co-Author
Quantifying the relative associations between biotic and abiotic factors and the structure of stream fish communities at the landscape scale, Community Ecology - April 30, 2024
Collaborators: Christopher Custer, Author; Douglas Fischer, Co-Author; Geoffrey Smith, Co-Author; Aaron Henning; Matthew Shank; Timothy Wertz; Tyler Wagner
Assembling the right pieces: developing an interdisciplinary research team to study the disease and decline of a world-class Smallmouth Bass fishery. , Fisheries - May 10, 2023
Collaborators: Geoffrey Smith; Vicki Blazer; Heather Walsh; Timothy Array; Dustin Shull; Tyler Wagner
Targeted and Non-targeted Analysis of Young-of-Year Smallmouth Bass Using Comprehensive Two-Dimensional Gas Chromatography Coupled with Time-of-Flight Mass Spectrometry, Science of the Total Environment - February, 2022
Collaborators: Paige Teehan; Vicki Blazer, Co-Author; Frank Dorman, Co-Author
Optimization of a suite of microsatellite markers for flathead catfish (Pylodictis olivaris) with application to introduced populations in Pennsylvania, BMC Research Notes - August 16, 2021
Collaborators: Array White, Primary Author; Tyler Wagner, Co-Author; Mike Eackles, Co-Author; Geoffrey Smith, Co-Author; Julian Avery, Co-Author; David Kazyak, Co-Author
Ecological risk assessment of environmental stress and bioactive chemicals to riverine fish populations: an individual-based model of smallmouth bass, Environmental Science and Technology - October 16, 2020
Collaborators: Yan Li; Vicki Blazer; Luke Iwanowicz; Kelly Smalling; Donald Tillitt; Tyler Wagner
Spatiotemporal variation in occurrence and co-occurrence of emerging contaminants in rivers in the Chesapeake Bay Watershed, Science of the Total Environment - August 1, 2020
Collaborators: Catherine McClure; Kelly Smalling; Vicki Blazer; Adam Sperry; Dana Kolpin; Patrick Phillips; Michelle Hladik; Tyler Wagner
A fishery after the decline: The Susquehanna River Smallmouth Bass story, Fisheries - August 31, 2020
Collaborators: Geoffrey Smith, Co-Author; Yan Li, Co-Author; Vicki Blazer, Co-Author; Tyler Wagner, Co-Author
Modified QuEChERS Extraction for the Analysis of Young-of-Year Smallmouth Bass Using GC×GC-TOFMS, Analytical Methods
Collaborators: Paige Teehan, Primary Author; Vicki Blazer, Co-Author; Beate Gruber, Co-Author; Frank Dorman, Co-Author
Movement dynamics of smallmouth bass (Micropterus dolomieu) in a large river-tributary system, Fisheries Management and Ecology - June 30, 2019
Collaborators: Timothy Wertz, Co-Author; Geoffrey Smith, Co-Author; Vicki Blazer, Co-Author; Tyler Wagner, Co-Author
Spatial and temporal variability of myxozoan parasite, Myxobolus inornatus, prevalence in young of the year smallmouth bass in the Susquehanna River Basin, Pennsylvania, Journal of Fish Diseases - August 17, 2018
Collaborators: Vicki Blazer, Co-Author; Heather Walsh, Co-Author; Geoffrey Smith, Co-Author; Timothy Wertz, Co-Author; Tyler Wagner, Co-Author
Quantifying Temporal Trends in Fisheries Abundance Using Bayesian Dynamic Linear Models: A Case Study of Riverine Smallmouth Bass Populations, North American Journal of Fisheries Management - April 10, 2018
Collaborators: Vicki Blazer, Co-Author; Robert Lorantas, Co-Author; Geoffrey Smith, Co-Author; John Mullican, Co-Author; Brandon Keplinger, Co-Author; Tyler Wagner, Co-Author
Evaluation of genetic population structure of Smallmouth Bass in the Susquehanna River Basin, PA, North American Journal of Fisheries Management - May 16, 2017
Collaborators: Meredith Bartron, Co-Author; Timothy Wertz, Co-Author; Jonathan Niles, Co-Author; Cassidy Shaw, Co-Author; Vicki Blazer, Co-Author; Tyler Wagner, Co-Author
Comparative bioenergetics modeling of two Lake Trout morphotypes, Transactions of the American Fisheries Society - October 30, 2014
Collaborators: Tyler Wagner, Co-Author; John Sweka, Co-Author
Fall and early winter movement and habitat use of wild Brook Trout, Transactions of the American Fisheries Society - July 25, 2013
Collaborators: Robert Mollenhauer; Tyler Wagner; John Sweka
Estimating spatial and temporal components of variation for fisheries count data using negative binomial mixed models, Transactions of the American Fisheries Society - December, 2012
Collaborators: Brian Irwin, Primary Author; Tyler Wagner, Co-Author; James Bence, Co-Author; Weihei Lui, Co-Author; Daniel Hayes
A simple membrane osmometer system & experiments that quantitatively measure osmotic pressure, The American Biology Teacher - August, 2009
Collaborator: Stephen Marvel, Primary Author
Education
Ph D, Ecology, The Pennsylvania State University
MS, Wildlife and Fisheries Science, The Pennsylvania State University
BS, Biology, Lock Haven University
Papers and Presentations
November 8, 2024 - November 9, 2024
Posters
FOOD WEB ALTERATIONS IN SUSQUEHANNA RIVER BY NON-NATIVE FLATHEAD CATFISH (PYLODICTUS OLIVARIS).
Susquehanna River Symposium
Lewisburg, PA
November 8, 2024 - November 9, 2024
Posters
OCCURRENCE AND CONCENTRATIONS OF PER- AND POLYFLUOROALKYL SUBSTANCES IN INVASIVE CHANNA ARGUS POPULATIONS: A TRANSCRIPTOMICS APPROACH FOR DETECTING CONTAMINANT EXPOSURE
Susquehanna River Symposium
Lewisburg, PA
August 20, 2023 - August 24, 2023
Posters
Trophic Impacts of the Invasive Flathead Catfish (Pylodictis olivaris) in the Susquehanna River Basin, PA
American Fisheries Society, Annual Meeting
Grand Rapids, MI
May, 2023
Oral Presentations
Investigating angler perception of invasive Flathead Catfish in the Susquehanna River Basin, Pennsylvania
Northeast Association of Fish and Wildlife Agencies
Hershey, Pennsylvania
May, 2023
Oral Presentations
Investigating community level impacts and trophic positioning of invasive Flathead Catfish, Pylodictis olivaris, in the Susquehanna River
Northeast Association of Fish and Wildlife Agencies
Hershey, Pennsylvania
May, 2023
Oral Presentations
Variables influencing the occurrence of melanistic lesions in Smallmouth Bass in the Susquehanna River Basin, Pennsylvania
Northeast Association of Fish and Wildlife Agencies
Hershey, Pennsylvania
February, 2023
Oral Presentations
Diet analysis of invasive Flathead Catfish in the Susquehanna River Basin
Pennsylvania American Fisheries Society Spring Technical Meeting
Lock Haven, Pennsylvania
February, 2023
Posters
Piloting the use of stable isotope analysis to understand trophic dynamics of invasive Flathead Catfish Pylodictis olivaris
Pennsylvania American Fisheries Society Spring Technical Meeting
Lock Haven, Pennsylvania
November 4, 2022 - November 5, 2022
Posters
Using stable isotope analysis to investigate trophic positioning of Flathead Catfish in the Susquehanna River Basin, PA
17th Annual Susquehanna River Symposium
Lewisburg, PA
June 6, 2022 - June 8, 2022
Oral Presentations
Investigating Spatiotemporal Variability in Visual Health Assessments for Adult Smallmouth Bass
Chesapeake Community Research Symposium 2022
Annapolis, MD and Online
April 3, 2022 - April 5, 2022
Oral Presentations
Comparison of Collection Methods for Diet Studies of Invasive Flathead Catfish
2022 Annual Northeast Association of Fish and Wildlife Agencies (NEAFWA)
Long Branch, NJ and Online
February 25, 2022
Oral Presentations
Preliminary diet analysis of the invasive Flathead Catfish in the Susquehanna River Basin
2022 Keystone Coldwater Conference & PA American Fisheries Society Joint Meeting
State College, PA
November, 2021
Oral Presentations
Ecological risk assessment of environmental stress and bioactive chemicals to riverine fish populations: an individual based model of smallmouth bass Micropterus dolomieu
American Fisheries Society Annual Meeting
Baltimore, Maryland
November, 2021
Oral Presentations
Patterns in melanistic lesions in Smallmouth Bass in the Susquehanna River Basin, Pennsylvania
American Fisheries Society Annual Meeting
Baltimore, Maryland
November, 2021
Oral Presentations
Preliminary diet analysis of the invasive Flathead Catfish in the Susquehanna River Basin
American Fisheries Society Annual Meeting
Baltimore, Maryland
November, 2021
Oral Presentations
Where do we go from here?: Quantifying spatiotemporal variability in fish health observations from Smallmouth Bass Micropterus dolomieu after disease and population declines.
American Fisheries Society Annual Meeting
April, 2021
Oral Presentations
Comparing the use of multiple molecular techniques for identification of prey items in invasive Flathead Catfish (Pylodictis olivaris) diets
Southern Division of the American Fisheries Society Annual Meeting
Virtual
Flathead Catfish are a piscivorous invasive fish species introduced throughout the United States. It is important to understand how Flathead Catfish introductions alter ecosystem function and disrupt community structure through predation. Flathead Catfish are commonly collected with empty stomachs or degraded prey items in stomach contents making it difficult to identify prey using meristic or morphometric techniques. Molecular identification of individual prey items using DNA barcoding and Sanger sequencing is a more suitable approach for unidentifiable items but could be complicated when the diet is comprised of an inseparable slurry of prey. We investigated the use of universal fish DNA barcoding primers and both Sanger sequencing and next generation sequencing in the identification of prey items from a subset of Flathead Catfish diet samples (n=5). Sanger sequencing of individual prey items produced consistent species level identification. Sample preparation for next generation sequencing was labor intensive and it was often difficult to get desired DNA amplification from diet slurries. Next generation sequencing has been completed and samples are currently being analyzed through a bioinformatics pipeline for species identification. Next generation sequencing may be most advantageous to use in samples where contents are inseparable, whereas Sanger sequencing may be an easier and more direct approach for samples with separable prey items. Prey identification from fish species with degraded diet samples likely requires different methods to accommodate varying sample quality and quantity.
April, 2021
Oral Presentations
Let’s eat! A look at the diet of the invasive Flathead Catfish (Pylodictis olivaris) in the Susquehanna River Basin, PA
Southern Division American Fisheries Society Annual Meeting
virtual
February, 2021
Posters
Evaluating sampling techniques of Flathead Catfish, Plyodictis olivaris, in the Susquehanna River Basin for dietary analysis
Pennsylvania Chapter of the American Fisheries Society Spring Technical Meeting
Virtual
Introduced species often alter the community structure of the ecosystems they invade through direct and indirect effects, such as predation and competition. The Flathead Catfish, Pylodictis olivaris, is a large piscivorous fish prized by anglers, however the species can alter the structure and function of native aquatic communities when introduced outside its native range. Flathead Catfish were first documented in the Susquehanna River Basin in 2002; however, the effects of this introduction on native and naturalized fish and invertebrate communities are unknown. We initiated a multi-year molecular diet study in 2020 to investigate predatory impacts of Flathead Catfish in the Susquehanna River Basin. Flathead catfish were sampled from July through October in the Susquehanna River using low and high frequency boat electrofishing and baited tandem hoop nets. Out of 161 fish collected, 155 fish were included in our diet analysis and 63 had prey items in their stomachs. Visual analysis of stomach contents revealed that 25 of these samples contained fish, 24 contained crayfish, 6 were mixed crayfish and fish, and 7 had unidentifiable contents. With respect to gear type, Flathead Catfish collected using low and high frequency electrofishing had a higher percentage of stomachs containing prey (53% and 54%, respectively) compared to hoop nets (24%). High frequency electrofishing caught smaller fish (mean ± s.d.; 408± 195mm) when compared to hoop nets (700± 124mm) and low frequency electrofishing (667± 197mm). Molecular analysis of prey items is currently underway to determine which species are preyed upon to understand how Flathead Catfish diets vary temporally and by gear type. Our results suggest electrofishing (both high and low frequency) is more effective than hoop nets for sampling Flathead Catfish for diet collections. A combination of the two techniques would be best for collecting a broader size range, which is critical for understanding potential effects of this species as it continues to spread throughout the Pennsylvania river systems.
February 18, 2020 - February 20, 2020
Oral Presentations
Evaluation of molecular methods to identify diet contents of invasive Flathead Catfish Pylodictis olivaris in the Susquehanna River Basin, Pennsylvania
The Third International Catfish Symposium
Little Rock, Arkansas
Abstract—Flathead Catfish Pylodictis olivaris are an introduced, invasive species in the Susquehanna River Basin. The species range is expanding causing management agencies to be concerned about the predatory effects of Flathead Catfish on prey communities, including recreational sport fisheries, native and established fish species, species of greatest conservation need, and diadromous species that are the focus of restoration efforts. Currently, there is little information available on the prey species being consumed by Flathead Catfish in the Susquehanna River. Preliminary data suggests a variety of prey items in stomach contents including a mixture of partially digested fish and invertebrates which are not easily identifiable. The use of DNA barcoding is one approach that can be used to identify diet contents that are no longer visually identifiable. For this study, we are investigating the feasibility of DNA barcoding and the use of multiple molecular approaches to identify prey items in Flathead Catfish stomachs. To do so, we are testing the reliability of previously used DNA barcoding markers for both fish and invertebrates against potential prey items in the Susquehanna River Basin. We are comparing multiple methods for analysis including Sanger sequencing and next-generation sequencing for analysis of catfish diets. Findings from this study will validate methods that provide important information relevant to the management of Flathead Catfish in the Susquehanna River Basin.
February 6, 2020
Posters
Evaluating the Utility of Otolith Microchemistry to Determine Smallmouth Bass Environmental Life History Throughout the Susquehanna River Basin
Pennsylvania American Fisheries Society Spring Technical Meeting
Huntington, Pa
The Susquehanna River, previously noted as being one of the most imperiled rivers in the United States, has been of great interest in terms of ecological restoration efforts in recent years. The Smallmouth Bass is a popular and locally economically important recreational fishery in the Susquehanna River. Smallmouth Bass have exhibited disease and population changes including periods of decline since 2005. These recent disease-related mortality events and population fluctuations lead to an increased focus on fish health, contaminant exposure, and various aspects of life history and ontogeny. Previous studies using radio telemetry suggest that Smallmouth Bass utilize habitats in both the main-stem river and tributaries. However, minimal information exists as it relates to movement during early life history and how main-stem river and tributary spawned fish contribute to the larger population. Understanding more during this critical life stage may provide insight into the aforementioned declines and differential exposure to environmental stressors (e.g., contaminant and pathogen exposure) Because telemetry is not feasible for early life stages in Smallmouth bass, we sought to determine the feasibility of using otolith microchemistry to determine the environmental life history strategy of Smallmouth Bass in the Susquehanna River. Naturally occuring chemical markers in otoliths have shown to be a useful tool in describing environmental life history of numerous fishes in various environments. Laser ablation of individual otoliths was used to obtain Strontium (Sr86) to Calcium (Ca43) ratios for respective Smallmouth Bass samples from river and tributary sites in the Susquehanna River Basin. Different elemental signatures in otoliths were documented indicating fish may be moving and inhabiting different sites throughout their life. However, current data does not allow for identifying a specific main-stem reach or tributary. Further analyses of the otolith chemistry coupled with water chemistry will allow assignment of specific location these individuals. The continuation of this study and the information garnered will allow us to construct a database that will be valuable in directing future adaptive management schemes for the recovery of Smallmouth Bass in the Susquehanna River.
February 6, 2020
Posters
Investigating water quality and trout population changes in two acid mine drainage impaired streams after remediation
Pennsylvania American Fisheries Society Spring Technical Meeting
Huntington, Pa
Acid mine drainage (AMD) impairs streams throughout the state of Pennsylvania resulting in acidic stream conditions, toxic metals, and metal precipitates. Streams impaired by AMD represent important lost habitat for many species of conservation need in Pennsylvania including our state fish, the brook trout (Salvelinus fontinalis). Cooks Run and its tributaries, Rock and Camp runs located in Clinton County, Pennsylvania are wild trout streams impaired by AMD. In the late 1970s, a mining operation resulted in the impairment of over five miles of streams in Rock and Camp runs and Cooks Run, proper, eliminating fish populations. Remediation techniques have been tested over the years with little success leading to a more recent approach (2018-2019) to neutralize the AMD source through remining and source abatement. Between 1978-2019 water quality data (pH, total aluminum, total iron) and brook trout biomass data were collected at multiple points in time for Camp and Rock runs above and below mine discharges. Surface water samples were collected and sent to state approved laboratories, and brook trout were collected using backpack electrofishing in one-pass, 100- meter sections. Recent data demonstrated improvements in water quality below mine discharges including increasing pH levels, and declining concentrations of total iron and aluminum. During 2019 fish collections, one brook trout was collected below the AMD discharge point on one of the tributaries in an area previously uninhabited by trout. Yet, limited sampling (one season) and sample sizes (one fish) warrant future investigation and monitoring to evaluate potential trout recovery. In addition to trout and water quality monitoring, benthic macroinvertebrate samples have been collected to further evaluate remediation efforts. Future monitoring will help evaluate the success of remining and source abatement as a remediation technique for this site and provide insight for consideration of this technique for use elsewhere.
October 19, 2019
Panels
Life Below Water: Complexities of large river ecosystems
Susquehanna River Symposium
Lewisburg, PA
Co-led a breakout discussion following a plenary talk on collaborative research in science. Fielded meeting participant questions and discussed various parts of interdisciplinary research.
October 18, 2019 - October 19, 2019
Keynotes/Plenary Addresses
It takes a village: using collaborative and interdisciplinary science to unravel the complex dynamics of a Susquehanna River Fishery
Susquehanna River Symposium
Lewisburg, PA
Served as a co-author for a collaborative plenary talk at the 14th annual Susquehanna River Symposium. Helped put together the talk, assisted with figures, slides, etc., attended the conference and co-led a discussion after the plenary session.
June 10, 2019 - June 14, 2019
Oral Presentations
Spatial variability in young of year Smallmouth Bass infections in the Chesapeake Bay Watershed
International Association of Great Lakes Research 2019-Large Lakes Research: Connecting People & Ideas
Brockport, NY
Potential disease-causing agents including bacterial and viral pathogens and parasites have been found to co-occur in young of year (YOY) smallmouth bass in the Susquehanna River Basin, Chesapeake Bay Watershed, Pennsylvania. It is not well understood, however, how co-occurrence of infection (coinfection) varies with respect to site-specific characteristics. To evaluate prevalence of infection in YOY smallmouth bass using histology, 1,426 YOY smallmouth bass were collected during 2013-2016 from 46 in- and out-of-basin sites. A hierarchical model was used to quantify spatial variability of specific individual infection prevalence, prevalence of YOY with coinfections, and investigate land use relationships (agriculture and development) with infection. Prevalence of three or more infections was generally higher in the Susquehanna River Basin than out-of-basin sites within Pennsylvania. Coinfection prevalence had a high probability of being positively related to agriculture land use (probability =0.86) and negatively related to development (probability = 0.96) at the catchment scale. To expand modeling efforts, a joint distribution model is being used to partition relationships between infections at multiple spatial scales. Quantifying potential underlying factors for coinfection in YOY smallmouth bass provides insight on risk for future disease outbreaks and prioritization of potential management areas
February 22, 2019
Oral Presentations
Population status of Smallmouth Bass in the Susquehanna River Basin: consideration of population dynamics and fish health characteristics
Pennsylvania Chapter of the Wildlife Society and Pennsylvania Chapter of the American Fisheries Society 2019 Annual Conference
State College, PA
June 12, 2018 - June 14, 2018
Oral Presentations
Investigating occurrence of disease characteristics and trends in smallmouth bass abundance in rivers within the Chesapeake Bay Watershed.
Chesapeake Consortium Research and Modeling Symposium
Annapolis, MD
April 3, 2017 - April 7, 2017
Oral Presentations
Evaluating differences in field observations and histological prevalence of Myxozoan parasites in young-of-the-year smallmouth bass (Micropterus dolomieu) in the Susquehanna River Basin, PA
Fish Health Section Meeting
East Lansing, Michigan
February 9, 2017 - February 10, 2017
Oral Presentations
Investigating trends in riverine smallmouth bass catch per effort data in Pennsylvania
Pennsylvania and West Virginia Joint American Fisheries Society Technical Meeting
California University, California, PA
November 11, 2016 - November 12, 2016
Posters
Investigating movement dynamics and population genetics of smallmouth bass in the Susquehanna River Basin
Susquehanna River Symposium
Bucknell University, Lewisburg, PA
February 11, 2016 - February 12, 2016
Oral Presentations
Investigation of smallmouth bass population genetic structure in the Susquehanna River basin.
Pennsylvania American Fisheries Society Spring Technical Meeting
Susquehanna University, Selinsgrove, PA
November 13, 2015 - November 14, 2015
Posters
. Local and Regional Evaluation of Smallmouth Bass Population Genetic Structure in the Susquehanna River Basin
Susquehanna River Symposium
Bucknell University, Lewisburg, PA
July, 2015
Oral Presentations
Investigation of contaminants and disease characteristics of young of the year smallmouth bass in the Susquehanna River basin, PA.
Eastern Fish Health Meeting
Ithaca, NY
February 25, 2015 - February 27, 2015
Oral Presentations
Movement dynamics of smallmouth bass in the Susquehanna River Basin
Pennsylvania and Ohio Joint American Fisheries Society Technical Meeting
Erie, PA
August 31, 2014 - September 4, 2014
Oral Presentations
Evaluation of potential disease causing agents in young of the year smallmouth bass in the Chesapeake Bay watershed.
International Symposium on Aquatic Animal Health
Portland, OR
April, 2013
Oral Presentations
Comparative bioenergetics modeling of two representative strains of lean and humper lake trout (Salvelinus namaycush) morphotypes
Northeast Fish and Wildlife Conference
Saratoga Springs, NY
September 12, 2010 - September 16, 2010
Oral Presentations
Spatial and Temporal variation in Great Lakes catch-per-effort data
American Fisheries Society National Meeting
Pittsburgh, PA