
Long-term coastal fish community dynamics in the Michigan waters of the Great Lakes
Ecosystem changes have likely increased the importance of coastal ecosystems (<30 m depth) to lake-wide dynamics across the Great Lakes, but less is known about coastal habitats relative to offshore habitats. This project evaluates spatial and temporal dynamics of coastal fish communities in the Michigan waters of the Great Lakes. Using multiple long-term surveys maintained by the Michigan Department of Natural Resources, we assessed the dynamics of fish community composition, metrics of species diversity, and catch-per-unit-effort (CPUE) of key fish species across space and time. Permutation multivariate analyses of variance, non-metric multidimensional scaling, and other multivariate approaches demonstrate that fish communities in coastal habitats are highly heterogeneous and researchers and managers should use caution when extrapolating results from one area to broader scales.
Fetzer et al. 2017
Ecosystem changes have likely increased the importance of coastal ecosystems (<30 m depth) to lake-wide dynamics across the Great Lakes, but less is known about coastal habitats relative to offshore habitats. This project evaluates spatial and temporal dynamics of coastal fish communities in the Michigan waters of the Great Lakes. Using multiple long-term surveys maintained by the Michigan Department of Natural Resources, we assessed the dynamics of fish community composition, metrics of species diversity, and catch-per-unit-effort (CPUE) of key fish species across space and time. Permutation multivariate analyses of variance, non-metric multidimensional scaling, and other multivariate approaches demonstrate that fish communities in coastal habitats are highly heterogeneous and researchers and managers should use caution when extrapolating results from one area to broader scales.
Fetzer et al. 2017

Development of a Great Lakes ecosystem indicator database and IJC indicator calculations
Significant resources are being invested into the restoration and rehabilitation of the Great Lakes. The International Joint Commission recently identified a suite of environmental and human health indicators necessary to assess and communicate improvement in the overall health of the Great Lakes ecosystem. Through collaborations with Michigan State University, the University of Michigan, the International Joint Commission, and researchers from across the Great Lakes basin, this project assessed dataset availability, integrated datasets within a geo-referenced framework, and when possible, calculated spatial and temporal trends of indicators across the basin. Results of this effort will contribute to tracking progress towards achievement of the Great Lakes Water Quality Agreement Annex priorities.
Roth et al. 2016
Significant resources are being invested into the restoration and rehabilitation of the Great Lakes. The International Joint Commission recently identified a suite of environmental and human health indicators necessary to assess and communicate improvement in the overall health of the Great Lakes ecosystem. Through collaborations with Michigan State University, the University of Michigan, the International Joint Commission, and researchers from across the Great Lakes basin, this project assessed dataset availability, integrated datasets within a geo-referenced framework, and when possible, calculated spatial and temporal trends of indicators across the basin. Results of this effort will contribute to tracking progress towards achievement of the Great Lakes Water Quality Agreement Annex priorities.
Roth et al. 2016

Spatial and temporal drivers of carbon sources supporting age-0 fish production: testing the importance of environmental conditions and population density
Recent research in lake ecosystems has focused on identifying carbon sources supporting fish populations and understanding how individual niche breadth differs from population niche breadth. Despite overlap between these two research areas, few studies have integrated how individual specialization influences carbon use by fish. This project takes advantage of multiple long-term data sets and archived samples available for Oneida Lake, NY to determine spatial and temporal patterns of carbon use by age-0 fish. Preliminary results suggest fish integrate both littoral and pelagic energy pathways, and provide clear evidence that environmental conditions and population density interact to drive carbon sources supporting age-0 fish production.
Fetzer et al. 2015
Recent research in lake ecosystems has focused on identifying carbon sources supporting fish populations and understanding how individual niche breadth differs from population niche breadth. Despite overlap between these two research areas, few studies have integrated how individual specialization influences carbon use by fish. This project takes advantage of multiple long-term data sets and archived samples available for Oneida Lake, NY to determine spatial and temporal patterns of carbon use by age-0 fish. Preliminary results suggest fish integrate both littoral and pelagic energy pathways, and provide clear evidence that environmental conditions and population density interact to drive carbon sources supporting age-0 fish production.
Fetzer et al. 2015

Ontogenetic shifts in predation risk: evaluating the gauntlet of a diverse predator community
Predation requires spatial and temporal overlap between predators and prey, which can change seasonally if prey undergo ontogenetic shifts in habitat use and susceptibility to predation. As predator diversity increases, temporal and spatial refuges from predation may decline and lead to population declines. This project looks at timing and extent of predation on yellow perch by multiple predators. Smallmouth and largemouth bass predation is evaluated through diet analysis, a bioenergetics model, and simulations of bass and walleye predation. Seasonality and extent of adult yellow perch and white perch predation are compared before and after zebra mussel introductions to evaluate how water clarity influences predator-prey dynamics.
Fetzer et al. 2016
Predation requires spatial and temporal overlap between predators and prey, which can change seasonally if prey undergo ontogenetic shifts in habitat use and susceptibility to predation. As predator diversity increases, temporal and spatial refuges from predation may decline and lead to population declines. This project looks at timing and extent of predation on yellow perch by multiple predators. Smallmouth and largemouth bass predation is evaluated through diet analysis, a bioenergetics model, and simulations of bass and walleye predation. Seasonality and extent of adult yellow perch and white perch predation are compared before and after zebra mussel introductions to evaluate how water clarity influences predator-prey dynamics.
Fetzer et al. 2016

100 years of littoral fish community changes in Oneida Lake, NY
Littoral fish communities are often diverse due to high habitat heterogeneity and associated niche diversity; however, most research on fish community dynamics in lakes focuses on pelagic and demersal habitats. This project uses long-term littoral seine surveys to evaluate 100 years of littoral fish community dynamics. Littoral fish community is tracked during three time periods: historic (1915-1925), eutrophic (1960-1975), and mesotrophic (1989-2011). Preliminary results suggest dominant littoral fish species are resilient to ecosystem perturbations; however, rare species tend to decline or are extirpated over time.
Littoral fish communities are often diverse due to high habitat heterogeneity and associated niche diversity; however, most research on fish community dynamics in lakes focuses on pelagic and demersal habitats. This project uses long-term littoral seine surveys to evaluate 100 years of littoral fish community dynamics. Littoral fish community is tracked during three time periods: historic (1915-1925), eutrophic (1960-1975), and mesotrophic (1989-2011). Preliminary results suggest dominant littoral fish species are resilient to ecosystem perturbations; however, rare species tend to decline or are extirpated over time.

Developing “Manager’s Models”: teaching graduate students how science informs management
Addressing the complexity of current environmental problems requires scientists have an understanding of how science informs management and policy. This project proposes the development of “Manager’s Models” as a useful tool for students to conceptualize the socio-political systems where they work and to identify where and how their research informs stakeholders, managers, and policy makers within that system. We use Oneida Lake as a case study to illustrate application of this technique to graduate student training.
Addressing the complexity of current environmental problems requires scientists have an understanding of how science informs management and policy. This project proposes the development of “Manager’s Models” as a useful tool for students to conceptualize the socio-political systems where they work and to identify where and how their research informs stakeholders, managers, and policy makers within that system. We use Oneida Lake as a case study to illustrate application of this technique to graduate student training.

Cold temperature not starvation drives overwinter mortality of gizzard shad.
For my Master’s thesis, I used a combination of experiments and field sampling to evaluate drivers of gizzard shad overwinter mortality at the northern extent of their range. In-situ and ex-situ experiments were used to evaluate gizzard shad mortality and thermal tolerance. Field sampling measured winter habitat conditions across Oneida Lake and monitored gizzard shad abundance and condition through under-the-ice gillnet sampling. Results from both experiments and field sampling suggest cold-stress and inability to acclimate, not starvation, drive gizzard shad mortality at low temperatures.
Fetzer et al. 2011
For my Master’s thesis, I used a combination of experiments and field sampling to evaluate drivers of gizzard shad overwinter mortality at the northern extent of their range. In-situ and ex-situ experiments were used to evaluate gizzard shad mortality and thermal tolerance. Field sampling measured winter habitat conditions across Oneida Lake and monitored gizzard shad abundance and condition through under-the-ice gillnet sampling. Results from both experiments and field sampling suggest cold-stress and inability to acclimate, not starvation, drive gizzard shad mortality at low temperatures.
Fetzer et al. 2011

Opae’ula shrimp ecology
A field course with the Department of Ecology and Evolutionary Biology provided a unique opportunity to study predator effects on the diel migration of Opae’ula shrimp in Hawaiian Anchaline ponds. We found that in ponds with invasive mosquito fish, Opae’ula undergo diel migrations and are only active at night. In fishless ponds, Opae’ula do not undergo migrations and are present during both night and day.
Carey et al. 2011
A field course with the Department of Ecology and Evolutionary Biology provided a unique opportunity to study predator effects on the diel migration of Opae’ula shrimp in Hawaiian Anchaline ponds. We found that in ponds with invasive mosquito fish, Opae’ula undergo diel migrations and are only active at night. In fishless ponds, Opae’ula do not undergo migrations and are present during both night and day.
Carey et al. 2011

Monitoring of Oneida Lake
My work as part of the Cornell Warmwater Fisheries Unit has been a great opportunity to gain expertise in the development and implementation of a long-term monitoring program. It has also provided more than a few opportunities to get out on the lake and catch some fish. There are few substitutes for field observations to develop an understanding of your study system and to inspire interesting questions. These observations can even lead to a unexpected papers, such as the first observation of Hemimysis anomola in an inland lake!
Brooking et al. 2010
My work as part of the Cornell Warmwater Fisheries Unit has been a great opportunity to gain expertise in the development and implementation of a long-term monitoring program. It has also provided more than a few opportunities to get out on the lake and catch some fish. There are few substitutes for field observations to develop an understanding of your study system and to inspire interesting questions. These observations can even lead to a unexpected papers, such as the first observation of Hemimysis anomola in an inland lake!
Brooking et al. 2010

Global patterns of aquatic food chain lengths: A meta-analysis of published stable isotope food webs
Food chain length (FCL) is a fundamental ecosystem attribute, and is widely known to influence ecosystem function. This research took advantage of published food webs measured through d13C and d15N to explore patterns of FCL in lakes, rivers, and marine ecosystems. Marine and lake FCL were longest at ~4 trophic levels and shortest in rivers at 3.5 trophic levels. At the global scale, no relationships were observed between ecosystem size, mean annual air temperature, and latitude. Interestingly, FCL measured through stable isotopes were consistent with those measured through connectance food webs.
Vander Zanden and Fetzer 2007
Food chain length (FCL) is a fundamental ecosystem attribute, and is widely known to influence ecosystem function. This research took advantage of published food webs measured through d13C and d15N to explore patterns of FCL in lakes, rivers, and marine ecosystems. Marine and lake FCL were longest at ~4 trophic levels and shortest in rivers at 3.5 trophic levels. At the global scale, no relationships were observed between ecosystem size, mean annual air temperature, and latitude. Interestingly, FCL measured through stable isotopes were consistent with those measured through connectance food webs.
Vander Zanden and Fetzer 2007

Tracking the invasive history of rusty crayfish in Wisconsin
As an undergraduate, I worked with a team documenting the spread of rusty crayfish and the decline of native crayfish across Wisconsin lakes and streams. This research compared historical and contemporary crayfish distributions from diverse collections (Milwaukee Public Museum; University of Notre Dame; Center for Limnology; Wisconsin Department of Natural Resources). Contemporary sample collection consisted of traveling throughout Wisconsin, camping at state parks, and spending countless hours catching crayfish. This was the job that convinced me to be a limnologist. It was awesome!
Olden et al. 2006
As an undergraduate, I worked with a team documenting the spread of rusty crayfish and the decline of native crayfish across Wisconsin lakes and streams. This research compared historical and contemporary crayfish distributions from diverse collections (Milwaukee Public Museum; University of Notre Dame; Center for Limnology; Wisconsin Department of Natural Resources). Contemporary sample collection consisted of traveling throughout Wisconsin, camping at state parks, and spending countless hours catching crayfish. This was the job that convinced me to be a limnologist. It was awesome!
Olden et al. 2006