Michael J Wiley | University of Michigan (original) (raw)

Papers by Michael J Wiley

Pearson correlation matrix with two-tailed significance test.

Total standardized effects of basin cropland and riparian forested wetland on nutrients in the na... more Total standardized effects of basin cropland and riparian forested wetland on nutrients in the national and regional SEMs.

Study unit features: summary of dominant study unit features. Mean values and ranges are shown fo... more Study unit features: summary of dominant study unit features. Mean values and ranges are shown for annual precipitation, air temperatures, and study site basin area.

Site variable means (mean and standard deviation of environmental, physical habitat, water chemis... more Site variable means (mean and standard deviation of environmental, physical habitat, water chemistry, and invertebrate variables for sampled sites).

Ecology, 1981

Abstract. The effects of manipulations of density and sediment type on the emigration rates of ch... more Abstract. The effects of manipulations of density and sediment type on the emigration rates of chironomid larvae (Diptera:Chironomidae) from Hunt Creek, Montmorency County, Michigan, USA, were examined in artificial stream chambers. Both basic sediment ...

River valley segments are adjacent sections of streams and rivers that are relatively homogeneous... more River valley segments are adjacent sections of streams and rivers that are relatively homogeneous in hydrology, limnology, channel morphology, riparian dynamics, and biological communities. River valley segments have been advocated as appropriate spatial units for assessing, monitoring, and managing rivers and streams for several reasons; however, methods for delineating these spatial units have been tedious to implement or have lacked objectivity, which arguably has limited their use as river and stream management units by natural resource agencies. We describe a spatially constrained clustering program that we developed for delineating river valley segments from geographic information system digital river network databases that is flexible, easy-to-use, and improves objectivity in the river valley segment delineation process. This program, which we refer to as the valley segment affinity search technique (VAST), includes a variety of options for determining spatial adjacency in stream reaches, as well as several data transformation methods, types of resemblance coefficients, and cluster linkage methods. The usefulness of VAST is demonstrated by using it to delineate river valley segments for river network databases for Michigan and Wisconsin, USA, and by comparing river valley segments delineated by VAST to an expert-opinion delineation previously completed for a Michigan river network database.

Microbial Ecology

Riverine floodplains are ecologically and economically valuable ecosystems that are heavily threa... more Riverine floodplains are ecologically and economically valuable ecosystems that are heavily threatened by anthropogenic stressors. Microbial communities in floodplain soils mediate critical biogeochemical processes, yet we understand little about the relationship between these communities and variation in hydrologic connectivity related to land management or topography. Here, we present metagenomic evidence that differences among microbial communities in three floodplain soils correspond to a long-term gradient of hydrologic connectivity. Specifically, all strictly anaerobic taxa and metabolic pathways were positively associated with increased hydrologic connectivity and flooding frequency. In contrast, most aerobic taxa and all strictly aerobic pathways were negatively related to hydrologic connectivity and flooding frequency. Furthermore, the genetic potential to metabolize organic compounds tended to decrease as hydrologic connectivity increased, which may reflect either the observed concomitant decline of soil organic matter or the parallel increase in both anaerobic taxa and pathways. A decline in soil N, accompanied by an increased genetic potential for oligotrophic N acquisition subsystems, suggests that soil nutrients also shape microbial communities in these soils. We conclude that differences among floodplain soil microbial communities can be conceptualized along a gradient of hydrologic connectivity. Additionally, we show that these differences are likely due to connectivity-related variation in flooding frequency, soil organic matter, and soil N. Our findings are particularly relevant to the restoration and management of microbially mediated biogeochemical processes in riverine floodplain wetlands.

Journal of the International Institute, Feb 1, 2005

ABSTRACT The spotted gar (Lepisosteus oculatus) is one of seven extant members of the family Lepi... more ABSTRACT The spotted gar (Lepisosteus oculatus) is one of seven extant members of the family Lepisosteidae and ranges from the southern Great Lakes region to the Gulf Coast. The spotted gar has a disjoint distribution and is more common in the Mississippi River basin than the Great Lakes Region. The Great Lakes basin population (peripheral) is poorly studied and may exhibit different life history traits from the Mississippi River basin population (core). We hypothesized that the peripheral population of spotted gars exhibited a faster growth rate and capacity for growth than those from the core population due to countergradient variation, which compensates for shorter length of growing season at higher latitudes. We reared young of the year spotted gars from both populations (N=60) in a common garden environment for 160 days to test for countergradient variation in growth. Individual fish were fed ad libitum and weighed and measured weekly to estimate growth. Results indicated gars from the peripheral population grew significantly larger and faster than those from core the population, suggesting countergradient variation in growth. DNA and morphometric analyses suggested increased divergence between peripheral and core populations, providing a strong basis for further conservation efforts.

Canadian Journal of Fisheries and Aquatic Sciences, 1992

Transactions of the American Fisheries Society, Apr 1, 2014

The accuracy of the Content should not be relied upon and should be independently verified with p... more The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden.

Thermal conditions and trout population characteristics were followed at 17 sites in northern low... more Thermal conditions and trout population characteristics were followed at 17 sites in northern lower Michigan over a 3-year period to determine the influence of temperature on growth and production of juvenile brook trout Salvelinus fortinalis and brown trout Salmo trutta. Thermal regimes were summarized from 25 separate indicators using principal components analysis. The first two principal axes accounted for 99.8% of the variation in the summarized temperature variables. The first component was strongly and negatively correlated with summer mean temperature (r=-0.98) while the second principal component was most strongly correlated with mean winter temperature (r=0.95). Growth rate of juvenile brook trout was not significantly correlated with density of juvenile brook or brown trout. Growth rate of juvenile brown trout was not significantly correlated with density of juvenile brook trout, but was negatively correlated with density (r=-0.52) and standing stock (r=-0.46) of juvenile brown trout. Temperature principal components explained 29.7% of the variation in the growth rate of juvenile brook trout and 47.6% of the variation in the growth rate of juvenile brown trout. Addition of density of juvenile trout to these models improved the fit to 33.5% for juvenile brook trout growth rate but did not improve the fit of the growth rate model for juvenile brown trout (R 2 =0.45). Production, as measured by standing stocks of juvenile brook and brown trout, was not significantly correlated with either principal temperature component. In order to allow for greater use of the data collected for this study, the basic temperature summaries were used to form simple linear regression (SLR) models for growth rate and standing stock of juvenile brook and brown trout. The best simple model for growth rate of juvenile brook trout explained 48.2% of the variance from the mean daily temperature fluctuation in July. The best brown trout growth rate model explained 53.1% of the variance using the mean daily temperature for the month of July. These types of data are easily collected by fisheries managers and will allow for estimation of expected growth rates at sites containing juvenile brook or brown trout. While lethal thermal limits for trout in laboratory settings have long been established (e.g., Fry et al. 1946) the influences of temperature on trout living within their range of thermal tolerance is poorly understood. Temperature can be considered a master variable with respect to growth and production of fish due to its influence on both rates of metabolism and foraging activity. Brett (1979) lists temperature, ration, and size of fish as the three main factors influencing the growth of fish. Elliott (1994) has examined thermal influences on growth and production of brown trout Salmo trutta in a series of laboratory and field studies. By following characteristics of fish populations (e.g., growth rate, density, standing stock) and

We developed simple decision support tools (plots) for fishery managers in Michigan that are base... more We developed simple decision support tools (plots) for fishery managers in Michigan that are based on habitat data and fish population estimates for several hundred stream sites throughout the state. We generated contour plots to show patterns in fish biomass for over 60 common species (and 120 species grouped at the family level) in relation to axes of catchment area (CA) and low-flow yield (LFY; 90% exceedance flow divided by CA), and then against axes of mean and weekly range in July temperature. The plots showed distinct patterns in fish density at each level of biological organization studied and were useful for quantitatively comparing river sites. Contour plots were also made for fish assemblage attributes such as species richness and total density. We demonstrated how these plots can be used to support stream management and provided examples pertaining to resource assessment, trout stocking, angling regulations, chemical reclamation of marginal trout streams, indicator species, instream flow protection, and habitat restoration. These tools are electronically available, so managers can easily access and incorporate them into decision protocols and presentations.

Through ecological classification, researchers both (1) identify and (2) describe naturally-occur... more Through ecological classification, researchers both (1) identify and (2) describe naturally-occurring, ecologically-distinct, spatial units from a holistic perspective. An ecological river classification involves the identification of structurally homogeneous spatial units which emerge along the channel network as a result of catchment processes interacting with local physiographic features. Our observations of Michigan rivers suggest that the natural ecological unit, as defined by the spatial scales of riverine physical and biological processes, is most closely approximated by the physical channel unit termed the valley segment. Valley segments are generally quite large, and characterized by relative homogeneity in hydrologic, limnologic, channel morphology, and riparian dynamics. Valley segment characteristics often change sharply at stream junctions, slope breaks, and boundaries of local landforms. We followed several steps in developing an ecological classification for the rivers of lower Michigan. Step 1-We first selected catchment size, hydrology, water chemistry, water temperature, valley character, channel character, and fish assemblages as fundamental attributes to describe ecological character of river valley segments. Steps 2-3-Two experienced aquatic ecologists worked together, interpreting map information on catchment and valley characteristics from a GIS, using their combined knowledge of ecological processes and interactions. We initially examined several key maps to become familiar with the general landscape patterns of a particular catchment; and to then identify initial valley segment units as defined by catchment and valley characteristics, and fish assemblages. Boundary definition required the integration of terrain features observed on several thematic maps (e.g., major stream network junctions, slope breaks, boundaries of major physiographic units or land cover units; or changes in stream sinuousity and meander wavelength patterns, riparian wetlands, or valley shape), combined with knowledge of fish distributions. We next developed categorizations for each component attribute

Sound management and protection of the Great Lakes Basin's abundant freshwater resources requires... more Sound management and protection of the Great Lakes Basin's abundant freshwater resources requires the ability to predict local habitat conditions and fish communities across regional spatial scales. In response to concerns over increased use and potential diversion of its plentiful freshwater resources, the State of Michigan enacted legislation in 2006 that required creation of an integrated assessment model to determine potential for water withdrawals to cause an adverse impact to Michigan's waters or water-dependent natural resources. As part of this effort, we developed a model to predict how fish assemblages in different types of Michigan streams would change in response to decreased base flows. The model uses habitat suitability information from Michigan (catchment size, base flow yield, July mean water temperature) for over 40 fish species to predict assemblage structure and characteristic fish assemblages in individual river segments under a range of base flow reductions. River segments were classified into eleven strata based upon catchment size and July river temperature, and fish assemblages were predicted for each category. By synthesizing model runs for individual fish species at representative segments of each river type, we developed curves describing how typical fish assemblages in each type respond to flow reduction. The strata-specific, fish response curves can be used to identify streamflow reduction levels resulting in adverse resource impacts (ARIs) to characteristic fish populations. Our model provides a framework for evaluating impacts of flow withdrawals on biotic communities across a diverse regional landscape.

Research projects in the Crane Creek coastal wetland complex (Ottawa National Wildlife Refuge) ar... more Research projects in the Crane Creek coastal wetland complex (Ottawa National Wildlife Refuge) are exploring wetland habitat rehabilitation strategies and their impact on Lake Erie fishes. Established methods of assessing fish assemblages (e.g., fyke nets) can be used to characterize fish (community composition and abundance) in a specific location, but provide little information on fish behavior and short-term rates of movement. From a habitat rehabilitation perspective, data on fish movement and behavior are critical to both evaluate the biological response to completed projects and guide the design of future projects (e.g., maintaining an appropriate level of hydrologic connectivity). DIDSON (Dual-frequency IDentification SONar) is a developing technology able to collect high-resolution fisheries data day or night in very shallow turbid water. A DIDSON was deployed for 11 days in Crane Creek at its connection to Lake Erie to explore how Great Lakes fishes used coastal wetland hab...

Pearson correlation matrix with two-tailed significance test.

Total standardized effects of basin cropland and riparian forested wetland on nutrients in the na... more Total standardized effects of basin cropland and riparian forested wetland on nutrients in the national and regional SEMs.

Study unit features: summary of dominant study unit features. Mean values and ranges are shown fo... more Study unit features: summary of dominant study unit features. Mean values and ranges are shown for annual precipitation, air temperatures, and study site basin area.

Site variable means (mean and standard deviation of environmental, physical habitat, water chemis... more Site variable means (mean and standard deviation of environmental, physical habitat, water chemistry, and invertebrate variables for sampled sites).

Ecology, 1981

Abstract. The effects of manipulations of density and sediment type on the emigration rates of ch... more Abstract. The effects of manipulations of density and sediment type on the emigration rates of chironomid larvae (Diptera:Chironomidae) from Hunt Creek, Montmorency County, Michigan, USA, were examined in artificial stream chambers. Both basic sediment ...

River valley segments are adjacent sections of streams and rivers that are relatively homogeneous... more River valley segments are adjacent sections of streams and rivers that are relatively homogeneous in hydrology, limnology, channel morphology, riparian dynamics, and biological communities. River valley segments have been advocated as appropriate spatial units for assessing, monitoring, and managing rivers and streams for several reasons; however, methods for delineating these spatial units have been tedious to implement or have lacked objectivity, which arguably has limited their use as river and stream management units by natural resource agencies. We describe a spatially constrained clustering program that we developed for delineating river valley segments from geographic information system digital river network databases that is flexible, easy-to-use, and improves objectivity in the river valley segment delineation process. This program, which we refer to as the valley segment affinity search technique (VAST), includes a variety of options for determining spatial adjacency in stream reaches, as well as several data transformation methods, types of resemblance coefficients, and cluster linkage methods. The usefulness of VAST is demonstrated by using it to delineate river valley segments for river network databases for Michigan and Wisconsin, USA, and by comparing river valley segments delineated by VAST to an expert-opinion delineation previously completed for a Michigan river network database.

Microbial Ecology

Riverine floodplains are ecologically and economically valuable ecosystems that are heavily threa... more Riverine floodplains are ecologically and economically valuable ecosystems that are heavily threatened by anthropogenic stressors. Microbial communities in floodplain soils mediate critical biogeochemical processes, yet we understand little about the relationship between these communities and variation in hydrologic connectivity related to land management or topography. Here, we present metagenomic evidence that differences among microbial communities in three floodplain soils correspond to a long-term gradient of hydrologic connectivity. Specifically, all strictly anaerobic taxa and metabolic pathways were positively associated with increased hydrologic connectivity and flooding frequency. In contrast, most aerobic taxa and all strictly aerobic pathways were negatively related to hydrologic connectivity and flooding frequency. Furthermore, the genetic potential to metabolize organic compounds tended to decrease as hydrologic connectivity increased, which may reflect either the observed concomitant decline of soil organic matter or the parallel increase in both anaerobic taxa and pathways. A decline in soil N, accompanied by an increased genetic potential for oligotrophic N acquisition subsystems, suggests that soil nutrients also shape microbial communities in these soils. We conclude that differences among floodplain soil microbial communities can be conceptualized along a gradient of hydrologic connectivity. Additionally, we show that these differences are likely due to connectivity-related variation in flooding frequency, soil organic matter, and soil N. Our findings are particularly relevant to the restoration and management of microbially mediated biogeochemical processes in riverine floodplain wetlands.

Journal of the International Institute, Feb 1, 2005

ABSTRACT The spotted gar (Lepisosteus oculatus) is one of seven extant members of the family Lepi... more ABSTRACT The spotted gar (Lepisosteus oculatus) is one of seven extant members of the family Lepisosteidae and ranges from the southern Great Lakes region to the Gulf Coast. The spotted gar has a disjoint distribution and is more common in the Mississippi River basin than the Great Lakes Region. The Great Lakes basin population (peripheral) is poorly studied and may exhibit different life history traits from the Mississippi River basin population (core). We hypothesized that the peripheral population of spotted gars exhibited a faster growth rate and capacity for growth than those from the core population due to countergradient variation, which compensates for shorter length of growing season at higher latitudes. We reared young of the year spotted gars from both populations (N=60) in a common garden environment for 160 days to test for countergradient variation in growth. Individual fish were fed ad libitum and weighed and measured weekly to estimate growth. Results indicated gars from the peripheral population grew significantly larger and faster than those from core the population, suggesting countergradient variation in growth. DNA and morphometric analyses suggested increased divergence between peripheral and core populations, providing a strong basis for further conservation efforts.

Canadian Journal of Fisheries and Aquatic Sciences, 1992

Transactions of the American Fisheries Society, Apr 1, 2014

The accuracy of the Content should not be relied upon and should be independently verified with p... more The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden.

Thermal conditions and trout population characteristics were followed at 17 sites in northern low... more Thermal conditions and trout population characteristics were followed at 17 sites in northern lower Michigan over a 3-year period to determine the influence of temperature on growth and production of juvenile brook trout Salvelinus fortinalis and brown trout Salmo trutta. Thermal regimes were summarized from 25 separate indicators using principal components analysis. The first two principal axes accounted for 99.8% of the variation in the summarized temperature variables. The first component was strongly and negatively correlated with summer mean temperature (r=-0.98) while the second principal component was most strongly correlated with mean winter temperature (r=0.95). Growth rate of juvenile brook trout was not significantly correlated with density of juvenile brook or brown trout. Growth rate of juvenile brown trout was not significantly correlated with density of juvenile brook trout, but was negatively correlated with density (r=-0.52) and standing stock (r=-0.46) of juvenile brown trout. Temperature principal components explained 29.7% of the variation in the growth rate of juvenile brook trout and 47.6% of the variation in the growth rate of juvenile brown trout. Addition of density of juvenile trout to these models improved the fit to 33.5% for juvenile brook trout growth rate but did not improve the fit of the growth rate model for juvenile brown trout (R 2 =0.45). Production, as measured by standing stocks of juvenile brook and brown trout, was not significantly correlated with either principal temperature component. In order to allow for greater use of the data collected for this study, the basic temperature summaries were used to form simple linear regression (SLR) models for growth rate and standing stock of juvenile brook and brown trout. The best simple model for growth rate of juvenile brook trout explained 48.2% of the variance from the mean daily temperature fluctuation in July. The best brown trout growth rate model explained 53.1% of the variance using the mean daily temperature for the month of July. These types of data are easily collected by fisheries managers and will allow for estimation of expected growth rates at sites containing juvenile brook or brown trout. While lethal thermal limits for trout in laboratory settings have long been established (e.g., Fry et al. 1946) the influences of temperature on trout living within their range of thermal tolerance is poorly understood. Temperature can be considered a master variable with respect to growth and production of fish due to its influence on both rates of metabolism and foraging activity. Brett (1979) lists temperature, ration, and size of fish as the three main factors influencing the growth of fish. Elliott (1994) has examined thermal influences on growth and production of brown trout Salmo trutta in a series of laboratory and field studies. By following characteristics of fish populations (e.g., growth rate, density, standing stock) and

We developed simple decision support tools (plots) for fishery managers in Michigan that are base... more We developed simple decision support tools (plots) for fishery managers in Michigan that are based on habitat data and fish population estimates for several hundred stream sites throughout the state. We generated contour plots to show patterns in fish biomass for over 60 common species (and 120 species grouped at the family level) in relation to axes of catchment area (CA) and low-flow yield (LFY; 90% exceedance flow divided by CA), and then against axes of mean and weekly range in July temperature. The plots showed distinct patterns in fish density at each level of biological organization studied and were useful for quantitatively comparing river sites. Contour plots were also made for fish assemblage attributes such as species richness and total density. We demonstrated how these plots can be used to support stream management and provided examples pertaining to resource assessment, trout stocking, angling regulations, chemical reclamation of marginal trout streams, indicator species, instream flow protection, and habitat restoration. These tools are electronically available, so managers can easily access and incorporate them into decision protocols and presentations.

Through ecological classification, researchers both (1) identify and (2) describe naturally-occur... more Through ecological classification, researchers both (1) identify and (2) describe naturally-occurring, ecologically-distinct, spatial units from a holistic perspective. An ecological river classification involves the identification of structurally homogeneous spatial units which emerge along the channel network as a result of catchment processes interacting with local physiographic features. Our observations of Michigan rivers suggest that the natural ecological unit, as defined by the spatial scales of riverine physical and biological processes, is most closely approximated by the physical channel unit termed the valley segment. Valley segments are generally quite large, and characterized by relative homogeneity in hydrologic, limnologic, channel morphology, and riparian dynamics. Valley segment characteristics often change sharply at stream junctions, slope breaks, and boundaries of local landforms. We followed several steps in developing an ecological classification for the rivers of lower Michigan. Step 1-We first selected catchment size, hydrology, water chemistry, water temperature, valley character, channel character, and fish assemblages as fundamental attributes to describe ecological character of river valley segments. Steps 2-3-Two experienced aquatic ecologists worked together, interpreting map information on catchment and valley characteristics from a GIS, using their combined knowledge of ecological processes and interactions. We initially examined several key maps to become familiar with the general landscape patterns of a particular catchment; and to then identify initial valley segment units as defined by catchment and valley characteristics, and fish assemblages. Boundary definition required the integration of terrain features observed on several thematic maps (e.g., major stream network junctions, slope breaks, boundaries of major physiographic units or land cover units; or changes in stream sinuousity and meander wavelength patterns, riparian wetlands, or valley shape), combined with knowledge of fish distributions. We next developed categorizations for each component attribute

Sound management and protection of the Great Lakes Basin's abundant freshwater resources requires... more Sound management and protection of the Great Lakes Basin's abundant freshwater resources requires the ability to predict local habitat conditions and fish communities across regional spatial scales. In response to concerns over increased use and potential diversion of its plentiful freshwater resources, the State of Michigan enacted legislation in 2006 that required creation of an integrated assessment model to determine potential for water withdrawals to cause an adverse impact to Michigan's waters or water-dependent natural resources. As part of this effort, we developed a model to predict how fish assemblages in different types of Michigan streams would change in response to decreased base flows. The model uses habitat suitability information from Michigan (catchment size, base flow yield, July mean water temperature) for over 40 fish species to predict assemblage structure and characteristic fish assemblages in individual river segments under a range of base flow reductions. River segments were classified into eleven strata based upon catchment size and July river temperature, and fish assemblages were predicted for each category. By synthesizing model runs for individual fish species at representative segments of each river type, we developed curves describing how typical fish assemblages in each type respond to flow reduction. The strata-specific, fish response curves can be used to identify streamflow reduction levels resulting in adverse resource impacts (ARIs) to characteristic fish populations. Our model provides a framework for evaluating impacts of flow withdrawals on biotic communities across a diverse regional landscape.

Research projects in the Crane Creek coastal wetland complex (Ottawa National Wildlife Refuge) ar... more Research projects in the Crane Creek coastal wetland complex (Ottawa National Wildlife Refuge) are exploring wetland habitat rehabilitation strategies and their impact on Lake Erie fishes. Established methods of assessing fish assemblages (e.g., fyke nets) can be used to characterize fish (community composition and abundance) in a specific location, but provide little information on fish behavior and short-term rates of movement. From a habitat rehabilitation perspective, data on fish movement and behavior are critical to both evaluate the biological response to completed projects and guide the design of future projects (e.g., maintaining an appropriate level of hydrologic connectivity). DIDSON (Dual-frequency IDentification SONar) is a developing technology able to collect high-resolution fisheries data day or night in very shallow turbid water. A DIDSON was deployed for 11 days in Crane Creek at its connection to Lake Erie to explore how Great Lakes fishes used coastal wetland hab...