Brent Knights (Former Employee)
Science and Products
Filter Total Items: 52
Managing the Mississippi River floodplain: Achieving ecological benefits requires more than hydrological connection to the river: Chapter Managing the Mississippi River floodplain: Achieving ecological benefits requires more than hydrological connection to the river: Chapter
Floodplains are vital to the structure and function of river-floodplain ecosystems. Among the many ecological services provided by floodplains are nutrient cycling and seasonal habitats for fish, including spawning, nursery, foraging and wintering habitats. Connections between the river channel and floodplain habitats are essential to realize these ecological services, but spatial and...
Authors
Harold Schramm, William B. Richardson, Brent C. Knights
Differences between main-channel and off-channel food webs in the upper Mississippi River revealed by fatty acid profiles of consumers Differences between main-channel and off-channel food webs in the upper Mississippi River revealed by fatty acid profiles of consumers
Large river systems are often thought to contain a mosaic of patches with different habitat characteristics driven by differences in flow and mixing environments. Off-channel habitats (e.g., backwater areas, secondary channels) can become semi-isolated from main-channel water inputs, leading to the development of distinct biogeochemical environments. Observations of adult bluegill...
Authors
James H. Larson, Michelle Bartsch, Steve Gutreuter, Brent C. Knights, Lynn Bartsch, William B. Richardson, Jonathan M. Vallazza, Michael T. Arts
Can mercury in fish be reduced by water level management? Evaluating the effects of water level fluctuation on mercury accumulation in yellow perch (Perca flavescens) Can mercury in fish be reduced by water level management? Evaluating the effects of water level fluctuation on mercury accumulation in yellow perch (Perca flavescens)
Mercury (Hg) contamination of fisheries is a major concern for resource managers of many temperate lakes. Anthropogenic Hg contamination is largely derived from atmospheric deposition within a lake’s watershed, but its incorporation into the food web is facilitated by bacterial activity in sediments. Temporal variation in Hg content of fish (young-of-year yellow perch) in the regulated...
Authors
James H. Larson, Ryan P. Maki, Brent C. Knights, Brian R. Gray
Fatty acid composition at the base of aquatic food webs is influenced by habitat type and watershed land use Fatty acid composition at the base of aquatic food webs is influenced by habitat type and watershed land use
Spatial variation in food resources strongly influences many aspects of aquatic consumer ecology. Although large-scale controls over spatial variation in many aspects of food resources are well known, others have received little study. Here we investigated variation in the fatty acid (FA) composition of seston and primary consumers within (i.e., among habitats) and among tributary...
Authors
James H. Larson, William B. Richardson, Brent C. Knights, Lynn Bartsch, Michelle Bartsch, J. C. Nelson, Jason A. Veldboom, Jonathan M. Vallazza
Persistent disturbance by commercial navigation afters the relative abundance of channel-dwelling fishes in a large river Persistent disturbance by commercial navigation afters the relative abundance of channel-dwelling fishes in a large river
We provide the first evidence for chronic effects of disturbance by commercial vessels on the spatial distribution and abundance of fishes in the channels of a large river. Most of the world's large rivers are intensively managed to satisfy increasing demands for commercial shipping, but little research has been conducted to identify and alleviate any adverse consequences of commercial...
Authors
S. Gutreuter, J.M. Vallazza, B.C. Knights
Mercury in soils, lakes, and fish in Voyageurs National Park (Minnesota): Importance of atmospheric deposition and ecosystem factors Mercury in soils, lakes, and fish in Voyageurs National Park (Minnesota): Importance of atmospheric deposition and ecosystem factors
Concentrations of methylmercury in game fish from many interior lakes in Voyageurs National Park (MN, U.S.A.) substantially exceed criteria for the protection of human health. We assessed the importance of atmospheric and geologic sources of mercury to interior lakes and watersheds within the Park and identified ecosystem factors associated with variation in methylmercury contamination...
Authors
J.G. Wiener, B.C. Knights, M.B. Sandheinrich, Jeffrey D. Jeremiason, M. E. Brigham, D.R. Engstrom, L. G. Woodruff, W.F. Cannon, S.J. Balogh
Science and Products
Filter Total Items: 52
Managing the Mississippi River floodplain: Achieving ecological benefits requires more than hydrological connection to the river: Chapter Managing the Mississippi River floodplain: Achieving ecological benefits requires more than hydrological connection to the river: Chapter
Floodplains are vital to the structure and function of river-floodplain ecosystems. Among the many ecological services provided by floodplains are nutrient cycling and seasonal habitats for fish, including spawning, nursery, foraging and wintering habitats. Connections between the river channel and floodplain habitats are essential to realize these ecological services, but spatial and...
Authors
Harold Schramm, William B. Richardson, Brent C. Knights
Differences between main-channel and off-channel food webs in the upper Mississippi River revealed by fatty acid profiles of consumers Differences between main-channel and off-channel food webs in the upper Mississippi River revealed by fatty acid profiles of consumers
Large river systems are often thought to contain a mosaic of patches with different habitat characteristics driven by differences in flow and mixing environments. Off-channel habitats (e.g., backwater areas, secondary channels) can become semi-isolated from main-channel water inputs, leading to the development of distinct biogeochemical environments. Observations of adult bluegill...
Authors
James H. Larson, Michelle Bartsch, Steve Gutreuter, Brent C. Knights, Lynn Bartsch, William B. Richardson, Jonathan M. Vallazza, Michael T. Arts
Can mercury in fish be reduced by water level management? Evaluating the effects of water level fluctuation on mercury accumulation in yellow perch (Perca flavescens) Can mercury in fish be reduced by water level management? Evaluating the effects of water level fluctuation on mercury accumulation in yellow perch (Perca flavescens)
Mercury (Hg) contamination of fisheries is a major concern for resource managers of many temperate lakes. Anthropogenic Hg contamination is largely derived from atmospheric deposition within a lake’s watershed, but its incorporation into the food web is facilitated by bacterial activity in sediments. Temporal variation in Hg content of fish (young-of-year yellow perch) in the regulated...
Authors
James H. Larson, Ryan P. Maki, Brent C. Knights, Brian R. Gray
Fatty acid composition at the base of aquatic food webs is influenced by habitat type and watershed land use Fatty acid composition at the base of aquatic food webs is influenced by habitat type and watershed land use
Spatial variation in food resources strongly influences many aspects of aquatic consumer ecology. Although large-scale controls over spatial variation in many aspects of food resources are well known, others have received little study. Here we investigated variation in the fatty acid (FA) composition of seston and primary consumers within (i.e., among habitats) and among tributary...
Authors
James H. Larson, William B. Richardson, Brent C. Knights, Lynn Bartsch, Michelle Bartsch, J. C. Nelson, Jason A. Veldboom, Jonathan M. Vallazza
Persistent disturbance by commercial navigation afters the relative abundance of channel-dwelling fishes in a large river Persistent disturbance by commercial navigation afters the relative abundance of channel-dwelling fishes in a large river
We provide the first evidence for chronic effects of disturbance by commercial vessels on the spatial distribution and abundance of fishes in the channels of a large river. Most of the world's large rivers are intensively managed to satisfy increasing demands for commercial shipping, but little research has been conducted to identify and alleviate any adverse consequences of commercial...
Authors
S. Gutreuter, J.M. Vallazza, B.C. Knights
Mercury in soils, lakes, and fish in Voyageurs National Park (Minnesota): Importance of atmospheric deposition and ecosystem factors Mercury in soils, lakes, and fish in Voyageurs National Park (Minnesota): Importance of atmospheric deposition and ecosystem factors
Concentrations of methylmercury in game fish from many interior lakes in Voyageurs National Park (MN, U.S.A.) substantially exceed criteria for the protection of human health. We assessed the importance of atmospheric and geologic sources of mercury to interior lakes and watersheds within the Park and identified ecosystem factors associated with variation in methylmercury contamination...
Authors
J.G. Wiener, B.C. Knights, M.B. Sandheinrich, Jeffrey D. Jeremiason, M. E. Brigham, D.R. Engstrom, L. G. Woodruff, W.F. Cannon, S.J. Balogh