Brent Knights (Former Employee)
Science and Products
Filter Total Items: 50
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
A comparison of internal and external radio transmitters with northern leopard frogs (Rana pipiens) A comparison of internal and external radio transmitters with northern leopard frogs (Rana pipiens)
Abstract has not been submitted
Authors
S.E. Weick, M. G. Knutson, B.C. Knights, B.C. Pember
Hydrologic and hydraulic factors affecting passage of paddlefish through dams in the Upper Mississippi River Hydrologic and hydraulic factors affecting passage of paddlefish through dams in the Upper Mississippi River
Populations of paddlefish Polyodon spathula have been adversely affected by dams that can block their movements. Unlike high-head dams that preclude fish passage (unless they are equipped with fishways), the dams on the upper Mississippi River are typically low-head dams with bottom release gates that may allow fish passage under certain conditions. We evaluated the relation of dam head...
Authors
S. J. Zigler, M. R. Dewey, B.C. Knights, A.L. Runstrom, M.T. Steingraeber
Science and Products
Filter Total Items: 50
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
A comparison of internal and external radio transmitters with northern leopard frogs (Rana pipiens) A comparison of internal and external radio transmitters with northern leopard frogs (Rana pipiens)
Abstract has not been submitted
Authors
S.E. Weick, M. G. Knutson, B.C. Knights, B.C. Pember
Hydrologic and hydraulic factors affecting passage of paddlefish through dams in the Upper Mississippi River Hydrologic and hydraulic factors affecting passage of paddlefish through dams in the Upper Mississippi River
Populations of paddlefish Polyodon spathula have been adversely affected by dams that can block their movements. Unlike high-head dams that preclude fish passage (unless they are equipped with fishways), the dams on the upper Mississippi River are typically low-head dams with bottom release gates that may allow fish passage under certain conditions. We evaluated the relation of dam head...
Authors
S. J. Zigler, M. R. Dewey, B.C. Knights, A.L. Runstrom, M.T. Steingraeber