James Larson
James Larson
Science and Products
Filter Total Items: 44
Using a gradient in food quality to infer drivers of fatty acid content in two filter-feeding aquatic consumers
Inferences about ecological structure and function are often made using elemental or macromolecular tracers of food web structure. For example, inferences about food chain length are often made using stable isotope ratios of top predators and consumer food sources are often inferred from both stable isotopes and fatty acid (FA) content in consumer tissues. The use of FAs as tracers implies some de
Authors
James H. Larson, William B. Richardson, Jonathan M. Vallazza, Lynn A. Bartsch, Michelle R. Bartsch
Spatial and temporal dynamics of suspended particle characteristics and composition in Navigation Pool 19 of the Upper Mississippi River
Suspended particles are an essential component of large rivers influencing channel geomorphology, biogeochemical cycling of nutrients, and food web resources. The Upper Mississippi River is a large floodplain river that exhibits pronounced spatiotemporal variation in environmental conditions and biota, providing an ideal environment for investigating dynamics of suspended particles in large river
Authors
Amanda S. Milde, William B. Richardson, Eric A. Strauss, James H. Larson, Jonathan M. Vallazza, Brent C. Knights
Mercury and water level fluctuations in lakes of northern Minnesota
Large lake ecosystems support a variety of ecosystem services in surrounding communities, including recreational and commercial fishing. However, many northern temperate fisheries are contaminated by mercury. Annual variation in mercury accumulation in fish has previously been linked to water level (WL) fluctuations, opening the possibility of regulating water levels in a manner that minimizes or
Authors
James H. Larson, Ryan P. Maki, Victoria G. Christensen, Mark B. Sandheinrich, Jaime F. LeDuc, Claire Kissane, Brent C. Knights
Lake levels and water quality in comparison to fish mercury body burdens, Voyageurs National Park, Minnesota, 2013–15
Within Voyageurs National Park in Minnesota, lake levels are controlled by a series of dams to support a variety of uses. Previous research indicates a link between these artificially maintained water levels, referred to as rule curves, and mercury concentrations in fish owing to the drying and rewetting of wetlands and other nearshore areas, which may release methylmercury into the water when inu
Authors
Victoria G. Christensen, James H. Larson, Ryan P. Maki, Mark B. Sandheinrich, Mark E. Brigham, Claire Kissane, Jamie F. LeDuc
Do water level fluctuations influence production of walleye and yellow perch young-of-the-year in large northern lakes?
Many ecological processes depend on the regular rise and fall of water levels (WLs), and artificial manipulations to WL regimes can impair important ecosystem services. Previous research has suggested that differences in WL between late summer and early spring may alter the suitability of shoals used by Walleyes Sander vitreus for spawning. Other species, such as the Yellow Perch Perca flavescens,
Authors
James H. Larson, David F. Staples, Ryan P. Maki, Jon M. Vallazza, Brent C. Knights, Kevin E. Peterson
Do rivermouths alter nutrient and seston delivery to the nearshore?
Tributary inputs to lakes and seas are often measured at riverine gages, upstream of lentic influence. Between these riverine gages and the nearshore zones of large waterbodies lie rivermouths, which may retain, transform and contribute materials to the nearshore zone. However, the magnitude and timing of these rivermouth effects have rarely been measured.During the summer of 2011, 23 tributary sy
Authors
James H. Larson, Paul C. Frost, Jon M. Vallazza, John C. Nelson, William B. Richardson
Genetic analysis shows that morphology alone cannot distinguish asian carp eggs from those of other cyprinid species
Fish eggs and embryos (hereafter collectively referred to as “eggs”) were collected in the upper Mississippi River main stem (~300 km upstream of previously reported spawning by invasive Asian carp) during summer 2013. Based on previously published morphological characteristics, the eggs were identified as belonging to Asian carp. A subsample of the eggs was subsequently analyzed by using molecular
Authors
James H. Larson, S. Grace McCalla, Duane Chapman, Christopher B. Rees, Brent C. Knights, Jonathan M. Vallazza, Amy E. George, William B. Richardson, Jon Amberg
Spatial variation in biofouling of a unionid mussel (Lampsilis siliquoidea) across the western basin of Lake Erie
Invasion of North American waters by nonnative Dreissena polymorpha and D. rostriformis bugensishas resulted in declines of the Unionidae family of native North American mussels. Dreissenid mussels biofoul unionid mussels in large numbers and interfere with unionid movement, their acquisition of food, and the native mussels' ability to open and close their shells. Initial expectations for the Grea
Authors
James H. Larson, Mary Anne Evans, William B. Richardson, Jeff Schaeffer, John C. Nelson
Measuring spatial variation in secondary production and food quality using a common consumer approach in Lake Erie
Lake Erie is a large lake straddling the border of the U.S. and Canada that has become increasingly eutrophic in recent years. Eutrophication is particularly focused in the shallow western basin. The western basin of Lake Erie is hydrodynamically similar to a large estuary, with riverine inputs from the Detroit and Maumee Rivers mixing together and creating gradients in chemical and physical condi
Authors
James H. Larson, William B. Richardson, Mary Anne Evans, Jeff Schaeffer, Timothy Wynne, Michelle Bartsch, Lynn Bartsch, J. C. Nelson, Jon M. Vallazza
Human activities cause distinct dissolved organic matter composition across freshwater ecosystems
Dissolved organic matter (DOM) composition in freshwater ecosystems is influenced by interactions between physical, chemical, and biological processes that are controlled, at one level, by watershed landscape, hydrology, and their connections. Against this environmental template, humans may strongly influence DOM composition. Yet, we lack a comprehensive understanding of DOM composition variation
Authors
Clayton J. Williams, Paul C. Frost, Ana M. Morales-Williams, James H. Larson, William B. Richardson, Aisha S. Chiandet, Marguerite A. Xenopoulos
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 (Lepomis macroch
Authors
James H. Larson, Michelle Bartsch, Steve Gutreuter, Brent C. Knights, Lynn Bartsch, William B. Richardson, Jonathan M. Vallazza, Michael T. Arts
Relationships between land cover and dissolved organic matter change along the river to lake transition
Dissolved organic matter (DOM) influences the physical, chemical, and biological properties of aquatic ecosystems. We hypothesized that controls over spatial variation in DOM quantity and composition (measured with DOM optical properties) differ based on the source of DOM to aquatic ecosystems. DOM quantity and composition should be better predicted by land cover in aquatic habitats with allochtho
Authors
James H. Larson, Paul C. Frost, Marguerite A. Xenopoulos, Clayton J. Williams, Ana M. Morales-Williams, Jonathan M. Vallazza, J. C. Nelson, William B. Richardson
Science and Products
Filter Total Items: 44
Using a gradient in food quality to infer drivers of fatty acid content in two filter-feeding aquatic consumers
Inferences about ecological structure and function are often made using elemental or macromolecular tracers of food web structure. For example, inferences about food chain length are often made using stable isotope ratios of top predators and consumer food sources are often inferred from both stable isotopes and fatty acid (FA) content in consumer tissues. The use of FAs as tracers implies some de
Authors
James H. Larson, William B. Richardson, Jonathan M. Vallazza, Lynn A. Bartsch, Michelle R. Bartsch
Spatial and temporal dynamics of suspended particle characteristics and composition in Navigation Pool 19 of the Upper Mississippi River
Suspended particles are an essential component of large rivers influencing channel geomorphology, biogeochemical cycling of nutrients, and food web resources. The Upper Mississippi River is a large floodplain river that exhibits pronounced spatiotemporal variation in environmental conditions and biota, providing an ideal environment for investigating dynamics of suspended particles in large river
Authors
Amanda S. Milde, William B. Richardson, Eric A. Strauss, James H. Larson, Jonathan M. Vallazza, Brent C. Knights
Mercury and water level fluctuations in lakes of northern Minnesota
Large lake ecosystems support a variety of ecosystem services in surrounding communities, including recreational and commercial fishing. However, many northern temperate fisheries are contaminated by mercury. Annual variation in mercury accumulation in fish has previously been linked to water level (WL) fluctuations, opening the possibility of regulating water levels in a manner that minimizes or
Authors
James H. Larson, Ryan P. Maki, Victoria G. Christensen, Mark B. Sandheinrich, Jaime F. LeDuc, Claire Kissane, Brent C. Knights
Lake levels and water quality in comparison to fish mercury body burdens, Voyageurs National Park, Minnesota, 2013–15
Within Voyageurs National Park in Minnesota, lake levels are controlled by a series of dams to support a variety of uses. Previous research indicates a link between these artificially maintained water levels, referred to as rule curves, and mercury concentrations in fish owing to the drying and rewetting of wetlands and other nearshore areas, which may release methylmercury into the water when inu
Authors
Victoria G. Christensen, James H. Larson, Ryan P. Maki, Mark B. Sandheinrich, Mark E. Brigham, Claire Kissane, Jamie F. LeDuc
Do water level fluctuations influence production of walleye and yellow perch young-of-the-year in large northern lakes?
Many ecological processes depend on the regular rise and fall of water levels (WLs), and artificial manipulations to WL regimes can impair important ecosystem services. Previous research has suggested that differences in WL between late summer and early spring may alter the suitability of shoals used by Walleyes Sander vitreus for spawning. Other species, such as the Yellow Perch Perca flavescens,
Authors
James H. Larson, David F. Staples, Ryan P. Maki, Jon M. Vallazza, Brent C. Knights, Kevin E. Peterson
Do rivermouths alter nutrient and seston delivery to the nearshore?
Tributary inputs to lakes and seas are often measured at riverine gages, upstream of lentic influence. Between these riverine gages and the nearshore zones of large waterbodies lie rivermouths, which may retain, transform and contribute materials to the nearshore zone. However, the magnitude and timing of these rivermouth effects have rarely been measured.During the summer of 2011, 23 tributary sy
Authors
James H. Larson, Paul C. Frost, Jon M. Vallazza, John C. Nelson, William B. Richardson
Genetic analysis shows that morphology alone cannot distinguish asian carp eggs from those of other cyprinid species
Fish eggs and embryos (hereafter collectively referred to as “eggs”) were collected in the upper Mississippi River main stem (~300 km upstream of previously reported spawning by invasive Asian carp) during summer 2013. Based on previously published morphological characteristics, the eggs were identified as belonging to Asian carp. A subsample of the eggs was subsequently analyzed by using molecular
Authors
James H. Larson, S. Grace McCalla, Duane Chapman, Christopher B. Rees, Brent C. Knights, Jonathan M. Vallazza, Amy E. George, William B. Richardson, Jon Amberg
Spatial variation in biofouling of a unionid mussel (Lampsilis siliquoidea) across the western basin of Lake Erie
Invasion of North American waters by nonnative Dreissena polymorpha and D. rostriformis bugensishas resulted in declines of the Unionidae family of native North American mussels. Dreissenid mussels biofoul unionid mussels in large numbers and interfere with unionid movement, their acquisition of food, and the native mussels' ability to open and close their shells. Initial expectations for the Grea
Authors
James H. Larson, Mary Anne Evans, William B. Richardson, Jeff Schaeffer, John C. Nelson
Measuring spatial variation in secondary production and food quality using a common consumer approach in Lake Erie
Lake Erie is a large lake straddling the border of the U.S. and Canada that has become increasingly eutrophic in recent years. Eutrophication is particularly focused in the shallow western basin. The western basin of Lake Erie is hydrodynamically similar to a large estuary, with riverine inputs from the Detroit and Maumee Rivers mixing together and creating gradients in chemical and physical condi
Authors
James H. Larson, William B. Richardson, Mary Anne Evans, Jeff Schaeffer, Timothy Wynne, Michelle Bartsch, Lynn Bartsch, J. C. Nelson, Jon M. Vallazza
Human activities cause distinct dissolved organic matter composition across freshwater ecosystems
Dissolved organic matter (DOM) composition in freshwater ecosystems is influenced by interactions between physical, chemical, and biological processes that are controlled, at one level, by watershed landscape, hydrology, and their connections. Against this environmental template, humans may strongly influence DOM composition. Yet, we lack a comprehensive understanding of DOM composition variation
Authors
Clayton J. Williams, Paul C. Frost, Ana M. Morales-Williams, James H. Larson, William B. Richardson, Aisha S. Chiandet, Marguerite A. Xenopoulos
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 (Lepomis macroch
Authors
James H. Larson, Michelle Bartsch, Steve Gutreuter, Brent C. Knights, Lynn Bartsch, William B. Richardson, Jonathan M. Vallazza, Michael T. Arts
Relationships between land cover and dissolved organic matter change along the river to lake transition
Dissolved organic matter (DOM) influences the physical, chemical, and biological properties of aquatic ecosystems. We hypothesized that controls over spatial variation in DOM quantity and composition (measured with DOM optical properties) differ based on the source of DOM to aquatic ecosystems. DOM quantity and composition should be better predicted by land cover in aquatic habitats with allochtho
Authors
James H. Larson, Paul C. Frost, Marguerite A. Xenopoulos, Clayton J. Williams, Ana M. Morales-Williams, Jonathan M. Vallazza, J. C. Nelson, William B. Richardson