A5000117941- Fish Ecology and Management Studies
- Aquatic Ecosystems and Phytoplankton Dynamics
- Soil and Water Nutrient Dynamics
- Aquatic Invertebrate Ecology and Behavior
- Marine and coastal ecosystems
- Isotope Analysis in Ecology
- Freshwater macroinvertebrate diversity and ecology
- Fish biology, ecology, and behavior
- Hydrology and Watershed Management Studies
- Marine and fisheries research
- Aquatic Ecosystems and Biodiversity
- Fish Biology and Ecology Studies
- Physiological and biochemical adaptations
- Water Quality and Pollution Assessment
- Atmospheric and Environmental Gas Dynamics
- Sustainability and Ecological Systems Analysis
- Ecosystem dynamics and resilience
- Aquaculture Nutrition and Growth
- Environmental Toxicology and Ecotoxicology
- Marine Biology and Ecology Research
- Peatlands and Wetlands Ecology
- Plant and animal studies
- Species Distribution and Climate Change
- Soil erosion and sediment transport
- Atmospheric chemistry and aerosols
Miami University
2015-2024
University of Miami
2017-2021
Ecological Society of America
2016
John Wiley & Sons (United States)
2016
Leibniz Institute of Freshwater Ecology and Inland Fisheries
2013-2015
University of Oxford
2015
Pearson (United States)
2005-2013
University of Hawaiʻi at Mānoa
2008
University of Hawaii System
2008
Max Planck Society
1992
We explore the role of lakes in carbon cycling and global climate, examine mechanisms influencing pools transformations lakes, discuss how metabolism inland waters is likely to change response climate. Furthermore, we project changes as climate abundance spatial distribution biosphere, revise estimate for extent transformation waters. This synthesis demonstrates that annual emissions dioxide from atmosphere are similar magnitude uptake by oceans burial organic water sediments exceeds...
Abstract Traditional approaches to the study of food webs emphasize transfer local primary productivity in form living plant organic matter across trophic levels. However, dead matter, or detritus, a common feature most ecosystems plays frequently overlooked role as dynamic heterogeneous resource and habitat for many species. We develop an integrative framework understanding impact detritus that emphasizes ontogeny heterogeneity various ways explicit inclusion detrital dynamics alters...
▪ Abstract Animals are important in nutrient cycling freshwater ecosystems. Via excretory processes, animals can supply nutrients (nitrogen and phosphorus) at rates comparable to major sources, by support a substantial proportion of the demands primary producers. In addition, may exert strong impacts on species composition producers via effects ratios. either recycle within habitat, or translocate across habitats Nutrient translocation relatively large be particularly for stimulating new...
There is increasing evidence that species extinctions jeopardize the functioning of ecosystems. Overfishing and other human influences are reducing diversity abundance fish worldwide, but ecosystem-level consequences these changes have not been assessed quantitatively. Recycling nutrients one important ecosystem process directly influenced by fish. Fish vary widely in rates at which they excrete nitrogen phosphorus; thus, altering communities could affect nutrient recycling. Here, we use...
Rates of biogeochemical processes often vary widely in space and time, characterizing this variation is critical for understanding ecosystem functioning. In streams, spatial hotspots nutrient transformations are generally attributed to physical microbial processes. Here we examine the potential heterogeneous distributions fish generate recycling. We measured nitrogen (N) phosphorus (P) excretion rates 47 species an N-limited Neotropical stream, combined these data with population densities...
We assembled data from a global network of automated lake observatories to test hypotheses regarding the drivers ecosystem metabolism. estimated daily rates respiration and gross primary production (GPP) for up full year in each lake, via maximum likelihood fits free‐water metabolism model continuous high‐frequency measurements dissolved oxygen concentrations. Uncertainties were determined by bootstrap analysis, allowing lake‐days with poorly constrained rate estimates be down‐weighted...
Ecological stoichiometry offers a framework for predicting how animal species vary in recycling nutrients, thus providing mechanism identity mediates ecosystem processes. Here we show that variation the rates and ratios at which 28 vertebrate (fish, amphibians) recycled nitrogen (N) phosphorus (P) tropical stream supports theory. Mass‐specific P excretion rate varied 10‐fold among taxa was negatively related to body content. In addition, N : ratio excreted P. Body mass (negatively rates)...
In lakes, top predators (fish) often influence the abundance of primary producers (phytoplankton) through food web interactions: phytoplankton biomass is greater when planktivorous fish are abundant than they rare, and community structure affected by fish. Three mechanisms can account for these "top–down" effects fish: decreased herbivory zooplankton high; modification nutrient recycling rates herbivorous assemblage as varies; These processes were experimentally separated their relative...
Two predators of zooplankton, fish (yellow perch) and larval insects (Chaoborus), were manipulated within in situ mesocosms to assess their indirect effects on phytoplankton. The two caused similar reductions zooplankton size biomass, as a consequence, grazing rates However, phytoplankton increased relative predator—free controls only enclosures with not Chaoborus, suggesting that have independent rates. Estimation phosphorus excretion suggests render P more available ways: (1) by directly...
The efficiency of energy transfer through food chains [food chain (FCE)] is an important ecosystem function. It has been hypothesized that FCE across multiple trophic levels constrained by the at which herbivores use plant energy, depends on nutritional quality. Furthermore, number may also constrain FCE, because are less efficient in using production when they carnivores. These hypotheses have not tested experimentally with 3 or more levels. In a field experiment manipulating light,...
The effects of fish predation and food availability on population densities demography zooplankton were investigated in Dynamite Lake, Illinois, USA, a lake with high density size—selective planktivorous low levels. Fish predators (bluegill sunfish) levels (phytoplankton) manipulated replicated, factorial—design field experiments during two summers (1980 1981). Overall, affected much more by manipulations than predation. cladocerans Bosmina longirostris, Ceriodaphnia lacustris, Diaphanosoma...
The detritivorous fish, gizzard shad ( Dorosoma cepedianum ), provides nutrients to phytoplankton in reservoirs by ingesting organic detritus associated with sediments and excreting substantial quantities of such as N P soluble forms that are highly available phytoplankton. We estimated nutrient excretion a eutrophic reservoir (Acton Lake, Ohio) during April–October 1994 measuring field‐caught fish n = 135). Excretion rates were then extrapolated release the population using quadrat rotenone...
In situ enclosure experiments were conducted over two summers (1980—1981) to assess the effects of nutrient (N and P) enrichment zooplankton size structure on phytoplankton community an oligo—mesotrophic lake containing planktivorous fish small species. Exclusion from resulted in increase mean individual size, primarily because cladocerans Ceriodaphnia Diaphanosoma attained larger sizes. 1980, total cladoceran biomass was also greater absence fish. density significantly lower fishless...
Summary 1. Nutrients released from lake sediments can influence water column nutrient concentrations and planktonic productivity. We examined sediment release [soluble reactive phosphorus (SRP) ammonia (NH )] at two sites in a eutrophic reservoir (Acton Lake, OH, U.S.A.) that differed physical mixing conditions (a thermally stratified an unstratified site). 2. Sediment rates were estimated with three methods: core incubations, seasonal situ hypolimnetic accumulation published regression...
The hypothesis that a large zooplankton herbivore, Daphnia pulex, can competitively reduce the abundance of resident when colonizing community small species was tested in two lakes. When introduced to enclosures eutrophic Larimore Pond, D. pulex decreased phytoplankton by an order magnitude, resulting drastically reduced densities Tropocyclops prasinus and Mesocyclops edax, dominant crustaceans pond. also added oligo‐mesotrophic Dynamite Lake, along with nutrients, factorial design. Three...
There is ample evidence that tube‐dwelling invertebrates such as chironomids significantly alter multiple important ecosystem functions, particularly in shallow lakes. Chironomids pump large water volumes, and associated suspended dissolved substances, through the sediment thereby compete with pelagic filter feeders for particulate organic matter. This can exert a high grazing pressure on phytoplankton, microorganisms, perhaps small zooplankton thus strengthen benthic‐pelagic coupling....
Abstract Understanding the factors that affect water quality and ecological services provided by freshwater ecosystems is an urgent global environmental issue. Predicting how will respond to changes not only requires data, but also information about context of individual bodies across broad spatial extents. Because lake usually sampled in limited geographic regions, often for time periods, assessing controls compilation many data sets regions into integrated database. LAGOS-NE accomplishes...
The metabolic theory of ecology (MTE) and ecological stoichiometry (ES) are both prominent frameworks for understanding energy nutrient budgets organisms. We tested their separate joint power to predict nitrogen (N) phosphorus (P) excretion rates ectothermic aquatic invertebrate vertebrate animals (10,534 observations worldwide). MTE variables (body size, temperature) performed better than ES (trophic guild, classification, body N:P) in predicting rates, but the best models included from...
Abstract Nitrogen (N) and phosphorus (P) inputs influence algal community structure function. The rates ratios of N P supply, different forms (e.g., NO 3 NH 4 ), from external loading internal cycling can be highly seasonal. However, the interaction between seasonality in nutrient supply limitation remains poorly understood. We examined seasonal variation response to form a hyper‐eutrophic reservoir that experiences elevated, but seasonal, ratios. External is high spring declines summer,...