In this paper, we review recent advances in stable isotope mixing models (SIMMs) and place them into an overarching Bayesian statistical framework, which allows for several useful extensions. SIMMs are used to quantify the proportional contributions of various sources a mixture. The most widely application is quantifying diet organisms based on food they have been observed consume. At centre multivariate model propose compositional mixture corrected metabolic factors. component our isometric...

Summary Stable isotope analyses coupled with mixing models are being used increasingly to evaluate ecological management issues and questions. Such applications of stable often require simultaneous carbon nitrogen from the same sample. Correction values take account varying content 13 C‐depleted lipids is then frequently achieved by a lipid‐normalization procedure using model describing relationship between change in δ C following lipid removal original C:N ratio We evaluated applicability...

Biological invasions are a significant driver of human-induced global change and many ecosystems sustain sympatric invaders. Interactions occurring among these invaders have important implications for ecosystem structure functioning, yet they poorly understood. Here we apply newly developed metrics derived from stable isotope data to provide quantitative measures trophic diversity within populations or species. We then use test the hypothesis that belonging same functional feeding group...

Seasonal variations in the stable isotope composition (d 13 C and d 15 C) of crustacean zooplankton their putative food sources oligotrophic Loch Ness were recorded during 1998. Bulk particulate organic matter (POM) showed values consistent with a terrestrial plant origin from catchment exhibited little seasonal variation, whereas POM was more variable, probably due to associated microbial action. In contrast, phytoplankton relatively light some but constant. The isotopic signatures both...

Highly emissive (with an external quantum yield exceeding 35 percent at a 365-nanometer excitation wavelength) broadband phosphors can be synthesized from tetraalkoxysilane sol-gel precursor and variety of organic carboxylic acids. The air-stable were low temperatures (less than 300°C) displayed broad visible photoluminescence spectra that appeared white to the eye. Water-soluble prepared by substitution 3-aminopropyltriethoxysilane for in synthesis. These materials are most efficient...

1. It has long been known that substantial amounts of methane are produced in anoxic lake sediments, and the components cycle lakes have well described. At oxic–anoxic interfaces, methane-oxidising bacteria (MOB) convert to microbial biomass can be highly productive. However, only recently recognised as a potentially important carbon energy source for food webs, some instances also reported contribution river webs. Stable isotope analysis (SIA) provided compelling evidence this respect...

Global warming can affect all levels of biological complexity, though we currently understand least about its potential impact on communities and ecosystems. At the ecosystem level, has capacity to alter structure rates key processes they mediate. Here assessed effects a 4°C rise in temperature size taxonomic composition benthic aquatic mesocosms, detrital decomposition mediated. Warming had no effect biodiversity, but altered community two ways. In spring, warmer systems exhibited steeper...

Summary Many aquatic ecosystems sustain multiple invasive species and interactions among them have important implications for ecosystem structure functioning. Here, we examine two pairs of crayfish because their close proximity thus chance sympatric populations in the near future within Thames catchment, U.K. (signal, P acifastacus leniusculus virile crayfish, O rconectes virilis a river system; red swamp, Procambarus clarkii Turkish A stacus leptodactylus found suite ponds). We address...

There is widespread evidence that aquatic consumers use terrestrial resources depending on the features of surrounding catchments.

Abstract A literature survey of zooplankton stable isotope studies revealed inconsistencies between authors concerning (a) fixation and (b) allowance for gut clearance prior to δ 13 C 15 N determinations. To address whether commonly used preservation techniques induce changes in values, fresh lake (control) were compared with preserved (ethanol, methanol, formaldehyde, gluteraldehyde, frozen shock frozen) material. Differences up 1.1‰ carbon 1.5‰ nitrogen isotopic signatures found. Even...

Carbon stable isotopic composition was determined for zooplankton, POM, DOM and, in two cases, phytoplankton from 12 small forest lakes southern Finland during summer 1997. The were selected to provide a wide range of water colour (12-365 mg Pt l-1) but minimum variability other limnological characteristics. POM and showed similar isotope ratios (δ 13 C around - 28‰, comparable with values commonly reported terrestrial C3 vegetation) these no relationship colour. Zooplankton consistently...

The natural abundance of stable isotopes (δ13C and δ15N) was determined for components the pelagic food web in Loch Ness, a deep oligotrophic lake northern Scotland, compared with values from inflow rivers catchment vegetation. Phytoplankton δ13C low to reported other lakes, possibly reflecting high use 13C–depleted carbon dioxide respired organic matter before further isotopic fractionation during photosynthesis. appreciably lower than that dissolved particulate (DOM POM) loch. DOM POM were...

Reports of unexpectedly 13C-depleted chironomid larvae in lakes have led to an hypothesis that significant transfer detrital organic matter may occur via methane-cycle bacteria. However, date little is known how such might vary across species and lakes. We gathered data from 87 determine widespread this phenomenon be define boundaries for its likely magnitude. Carbon stable isotope values varied greatly between taxa. Very marked 13C-depletion was evident only certain taxa, especially...

Stable isotope analyses of chironomid trophic interactions have recently indicated the potential importance isotopically light biogenic methane as a carbon source. Mass balance ratios suggests that small proportional differences in ingestion such an distinct basal resource by individual consumers can result considerable intraspecific variability. To test this, we collected larvae two closely related species ( Chironomus anthracinus and plumosus ) from six lakes analyzed their δ 13 C 15 N....

Following the accidental introduction of carp Cyprinus carpio into Lake Naivasha during 1999, a sustainable population became rapidly established and in early 2004 principal species exploited commercial fishery. Over 9000 kg were harvested from lake between October 2005 2006, when fish captured fork lengths ( L F ) 200 800 mm (>8 kg). Diet <100 was dominated by zooplankton, >100 there shift to benthic macro‐invertebrates, with these feeding principally upon food resources previously...

We tested the hypothesis that low stable carbon isotope (δ 13 C) values commonly observed for zooplankton in humic lakes are due to their feeding on isotopically light methane‐oxidizing microbes, and thus methane‐derived is important food webs of these lakes. In replicate laboratory cultures, Daphnia longispina , a common crustacean zooplankter lakes, were fed microbial suspensions with or without enrichment by biogenic methane. The δ C indicated consumption C‐depleted methanotrophic...

Summary Many rivers are oversaturated in methane ( CH 4 ) and carbon dioxide CO 2 relative to the atmosphere, but we know little about biological controls on balance between these two important greenhouse gases how they might respond warming. We characterise potential response temperature production of subsequent microbial oxidation that , is sink source components cycle, contrasting river bed sediments: fine sediments, which largely anoxic, oxic, coarse gravels. In anaerobic both increased...

We have known about the processes of methanogenesis and methanotrophy for over 100 years, since days Winogradsky, yet their contributions to carbon cycle were deemed be negligible importance majority that period. It is only in last two decades methane has been appreciated its role global cycle, stable isotopes come forefront as tools identifying tracking fate methane-derived within food webs, especially aquatic ecosystems. While it not surprising chemosynthetic dominate contribute almost...

BACKGROUND: With the everincreasing emergence of antibiotic-resistant pathogens, in particular methicillin-resistant Staphylococcus aureus (MRSA) leg ulcers, a means reducing bacterial bioburden such other than by use either topical or systemic antibiotics, is urgently required. METHODS: We report case an immunosuppressed patient who developed hydroxyurea-induced ulcer with subclinical MRSA infection which was subsequently treated application manuka honey, without cessation hydroxyurea...

Abstract – The trophic ecology of many fish species in cold temperate lakes is often characterized by a generalist or opportunist strategy. In this study, the diets polytrophic brown trout Loch Ness, Scotland, have been examined using stable isotopes carbon and nitrogen to complement gut content analyses aging otolith annuli counts. Using isotope ratios, it was possible trace ontogeny from parr development natal river piscivory pelagic. Potential dilution maternal signatures eggs also...