Open AccessJournal Article
The role of standing dead Spartina alterniflora and benthic microalgae in salt marsh food webs: considerations based on multiple stable isotope analysis
TLDR
In this article, the stable isotope compositions (C, N, and S) of hve, senescent, and standing dead Spartina alterniflora were compared in order to determine the effects of aerial decomposition on the isotopic signature of aboveground S. alternjflora entering the food chain, which indicated that N2fixing microorganisms associdated with microalgal communities were an important source of N to salt marsh consumers.Abstract:
The stable isotope compositions (C, N, and S) of hve, senescent, and standing dead Spartina alterniflora were compared in order to determine the effects of aerial decomposition on the isotopic signature of aboveground S. dlterniflora tissue entering the food chain. Aerial decomposition of aboveground S. alterniflora resulted in a 6 to 18% increase in P S , and a 2 to 3 % decrease in 615N values; 613c values were unchanged. We describe mechanisms whereby the activity of fungi and epiphytic microorganisms may contribute to the observed shlfts in and 6I5N, respectively. The 613c value of salt marsh benthic and eplphytic microalgae ranged from -13.0% in summer to -17.6%0 in early spring. Average 6'\" values of microalgae and standing dead S. altemiflora were -0 3 and l.?%, respectively, reflecting the activity of NZ-fixing microorganisms. The 615N values for omnivorous and herbivorous salt marsh macrofauna ranged between 7.5 and 2.2% and for predatory Fundulus spp. averaged 9.2%. Given a presumptive + 3 % trophic shift in N assimilation, these results suggest that N2-fixing microorganisms associdted with microalgal communities were an important source of N to salt marsh consumers. The 6% 6'\"N, and 6\"'s values of primary producers were compared to the values of the following consumers: Fundulus spp., Uca spp., Ilyanassa obsoleta, and Littoraria irrorata. 6I3C VS 6 1 5 ~ and 613C vs 63JS dual isotope plots demonstrated that microalgae and standing dead S. alternjflora are important food resources in the North Carolina (USA) marshes we sampled. In addition, a compilation of literature values suggests that this is true in salt marshes throughout the East and Gulf coasts of North America. Future isotope studies of marsh food webs should include detrital Spartina spp. material in analyses of trophic structure.read more
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Influence of Diet On the Distribtion of Nitrogen Isotopes in Animals
Michael J. DeNiro,Samuel Epstein +1 more
TL;DR: In this article, the influence of diet on the distribution of nitrogen isotopes in animals was investigated by analyzing animals grown in the laboratory on diets of constant nitrogen isotopic composition and found that the variability of the relationship between the δ^(15)N values of animals and their diets is greater for different individuals raised on the same diet than for the same species raised on different diets.
Dissertation
Ecological interactions and geological implications of foraminifera and associated meiofauna in temperate salt marshes of eastern canada
TL;DR: In this paper, a Mesocosm and Microcosm Experiments on the Feeding of Temperate Salt Marsh Foraminifera are described, and a taxonomic resolution and Tidal Gradients in Food Webs for Two Temperate salt Marshes: How Much Detail is Enough?
Dissertation
Assessment of mangrove and salt marsh mesocosm functional value using periwinkle snails, littoraria angulifera and littoraria irrorata, as an indicator
TL;DR: Swartwood et al. as mentioned in this paper investigated whether the age structure, population density, and distribution of Littoraria angulifera in the Smithsonian Institution's Florida Everglades mesocosm in Washington, DC is analogous to that of wild populations.
Dissertation
Isotope geochemistry of organic sulfur compounds with links to biogeochemical sulfur cycling and radical chemistry
TL;DR: Oduro et al. as mentioned in this paper reported one of the first sulfur isotope constraints on the factors that control the expression on the S-isotope effects of VOSCs and their natural precursors.
DissertationDOI
Anoxic metabolism in permeable sediments
TL;DR: This thesis investigates the pathways of dissolved inorganic carbon production in anoxic permeable sediments and the challenge of replicating flow conditions under anoxic conditions using FTRs and experimental design.
References
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Journal ArticleDOI
Changes in the elemental (C, N) and isotopic (δ13C, δ15N) composition of estuarine plants during diagenesis and implications for ecological studies
TL;DR: The observed low levels of isotopic fractionation during decomposition support the usefulness of stable isotopes as natural tracers of organic matter as well as the need for further experimental studies performed under distinct environmental conditions.
Journal ArticleDOI
Bioaccumulation of PCBs by a seaweed bloom (Ulva rigida) and transfer to higher trophic levels in an estuarine food web
TL;DR: Study of an annually occurring green tide of Ulva rigida in the PCB-contaminated Superfund site of New Bedford Harbor, MA, USA provides evidence for a potentially overlooked impact of macroalgal blooms—their potential role in the trophic transfer of PCBs and other bioaccumulated pollutants.
Journal ArticleDOI
Physical factors mediate effects of grazing by a non-indigenous snail species on saltmarsh cordgrass (Spartina alterniflora) in New England marshes.
TL;DR: The nature of the physical conditions at a site may influence the susceptibility of S. alterniflora to grazing pressure by this ubiquitous snail species, and Accelerating anthropogenic impacts, such as sea-level rise, could further stress saltmarsh plants, leaving them increasingly susceptible to herbivory.
Aspects of the ecology of fishes associated with salt marshes and adjacent habitats in a temperate South African estuary
TL;DR: This dissertation represents the first intensive examination of the ichthyofauna associated with salt marshes in southern Africa and examines the species composition, diversity, size structure, distribution and estuarine dependence of fishes that utilize salt marsches in the Kariega Estuary.
The experimental control of spartina anglica and spartina x townsendii in estuarine salt marsh
TL;DR: Methods used for controlling Spartina anglica and Spartina x townsendii by field experiment suggest that swards are eradicated in the next phase of the management strategy, and nonherbicidal methods should be used to eradicate small foci.