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
Stable isotope indicators of movement and residency for brown shrimp ( Farfantepenaeus aztecus ) in coastal Louisiana marshscapes
Brian Fry,Donald M. Baltz,Mark C. Benfield,John W. Fleeger,Arian Gace,Heather L. Haas,Zoraida J. Quiñones-Rivera +6 more
TL;DR: The results support the view that small 10–20 mm postlarval and juvenile brown shrimp arriving in estuaries from offshore waters continue movement through sub-optimal habitats, but exhibit much less movement once an optimal habitat (marsh ponds or shallow channel margins) is reached.
Journal ArticleDOI
Separation of algae from detritus for stable isotope or ecological stoichiometry studies using density fractionation in colloidal silica
TL;DR: An economical method to partition fine particulate matter into predominantly algal and detrital components by centrifugation in colloidal silica is described, demonstrating the need to perform such separations in many aquatic environments.
Journal ArticleDOI
Diel feeding behavior of meiofauna and their relationships with microalgal resources
TL;DR: Diatoms dominated the benthic microalgae, but cyanobacteria and chlorophytes contributed significantly to the planktonic community, which implies that meiofauna represent an important link between microalgal primary production and higher trophic levels.
Journal ArticleDOI
Sources of sedimentary organic matter in the Mississippi River and adjacent Gulf of Mexico as revealed by lipid biomarker and δ13CTOC analyses
TL;DR: In this article, changes in the organic matter composition (C/N, δ 13 C TOC, and lipid biomarker compounds) of surface sediments were examined along the dispersal pathway from Mississippi River and marsh/estuarine end members to the adjacent shelf and canyon regions of the Gulf of Mexico.
Journal ArticleDOI
Influence of shallow-water habitats and shoreline development on abundance, biomass, and diversity of benthic prey and predators in Chesapeake Bay
TL;DR: In this article, the authors quantified bivalve diversity, density, and biomass in deep and shallow (<1.5 m MLW) unstructured subtidal habitats in 2 tributaries of lower Chesapeake Bay (Elizabeth- Lafayette River system and York River).