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Lower Trophic Relations Within The Lake Ontario Invertebrate Community As Assessed By Chemical Tracers, Donald Robert Uzarski
Lower Trophic Relations Within The Lake Ontario Invertebrate Community As Assessed By Chemical Tracers, Donald Robert Uzarski
Electronic Theses and Dissertations
The lower trophic food web of Lake Ontario plays an important role in the lake’s ecosystem, yet the trophic relationships of these taxa are not well understood. Utilizing carbon (δ13C) and nitrogen (δ15N) stable isotopes as a tool to trace the flow of energy through the system, the main objective of this thesis was to understand the isotopic variability and trophic relationships of invertebrate taxa through space and season in Lake Ontario. Using an extensive dataset collected in 2012 and 2013, this study was conducted in two research chapters. The first chapter assessed variation in the isotopic signature of three …
A Deep Life: The Application Of Stable Isotopes To Understand Deep-Sea Environments With A Focus On Latitudinal Gradients, Laurissa Christie
A Deep Life: The Application Of Stable Isotopes To Understand Deep-Sea Environments With A Focus On Latitudinal Gradients, Laurissa Christie
Electronic Theses and Dissertations
The deep-sea, defined as the area 200 m below the surface, is facing emerging chemical, physical and biological stressors. Currently, very little is known regarding deep-sea ecosystems both globally and in the Arctic. In this thesis I undertook a literature review on the current understanding of global deep-sea ecosystems through the use of stable isotopes. Specifically, I synthesized the available literature on spatial variation, energy pathways, depth, temporal variation, feeding behaviour, niche, trophic position and body size isotopic trends. This thesis then presents a case study examining the isotopic niche of five teleost and two decapod species within Arctic deep-sea …
Diet Reconstruction And Niche Of Lake Ontario Top Predators And Corresponding Prey Species, James Adam Mumby
Diet Reconstruction And Niche Of Lake Ontario Top Predators And Corresponding Prey Species, James Adam Mumby
Electronic Theses and Dissertations
Lake Ontario supports a diverse offshore fish community consisting of salmonids and forage fish with little known about the resource partitioning and habitat use of these species. To assess this, I used stable isotopes to determine the isotopic trends (forage fishes only), niche structure and overlap of both salmonids and forage fishes. I also estimated the salmonid trophic position (TP) and diet using stable isotopes. Forage fishes had high resource partitioning but was low between Myoxocephalus thompsonii and Cottus cognatus. Regional and temporal discrete subpopulations driven largely by nitrogen were only present in Alosa pseudoharengus, Osmerus mordax and Neogobius melanostomus. …
Using Stable Isotopes To Assess Population Structure And Feeding Ecology Of North Pacific Humpback Whales (Megaptera Novaeangliae), Briana Witteveen
Using Stable Isotopes To Assess Population Structure And Feeding Ecology Of North Pacific Humpback Whales (Megaptera Novaeangliae), Briana Witteveen
Electronic Theses and Dissertations
The North Pacific humpback whale (Megaptera novaeangliae) is a wide-ranging baleen whale species with a complex life history and population structure. As seasonal migrants, humpback whales are known to inhabit cooler, high-latitude waters when foraging and low-latitudes for mating and calving. Beyond this general migratory pattern, a number of demographic characteristics including, abundance, distribution, seasonal occurrence, and prey preferences remain unknown or poorly described. A complete understanding of humpback whale ecology is therefore lacking. Many methods used to explore these aspects of cetacean ecology are either prohibitively expensive or limited in the scope of what can be learned from their …
Stabel Isotope Turnover Rates And Diet-Tissue Discrimination In The Skin Of West Indian Manatees: Implcations For Evaluating Their Feeding Ecology And Habitat Use, Christy Alves
Electronic Theses and Dissertations
The West Indian manatee (Trichechus manatus) is an herbivorous marine mammal that occupies freshwater, estuarine, and marine habitats. Despite being considered endangered, relatively little is known about the feeding ecology of either of the two recognized subspecies, the Florida manatee (T.m. latirostris) and Caribbean or Antillean manatee (T.m. manatus). A better understanding of their respective feeding preferences and habitat use is essential to establish criteria on which conservation plans can be based. The present study expands on previous work on manatee feeding ecology by both assessing the application of stable isotope analysis to manatee tissue and providing critical baseline parameters …