Climate change is rapidly reducing the Arctic Ocean summer sea ice cover, consequently altering the patterns of primary production, with reducing ice algal-, but increasing phytoplankton primary production. As benthic consumers rely on the sinking phytodetritus for food, changes to food availability could render the benthos vulnerable if they prefer ice algae as a food source. The aim this thesis was to investigate the benthic macroinfaunal dietary reliance on ice algae and phytoplankton in North Water Polynya (NOW) and Lancaster Sound (LS) in Canadian Arctic Archipelago, and how a shift from one food source to another impacts the benthic community resource utilisation and nutrient cycling processes. I hypothesised that ice algae would be preferentially consumed and respired by the benthos. Natural abundance stable isotope analysis showed that phytoplankton is the main food source for macroinfauna in NOW and LS. 13C-15N isotope tracer experiments showed that while in NOW the accumulative macroinfaunal uptake of ice algal C was higher than uptake of ice algae, in LS more ice algal C and N was consumed. None of the major taxonomic groups exclusively preferred ice algae. No difference in bacterial uptake of the two algal types was observed at either site, but the respiration of phytoplankton C was significantly higher than respiration of ice algal C. The processing rates of phytoplankton-derived C were 39–46% higher than processing rates of ice algal C. Therefore, the hypothesis of ice algal preference by benthos must be rejected. I conclude that benthic macroinfauna exhibit great dietary flexibility, making them resilient against climate mediated changes in food sources, and that increasing availability of phytoplankton food can benefit the benthos in the future. Additionally, the transition from ice algae to phytoplankton dominated food can significantly enhance benthic organic matter processing, and especially respiration, rates in the future.

Thesis (M. Phil.)--University of Hong Kong, 1978.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 128-136). Also available via the Internet.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 60-68). Also available via the Internet.

Thesis--Lehigh University.

Thesis (Ph. D.)--College of William and Mary. / Vita. Includes bibliographical references.

The purpose of this investigation was to characterize the population dynamics of the benthos of selected pristine thermal springs.

In comparison with solar radiation, the energy of geothermal heat flowing through the sea bottom is extremely small; nevertheless, this energy is not insignificant in the circulation of the bottom water. Calculations indicate that in the deep basins of the South Atlantic the water volume transport necessary to remove this heat is at least one-tenth of the total northward flow of Antarctic Bottom Water. Plots of mean values of near bottom salinity and oxygen versus mean potential temperatures help to trace the movement of the bottom water. Geothermal and adiabatic warming associated with downslope flow combine to produce a deep temperature (in situ) minimum in portions of most of the deep basins of the world. Adiabatic or near adiabatic temperature gradients have been measured near the bottom in many of these basins. Evidence of superadiabatic gradients from temperature measurements made with reversing thermometers is inconclusive; however, careful measurements with closely spaced thermometers suggest that such gradients do exist over vertical distances of a few hundred meters in some of the deepest basins. Decreasing potential density with depth, as found in some of the Atlantic Basins in association with sharp temperature and salinity gradients, is not necessarily an indication of unstable equilibrium. This is demonstrated by the results of stability calculations in the manner prescribed by Hesselberg and Sverdrup (1915). / Graduation date: 1968

Thesis (M.S.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (February 7, 2007) Includes bibliographical references.

Thesis (M.Sc.)--College of William and Mary. / Vita. Includes bibliographical references.