Optimising recovery post-game or post-training could provide a competitive advantage to an athlete, especially if more than one bout of exercise is performed in a day. Active recovery is one common method that is thought to enhance the recovery process. Another recovery method that is gaining popularity is water immersion. The objective of this thesis was to analyse whether these two recovery methods provided greater recovery from explosive exercise than passive recovery. A physiological rationale that may explain the possibility of enhanced recovery with water immersion was initially investigated. The literature surrounding active recovery, water immersion and passive recovery on strength, cycling, running and jumping was then examined. Following these reviews an experimental study was conducted investigating the effects of water immersion, active recovery and passive recovery conducted after repeated bouts of explosive exercise. The rationale for active recovery post-exercise is that during intense exercise, fluid from the blood is forced into the working muscles due to the increase in mean arterial pressure, which increases muscle volume and decreases blood plasma fraction. Active recovery reduces this exercise induced edema and, with an associated increase in blood flow throughout the body, may increase the metabolism of waste substrates produced during exercise. Researchers have observed this increased substrate metabolism with reductions in post-exercise blood lactate accumulation following active recovery. Water immersion would appear to cause a similar physiological response to active recovery without the need to expend extra energy. When a large portion of the body is immersed, hydrostatic pressure acts on the body's fluids within the immersed region. Fluids from the extravascular space move into the vascular system reducing exercise-induced increases in muscular volume and reducing soft tissue inflammation. Additionally, blood volume increases and is redistributed towards the central cavity, which in turn increases cardiac preload, stroke volume, cardiac output, and blood flow throughout the body. Cardiac output increases in relation to the depth of immersion and have been observed to increase by as much as 102% during head-out immersions. These cardiovascular responses occur without any increase in energy expenditure. If extra-intravascular fluid movement is enhanced, then the movement and metabolism of waste substrates could increase. Observations of increased post-exercise blood lactate clearance with water immersion would support this theory. Most methodologies studying the performance benefits of active recovery and water immersion suffer many limitations. These limitations often consist of the experimental time schedule not replicating what is likely to occur in a practical situation, no isolation of water temperature and hydrostatic pressure effects, and lack of a sport-like exercise consisting of repeated expressions of explosive power. Light-intensity active recovery and water immersion do not appear to be detrimental to performance, but neither does there appear to be enough evidence to claim they are beneficial. Effects of active recovery and water immersion would seem to be trivial to small, with any benefits more likely following multiple bouts of high-intensity exercise and recovery or following muscle damaging exercise. There may be a link between blood plasma fraction and performance, however, evidence is inconclusive. Given these issues and limitations the aim of this research was to investigate whether combinations of active recovery, water immersion and passive recovery could maintain peak power and work during subsequent bouts of explosive exercise. We also investigated whether there was any difference in subjects' blood plasma faction and perceived fatigue between the recovery modes. A cross-over experiment was conducted on seven subjects over four weeks. On the same day of each week subjects performed three sessions of maximal jumping, each two hours apart, followed by a different recovery method. Each jump session consisted of three sets of 20 maximal jumps repeated every three seconds, with a minute's rest in-between. Immediately following the jumping subjects performed 10 minutes of either (A) active recovery on a cycle ergometer followed by seated rest, (I) immersion to the gluteal fold in 19°C water followed by seated rest, (AI) active recovery followed by immersion, or (P) seated passive rest. Jumping was conducted on an instrumented supine squat machine that allowed the measurement of total peak power and total work. Pre-jump, post jump and post-recovery blood was taken and the percentage of blood plasma fraction calculated. Perceived leg fatigue was also measured at these times. Observed differences in total peak power and total work between the recovery modes were non-significant. No differences were observed in the change of blood plasma fraction between the recovery modes or perceived fatigue. One reason for any lack of difference between the recovery modes may have been the brevity of the recovery time. Research that has observed significant benefits of active recovery and water immersion compared to passive recovery have used recovery times greater of 15 minutes or more. Additionally, changes in blood plasma fraction between active recovery, water immersion and passive recovery have not been apparent until at least 10 minutes post-recovery in previous research. Alternatively, rather than brevity, it may be that active recovery or water immersion simply does not provide any benefit to performance recovery. Overall there is a meagre amount of research into active recovery, water immersion and passive recovery. Further research that incorporates a variety of exercise and recovery protocols is required.

The transfer of prey resources between ecosystems can have dramatic consequences for both recipient and donor systems by altering food web stability and the likelihood of trophic effects cascading across the ecosystem boundary. Landscape-scale factors influence the importance, direction and magnitude of energy flows, but may also alter the ability of consumer organisms to respond to spatio-temporal changes in allochthonous prey availability. Here, I used flood and drying disturbance gradients to investigate interactions between these two processes on populations of a riparian fishing spider Dolomedes aquaticus (Pisauridae). The abundance of aquatic insects with a winged adult stage, a major component of the diet of D. aquaticus, was markedly higher at less flood-prone rivers and declined with increasing flood disturbance. It was expected that spider populations would be largest at these stable rivers where the aquatic prey abundance was highest. However, a habitat (loose, unembedded riverbank rocks) manipulation revealed that the lack of scouring floods at these sites led to habitat-limited populations, preventing response to the increased prey resource. In fact a peak shaped relationship of spider biomass and abundance was found, with the largest spider populations at intermediately disturbed rivers. In addition, patchy habitat availability was the most likely cause of the small scale (4 m2) aggregation of spiders seen at the most stable and disturbed rivers. These patterns were also associated with strong interactions between the spiders. Stable isotope analysis of field collected spiders and an experimental manipulation of spider densities and food availability indicated that cannibalism rates were likely to be significantly higher at stable and disturbed rivers than those intermediate on the disturbance gradient. Differences in D. aquaticus population size structure and life history traits across the flood disturbance gradient were driven by interactions between resource availability, environmental stability and cannibalism rates. To separate the effects of habitat availability and aquatic prey abundance I used drying rivers, as the amount of aquatic insect prey alters as the water recedes. Desiccation mortality and low aquatic prey biomass most likely caused the spiders' spatial distribution and size class structure to alter in drying river reaches, potentially also leading to differences in cannibalism rates. Overall, cross-ecosystem transfers of prey had large impacts on the distribution, cannibalism rates and life history traits of D. aquaticus but their effects were modified by the nature of the ecosystem boundary. Thus river flow regime controlled the magnitude of the subsidy and its use by a consumer. Hence, cross-ecosystem subsidies will not always lead to larger consumer populations and consumer responses will depend on interactions between large-scale processes.

[Truncated abstract] Estimating internal biogeochemical fluxes is essential to the understanding of the dynamic of aquatic ecosystems. Different ecological approaches have been used to gain insight into the internal cycling, but success has been limited. A critical point is the identification of the characteristic scales of patterns and the underlying processes affecting the behaviour of biological and chemical species. Failing to capture these scales leads to misinterpretation of field and numerical data. In this study, key aspects in the design of ecological surveys are identified to ensure that the internal biogeochemical processes are well represented. In the first part of this thesis, a 1D reaction-diffusion-advection equation is used to investigate the formation of patterns and relevant time and spatial scales. This is used to define an approach for the determination of a critical domain size that allows differentiation of the role of local and internal cycling from advective fluxes across the open boundaries in a shallow coastal ecosystem. By using a 3D numerical model, in conjunction with an extensive field data set, it is shown that domain sizes must be larger than this critical value in order to capture the patterns generated within the system. For smaller domains, transport processes control the evolution of the system across the boundaries misleading the interpretation of the internal ecological dynamics. The study of the influence of boundary fluxes on ecological patchiness was motivated by the need to define the size of the domain necessary for the assessment of the impact of a sewage outflow on a coastal regime. The quantification of biogeochemical processes has proven to be difficult to achieve especially under conditions of high spatial and temporal hydrodynamic and biogeochemical variability. In the second part of this thesis, a Lagrangian experimental design is employed to estimate biogeochemical rate coefficients in situ. A set of four drogues and a cross-transect sampling design is used to capture the patchy distribution of phytoplankton and nutrient species, and high transport and mixing rates. ... Total chlorophyll from both models shows similar behavior when the variability in the 3D model, expressed as Chlamax/Chlamin, is low. When Chlamax/Chlamin is high, the difference between the biomass predicted by the two models reaches 30% due to the generation of localised patches. Comparison of the 1D and 3D results highlights the need of using models that are able to resolve the spatial complexity to some extent, as the use of averaged properties may produce misleading results. This is especially important in the presence of patches with differential physiological and biogeochemical characteristics, and nonlinear processes, in which case biomass average is not necessarily linearly related to the averaged environment.

Freshwater ecosystems in south-western Australia have been extensively altered over the last two centuries as a result of human activities. The effect this has had on aquatic fauna, particularly invertebrates, is largely unknown because of inadequate knowledge of the pre-existing fauna. Future changes in the composition of aquatic fauna will also go undetected unless current distributions of existing species are well documented. This thesis addresses the problem by investigating the current distributions and conservation status of aquatic insects in south-western Australia from three orders: Odonata, Plecoptera and Trichoptera. Extensive distributional data was collected by identifying larval specimens from a large number of samples collected throughout the south-west as part of an Australia-wide macroinvertebrate bioassessment project. In addition, a database created from a species-level biological study of the wheatbelt region of Western Australia was utilised, and previously published records of occurrence for species within the south-west were compiled. These results were then used to assess the conservation status of each species using the IUCN red list criteria. Environmental parameters measured at time of sampling were also examined using logistic regression to determine which factors are important in influencing the distributions of aquatic insects in south-western Australia. The conservation value of sites based on Odonata, Plecoptera and Trichoptera compositions was also determined and the degree of protection provided for sites of high conservation value investigated.The high rainfall forested region of the south-west was found to be important for a large number of species, including the majority of those found to be rare and/or restricted. Overall, 37% of species were found to be threatened, with the Trichoptera containing both the greatest number and highest proportion of threatened species. Logistic regression results generally agreed with the distributions obtained for each species, with rainfall and other parameters indicative of streams in the headwaters of forested catchments being positively associated with species found to be restricted to the high rainfall region. Two parameters known to be affected by human disturbance in the south-west, conductivity and nutrient concentrations, were found to be important in determining the occurrence of many species and this could have important consequences for aquatic insect conservation. Widespread species occurring within the low rainfall region of the south-west did not show as many significant relationships to measured environmental parameters, possibly due to their greater ecological tolerances and adaptations which allow them to persist in a low rainfall environment. The implications of results are discussed, and recommendations for the conservation and management of aquatic insects in south-western Australia are given.

Thesis (M.S.)--Ohio University, August, 2006. / Title from PDF t.p. Includes bibliographical references.

Theses (Ph.D.)--University of New Hampshire (Dept. of Zoology), 2007. / Includes bibliographical references. Also available online.

Thesis (Ph. D.)--University of Hong Kong, 2008. / Includes bibliographical references (leaves 88-105) Also available in print.

Thesis (Ph. D.)--University of Adelaide, School of Earth and Environmental Sciences, Discipline of Environmental Biology, 2007. / Includes author's previously published papers. "May 2007." Includes bibliographical references (p. 163-174). Also available in print form. Also available in electronic format.

Thesis (Ph. D.)--University of California, San Diego, 1998. / Vita. Includes bibliographical references.

Thesis (Ph.D.) - Simon Fraser University, 2006. / Theses (School of Resource and Environmental Management) / Simon Fraser University. Senior supervisor : Dr. Frank A. P. C. Gobas. Included bibliographical references : leaves 226-248.