High bicarbonate (HCO3-) content and associated high pH of irrigation water is detrimental to plant growth. Sustain ableagricultural/horticultural production will increasingly have to rely on economically feasible and environmentally sound solutions to the problems associated with high levels of HCO3- in irrigation water. The ability of a mixed Glomus Tulasne & Tulasne species inoculum of arbuscular mycorrhizal fungi (AMF), Glomus ZAC-19 (containing Glomus albidum Walker & Rhodes, Glomus claroideum Schenck & Smith, and Glomus diaphanum Morton & Walker), to enhance plant tolerance to HCO3- was tested on the growth and nutrient uptake of Rosa multiflora Thunb. ex J. Murr. cv. Burr (rose). Arbuscular mycorrhizal colonized and non-inoculated (non-AMF) R. multiflora cv. Burr were treated with 0, 2.5, 5, and 10 mM HCO3-. Increasing HCO3- concentration and associated high pH reduced R. multiflora cv. Burr growth, nutrient uptake, and acid phosphatase activity (ACP), while increasing alkaline phosphatase activity (ALP). Inoculation with AMF enhanced plant tolerance to HCO3- as indicated by greater growth, nutrient uptake, leaf chlorophyll content, higher mycorrhizal inoculation effect (MIE), lower root iron reductase activity, and generally lower soluble and wall-bound ALP activity. While AMF colonization (arbuscules, vesicles, and hyphae formation) was reduced by increasing HCO3- concentration, colonization still occurred at high HCO3- concentration. At 2.5 mM HCO3-, AMF plant growth was comparable to plants at 0 mM HCO3-, further indicating the beneficial effect of AMF for alleviation of HCO3- plant stress.

<p>The primary aim of the current study falls within the main framework of the Frontier Program (Pitcher 2005), namely to address aspects of &ldquo / Animal Husbandry&rdquo / . Within this research area, the determination of the effects of handling/grading and chemicals (anaesthetics) on the growth and survivorship of abalone are highlighted as key research areas and these are thus one of the focuses of this research.</p>

Excessive bacterial levels are a major water quality concern. Better methods are needed to quantify the proportion of bacterial loading contributed by various sources, and best management practices are needed to restore water quality. This study assessed the ability of alternative water supplies and grazing management to reduce E. coli loading from cattle and evaluated the ability of quantitative polymerase chain reaction analysis of total and bovine-associated Bacteroides markers (AllBac and BoBac, respectively) to determine the percentage of bovine-associated fecal contamination. Runoff from seven small watersheds, representing ungrazed, properly stocked, and overstocked conditions, was analyzed for E. coli, AllBac, and BoBac to assess grazing management impacts on E. coli runoff and the effectiveness of Bacteroides markers. To determine the effectiveness of alternative water, instream E. coli levels and cattle movement were evaluated before and after alternative water was provided. The study found that when alternative off-stream water was provided, the amount of time cattle spent in the creek was reduced 43 percent and the direct deposition of E. coli into Clear Fork of Plum Creek was estimated to be reduced from 1.11E 07 to 6.34E 06 colony forming units per animal unit per day. Observed pre- and post-treatment E. coli loads suggested similar reductions; however, this study could not conclusively attribute observed E. coli loading reductions to providing alternative water because of the lack of statistical significance of these observations, possibly due to decreased streamflow during Year 2 (due to drought) and a corresponding increase in E. coli levels. The study found that rotational stocking, if timed appropriately, was very effective at reducing E. coli runoff. The impact of grazing timing in relation to runoff events was more significant than the impact of grazing management (i.e. ungrazed properly stocked or overstocked) or stocking rate. When runoff occurred more than two weeks following grazing, E. coli levels in runoff were decreased more than 88 percent. Finally, data suggest that AllBac and BoBac markers are good indicators of recent fecal contamination from cattle. However, although elevated BoBac/AllBac ratios generally aligned well with cattle presence, this ratio appeared to underestimate the percentage of bovine-associated fecal contamination.

Karst environments are unique landscapes that contain important resources, including freshwater aquifers and specialized ecosystems, which are easily disturbed due to the interconnected nature of the surface and subsurface. The anthropogenic impacts on karst are deleterious to the ecosystems that are dependent on the karst environment and also to groundwater supplies. The Karst Disturbance Index (KDI) is a holistic tool used to measure anthropogenic impacts associated with karst environments, which has been applied and refined through studies performed in Florida and Italy, yet still remains untested and susceptible to modification for other areas. Application of the KDI in Arecibo, Puerto Rico, which is geographically isolated, and highly vulnerable due to its sensitive karst resources, provides an opportunity to test the index in an island setting. This research resulted in two KDI scores for the study area using both the original and recently modified methods. The scores reflect a significant to severe disturbance to the municipality’s karst environment of 0.54 and 0.68, respectively. Issues regarding the KDI were found from the application and comparison of these methodologies and revealed the need for adding additional indicators, including Mogote Removal and Coastal Karst, as well as several additional refinements and recommendations pertaining to scale, weighting, and incorporating the two methods together to create a single, more practical KDI tool. The disseminated results of the assessment of the area using the KDI will educate and help to foster stewardship of this vital resource in Puerto Rico.

Graduation date: 1993

The Wood River, located in the Old Wives Lake watershed in southern Saskatchewan, is an important water resource for people living in this area. Agriculture dominates land use in the basin, while the river receives waste water effluent from the town of Gravelbourg twice yearly. Both land usage in the basin and the dumping of municipal waste water effluent have the potential to degrade water quality in the river. To date however, the water quality of the Wood River has been relatively unstudied. <p> The purpose of this study was threefold. First, to evaluate the water quality of the Wood River and compare it to similar river systems. Then, to evaluate the effects of nutrients on the pelagic phytoplankton in the river to determine the biological responsiveness to nutrient additions which might occur as a result of agricultural land use and municipal waste water effluent. Lastly to propose mitigative measures that could help to reduce the potential threat of increased nutrients. <p> To determine the effect that agricultural land use and municipal waste water effluent was having on river water quality, nutrient and chlorophyll a (a measure of algal biomass) levels in the river were examined. Five sites, having different land use patterns, were chosen for this purpose. These included a reference site at a regional park not directly affected by agriculture, a site where agricultural land use dominated, a site utilized by cattle, a reservoir within the river system used for drinking water and surrounded by agriculture and finally, a site just downstream from where Gravelbourg's municipal waste is released.<p>Nitrogen (N) and phosphorus (P) levels were high in the Wood River when compared to similar systems. The mean TP concentration for the Wood River over the two years of this study was 474 Ýg/L (¡Ó 246 STD) while the mean ammonia concentration was 223 Ýg/L (¡Ó 993 STD). These concentrations exceeded water quality guidelines. Algal biomass and nutrient concentrations were higher at sites where nonpoint source pollution from agriculture or point source pollution from sewage effluents was present. Nutrient enrichment bioassays also indicated that the algal population in the Wood River was responsive to additions of nutrients, therefore, increases in nutrients will increase algal biomass in the river. The bioassays also revealed that at the sites where agriculture and municipal waste water were present, the algal population was N limited indicating an excess of P in the river. The municipal point source of pollution had a great effect on algal biomass and these effects lasted for about three weeks after the release. Different land use patterns and municipal waste water effluent were potentially having a negative effect on the water quality of the Wood River. <p>An examination of mitigative strategies available in the Old Wives Lake area revealed that land management tools including the implementation of soil conservation practices and riparian management could be useful in protecting the Wood River from degradation. Neither soil conservation practices nor riparian management are used extensively in the watershed, and both of these practices could help improve the water quality of the Wood River.

The primary aim of the research summarized in this thesis was to confirm or refute that algae are involved in metal sedimentation from surface water, and whether this activity, if any, is enhanced by increased phosphorus availability. <p>A small-scale laboratory-based experiment was devised to elucidate the role of the chlorophyte alga Chlamydomonas noctigama in the removal of arsenic, nickel and uranium from mine water. Results indicated that the presence of <i>C. noctigama</i> significantly enhanced the removal of these metals relative to treatments without cells. Metals were present in greater concentrations in particulate matter in treatments with cells compared to treatments without cells, and there was a corresponding decrease in the concentrations of dissolved metals. This leads to the conclusion that sedimentation was mainly biotically induced. <p>Additional evidence of biotic involvement in metal removal from water by <i>C. noctigama</i> was obtained by using EDX spectroscopy and X-PEEM spectromicroscopy to observe complexation of arsenic, nickel and uranium to C. noctigama cells. Arsenic, the metal which was present at the lowest concentration in the DJX water, was present on scanned cells in low concentrations, and nickel and uranium, which were present at high concentrations in the DJX water, were present at higher concentrations. Examination of a single cell using X-PEEM spectromicroscopy showed uranium co-localized with carbon and phosphorus on the exterior of the cell. Crystalline particulate matter may have increased in the presence of cells. EDX spectroscopy showed that the crystalline particulate matter was possibly hydroxyapatite that contained various metals, including arsenic, nickel and uranium. EDX spectroscopy was used to determine the frequencies at which the cell-metal and particulate matter-metal associations occurred, and the relative concentrations of the metals associated with particulate matter. <p>No correlation between metal removal and phosphorus concentration in the media, or between algal density and phosphorus concentration was observed. However, phosphorus concentrations were not growth-limiting in these experiments, and so the effect of phosphorus on abiotic precipitation of metals remains unclear. <p> Results suggest two mechanisms by which <i>C. noctigama</i> may remove arsenic, nickel and uranium from solution: by direct sorption to the exterior of the cell, and by sorption to a cell product. <p>An experiment using cells preserved in Lugols iodine (a common phytoplankton sample preservative) indiated that Lugols preserved samples could not be used to quantify metals using spectroscopy. Consequently, historical samples preserved with Lugols iodine cannot be analyzed by this method.

University of Macau / Faculty of Science and Technology / Department of Civil and Environmental Engineering

The Wood River, located in the Old Wives Lake watershed in southern Saskatchewan, is an important water resource for people living in this area. Agriculture dominates land use in the basin, while the river receives waste water effluent from the town of Gravelbourg twice yearly. Both land usage in the basin and the dumping of municipal waste water effluent have the potential to degrade water quality in the river. To date however, the water quality of the Wood River has been relatively unstudied. <p> The purpose of this study was threefold. First, to evaluate the water quality of the Wood River and compare it to similar river systems. Then, to evaluate the effects of nutrients on the pelagic phytoplankton in the river to determine the biological responsiveness to nutrient additions which might occur as a result of agricultural land use and municipal waste water effluent. Lastly to propose mitigative measures that could help to reduce the potential threat of increased nutrients. <p> To determine the effect that agricultural land use and municipal waste water effluent was having on river water quality, nutrient and chlorophyll a (a measure of algal biomass) levels in the river were examined. Five sites, having different land use patterns, were chosen for this purpose. These included a reference site at a regional park not directly affected by agriculture, a site where agricultural land use dominated, a site utilized by cattle, a reservoir within the river system used for drinking water and surrounded by agriculture and finally, a site just downstream from where Gravelbourg's municipal waste is released.<p>Nitrogen (N) and phosphorus (P) levels were high in the Wood River when compared to similar systems. The mean TP concentration for the Wood River over the two years of this study was 474 Ýg/L (¡Ó 246 STD) while the mean ammonia concentration was 223 Ýg/L (¡Ó 993 STD). These concentrations exceeded water quality guidelines. Algal biomass and nutrient concentrations were higher at sites where nonpoint source pollution from agriculture or point source pollution from sewage effluents was present. Nutrient enrichment bioassays also indicated that the algal population in the Wood River was responsive to additions of nutrients, therefore, increases in nutrients will increase algal biomass in the river. The bioassays also revealed that at the sites where agriculture and municipal waste water were present, the algal population was N limited indicating an excess of P in the river. The municipal point source of pollution had a great effect on algal biomass and these effects lasted for about three weeks after the release. Different land use patterns and municipal waste water effluent were potentially having a negative effect on the water quality of the Wood River. <p>An examination of mitigative strategies available in the Old Wives Lake area revealed that land management tools including the implementation of soil conservation practices and riparian management could be useful in protecting the Wood River from degradation. Neither soil conservation practices nor riparian management are used extensively in the watershed, and both of these practices could help improve the water quality of the Wood River.

The presence of nutrients in snowmelt runoff from agricultural watersheds has been reported by previous studies. However, no study has answered the most important question what areas of the watershed contribute nutrients to snowmelt runoff? or addressed the factors that control snowmelt runoff water quality. This study was designed to (1) find the areas that contribute nutrient to snowmelt runoff (termed as critical source areas, CSA), and (2) understand the source and transport factors that control the snowmelt runoff water quality in the Canadian prairies. The findings of this study will provide vital information to understand snowmelt runoff water quality and for sustainable management of soil nutrients and snowmelt runoff water quality in the Canadian prairies. <p>Source and transport factors and snowmelt runoff water quality were studied for two years on shoulder, backslope and footslope landform segments. The distribution of fall soil nutrients in the top 5 cm soil layer (available soil P [ASP], nitrate [NO3-] and ammonium [NH4+]), snow depth, snow water equivalent (SWE), snowmelt runoff and snowmelt runoff water quality (total P [TP], total dissolved P [TDP], NO3-N and sediment) were studied using closed and open plots placed on each landform segment. The influence of source and transport factors was evaluated in relation to snowmelt runoff water quality. <p>The ASP had a distribution pattern of backslope < shoulder < footslope in 2003 before manure application (bma) and shoulder = backslope = footslope in 2004. The NO3- distributed as shoulder = backslope = footslope in 2003 (bma) and shoulder < backslope < footslope in 2004. However, NH4+ had a stable distribution of shoulder = backslope < footslope in 2003 bma and in 2004. The pre-melt SWE increased in the down slope direction having the lowest in the shoulder and backslope and the highest in the footslope in 2005. The average daily snowmelt runoff from 1 m2 plots did not vary between the shoulder and the backslope. Infiltration was dominant in 2004 while runoff was dominant in 2005. Of the three landform segments, the shoulder was the greatest contributor of runoff to the depression. The backslope contributed the least. <p>Hog manure injection did not seem to influence snowmelt runoff water quality. Most nutrients and sediments were from the land surface. Analysis revealed that fall soil nutrient concentrations were not a dominant factor controlling the nutrients in the snowmelt runoff in this site. However, snowmelt runoff volume controlled snowmelt runoff water quality. Snowmelt runoff water quality did not vary between the landform segments. However, as a result of the dominance of shoulder in this landscape, the total transport of nutrients and sediment was the highest from shoulder. Where landform characteristics are similar to the study watershed, it may be argued that all landform segments are CSA. Runoff volume is the most influential factor in determining the importance of CSA and controlling the snowmelt runoff water quality.