- Title
- Investigation of lake stratification and environmental variables regulating phytoplankton growth in Grahamstown Reservoir
- Creator
- Golshan, Azadeh
- Relation
- University of Newcastle Research Higher Degree Thesis
- Resource Type
- thesis
- Date
- 2020
- Description
- Research Doctorate - Doctor of Philosophy (PhD)
- Description
- Phytoplankton are a natural component of aquatic ecosystems; however, when present in high cell densities as “blooms”, they can pose a significant potential threat to human and ecological health. These phytoplankton blooms are often composed of microorganisms with the potential to produce toxins (cyanobacteria) that can cause adverse health effects in humans and animals through the contamination of waterways used for recreational purposes and as drinking water supplies. There is general agreement that nutrient enrichment of water bodies with nitrogen (N) and phosphorus (P) is the main reason for bloom formation, and that nutrients are typically introduced by inflows to a waterbody. However, sediments can also play an important role in releasing nutrients to water bodies. This can occur by reactivation of sediments under depleted dissolved oxygen levels during thermal stratification. Thus, in order to reduce the nutrient enrichment of aquatic systems, it is important to target both the external and internal nutrient loadings in managing a water reservoir. However, it is also essential to investigate the environmental factors other than nutrients, such as water clarity, water temperature and dissolved oxygen concentration that may influence the formation of algal blooms. This holistic approach has been applied in this study to investigate variations in water quality and the abundance of cyanobacteria in Grahamstown Reservoir, the principal drinking water reservoir of Newcastle and the lower Hunter Region in New South Wales, Australia. Multivariate data analysis methods based on Principal Component Analysis (PCA) and Multivariate Curve Resolution Alternating Least Squares (MCR-ALS) were used in the identification of important water quality variables, as well as the main sources or factors which can influence water quality within Grahamstown Reservoir. PCA and MCR-ALS further were applied to investigate seasonal changes in the abundance and species composition of cyanobacteria in the reservoir in response to changes in environmental factors. Moreover, the seasonal thermal stratification pattern and its role in the formation of algal blooms was also investigated in Grahamstown Reservoir. A part of this study was also focused on an overview of the issues relating to taste and odour problems in Grahamstown Reservoir. This part of the project was aimed at assessing the occurrence of cyanobacteria abundance to better understand their relative potential to produce significant tastes and odours which affect water quality. The water quality data examined in this study has been collected from different sites within Grahamstown Reservoir by routine sampling by Hunter Water Corporation (HWC) who manage the drinking water storage. The expected outcome of this study is the identification of the factors and sources of contaminants which could influence the water quality of Grahamstown Reservoir and thereby further inform the management strategies needed to prevent and minimise the risk of algal blooms in the future. Also, determination of the environmental factors other than nutrients that may influence the formation of algal blooms.
- Subject
- water quality; cyanobacteria; thermal stratification; multivariate analysis; drinking water reservoir
- Identifier
- http://hdl.handle.net/1959.13/1414066
- Identifier
- uon:36697
- Rights
- Copyright 2020 Azadeh Golshan
- Language
- eng
- Full Text
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| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | ATTACHMENT01 | Thesis | 6 MB | Adobe Acrobat PDF | View Details Download | ||
| View Details Download | ATTACHMENT02 | Abstract | 617 KB | Adobe Acrobat PDF | View Details Download |