M.Sc. / Richards Bay Harbour is notably one of the fastest growing, economically important harbours in South Africa. However, this economic growth has lead to increased anthropogenic activities surrounding the harbour, which may result in higher contaminant, including metal, concentrations within the harbour. These contaminants may negatively influence the natural ecosystem functioning within the harbour. Consequently, assessment of the extent and effect of contamination, through continuous biomonitoring of Richards Bay Harbour, is essential. In the present study, the main aim was to assess the marine health in Richards Bay Harbour by studying spatial and temporal variation of bioaccumulation and biological responses within the mussel, Perna perna, using an active biomonitoring (ABM) approach. The ABM approach was preferred over the traditional passive biomonitoring of resident mussels since it eliminates several inherent factors that may mask the mussels’ true responses to the ambient environment. This approach entailed the transplantation of reference mussels from a relatively uncontaminated environment into Richards Bay Harbour, which is known to be contaminated by metals. In order to identify the reference mussel population for transplantation purposes, a study was undertaken to assess metal levels in two other P. perna populations within the same ecoregion as Richards Bay Harbour, namely Dawson’s Rocks and Sheffield Beach. The results showed that most metal concentrations were lower at Sheffield Beach, which consequently lead to the selection of this population as a reference. The effect of size differences on metal bioaccumulation was also assessed using the three latter mentioned mussel populations, which showed that, although local conditions strongly influence the relationship between metal bioaccumulation and size, utilisation of a narrow size range would minimise the size effect on bioaccumulation and should be used for ABM studies. / Prof. V. Wepener

Changes in trophic status are often related to increases or decreases in the allocthonous inputs of nutrients from changes in land use and management practices. Lake and reservoir managers are continually faced with the questions of what to monitor, how to monitor it, and how much change is necessary to be considered significant. This study is a compilation of four manuscripts, addressing one of these questions, using data from six reservoirs in Texas.

Thesis (M.Sc. (Aquaculture)) -- University of Limpopo, 2020 / The aim of the study was to assess the extent to which biological indicators and biomarkers can be used to monitor the pollution status of the Sand and Blood Rivers. Physico-chemical parameters were assessed as a primary approach in assessing pollution status of the Sand and Blood Rivers. Temperature, pH, dissolved oxygen (DO), biological oxygen demand (BOD), turbidity, total dissolved solids (TDS), total nitrogen, phosphorus and ammonia were assessed during the rainy and dry seasons. Physico-chemical parameters showed spatial and temporal variation. The hierarchical average linkage cluster analysis grouped the reference sites (S1 and B1) into one group and sites after points of discharge (B2, S2, S3, S4 and S5) into another group. This grouping was due to the pollution status of each site, with the reference sites less polluted than the sites downstream of the wastewater treatment plant effluent points of discharge. The canadian council of ministers of the environment water quality index (CCME WQI) categorized reference sites as good, whilst sites after points of discharge were categorized as poor. This shows that the Sand and Blood Rivers are degrading. Heavy metal contamination in water, sediment and grass from the Sand and Blood Rivers was evaluated during the rainy season and dry season. All assessed heavy metals (Cadmium, Chromium, Copper, Iron, Lead, Manganese, Nickel, and Zinc) were below the detection limit in water, with an exception for Iron and Manganese. All metals assessed were also below the probable effect levels (PEL) according to the CCME. Geo-accumulation Index showed that the Sand and Blood Rivers were not contaminated with heavy metals. The enrichment factor (EF) further showed that only site B2 was enriched with manganese from anthropogenic activities. Heavy metal assessment in Cyperus exaltatus showed that this grass is a poor candidate for phytoremediation. Macroinvertebrates were used as biological indicators to assess pollution status of the Sand and Blood Rivers. Macroinvertebrates were sampled according to South African scoring system (SASS) and identified using aquatic invertebrates of South African rivers field guide. The SASS and average score per taxon (ASPT) categorized all sampling sites as critically modified. The family-level biotic index (FBI) also showed that the Sand and vi Blood Rivers are enriched with organic pollution. The reference sites recorded high macroinvertebrates diversity, compared to the sites after points of discharge. All indices used showed spatial and temporal variation in the water quality of the Sand and Blood Rivers. The relationship between macroinvertebrates and physico-chemical parameters were explored with the use of canonical correspondence analysis (CCA). The CCA triplots showed that the reference sites were associated with pollution sensitive taxa, whilst pollution tolerant taxa were associated with sites after points of discharge. Moreover, sites after points of discharge strongly correlated with phosphorus, nitrogen, ammonia, BOD and TDS. Clarias gariepinus gills and liver histology were used as biomarkers in assessing pollution status in the Sand and Blood Rivers. Gills and liver samples were qualitatively and semi-quantitatively assessed. Fish from the reference sites had less gill lesions than fish from sites downstream. Alterations such as hyperplasia of interlamellar, fusion of secondary lamellae, epithelial lifting and hyperplasia of secondary lamellae were observed in fish collected from downstream. Fish from downstream also showed more liver alterations than fish from the reference sites. Alterations such as melano-macrophage centers (MMC), macrovesicular steatosis, sinusoid congested with kupffer cells, nuclei pleomorphism and vacuolation were identified in liver of fish from sites S4 and S5. This was further confirmed by the high gill and liver indices of fish from downstream. Acetylcholinesterase enzyme (AChE) enzyme in brain and lactate dehydrogenase (LDH) in liver of Clarias gariepinus were used as biomarkers in assessing pollution status of the Sand and Blood Rivers. Both AChE and LDH enzymes were lower on fish from downstream compared to fish from the reference sites. This shows that AChE and LDH enzymes on fish from downstream were inhibited. This was attributed to the use of pesticides on farms surrounding the Sand and Blood Rivers and also the discharge of poorly treated sewage effluent from the Polokwane and Seshego wastewater treatment plants (WWTP’s). The Sand and Blood Rivers are surrounded by farms that utilize pesticides in their practice. This study showed that biological indicators and biomarkers can be used to assess pollution status of the Sand and Blood Rivers. However, biological vii indicators and biomarkers should be used in concurrence with physico-chemical parameters. / Department of Agriculture Forestry and Fisheries, Water Research Commission (WRC) and Aquaculture Research Unit.

Rapid Bioassessment Protocols integrate a suite of community, population, and functional metrics, determined from the collection of benthic macroinvertebrates or fish, into a single assessment. This study was conducted in Dallas County Texas, an area located in the blackland prairie eco-region that is semi-arid and densely populated. The objectives of this research were to identify reference streams and propose a set of metrics that are best able to discriminate between differences in community structure due to natural variability from those caused by changes in water quality due to watershed impacts. Using geographic information systems, a total of nine watersheds, each representing a different mix of land uses, were chosen for evaluation. A total of 30 metrics commonly used in RBP protocols were calculated. Efficacy of these metrics to distinguish change was determined using several statistical techniques. Ten metrics were used to classify study area watersheds according to stream quality. Many trends, such as taxa presence along habitat quality gradients, were observed. These gradients coincided with expected responses of stream communities to landscape and habitat variables.

The tunicate Styela plicata (Ascidiacea) was investigated for its potential use in bioremediation of bacteria and microalgae blooms from estuarine waters. Salinity tolerances, filtration rate, substrate selection, and effects on digested bacteria and ichthyofaunal communities were examined. If acclimated slowly, Styela can be placed in salinities as low as 24 parts per thousand (ppt) before increased fatalities result. An immediate decrease in salinity from 32 ppt to 20 ppt was not detrimental at short term exposure (four days). One average-sized (~40g) Styela, exposed to 105 and 106 bacteria or microalgae mL-1, can filter as much as 4.7 L hr-1 and 3.3 L hr-1, respectively. Individual tunicate filtration rates varied from hour to hour, independent of organism size, indicating that filtration rates for this species would be better reported on a population basis rather than on an individual weight or size basis. Bacterial viability in tunicate feces was assessed by ATP analysis. Bacteria were found to be non-viable after passage through the tunicate digestive tract. Filtration of eggs or larvae of recreationally or commercially important fish is of concern. The smallest eggs (~0.6mm) reported in the Indian River Lagoon belong to Cynoscion nebulosus (spotted seatrout) and Bairdiella chrysoura (silver perch). Over the course of two hours, 72.5% of 0.5 mm glass beads (simulated fish eggs) were initially retained, but many were later expelled by the tunicates. For 1.0 mm beads, 49.4% were initially retained and for 2.0 mm beads, 43.5% were initially retained. Neither the size of the oral siphon nor the size of the overall animal was correlated to bead retention. Substrate selection was investigated using the tunicate Phallusia nigra. / Newly hatched larvae preferred settling on wood (53.7%), as compared to polyethylene (30.9%), high-density polyethylene (13.0%), and polyvinyl chloride (2.4%). Overall, results of this study indicate S. plicata is very effective at removing bacteria and microalgae from estuarine waters. However, further testing is warranted regarding the unwanted removal of fish eggs and larvae before utilization of S. plicata for bioremedial purposes. / by Lisa Denham Draughon. / Thesis (Ph.D.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.

Submitted in fulfilment of the requirements for the Master of Technology Degree: Environmental Health, Durban University of Technology, 2012. / Waterborne diseases represent substantial global burden of disease and children under the age of five are more susceptible to these diseases compared to adults. The aim of this study was to determine the microbiological quality of Nyabarongo River water used for domestic purposes, women’s knowledge, attitudes and practices (KAP) on water usage and waterborne diseases and its link to the diarrhoea outbreaks experienced in two rural communities: Rusheshe and Ayabaraya of Masaka in Rwanda. A total of 35water samples were collected from Nyabarongo River and from study households which used slow sand filtration (SSF) or Sûr’Eau as treatment methods and analyzed for total coliform and faecal coliform indicators. For household samples turbidity was also analyzed. Retrospective records from Masaka Health Centre were reviewed to determine the prevalence of waterborne diseases from the study areas during 2010. Further, a structured questionnaire was administered to 324 women residents of the study areas to elicit information on their KAP on water handling and waterborne diseases. SPSS Predictive Analytic Software (PASW) Statistics version 18.0 (IBM, Somers, NY) and STATA Release (Version 11.0, College Station, Texas USA) were used for data analysis. Results showed that the mean values of total and faecal coliforms of river and household water samples were above the WHO and Rwandan recommended guidelines. The mean values of total coliform and faecal coliform were significantly lower (p ≤ 0.05) in both filtered and Sûr’Eau treated water than in river water. No statistical differences of means were observed for both total coliform and faecal coliform counts between samples taken from filtered and Sûr’Eau treated water containers (p=0.80 (TC) and p = 0.56 (FC). However, turbidity values were significantly lower in filtered water using SSF than in Sûr’Eau treated water samples (p =0.002). Out of 2814 records form Masaka Health Centre during 2010, 160 cases were identified as having diarrhoeal diseases. Furthermore, respondents who used Nyabarongo River as source of water were more likely to have symptoms of diarrhoea (OR =5.35; CI: 2.12 - 14.46; p <0.05). The frequency of diarrhoea were significantly higher among people who did not wash hands before food preparation (p = 002) and after using a toilet (p = 0.007) than among those who did. There was a statistically significant association of level of education levels and drinking water treatment practices at the household level (p < 0.05). Respondents with primary school education only and those with high school education were more likely to wash their hands after using a toilet (OR= 5.24, CI 1.42-19.38, p =0.01 and OR = 7.15, CI = 1.79 -28.62, p=0.01, respectively) than those who did not attend school. No significant associations were identified between educational levels and washing hands before food preparation. The findings of this study points to the facts that water sourced from Nyabarongo River is unsafe for human consumption even after prescribed treatment, such as the use of SSF and Sûr’Eau, and could increase the prevalence of waterborne diseases and therefore calls for urgent provision of potable water. Women in the study areas had limited knowledge regarding water storage practices for prevention of household water contamination and this; underscore the need for more water handling practices and hygiene education in rural communities. / Durban University of Technology.

published_or_final_version / Ecology and Biodiversity / Doctoral / Doctor of Philosophy

Coral reefs worldwide are threatened by many environmental disturbances including harmful algal blooms (HABs) which have been increasing on Florida coasts over the past decade. Research has mainly focused on HAB identification, percent cover and other effects on the benthos but the relationship of HABs with upper trophic levels has received less attention. To study this relationship, a two-year investigation on a 10-m deep reef off of Hallandale Beach, was conducted. Stationary fish census coupled with benthic transect videos were conducted quarterly between April 2005-July 2007. A significant correlation between Lyngbya sp. blooms and alterations in fish assemblages was observed. Lyngbya had a negative interaction with fish species and abundance; additionally, HAB sample periods were significantly different from low algal abundance periods. Blooms of Dictyota sp. had no measurable relationship with the fish assemblage indicating HABs may have variable impacts on fishes depending on family, species and chemistry of the algae. / by Rex E. Baumberger, Jr. / Thesis (M.S.)--Florida Atlantic University, 2008. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2008. Mode of access: World Wide Web.

The wide use and accessibility of surface waters leads to multiple sources of contamination. The two main forms of pollution are from point and nonpoint sources. Point sources are regulated by the federal government; however, nonpoint sources are more difficult to regulate since there is no defined origin. Due to this problem, surface water monitoring is performed by state agencies which can include the testing of several different water quality indicators chosen by the state. This thesis examines several water quality indicators from two watershed subbasins with different land uses. The types of contamination and sources were evaluated from the data, which was analyzed based on sampling site, season, and two statistical tests. The water quality indicators that were examined in this study included physical, chemical, and microbiological indicators. The two subbasins that were monitored were located in the Wachusett reservoir watershed in central Massachusetts. One subbasin, Malagasco Brook, was located south of the reservoir. Six sampling sites were chosen in proximity to a swampy area, a nursery, and condominium housing complex. The second subbasin, Beaman Pond, was located to the northwestern side of the reservoir and was monitored at three sites. These sites were located in a residential area in addition to a special use two acre farm. Analyses were performed by site and by season to find trends in the data. Statistical correlation and ANOVA analyses were performed in order to better understand the relationships of the water quality indicators. From these analyses, it was determined that organic carbon and human sources of contamination were significant in the Malagasco Brook subbasin. Organics originated in the headwaters and nursery area, and the residential area was a possible source of microorganisms. The Beaman Pond subbasin was found to be affected by both human and animal sources of contamination. Downstream of the farm, animal contamination was found and supported by measurement of microbial source tracking indicators. The other two sites were affected by human sources, a result of septic systems. Strong correlations were found between several water quality parameters, including temperature and dissolved oxygen, turbidity and particle counts, and fecal coliforms and enterococcus. Based on data usefulness and ease of measurement, it is recommended that temperature, DO, conductivity, pH, dissolved organic carbon, turbidity or particle counts, and fecal coliforms be included in a routine watershed monitoring program.

Few studies, and none in Oregon, have examined the presence and change of water quality parameters over time in popular natural swimming areas. This information is necessary to better understand water quality and risk of illness from either fecal contamination or cross-infection from other swimmers. The purpose of this study was to quantitatively measure bacterial and selected physical and chemical parameters, and collect background information for changes to the current state water quality criteria. Five natural swimming areas in Linn, Benton and Polk counties were chosen and sampled biweekly for physical, chemical, and bacterial parameters over a nine week period from June 28 to August 31, 1996. The results showed differences in bacterial levels over the sampling period which often varied by degrees of magnitude between sites. For example, the range in Escherichia coli levels was between 0 and 1000 colonies/100mL sample for two sites on the same sampling day. Similarly, the range in fecal coliform levels was between 5 and 500 colonies/100mL sample. The daily colony counts at each site exceeded the state standards at least 10% of the time for E. coli and 21% of the time for fecal coliform. At the most popular swimming site, Montieth Park. the fecal coliform regulatory levels were exceeded 79% of the time and E. coli levels were exceeded 42% of the time. This may be due to turbidity, high bather load, or a broken sewer line. The 30 day log mean of these values shows consistently elevated fecal coliform problems only at Montieth Park. For the other sites, the log means did not exceed the state and federal regulatory limits for fecal coliform or E. coll. This raises questions about which estimates should be used to assess public health risk. None of the other parameters in this study were correlated with bacterial counts, so it appears that none of these factors is solely responsible for elevated bacterial levels. Further testing should be done at Montieth Park to determine the cause of the elevated fecal coliform levels. Any follow-up studies should test several different indicator organisms in addition to E. coli for comparison and assessment of their relationship to public health risk. / Graduation date: 1997