Some preliminary investigations of the effects of temperature, light intensity, salinity and to a lesser extent, water movement, were performed under controlled laboratory culture conditions on the subtidal red alga Gelidium capense, with regards to its potential for aquaculture for its use in the agar and paper-making industries. Agar was also extracted from a wild population and its concentration measured. Four temperature conditions {l0°C, 15°C, 20°c and 25°C) and three salinities (35ppt, 18ppt and 9ppt) were tested as well as four irradiances (120-140 μmol photons m⁻²s⁻¹ , 80-100 μmol photons m⁻²s⁻¹, 60-70 μmol photons m⁻²s⁻¹ and 30-50 μmol photons m⁻²s⁻¹). Water movement was achieved either through aeration or using a flask shaker. A combination of full salinity {35ppt) and 15°C temperature with a light intensity of 80- 100 μmol photons m⁻²s⁻¹ yielded the most optimal growth rates (5 .07% day⁻¹) while poor growth rates (- 1.61% day⁻¹) were observed for the 18ppt and 9ppt salinities and the lowest light intensities. Interestingly, G. capense did not thrive at 20°c or 25°C and instead discoloured rapidly, showed necrosis within a few days, which is in contrast to the findings of most studies focussed on other species of Gelidium under similar conditions. Slow growth rates were achieved at 10°c. The mean agar yield measured ten percent (9.66% ± 1.81) of dry algal weight which is less than a third of the agar yields of some other species of Gelidium and Graci/aria. This suggests that this species may not be as valuable as other Gelidium species in terms of its agar content. It does, however, have high rhizine content and this may lend it to be beneficial in the papermaking industry.

This study was a first attempt at investigating whether algal groups respond to environmental differences including human impacts in wetlands in the Western Cape of South Africa. Samples were collected from three permanent and three temporary wetlands in Betty's Bay and a temporary wetland in Onrust, near the town of Hermanus. The environmental variables which were measured were pH, conductivity, water depth, whether wetlands were temporary or permanent and whether the samples were from the wetland or from waterlogged soils next to the wetlands. The wetlands sampled were found to be very similar and overall there was not a strong species response to the environmental variables. When only the diatom species data were analysed, however, it was possible to differentiate between samples from Bass Lake and Vermont Vlei. These wetlands had contrasting pH and conductivity values, with Bass Lake having an average pH of 6.8 and a mean conductivity of 262.5 µSiem and Vermont Vlei having an average pH of 8.4 and 152.1 µSiem for the average conductivity value. This suggests that diatom species are sensitive to small differences in pH and conductivity. Diatoms were found on average to make up 91 % of the taxa sampled in the different wetlands and were ubiquitous in their distribution among the different wetlands. The algal taxa that occurred in the greatest number of samples included Amphora sp., Cymbella sp., Navicula sp., Nitzschia sp., Pinnularia sudetica, Rhizoclonium hieroglyphicum, Surirella sp. and Synedra sp .. The average Shannon-Wiener biodiversity index was 3.53 for the seven wetlands. It is recommended that in future studies there should be greater standardisation in sampling with specific micro-habitats sampled to make algal groups comparable. It is also possible that a greater number of wetlands with a wider range in water chemistry properties are needed to be able to detect clear algal species responses to environmental gradients.

Submitted by Mario BC (mario@bc.ufrpe.br) on 2016-06-02T14:10:37Z No. of bitstreams: 1 Samara Rodrigues.pdf: 2007129 bytes, checksum: 302f3c0c854772f4f4281af71ee55629 (MD5) / Made available in DSpace on 2016-06-02T14:10:37Z (GMT). No. of bitstreams: 1 Samara Rodrigues.pdf: 2007129 bytes, checksum: 302f3c0c854772f4f4281af71ee55629 (MD5) Previous issue date: 2015-02-09 / The Dictyotales order (Phaeophyceae) is distributed in temperate and tropical flora. In Brazil, they occur from Maranhão to Rio Grande do Sul, besides Atol das Rocas and the archipelagos of Fernando de Noronha and Trindade. In the Northeast, this order is the most significant in numbers of species within the Phaeophyceae. Given its importance, this study aimed to make the taxonomic and floristic study of the order on the coast of the state of Alagoas, which has a great phycological diversity. Four sampling stations were selected along the coast. Samples were collected seasonally in the dry and rainy season, during low tides, in the intertidal zones using a spatula and/or in free dives. The collected material was fixed in 4% formalin and transported to the Federal Rural University of Pernambuco (UFRPE). The taxonomic identification was based on morphological and anatomical characters and was confirmed by specialized bibliographies. The taxonomic position was organized according to Wynne (2011). In the studied area the Dictyotales were represented by 20 taxa, distributed among the genera Canistrocarpus (three), Dictyopteris (five), Dictyota (six), Lobophora (one), Padina (four) and Spatoglossum (one). Five species are being cited as the first occurrence to Alagoas´ coast (C. crispatus (J.V. Lamour.) De Paula & De Clerck, D. jamaicensis W.R. Taylor, D. polypodioides (A.P.D.E. Candolle) J.V.Lamouroux, D. pinnatifida Kützing and P. antillarum (Kützing) Piccone). The study provides identification key to the species level and for each species identified a description, comments and ecological illustration. Among the 20 species of Dictyotales found, only Canistrocarpus cervicornis, C. crispastus, Dictyopteris delicatula, Dictyota jamaicensis, Padina antillarum and Spatoglossum schroederi occurred in the four sampling stations. The greatest richness was found in rocky substratum with occurrence of all species. Of the 20 taxa, 19 were common in both the seasons. Regarding the frequency of occurrence, in the dry and rainy season two taxa occurred as very common C. cervicornis and Dictyopteris delicatula. The similarity analysis (ANOSIM) showed significant differences between the sampling sites. The genera that had some problems in their identification were mostly Canistrocarpus and Dictyota, but with the observation of morphological and anatomical characters, conflicts were resolved. Chemical and biomolecular analyzes should be undertaken to better define the taxonomic limits of conflicting species of these genera. / A ordem Dictyotales (Phaeophyceae) está distribuída na flora tropical e temperada. No Brasil, os seus representantes ocorrem desde o Maranhão até o Rio Grande do Sul, além do Atol das Rocas e Arquipélagos Fernando de Noronha e Trindade. No Nordeste, essa ordem é a mais expressiva em números de representantes dentro das Phaeophyceae. Diante dessa importância, este trabalho teve como objetivo realizar o estudo taxonômico e florístico da referida ordem no litoral do estado de Alagoas. Foram eleitas quatro estações de coleta ao longo do litoral. As coletas foram realizadas sazonalmente, no período seco (novembro e dezembro de 2013 e janeiro de 2014) e chuvoso (maio a julho de 2014), durante as marés baixas, nas zonas entremarés, com auxílio de espátula e/ou através de mergulhos livres. O material coletado foi fixado em formol a 4% e transportado à Universidade Federal Rural de Pernambuco (UFRPE). A identificação taxonômica baseou-se nos caracteres morfo-anatômicos e foi confirmada através de bibliografia especializada. A posição taxonômica foi organizada de acordo com Wynne (2011). Na área estudada as Dictyotales foram representadas por 20 táxons específicos, distribuídos entre os gêneros Canistrocarpus (três), Dictyopteris (cinco), Dictyota (seis), Lobophora (um), Padina (quatro) e Spatoglossum (um). Cinco espécies estão sendo citadas como primeira ocorrência para o litoral alagoano (C. crispatus (J.V. Lamour.) De Paula & De Clerck, Dictyopteris jamaicensis W.R.Taylor, D. polypodioides (A.P.De Candolle) J.V.Lamouroux, Dictyota pinnatifida Kützing e P. antillarum (Kützing) Piccone). O estudo fornece chave de identificação em nível específico e para cada espécie identificada, uma descrição, comentários ecológicos e ilustração. Dentre as 20 espécies encontradas, Canistrocarpus cervicornis, C. crispastus, Dictyopteris delicatula, Dictyota jamaicensis, Padina antillarum e Spatoglossum schroederi ocorreram nas quatro estações de coleta. A maior riqueza foi encontrada no substrato consolidado rochoso, com a ocorrência de todas as espécies. Dos 20 táxons encontrados, 19 foram comuns em ambos os períodos estacionais. Com relação à frequência de ocorrência, dois táxons ocorreram como muito frequentes C. cervicornis e Dictyopteris delicatula. A análise de similaridade (ANOSIM) mostrou diferenças significativas entre os locais de amostragem. Os gêneros que apresentaram alguma problemática em sua identificação foram principalmente Canistrocarpus e Dictyota, mas com a observação de caracteres morfológicos e anatômicos os conflitos foram resolvidos. Análises químicas e biomoleculares devem ser realizadas para melhor definir os limites taxonômicos das espécies conflitantes desses gêneros.

This thesis investigates the diversity of two silica-scaled protist groups, Paraphysomonadida and Thaumatomonadida by light and electron microscopical observations and sequencing (rDNA) on novel clonal cultures. Despite these groups of protist dominating pelagic, littoral as well as inland freshwater and soil habitats, they are taxonomically poorly understood to the extent that any progress in ecological theory is hampered. Now that environmental DNA sequencing is being carried out faster than we can characterise protists from culture it is important that we understand how molecular and physical diversity match up, especially because so many protists are morphospecies. Nearly one hundred isolates were cultured on which both morphological and molecular data was carried out in parallel to reveal around 50 new species of protist from eight different genera: two heterokont genera, Paraphysomonas and Incisomonas n. gen., and six cercozoan genera, Thaumatomonas, Allas, Reckertia, Thaumatospina n. gen., Cowlomonas n. gen., and Scutellomonas n. gen. These data make major contributions to taxonomy and understanding aspects of protist diversity where previously morphological diversity was heavily biased towards over- generalized morphotypes. This thesis quickly showed that gross lumping of morphospecies was true of Paraphysomonas, for which many of the isolates cultured herein might have been regarded as one species (not more than 20). The many cultured isolates exhibited varied cell and scale morphology, and by sequencing (rDNA), it was possible to see the evolution of scale morphology map on to trees. This marriage of molecular and morphological data made it possible to view distinct groups of species that shared scale detail that might have otherwise been overlooked had either method been used alone. This research has shed significant light on how scale morphology can be used as reliable taxonomic marker for protists, the insights of which can be applied to make taxonomic improvements to other silica-scaled protist groups.

Shallow lakes are an important ecological and socio-economic resource. However, the impact of human pressures, both at the lake and catchment scale, has precipitated a decline in the ecological status of many shallow lakes, both in the UK, and throughout Europe. There is now, as direct consequence, unprecedented interest in the assessment and monitoring of ecological status and trajectory in shallow lakes, not least in response to the European Union Water Framework Directive (2000/60/EC). In this context, the spatially-resolving and panoramic data provided by remote sensing platforms may be of immense value in the construction of effective and efficient strategies for the assessment and monitoring of ecological status in shallow lakes and, moreover, in providing new, spatially-explicit, insights into the function of these ecosystems and how they respond to change. This thesis examined the use of remote sensing data for the assessment of (i) phytoplankton abundance and species composition and (ii) aquatic vegetation distribution and ecophysiological status in shallow lakes with a view to establishing the credence of such an approach and its value in limnological research and monitoring activities. High resolution in-situ and airborne remote sensing data was collected during a 2-year sampling campaign in the shallow lakes of the Norfolk Broads. It was demonstrated that semi-empirical algorithms could be formulated and used to provide accurate and robust estimations of the concentration of chlorophyll-a, even in these optically-complex waters. It was further shown that it was possible to differentiate and quantify the abundance of cyanobacteria using the biomarker pigment C-phycocyanin. The subsequent calibration of the imagery obtained from the airborne reconnaissance missions permitted the construction of diurnal and seasonal regional-scale time-series of phytoplankton dynamics in the Norfolk Broads. This approach was able to deliver unique spatial insights into the migratory behaviour of a potentially-toxic cyanobacterial bloom. It was further shown that remote sensing can be used to map the distribution of aquatic plants in shallow lakes, importantly including the extent of submerged vegetation, which is central to the assessment of ecological status. This research theme was subsequently extended in an exploration of the use of remote sensing for assessing the ecophysiological response of wetland plants to nutrient enrichment. It was shown that remote sensing metrics could be constructed for the quantification of plant vigour. The extrapolation of these techniques enabled spatial heterogeneity in the ecophysiological response of Phragmites australis to lake nutrient enrichment to be characterised and assisted the formulation of a mechanistic explanation for the variation in reedswamp performance in these shallow lakes. It is therefore argued that the spatially synoptic data provided by remote sensing has much to offer the assessment, monitoring and policing of ecological status in shallow lakes and, in particular, for facilitating the development of pan-European scale lake surveillance capabilities for the Water Framework Directive (2000/60/EC). It is also suggested that remote sensing can make a valuable contribution to furthering ecological understanding and, most significantly, in enabling ecosystem processes and functions to be examined at the lake-scale.

Coal seams are commonly associated with poor quality water that requires treatment. Water treatment can be very expensive and can severely affect the profitability of mining projects. This study investigated the potential cultivation of Arthrospira maxima (Spirulina) in coal seam water to beneficiate coal seam water in order to effectively offset the water treatment cost. The study was conducted in Northern South Africa and formed part of a larger Coal Seam Water Beneficiation Project (CSWBP). The study consisted of laboratory based Flask Studies and outdoor High Rate Algal Pond Studies. The Flask Studies that were carried out in the on-site field laboratory, found that the coal seam water could provide a suitable medium for Spirulina cultivation. In addition, it was found that the optimal pH for the selected strain ranged between 9 - 10.5 and that the addition of excess iron, up to 100 times the concentration found in defined growth media such as Schlösser’s, to the culture media could enhance productivity. The High Rate Algal Pond Studies (HRAP) were carried out over a period of 18 months. The studies showed that the coal seam water at the CSWBP is a valuable resource that can reduce media costs by 50% without affecting productivity. In a study encompassing 334 days it was shown that heating the culture through plate heat exchangers would result in a significant increase in productivity and a heated productivity of 19.86 g/m2/day was recorded. An unheated productivity of 14.11 g/m2/day was recorded. Therefore, it was found that it would be economically feasible to beneficiate coal seam water found at the CSWBP through the cultivation of Arthrospira maxima (Spirulina). / Environmental Sciences / M. Sc. (Environmental Science)

Coal seams are commonly associated with poor quality water that requires treatment. Water treatment can be very expensive and can severely affect the profitability of mining projects. This study investigated the potential cultivation of Arthrospira maxima (Spirulina) in coal seam water to beneficiate coal seam water in order to effectively offset the water treatment cost. The study was conducted in Northern South Africa and formed part of a larger Coal Seam Water Beneficiation Project (CSWBP). The study consisted of laboratory based Flask Studies and outdoor High Rate Algal Pond Studies. The Flask Studies that were carried out in the on-site field laboratory, found that the coal seam water could provide a suitable medium for Spirulina cultivation. In addition, it was found that the optimal pH for the selected strain ranged between 9 - 10.5 and that the addition of excess iron, up to 100 times the concentration found in defined growth media such as Schlösser’s, to the culture media could enhance productivity. The High Rate Algal Pond Studies (HRAP) were carried out over a period of 18 months. The studies showed that the coal seam water at the CSWBP is a valuable resource that can reduce media costs by 50% without affecting productivity. In a study encompassing 334 days it was shown that heating the culture through plate heat exchangers would result in a significant increase in productivity and a heated productivity of 19.86 g/m2/day was recorded. An unheated productivity of 14.11 g/m2/day was recorded. Therefore, it was found that it would be economically feasible to beneficiate coal seam water found at the CSWBP through the cultivation of Arthrospira maxima (Spirulina). / Environmental Sciences / M. Sc. (Environmental Science)