Environmental Research Institute - Masters by Research Theses
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Item Optimising submarine cable routes from offshore wind farms – site suitability mapping(University College Cork, 2024) Walsh, Kevin; Holloway, Paul; Lim, Aaron; Irish Research CouncilThe Irish Government’s Climate Action Plan aims to increase renewable energy generation capacity to 22 GW by 2030, with at least 5 GW of this to be produced by offshore windfarms. The potential to harness and develop this resource is significant; however not all areas offshore are suitable. Moreover, not all routes from windfarms to land are suitable for the submarine cables needed to transfer the energy produced offshore back to the onshore grid. This project leverages geospatial analysis to identify optimal routes for submarine export cables, enhancing our understanding of marine and coastal geomorphology and the potential hazards associated with these environments. This research is focused on the South and West coasts of Ireland, a region with substantial potential for offshore wind energy development, particularly floating wind turbine platforms. A comprehensive geospatial repository of publicly available data was compiled, incorporating key features relevant to submarine cable route feasibility. These criteria layers include bathymetric, geological and ecological data, as well as information on human activities in the area, to assess the potential hazards to a submarine cable within a particular region. Criteria weights were calculated for two scenarios using the Analytical Hierarchical Process, based on expert opinion, while a third scenario applied equal weighting to each layer to evaluate the impact of these weights The resulting maps classify regions off the South and West coasts of Ireland into zones of suitability for submarine export cables. A Least Cost Path Algorithm was then implemented in ArcGIS Pro along these surfaces, which identified the most optimal routes for each scenario. Particular focus was paid to those parts of the study area where there are current plans for offshore wind energy development, as identified during phase I and II of the Irish Governments Offshore Renewable Energy Development Plan. In a novel application, INFOMAR sub-bottom profile data was analysed within two key regions off the South Coast highlighted from the route selection analysis. This study presents some of the first examples of utilising this openly available dataset for spatial planning of offshore infrastructure. The resulting sediment thickness maps derived from this analysis facilitated routing through areas where seabed sediment depths are adequate for cable burial, thereby minimising the risk of damage from external hazards that could shorten the lifespan of the cable and lead to costly repairs. The findings detailed within this study provide a useful tool for policy makers and developers in the feasibility stages. In a broader context, given the vast size of Ireland’s offshore territory, these findings can be applied by planners to create objective and standardised cable routes having both immediate economic and environmental benefits. The use of publicly available data herein can reduce the reliance on extensive geophysical surveys, which are not only expensive and time-consuming but also can be environmentally detrimental, particularly due to the impact of anthropogenic sound on marine mammals. By lowering the costs associated with marine surveys and identifying optimal routes that reduce the risk to submarine cables, this approach can encourage international developers to invest in offshore energy in Ireland, ultimately supporting the rapid and widescale rollout of renewable energy needed to meet national targets. The innovative approaches and datasets detailed in this thesis not only advance the precision of submarine cable routing but also establish a replicable framework for offshore wind energy projects, thereby contributing to the efficient and sustainable growth of global renewable energy infrastructure.Item Assessment of the effectiveness of SuperFifty® Prime in preventing cold stress in pepper (Capsicum annuum cv. Kurtovska Kapija)(University College Cork, 2024) Mahony, Cian; Henriques, Rossana; Jansen, Marcel A. K.; BioAtlantisThe occurrence of abiotic stress is becoming increasingly common as climate change progresses, and this poses a major challenge for agriculture. Plant Biostimulants are a new form of abiotic stress management which induces the plants natural defence systems in a process known as “molecular priming”. SuperFifty® Prime is a highly concentrated A. nodosum extract (500g/L) which has been proven to mitigate the detrimental effects of different abiotic stressors. Peppers were chosen for this experiment (Capsicum annuum) as they are a commercially important crop with an extremely low tolerance to cold conditions. In this project we aimed to investigate how a priming and recovery application of SuperFifty® Prime on a cold sensitive crop helped avoid and mitigate the damage caused by cold and uncover the molecular mechanisms behind this protection. At the physiological level, the results showed that two applications of SuperFifty® Prime improved plant performance as demonstrated by monitoring the following parameters: fresh weight, electrolyte leakage, chlorophyll content, flavonoid content and the occurrence of necrotic tissue. The application of SuperFifty® Prime also improved plant recovery after the cold stress event. At final harvest, there was no significant difference in yield parameters between Primed Cold-Treated and Unprimed Untreated plants. At the molecular level, five genes of interest were selected. Three of these genes; ICE 1, CBF 1 and COR 314, are part of most studied cold signalling pathway known as the ICE-CBF-COR transcriptional cascade. The two other selected genes; PAL 1 and CHS 1, are important for flavonoid production. A similar pattern of expression was observed for all five genes with a clear difference between Primed and Unprimed Cold-Treated plants. Expression of ICE 1 and COR 314 are also upregulated in Primed Untreated plants, despite these plants not experiencing cold stress inducing conditions. Based on the evidence from this experiment, two applications of SuperFifty® Prime improved yield and productivity in Primed Cold- Treated plants and has the potential to improve grower incomes in areas affected by cold stress.Item Design and optimisation of a small, robust outdoor duckweed bioreactor for operation under ‘on-site’ farmyard conditions(University College Cork, 2024) O'Sullivan, Grace; Byrne, Edmond; Kavousi, Fatemeh; Department of Agriculture, Food and the Marine, IrelandDuckweed (Lemnaceae) is a small, aquatic plant that is ubiquitous across Ireland. It grows remarkably fast, with a doubling time of one to two days. Duckweed is typically found on slow moving water bodies, but it can grow on agricultural waste streams such as yard washings. Usefully, the plant removes excess nutrients (nitrogen and phosphorus) from wastewater to produce a high protein crop. Duckweed dry weight can contain up to 40% protein. Duckweed is currently being investigated for use in human nutrition, biofuel production, and the remediation of waste streams (Appenroth et al., 2017, Xu et al., 2012, Zhou et al., 2023). The rising need for sustainable agriculture systems magnifies the importance of a circular economy approach to farming. This project involves the design and optimisation of an outdoor duckweed growth system suitable for use on farms. It offers farmers a plausible solution to managing the large volumes of nutrient-rich wastewater produced on farms daily, whilst also generating high-value biomass. Hence, it can help provide a circular economy approach to sustainable agriculture. Currently, two main styles of growth systems are used in the production of duckweed: ponds and raceway systems. A literature survey (undertaken as part of this research) reveals that limited studies have been completed on the effect of system design on duckweed cultivation. The approach undertaken in this project involves a systematic analysis of fluid flow using Computational Fluid Dynamics (CFD) and tracer response experiments to inform the design of a system optimal for duckweed production. ANSYS Fluent is used to optimise the system geometry and interpret the effects of the geometry on nutrient distribution. Relative growth rate and nutrient uptake experiments were also employed to gain experiential knowledge and thus a holistic understanding of the impact of design on duckweed growth. From this study, it can be concluded that low levels of mixing within a cultivation system have a positive effect on both the relative growth rate of duckweed and its remediation ability. However, at higher flow rates the growth of duckweed is negatively impacted. The results also feature the design of a medium-scale outdoor duckweed cultivation system, informed by the literature review and experimental work. This work will inform stakeholders on the most suitable system for duckweed production in a farm setting. In addition to this, it will provide guidance on the style of system that is most suitable for large scale duckweed production sites worldwide.Item The influence of community-defined land use plans and de facto land use practices on the relative abundance and distribution of large wild mammals in a community-based Wildlife Management Area in southern Tanzania(University College Cork, 2023) Duggan, Lily; Killeen, Gerry; Butler, Fidelma; Mombo, Felister; AXA Research FundThis study investigates the relationship between community-defined land use plans and de facto land use practices, and the influence of the latter on the relative abundance and distribution of large wild mammals in a community-based Wildlife Management Area (WMA) adjacent to Nyerere National Park (NNP) in southern Tanzania. The WMA model represents a relatively new approach to community-based conservation in Tanzania, in which local villages set aside part of their land for wildlife conservation and manage that resource collectively, so that their stakeholder communities can leverage economic and social benefits from income-generating activities like tourism. The Ifakara-Lupiro-Mangula (ILUMA) WMA acts as a key buffer zone between the fully domesticated habitats of the villages to the north and west, and Nyerere National Park to the east. All observed signs of wildlife and human activity were recorded across 32 locations inside ILUMA and in the permanent settlements and national park that border it to the west and east, respectively. For the great majority of wild mammal species, surveys around water bodies within a 2km radius of suitable camping locations proved more sensitive than those along transects between them. The latter transect surveys were only more sensitive for Sable and Spotted Hyena, which are known to routinely commute considerable distances across their home ranges, and for Greater Kudu that seldom drink surface water. Across much of ILUMA WMA, in areas where agreed land use plans were not adhered to, rampant cattle herding and land clearing for cultivation of rice and other tillage crops were associated with reductions in wildlife richness and biodiversity, as well as overall ecosystem integrity. Many unauthorised human activities were recorded inside ILUMA, such as livestock herding, charcoal burning and agriculture, and, where they occur at a high density, wildlife populations are negatively affected. Although all these activities impact wildlife to some degree, cattle herding had the most severe negative effect on wildlife (Species Richness, P=0.002, Simpson’s Index of Diversity, P=0.0022) and ecosystem integrity (P <<0.0001). Nevertheless, several well-managed authorised human settlements within the WMA, where fishing is the primary authorised livelihood, support thriving wildlife populations and pristine land cover, so human settlement per se was not found to be associated with reductions of any of these composite indices (P≥0.4532), except for the novel subjective natural ecosystem integrity index (P=0.0256). Correspondingly, the best conserved parts of the WMA were those closest to the national park to the east and the fishing villages to the north, where compliance with agreed land use plans is highest. Overall, this study illustrates how well-managed WMAs can host resident local communities undertaking selective and appropriately regulated natural resource extraction activities, while maintaining a rich and diverse local wildlife population and acting as an effective buffer zone between fully domesticated areas of human habitation and pristine environments such as national parks. Furthermore, this study also developed and evaluated a novel method for synthesizing consensus subjective impressions of the investigators and intuitively expressing them in semi-quantitative format as a readily interpreted subjective natural ecosystem integrity index that accounts for all aspects of land use, wildlife and human activities. Crucially, however, this alternative to statistical syntheses of extensive, formally collected survey data is intuitively accessible to all manner of stakeholders, including relevant communities, and should be far better suited to routine programmatic monitoring through participatory approaches.Item Blood host preferences and competitive inter-species dynamics within an African malaria vector species complex inferred from signs of animal activity around aquatic larval habitats distributed across a gradient of fully domesticated to fully pristine ecosystems in southern Tanzania(University College Cork, 2023) Walsh, Katrina; Killeen, Gerard; Butler, Fidelma; Kaindoa, Emmanuel; AXA Research Fund; University College CorkThe effectiveness of current first-choice vector control interventions on the semi-zoophagic vector Anopheles arabiensis are limited, among other things, by insecticide resistance and their ability to acquire non-human bloodmeals. Across much of southern Tanzania, in areas where humans and cattle are readily available, it is the predominant member sibling species of the Anopheles gambiae complex. However, little is known about its population dynamics or blood utilization behaviours in pristine natural ecosystems, where these known preferred hosts are scarce or completely absent. This study investigated larval habitat occupancy and species composition of the An. gambiae complex, together with the availability of various potential mammalian blood host species, across a gradient of fully domesticated to fully pristine ecosystems in southern Tanzania. Potential aquatic habitats were surveyed at 40 locations encompassing permanent human settlements, a community-owned Wildlife Management Area with varying degrees of human activity, and Nyerere National Park (NNP), which had very little. To investigate the effects of potential host availability on the species composition of the complex, all direct observations, tracks and signs of humans, livestock and wild animals observed around the surveyed larval habitats were recorded in parallel. The resulting data were analysed by logistic regression using generalized linear mixed models. Odds of habitat occupancy by An. gambiae complex larvae decreased by 62% (P<0.0001) across the full range of natural ecosystem integrities observed, from fully domesticated to completely pristine areas, suggesting that the availability of suitable blood hosts had a modest effect on overall habitat utilization by this taxon. However, while only An. arabiensis, a key vector of residual malaria transmission, was found in fully domesticated ecosystems, its non-vector sibling species An. quadriannulatus also occurred in conserved areas and dominated the most pristine natural ecosystems. The proportion of An. arabiensis versus An. quadriannulatus was positively associated with the number of times humans and/or cattle (P=0.0007) were detected at a location and negatively associated with distance inside NNP and away from human settlements (P<0.0001). Nevertheless, An. arabiensis was found even in absolute pristine environments that were >40km away from any signs of human or livestock, suggesting this species can survive on blood from one or more wild animal species. High proportions of An. quadriannulatus inside NNP were positively associated with the number of times impala were detected (P<0.0001), suggesting they may be a preferred blood source for this non-vector, giving it a competitive advantage over An. arabiensis where this antelope is abundant. Despite being detected less frequently, bushpig were also positively associated with high proportions of An. quadriannulatus, suggesting they provide a second preferred blood source, particularly in the miombo woodlands of the buffer zone where impala were scarce. Overall, it seems that the availability of preferred hosts influences the competitive balance between these sibling species and that refugia populations of An. arabiensis can persist in wild areas, thus presenting both challenges and opportunities for control interventions: While such refuge populations deep inside pristine conservation area may confound attempts to repeat historical successes with eliminating this species from areas outside its natural range, it may also constitute a reservoir of diverse, unselected genomes with original wild-type insecticide susceptibility traits that could repopulate areas around human settlements that had otherwise been considered lost from the natural gene pool.