Integrating state-space modelling and systematic conservation planning to recommend penguin-fishery management zones in Algoa Bay, South Africa
- Authors: Stockdale, Victoria , Goodall, Victoria , Clifford-Holmes, Jia
- Date: 2023-12
- Subjects: Biodiversity conservation -- South Africa -- Port Elizabeth , Natural resource conservation , Marine ecology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62611 , vital:72828
- Description: Direct anthropogenic impacts on vulnerable marine ecosystems are growing and require effective conservation measures. Integrating the cost impacts of conservation interventions and optimising the spatiotemporal scale of management interventions may improve cohesion between opposing marine users. This study aimed to integrate spatial and temporal models to advise dynamic penguin-fishery management plans in Algoa Bay, off Gqeberha, South Africa, that would maximise penguin foraging success while minimising the impact on the fishing industry. Determining the foraging locations important to breeding penguins is fundamental when understanding the relationship between fisheries and prey availability. Using Global Positioning System (GPS) data gathered from feeding trips of breeding African penguins between 2012 and 2017, and a hidden Markov model, three behavioural states (foraging, commuting, transitioning) were inferred and used as conservation targets in spatial prioritisation using the prioritizr package in R. The cost to the fishery was estimated using the catch of pelagic fish by the fishing industry between 2012 and 2015 as the proxy. The energetic cost to penguins was the distance they travelled from their breeding colony. Nine prioritisation scenarios, varying in levels of conservation for penguins, spatial cohesion and costs to fisheries, were developed using all year’s combined data to explore an ‘optimal’ closure configuration. The optimal closure was determined as an area which met the targets for penguin conservation, with a low cost to the fishery, close to the breeding colony and spatially clumped. The best solution from each scenario was isolated and the solution for the conservation target of 20% foraging habitat, 10% commuting habitat and 10% transitioning habitat and a boundary penalty of 0.01 (a dimensionless value that is used to reduce spatial fragmentation – increasing the value of the parameter signals that it is important to minimise the total exposed boundary of the prioritisation by favouring solutions where units are clumped together) was chosen as the optimal closure. This configuration was used as a static closure and applied to individual fishing seasons to estimate how the cost of a static closure design to the fishery would vary between seasons. Subsequently, a dynamic closure was designed using the same optimal configuration criteria every year, and the cost to the fishing industry was compared seasonally with the cost of a static closure. The cost to fisheries of dynamic closures was consistently lower than that of a static closure and the area required to meet the penguin feeding targets was drastically reduced. While dynamic closure scenarios show promise to minimise costs to the industry while meeting penguin conservation targets, these configurations were designed retrospectively with data collected after the end of the fishery seasons. For efficient management, the closures need to be designed by using data collected at an appropriate temporal scale. For that, the critical missing dimension to this study is the addition of real-time data on pelagic fish positions, areas of fishing intensity and sites of penguin foraging to create appropriate recommendations for up-to-date fishery exclusion zones. Therefore, the priority now is to explore methods of collecting real-time data on pelagic fish abundance, feeding behaviour of penguins at sea, site and mass of pelagic fishery catch, and using these data to delineate real-time, dynamic closures, coupled with a governance and management strategy that can implement dynamic closures. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
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- Date Issued: 2023-12
An evaluation of the effectiveness of area-based conservation interventions in avoiding biodiversity loss in South Africa
- Authors: Von Staden, Lize
- Date: 2023-04
- Subjects: Environmental policy , Conservation of natural resources -- Government policy -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/61115 , vital:69762
- Description: Counterfactual impact evaluation studies form an important evidence base for the effectiveness of conservation projects, programs, and policies (collectively referred to as conservation interventions). In South Africa, counterfactual impact evaluation methods have rarely been applied to local conservation interventions, and therefore evidence for the effectiveness of key strategic national conservation approaches is lacking. This study evaluated three area-based interventions that together aim to avoid the loss of areas most important for the persistence of biodiversity in the terrestrial realm as evidence towards the effectiveness of South Africa’s landscape approach to biodiversity conservation. The first intervention, South Africa’s National Protected Area Expansion Strategy (NPAES), set ambitious targets to double the extent of South Africa’s protected area network while ensuring that the expansion preferentially occurs in areas of under-represented biodiversity. The strategy was evaluated in terms of its effectiveness in guiding protected area expansion towards more equitable representation of South Africa’s biodiversity through an assessment of changes in indicators of protected area expansion decision-making before and after the implementation of the strategy. The second intervention is the use of maps of biodiversity priorities to guide land use change decisions outside protected areas. Impact was evaluated as avoided loss of Critical Biodiversity Areas (CBAs), which need to remain in a natural condition to meet in situ conservation targets for species, ecosystems, and ecological processes. Avoided loss in CBAs was benchmarked against avoided loss in protected areas, to contextualize the effectiveness of land use planning as a conservation intervention. Lastly, the effectiveness of stricter land use regulations for threatened ecosystems to reduce land conversion pressure on these ecosystems was evaluated. Key findings were that protected areas are highly effective conservation interventions where they can be implemented, but their capacity for conservation impact is limited by severe constraints on strategic expansion. , Thesis (PhD) -- Faculty of Science, School of Environmental Sciences, 2023
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- Date Issued: 2023-04
A case study assessment of the ecological and social status of the South African boat-based whale watching industry
- Authors: Tolsma, Minke
- Date: 2022-04
- Subjects: Whale watching --South Africa , Dolphin watching
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/55887 , vital:54397
- Description: Boat-based whale-watching (BBWW) is a rapidly growing marine tourism industry globally and in South Africa (SA). BBWW in SA was established in 1998, and since then the number of permits available has doubled from 20 to 40. However, the establishment and past growth of the industry was undertaken without ecological research or impact assessments. Global research has shown that BBWW has the potential to cause short-term changes in cetacean behaviour and movement, which in turn can have long-term population-level consequences. National policies to grow ocean economies in SA may encourage excessive growth in the BBWW industry, impacting the ecological sustainability. In the absence of long-term impact data, the BBWW industry should be managed to minimise short-term changes. This study aimed to determine the social and ecological status of the SA BBWW industry, using Plettenberg Bay as a case study, to inform its long term sustainability. To achieve this aim: 1) the short-term behavioural and movement responses of six cetacean species to encounters with commercial BBWW vessels were measured; 2) the efficacy of three permit regulations (approach speed, approach angle, and encounter duration) to prevent short-term behavioural changes in three cetacean species was measured; 3) rates of compliance of BBWWoperators with current regulations were recorded; 4) BBWW tourists’ expectations of and satisfaction with the industry were investigated; as well as 5) operators’ views on the current permit regulations of the industry All research was conducted between September 2018 and November 2020 in Plettenberg Bay (SA) where two BBWW companies operating two vessels each are active. Three dolphin (bottlenose, common and humpback dolphins) and three whale (Bryde’s, humpback and southern right whales) species are targeted by the industry, and were encountered during this study. , Thesis (PhD) -- Faculty of Science, School of Environmental Sciences, 2022
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- Date Issued: 2022-04
The foraging ecology of female Cape fur seals (Arctocephalus pusillus pusillus) in South Africa
- Authors: Botha, Jonathan Aubrey , Kirkman, Stephen , Lombard, Amanda
- Date: 2022-04
- Subjects: Seals (Animals)--Habitat—Conservation , Marine ecology—South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/55965 , vital:54559
- Description: The marine environment is spatially and temporally dynamic and many marine ecosystems are experiencing impacts of broad-scale climate change. Within these ecosystems, marine predators play a crucial role in ecosystem function through their top-down influences on prey populations. These predators may also respond to bottom-up influences and changes at lower trophic levels. A thorough understanding of marine predator foraging ecology is thus important to improve our understanding of ecosystem function, inform conservation and management measures, and to predict the response of predators to future environmental change. The Cape fur seal (Arctocephalus pusillus pusillus) comprises a major proportion of the southern African marine predator biomass. However, little is known about the foraging distribution and behaviour of the species, despite its obvious importance within the ecosystem and increasing concerns regarding seal-fisheries conflict. Using a variety of technologies, including, GPS and satellite-linked tags, dive behaviour recorders, accelerometers and stable isotope analysis, this thesis investigated the foraging ecology of female Cape fur seals breeding on the coast of South Africa. First, to identify important foraging areas and assess the influence of geographic, temporal and environmental factors on these areas, lactating females from three breeding colonies were fitted with GPS or Argos-linked tracking devices, while individuals from two of these colonies were also fitted with dive behaviour recorders. Results revealed geographic differences in the foraging distributions and ranges of individuals between breeding colonies, which likely reflects a combined influence of ecological setting and density dependant competition. In addition, dive behaviour recorders revealed the occurrence of benthic foraging at both sites where they were deployed, and the dominance of this strategy in some individuals. , Thesis (PhD) -- Faculty of Science, School of Environmental Sciences, 2022
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- Date Issued: 2022-04
Spatial analysis of the impact of human activities on the marine environment in Algoa Bay, South Africa
- Authors: Maphoto, Tidimalo Mary Anne
- Date: 2021-10-29
- Subjects: Marine resources conservation Algoa Bay South Africa , Spatial analysis (Statistics) , Human ecology , Nature Effect of human beings on , Marine ecology Algoa Bay South Africa , Integrated coastal zone management Algoa Bay South Africa , Marine spatial planning Algoa Bay South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192086 , vital:45194
- Description: Background: Humans have a long history of using the marine environment in multiple ways and continued use has led to a decline in the ecosystem services provided by marine systems in many places. In addition, human activities have steadily increased with time and advances in technology, further increasing impacts on marine systems. To understand and manage these impacts, we need to assess the spatial distribution and intensity of human activities in the marine environment, and quantify, where possible, their cumulative impacts on marine ecosystems. The spatial consideration of human activities and their associated impacts is important for conservation planning, Integrated Ocean Management and Marine Spatial Planning (MSP) initiatives. The main deliverable of this research study was to develop a cumulative impacts layer of human activities in Algoa Bay, South Africa, to support the Algoa Bay Marine Spatial Planning Project. Objective and Relevance: This research analyses the spatial impacts of human activities on the Algoa Bay marine environment (excluding the seashore). Algoa Bay is located on the south coast of South Africa in the Eastern Cape. The research explores stakeholders' perceptions of their knowledge of the human activities that take place in the bay. This research is informed by an expert-based geographical information systems (GIS) approach and cumulative impact assessment in order to map the spatial impacts of the activities as part of marine spatial planning. "Experts" were defined as stakeholders that contributed valuable knowledge of the human activities and their impacts; this definition of expert included "professional" and "non-professional" contributors to knowledge. The spatial aspect of the research is a significant contribution to the field as it will help inform decision-making in the Algoa Bay Marine Spatial Planning Project. Design and Methods: A mixed-method approach was used to generate data. A snowball sampling approach was used to identify research participants from key informants. Primary data were collected through questionnaire surveys, interviews and a focus group. Secondary data sources consisted of GIS data and reports from scientific organizations. Findings and Conclusion: The research findings indicate that the top three pressures that cause the greatest impact on the Algoa Bay marine environment are fishing, pollution and shipping. The cumulative impact of these activities was highest near harbours in Algoa Bay. The marine ecosystems that were most impacted by pressures were the Agulhas Island and the Agulhas Mixed Shore. The Warm Temperate marine ecosystems had fairly low cumulative impacts. The research findings indicate that there is a complex mix of human activities that impact the marine environment. This research supports the findings of other researchers that reveal that the highest cumulative impact is in areas closer to the coast and harbours owing to high population densities. Value of Study: This study builds onto the existing data by expanding the knowledge base and including more stakeholders to integrate as many human activities as possible and bring a holistic picture of the ocean's uses to inform MSP in Algoa Bay. , Thesis (MSc) -- Faculty of Science, Geography, 2021
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- Date Issued: 2021-10-29
Spatial fisheries management options for inclusion in marine spatial planning in South Africa
- Authors: Reed, Jodie Romay
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/52068 , vital:43451
- Description: Integration of sectoral based management into a coherent and coordinated spatial management framework is one of the central challenges of marine spatial planning ȋMSPȌǤ MSP initiatives aim to provide operational frameworks to promote sustainable use of the economic potential of the ocean while maintaining the value of marine biodiversity and the integrity of marine ecosystems to provide servicesǤ The ecosystem services associated with fisheries in terms of food and job provision are some of the most well recognised and highly valued in the marine realm and maintaining these benefits depends on a holistic understanding of the ecosystemǡ human uses and the management thereofǡ including areaǦbased managementǤ In ͲͰͱǡ South Africa was the first African country to enact MSP legislationǤ The development of MSP was advanced through a Presidential ocean economy initiative ȋOperation Phakisaǣ Oceans EconomyȌ that aimed to fast track marine transport and manufacturingǡ aquacultureǡ and the development of oil and gasǡ small harbourǡ and coastal and marine tourismǤ A dedicated ocean governance component was included to develop an overarchingǡ integrated ocean governance frameworkǤ The absence of fisheries in the plans and initiatives was conspicuousǤ The implementation of MSPǡ howeverǡ provides an opportunity to safeguard the ecosystem services provided by fisheries but only if the interests of fisheries can be adequately reflected in spatial plans and analysesǤ Furthermoreǡ the implementation of MSP may provide new opportunities for innovation in spatial approaches to local fisheries management that could address numerous spatial conflicts that have been reportedǤ Integration of spatial fisheries management approaches into MSP can also support the implementation of ecosystemǦbased management ȋEBMȌǡ by including mechanisms such as habitat protectionǡ effective management of areas important for vulnerable life history stagesǡ and bycatch managementǤ This study aimed to identifyǡ assess and further develop spatial management options for fisheries to facilitate the integration of fisheries management and MSPǤ This was achieved by firstlyǡ identifying existing spatial management instruments and assessing the way in which these instruments may be implemented to support spatial fisheries managementǤ Secondlyǡ the application of two contrasting spatial management optionsǡ applied to two pelagic fisheriesǡ was examined to assess their effectiveness at achieving fisheries management objectives with a focus on bycatch reductionǡ while minimising the costs to the fisheries. , Thesis (PhD) -- Faculty of Science, Ocean Sciences, 2021
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- Date Issued: 2021-04
A trait-based approach to identify indicators for measuring rocky reef ecosystem condition in South Africa
- Authors: Smit, Kaylee
- Date: 2020
- Subjects: Environmental management -- Evaluation , Environmental monitoring -- Methodology Marine ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/49292 , vital:41618
- Description: An important yet challenging task for effective ecosystem-based management of marine ecosystems is the reliable measurement and monitoring of changes in ecosystem condition. In South Africa, the National Biodiversity Assessment (NBA) has relied on cumulative pressure mapping, based on the calculation of cumulative impact scores, as a proxy for measures of marine ecosystem condition. While this method is practical for broad scale assessments where ecological data are lacking, there is a need to groundtruth this approach at local scales using in-situ data. The aim of this thesis was to identify potential indicators that can be used to measure the ecosystem condition of subtidal rocky reefs on the East coast of South Africa to groundtruth national pressure-based condition assessments. This thesis constituted the first attempt to conduct a comprehensive assessment of rocky reef ecosystem condition to validate national pressure-based assessments in South Africa. Based on a comprehensive literature review, a traits-based approach was selected to ensure that ecosystem structure and function were included in condition measurements. Fish and benthic community data were collected using baited remote underwater stereo-video systems (144 video samples) from the Natal Shelf ecoregion. Sampling spanned a gradient of low to high human pressures, which incorporated an effective Marine Protected Area (to define reference conditions), as well as areas exposed to intermediate levels of human pressures and a highly impacted area offshore of a large metropolitan port city. Structural and functional indicators were compared among localities and suitable functional indicators were aggregated into multimetric indices (MMIs) to provide an integrated measurement of ecosystem condition. Approximately 840 benthic biota and 10 400 fish (representing 176 identified fish species) were counted. Results showed that functional indicators, particularly size-based ones, were more effective at detecting changes in ecosystem condition compared with structural indicators based on taxonomy. Reefs in good ecological condition had a higher biomass of target species and a higher proportion of large predatory fish with more adults, compared with impacted areas. Benthic communities, however, appeared less responsive to cumulative pressures. The MMIs, using fish and benthic community data, were used to compare condition categories with those from the NBA. Results showed that the pressure-based assessments provided a reasonable proxy of broad patterns of rocky reef ecosystem condition. However, fine-scale discrepancies between results from the data-driven approach versus the proxy method suggested that broad-scale proxies might overestimate condition in some areas and underestimate it in others. To build on these results, the applicability of structural and functional indicators and MMIs were tested using an independent stereo-BRUVs dataset from the Agulhas Shelf ecoregion. Findings showed that not all MPAs were in good ecological condition compared with adjacent impacted areas, as was estimated by the NBA. However, there is a need to improve the quality of trait data and to test indicators and indices in other ecoregions, ecosystem types and in response to a broader range of improved pressure data. Furthermore, there is a need to apply innovative research to guide the calculation of thresholds for condition categories to advance condition assessments.
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- Date Issued: 2020
Involving fishermen in seabirds’ conservation: bridging the gap between socio-economic needs of industry and the needs of seabirds
- Authors: Ginsburg, Tayla
- Date: 2019
- Subjects: Sea birds -- Ecology , Island ecology Island animals -- Conservation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/42184 , vital:36633
- Description: Marine ecosystems and species face multiple threats, particularly intensive industrial-scale fishing activities. As the human population continues to increase exponentially and drive a greater demand for food, commercial fishing effort will likely intensify. While terrestrial protected areas are well developed, marine protected areas (MPAs) are less so, both in the area covered and management practices. There is currently a drive to increase the extent of MPAs, both globally and in South Africa, particularly for those ecosystems and marine species that can benefit from area-based management. The size, shape, location zonation of MPAs generally remain static through time. However, the ocean is a dynamic environment and static MPAs are not always able to achieve conservation objectives for their component ecosystems and species. Dynamic Ocean Management (DOM) is an approach that integrates near real-time data on biological, oceanographic, social and/or economic variables to adjust an MPAs boundary and zonation in both space and time. The aim of this thesis was to assess the viability of applying DOM to a fishing exclusion zone within a zoned MPA in Algoa Bay, South Africa, to support conservation objectives for the Endangered African penguin Spheniscus demersus. Algoa Bay supports half of the world’s remaining population of this species. First, the degree of spatial overlap between foraging penguins and purse-seine fishers in Algoa Bay was determined over five years. In all years, purse-seiner fishing vessels were located around or near to St Croix Island and a large proportion of the total pelagic fish catch from the Bay was removed from this area. Breeding penguins travelled significantly further while foraging when the overlap (and subsequent competition for pelagic fish) was higher, suggesting that African penguins would benefit from a fishing exclusion zone around St Croix Island owing to reduced competition. However, an exclusion zone can have socio-economic impacts on fisheries as a result of the lost fishing area. A common concern raised by fishers is the direct loss of income, either as a result of increased fuel costs to reach alternate fishing grounds or decreased catch. An analysis of catch and travel time (as a proxy for fuel costs) when a 20 km exclusion zone was present or absent around St Croix Island revealed that the exclusion zone scenarios had no significant impact on either variable. Interviews with individuals in the local purse-seine fishery (both fishers and factory managers) showed a consensus that the marine environment needs protection and that MPAs have various environmental benefits. Despite this, individuals were concerned about how they would be impacted by the exclusion zone in the MPA. The interviews highlighted the willingness of individuals in the purse-seine fishery to talk to and work with scientists.
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- Date Issued: 2019