Browsing by Author "Gammage, Louise"

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    Cretaceous bryozoan fossils from Needs Camp, South Africa
    (2023) Duma, Nothando; Gammage, Louise
    Fossil Bryozoa in South Africa is understudied and has received little attention, despite the country's very rich geological and fossil heritage conservation. Published literature regarding bryozoan fossils from South Africa comprise of four papers with the most recent being a little over two decades old. The upper and lower Needs Camp quarries in the Igoda Formation, situated about 20 km northwest of East London, is of great scientific importance, necessitating that the sites be preserved for the purposes of research. The Needs Camp fossils include corals, foraminifera, bivalves etc. and date the deposits to the Late Cretaceous. Gaps in the fossil record hamper efforts to understand important geological events and palaeoenvironmental conditions. This study aims to examine and identify some bryozoans from the Needs Camp fossil deposits lodged in the marine invertebrate collections of the Iziko South African Museum, Cape Town. The approach will be a combination of traditional morphological methods and cutting-edge scanning electron microscopy (SEM) technology. Limestones were dissolved by water, the fragments and fossils extracted from the stone were sieved and placed in an ultrasonic bath. These were left to dry then later examined under a light microscope, after they were separated into broad categories according to their colony form and examined using the SEM. In total, 14 species were identified from this study, of which ten were identified to genus-level. Genera reported for the first time in South Africa from this study, include Supercytis, Onychocella, Aechmella, Ogiva, Gastropella, Chiplonkarina, Pithodella, Wilbertopora, Hoplocheilina, Tremogasterina and Bountyella. Keywords: Bryozoa, fossils, Needs Camp, Late Cretaceous, scanning electron microscopy
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    Social vulnerability of fishing communities in the southern Cape to change, including additional pressures of COVID-19
    (2025) Netshithuthuni, Humbelani; Gammage, Louise; Ward, Catherine
    Marine systems are critical for providing support to the lives and livelihood of millions of people including small-scale fishers (SSFs). However, these communities are faced with many challenges such as resource scarcity, climate change and variability, policy and regulation and the more recent COVID-19 pandemic. This dissertation examines the social vulnerabilities of SSFs in the southern Cape, particularly in the two fishing towns of Bitouville and Melkhoutfontein, to better understand how challenges impact the ability of SSFs to support their livelihoods and how this has changed over the last 10 years. This research made use of a mixed-method technique that included both qualitative and quantitative aspects, drawing on the Global Understanding and Learning for Local Solutions (GULLS) survey that was first implemented in 2013/14 and amended to suit the local context of the southern Cape, which was administered through face-to-face interviews in 2023. Social vulnerability scores were calculated in line with the GULLS framework to gain a deeper insight into the vulnerabilities faced by SSFs and how these have evolved over the last decade. In both Bitouville and Melkhoutfontein communities, vulnerabilities of SSFs were exacerbated by the more recent COVID-19 pandemic, which led to the loss of income sources and available sea days, which in turn contributed to food insecurity. Regarding the evolution of the drivers of changes in 2013/14 and 2023, the results of this study revealed an increase in the social vulnerability scores in both Bitouville and Melkhoutfontein over time as a result of increased exposure to challenges linked to resource scarcity, climate change and variability, and policy and regulation. For example, the continued delay in the implementation of South Africa's small-scale fishing policy (SSFP) has contributed to increased vulnerability as this impacts SFFs' access to fishing rights. The results also revealed that SSFs in Bitouville faced more vulnerabilities compared to their counterparts in Melkhoutfontein, which was attributed to their higher social dependency on fishing, limited livelihood opportunities, higher exposure to environmental changes, and lower adaptive capacity. The vulnerability of these two fishing communities is thus increasing due to compounding stressors such as resource scarcity, climate variability, the COVID-19 pandemic and policy and regulation. This research highlighted the importance of improving the adaptive strategies of SSFs, as limited improvement in these strategies places the livelihoods of these fishing communities at greater risk and exacerbates vulnerabilities in the important, livelihood-intensive southern Cape fisheries.
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    Testing of a standardised protocol for visual health assessment of southern right whales (Eubalaena australis)
    (2023) Moles, Matej; Gammage, Louise
    Since the late 1960s, southern right whales (Eubalaena australis) have been studied extensively in their coastal calving grounds (including South Africa). These studies have indicated a strong recovery of the species post-whaling. However, in most recent years, a decrease was observed in reproductive rates and coastal prevalence of the South African population, raising concerns about continued population recovery. As reproductive success and the migratory behaviour of this capital breeder is strongly mediated through body condition and overall health, understanding the past and current state of these parameters is crucial in understanding the observed population-level changes. The aim of this project was to build on the global, standardised qualitative visual health assessment protocol (Charlton et al., 2021), and assess the different parameters in relation to quantitative data on body condition. A dataset of 78 non-unique whales photographed in September of 2019 and 2021 was used for the analysis. Results showed that there is a moderate relationship between qualitative and quantitative body condition measurements, but only on 2 levels. This suggests that body condition of southern right whales can be scored visually relatively accurately to be either good or poor, allowing retrospective analyses of historical aerial images. Results of the study further showed that the other visual health parameters, known to be indicators of health in the species, did not correlate with quantitative, nor qualitative measurements of body condition. This suggests that, at least in South African southern right whales, poor body condition does not necessarily reflect poor health, and that thus all health parameters need to be evaluated in order to assess health condition of individual whales. This study advances our knowledge and understanding of how to assess visual health in southern right whales and concludes that body condition alone may not be enough to detect individuals in poor health.