https://www.um.edu.mt/library/oar/handle/123456789/131569 Wed, 22 Apr 2026 11:33:23 GMT 2026-04-22T11:33:23Z https://www.um.edu.mt/library/oar/handle/123456789/143493 Title: Linking lampuki (dolphin fish) catches to environmental and satellite data Abstract: The Mediterranean Sea supports numerous small-scale fisheries and habitats, which is essential for economies, cultural heritage, and food security. The Lampuki (Coryphaena hippurus) fishery, which uses conventional fish aggregating devices (FADs), is one of the most iconic in Malta. However, recent catch decreases raise questions with regards to fishing pressures, climate change, and environmental variability. This study investigates whether environmental variability, particularly sea temperature, chlorophyll-a (chl-a) concentration, and current speed, acts as a primary driver of Lampuki catch fluctuations in Maltese waters, we test the hypothesis that changes in sea temperature, chl-a concentrations, and current speed alter Lampuki distribution and abundance, leading to corresponding changes in catch rates in Maltese waters. Fishery records from 2019 to 2024 were integrated with satellite-derived and modelled environmental data from the Copernicus Marine Service across depth layers (1 to 1000m). Catch weight was analysed at the General Fisheries Commission for the Mediterranean (GFCM) subarea level and catch per area (CPA) was calculated to enable comparison among regions of varying sizes. Environmental variables included temperature, salinity, oxygen, currents, and chla. The Pearson correlation was then used to assess the relationship between these variables and catch variability. The findings demonstrated a considerable drop in catches over the past few seasons in all geographic sub-areas (GSAs), with reductions of ~69% from 2019 to 2024. Temperature exhibited the strongest positive correlation with catches (r = 0.34 - 0.59 across GSAs), whereas chlorophyll-a consistently showed negative correlations (r = -0.32 to -0.57). Current speed displayed weaker and spatially inconsistent relationships. These findings show the importance of integrating real-time environmental monitoring to understand environmental drivers and any occurring fluctuations. The results give a scientific basis for adaptive management, e.g., refining FAD deployment strategies and monitoring Lampuki availability with the ever-changing oceanic conditions. Description: M.Sc.(Melit.) Wed, 01 Jan 2025 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/143493 2025-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/138768 Title: Stratigraphic insights and geospatial reconnaissance of Ta’ Ghammar Hill, Gozo : unravelling earth’s chronological tapestry through advanced remote sensing illuminating millennia of mystery : where cutting edge technology meets the timeless story of stone Abstract: This research examines the geological structure of Ta’ Ghammar Hill, an underexplored hill in Gozo, Malta. The geological stratigraphy of these sites remains poorly documented, despite its critical role in the formation of perched aquifers. These aquifers, present in Gozo’s smaller hills, remain uncontaminated due to the absence of agricultural and industrial activity on the plateaus, many of which have been abandoned altogether. Sites like Gelmus, Ta’ Kuljat, Ghar Ilma, Nuffara and the study area, should all contain the necessary geological members needed for this aquifer to naturally form, but their subsurface structure remains largely unknown. For detailed subsurface stratigraphy analysis, the study integrates Unmanned Aerial Vehicle (UAV)-based photogrammetry and the (Horizontal to Vertical Ratio (H/V)) methods, ensuring high-resolution mapping of geological formations. The research successfully delineates the boundary between the Upper Coralline Limestone and the underlying Blue Clay Formation, a crucial interface for perched aquifer development. Validation against Planning Authority LiDAR and orthophotos datasets demonstrates both accuracy and feasibility of the methodology of the photogrammetry results and the H/V curves which contain a level of uniformity within all the results and also conform to other studies done in Malta. The findings from the photogrammetry, H/V and synthetic H/V reveal a coherent geological structure which in theory is capable to store water, a fact corroborated by numerous of vegetative indicators such as the dense giant reed growth, suggesting active groundwater retention present at ta’Ghammar. These insights offer a compelling case for including small hills like Ta’ Ghammar in water resource planning and conservation strategies in Malta. More broadly, the study highlights a replicable and most importantly cost-effective methodology of identifying the stratigraphy Description: B.Sc. (Hons)(Melit.) Wed, 01 Jan 2025 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/138768 2025-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/138767 Title: Thermal echoes : refining land surface temperature monitoring over the Maltese island Abstract: This research investigates Land Surface Temperature (LST) variations across the Maltese Islands using satellite remote sensing validated with in-situ observations. The main objective is to assess the accuracy and spatial variability of LST derived from Landsat 8, MODIS (Terra and Aqua), and Sentinel-3 satellites by comparison with ground-based measurements. Emphasis is placed on examining how rural and urban land use types influence the formation of urban heat island (UHI) effects. Monthly ground observations were conducted over a six-month period, cap turing both morning and nighttime conditions to assess diurnal temperature variation. Meteorological parameters such as humidity, wind speed, and wind direction,were also recorded to analyse their relationship with satellite in-situ LST discrepancies. Satellite derived and in-situ LST measurements showed strong correlations across all platforms. In the morning, Landsat 8 exhibited a slight positive mean bias (+1.04 °C), indicating a minor overestimation, whereas MODIS and Sentinel3 underestimated temperatures (-3.82 °C and -1.89 °C respectively). Despite these biases, high correlation coefficients (0.82 to 0.85) confirmed satellite reliability. Nighttime observations initially revealed significant negative biases for MODIS (-6.91 °C) and Sentinel-3 (-6.89 °C). After applying corrections, residuals reduced substantially, approaching zero, and correlation (r value) strengthened (0.87 for MODIS, 0.75 for Sentinel-3), significantly improving nighttime LST accuracy. Urban and rural areas exhibited distinct thermal patterns, with a pronounced nighttime UHI effect as urban regions retained more heat. Interestingly, daytime patterns reversed seasonally, with rural zones warmer than urban areas during hotter months due to sparse vegetation and soil exposure, highlighting the importance of land cover and solar geometry Description: B.Sc. (Hons)(Melit.) Wed, 01 Jan 2025 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/138767 2025-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/138764 Title: Seasonal variability of sea temperature profiles in the central Mediterranean Abstract: This study investigates the seasonal variability of sea temperature profiles across eight purposefully chosen sites in the Central Mediterranean, with a focus on how stratification and internal structures such as the thermocline, respond to surface warming and regional oceanographic processes. Using two years of high-resolution numerical temperature data, the analysis explores temporal and spatial differences in temperature profiles, gradient profiles, thermocline depth, thickness, intensity, and boundary limits. A range of statistical techniques, including Pearson correlations, cross-correlation analysis, autocorrelation and partial autocorrelation functions, were used to explore the links between both sea surface temperature and thermocline features, as well as between thermocline depth and other thermocline metrics. Results revealed consistent seasonal cycles, with weak stratification and deep mixing during winter, and a sharp, shallow thermocline forming in summer. While this seasonal signal was evident across all sites, numerous regional differences emerged where some sites exhibited deeper and more stable thermoclines whilst other locations demonstrated more variable behaviour, often influenced by mesoscale features such as eddies or coastal currents. Sea surface temperature was linked to a thicker, stronger, and shallower thermocline, with temperature changes at the surface typically preceding changes in subsurface structure. Thermocline depth also showed strong internal associations, reflecting how its position influences both the range and sharpness of the stratified layer. The autocorrelation and partial autocorrelation results showed that thermocline features typically follow a strong yearly pattern, where values tend to repeat from one year to the next, and summer conditions are usually the opposite of those in winter. These findings support the study’s hypothesis that seasonal heating, modified by regional mesoscale circulation and dynamics, drives the evolution of temperature stratification. The results contribute to a more refined understanding of thermal structure in semi-enclosed seas and provide a basis for future forecasting or modelling efforts concerning stratification dynamics. Description: B.Sc. (Hons)(Melit.) Wed, 01 Jan 2025 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/138764 2025-01-01T00:00:00Z