Fugro (United Kingdom)

Overfishing is a key barrier to sustainable fisheries management in South Asia. Focusing on Sri Lanka’s tuna sector, this article examines how global value chain dynamics interact with local socio-economic realities, national fisheries policy and institutional constraints, and regional governance mechanisms—and the gaps within them—to perpetuate unsustainable fishing practices. Our analysis provides four actionable insights for lead buyers, fishing communities, and policymakers, including aligning market incentives with sustainable fishing practices, empowering fishers as ocean stewards, integrating science-based management into national policy, and fostering regional cooperation. These insights offer pathways to promote a resilient blue economy and advance progress toward UN Sustainable Development Goal 14.

The dynamics of dissolved inorganic carbon (DIC), stable carbon isotopes of DIC (δ13CDIC), and anthropogenic CO2 (CO2ant) in the upper 500 m of the water column were examined in two upwelling-favourable regions: the Sri Lankan Dome (SLD) and the central Bay of Bengal (BOB) in the Northern Indian Ocean over the period 1995 to 2016. This study aimed to investigate the spatiotemporal variability of these carbon parameters and assess the influence of CO2ant in these oceanic environments. Data from the GLODAPv2.2022 database, including cruise-based biogeochemical bottle measurements, were utilized to examine temporal trends in DIC and δ13CDIC. The TrOCA (Tracer combining Oxygen, Carbon, and Alkalinity) approach was employed to calculate CO2ant. Although DIC concentrations showed minimal variability across the water column in both the SLD and central BOB, significant fluctuations in CO2ant and δ13CDIC were observed in the upper 50 m in both regions between 1995 and 2016. Specifically, δ13CDIC values in the upper 50 m decreased by 0.45 ‰ (at a rate of 0.021 ‰ yr-1) in the SLD and by 0.41 ‰ (at a rate of 0.02 ‰ yr-1) in the central BOB over the study period. This decline is likely attributable to the combined effects of upwelling of remineralized DIC and increased CO2ant invasion in the upper 50 m of these oceanic regions, occurring at rates of 0.93 µmol kg-1 yr-1 in the SLD and 1.97 µmol kg-1 yr-1 in the central BOB. Additionally, a weaker correlation between δ13CDIC and CO2ant was observed in the central BOB, whereas a stronger correlation in the SLDsuggests that the invasion of isotopically lighter CO2ant contributed significantly to the observed depletion of δ¹³CDIC in both regions from 1995 to 2016. These findings underscore the significant role of anthropogenic CO2 in influencing carbon dynamics in the upper ocean of these upwelling-prone regions.

An automated water sampling device was developed to collect environmental DNA (eDNA) in aquatic environments with minimal human intervention. Dartmouth Ocean Tech-nologies Inc. (DOT) and NatureMetrics have collaborated to produce an eDNA Sampler equipped with NatureMetrics filters to achieve higher volume filtration. The “DOT-NM eDNA Sampler” demonstrated significantly improved filtering capabilities during benchtop testing when tested in parallel with a standard DOT eDNA Sampler loaded with comparable filter membranes. After benchtop testing, the unit was deployed for a 5-day period in Portchester, UK. A parametric study was performed using different sampling volumes: 1 L, 2 L, and 5 L. Results show that significantly-larger volumes are possible before filter clogging. Metabarcoding analysis of samples revealed a similar number of eukaryotic species detected for each of the three tested volumes. The same analysis, however, revealed a positive correlation between the number of vertebrates detected and the sampled volume. This result highlights the benefit of higher filtration volumes when using environmental DNA sampling to identify vertebrates in an environment.

Analysis and calculation of lateral pile load capacities using appropriate methods is a challenging task for geotechnical engineers. Primarily, piles in Dubai, UAE, are rock fully socketed with top strata of medium dense to dense silty sand or sedimentary rock resisting lateral loads. In this study, the results of two field pile lateral load tests were chosen for examining different methods used by local geotechnical engineers, where ground lithology constitutes fragile sandstone up to ∼8 m below ground level overlying extremely weak conglomerate/siltstone. Assessing the efficacy of design parameters and analysis methodology is a pivotal aspect in preliminary evaluation of the lateral load capacity of piles. In this research, two commonly adopted approaches (non-linear p–y analysis using the LPile software and finite-element analysis using the Plaxis 3D software) were assessed by comparing them with field test results to predict the lateral load capacity precisely. Design parameters were based on borehole data and laboratory tests near the test location. Even though finite-element analysis predicted better than non-linear p–y analysis, lateral load capacities were underestimated in both piles analysed, which was related to assessment of input parameters. In addition, finite-element analysis was used to back-calculate the elastic modulus of rock that yields lateral deflections of piles close to field test results.

Abstract The Regional Ocean Modeling System (ROMS) is a free-surface, terrain-following, primitive equations ocean model and it was implemented to perform a high-resolution 10-year hindcast study of Solomon’s Sea circulation patterns. The model was executed with a resolution of 1/36°, initial conditions from HYCOM+NCODA Global 1/12° and was forced by CFSR/CFSV2 momentum, mass and heat fluxes. The model was validated by comparing the simulated temperatures, salinities and flow patterns with satellite data, Argo floats and Ship ADCP measurements. In general, the model captured the main circulation patterns and performed well for the Solomon Sea. The modelled Temperature and Salinity profiles were comparable with the observations, with some error variability in the thermocline layer, which agreed with previous studies.

Geotechnical design of tunnels requires a level of precision and accuracy in the determination of subsurface parameters that is more rigorous than most applications of geophysical logs. Misunderstanding of the geo-mechanical and hydraulic properties can slow tunnel construction, increase risk and cost, and in the worst cases, leads to failure of tunneling equipment and excavation support with potential catastrophic results. As such, these projects demand a wealth of measurements of the subsurface by geophysical means. Establishing the nature and condition of ground and groundwater that will impact upon the proposed alignment and associated structures is key. This sometimes can be accomplished by near-surface techniques, but many complex geologies require high resolution borehole measurements to fully understand the setting for intended projects. As a case study, we present work done in the planning of a nearshore cable tunnel for the National Grid beneath the Menai Strait in North West Wales, United Kingdom. Advanced wireline logging was conducted in nine boreholes along the proposed project. The expansive suite of logs, including borehole magnetic resonance (BMR), optical and acoustic televiewer, orientated four arm caliper, gamma-gamma density and full-waveform sonic led to an accurate understanding of the rock strength and geo-mechanical properties (Figures 1, 2 and 4). The suite of downhole logs provided for a comprehensive interpretation of the subsurface and allowed confidence in future planning and design. BMR was particularly useful in identifying secondary porosity and permeability in this fractured formation. These quantitative results were qualitatively supported by image logs showing the fracture network (Figure 2 and 3) and gamma-gamma density logs that showed decreased response in the fractured regions. Permeability indications were also measured by in-situ geohydraulic permeability tests using packers, which further corroborated the geophysical measurements. Double packers were used to test discrete areas (3-meter to 4-meter long zones) along specific sections of the borehole. The in-situ permeability results can be used to refine and support the BMR data to provide continuous data for the whole borehole length. This was successfully accomplished, strengthening the known concept of partially replacing in situ permeability tests with BMR wireline data acquisition.

The geomorphological character of Selmun is primarily defined by the tectonic structure, geological outcrops and the supply of sediments to the coastal zone. The geomorphology becomes remarkably varied within hundreds of metres and displays diverse inland and coastal landforms. Contrasting topography—with high plateaux and valleys—offers an outstanding scenery with various strategic viewpoints such as islets, rocky headlands, narrow bays, pocket beaches, shore platforms, ‘rdum’ (scree slopes), valleys and subsidence structures. Located on the north-eastern part of Malta, Selmun also offers shelter to a variety of protected endemic habitats from coastal vegetated sea cliffs to Holm Oak woodlands, through the provision of three Special Areas of Conservation (SAC). Against this natural backdrop, this rural site also represents a long history of anthropogenic land uses which aimed to maximise the possibilities offered by the diverse landforms such as historical military defence at strategic heights and viewpoints to guard numerous embayments, agricultural terracing on fertile sloping hills and valleys, and salt harvesting on shore platforms. With the presence of St Paul’s Islands, this area is also mentioned in an important biblical narrative which is related to the early conversion of the Maltese to Christianity. Selmun can thus be truly considered as a representative niche of diversity in the Maltese rural geomorphological landscape and demonstrates how both the land use and history unfold through the opportunities offered by such a natural landscape.

Methane gas recovery from gas hydrate–bearing sands requires dissociation of the hydrate. Understanding changes in the stiffness of the sand is essential if future production scenarios are to be modelled realistically. This paper reports the results of resonant column tests conducted to measure changes in shear and flexural Young’s modulus (stiffness) of sand specimens during the formation and dissociation of hydrate within the pore space. Factors such as hydrate saturation, effective stress, and dissociation method (thermal stimulation and depressurization) were evaluated. Results show a nonlinear relationship between stiffness and hydrate volume, with hydrate formation and dissociation giving markedly different changes in stiffness. Stiffness increases more slowly during the initial stages of hydrate formation, compared to later stages, with the eventual stiffness being independent of the effective stress applied at the start of formation. In contrast, the onset of dissociation leads to a rapid reduction in stiffness, with thermal stimulation giving a greater reduction compared to depressurization for similar changes in hydrate volume. These results highlight the impact of hydrate morphology on changes in stiffness during the hydrate formation process or its dissociation. We present and discuss a conceptual model to explain the differences observed.

Abstract As oil and gas developments move into deeper waters, potential exposure to geohazards becomes an important project risk driver. Landslide deposits and features observed on the seabed in the vicinity of potential future development indicate processes that were active in the geological past and can be expected to continue in the future. Rapid yet spatially extensive analysis of landslide risk is a key requirement of the geohazard assessment for many oil and gas developments, with an aim to provide an estimate of the annual probability of slope failure across the entire proposed development area as an input to the QRA. Well‐established methods exist for probabilistic assessment of slope stability through GIS‐based application of a limit equilibrium infinite slope geomechanical model. Shear band propagation is an effective mechanism to explain large landslides observed in the sediment record that cannot be explained through limit equilibrium alone. A novel GIS‐based probabilistic slope stability assessment using SBP approach allows for improved pixel‐based estimates of the annual probability of failure for a variety of observed landslide mechanisms, such as slab, spreading, ploughing and run‐out failures. This GIS‐based tool has been successfully employed as part of a landslide risk assessment of the ACG development, Caspian Sea, contributing to a landslide risk score for each geohazard province within the area.