Current Research on Geography, Earth Science and Environment Vol. 3

Last 145 kyr Sea-surface Evolution in the Newfoundland Basin of the Northwest Atlantic: Insights from Sedimentology and Micropaleontology

Harunur Rashid — 2025-09-25

The Newfoundland Basin lies on the southeastern Grand Banks of the Northwest Atlantic, a key area where the exchange between subpolar and subtropical gyres takes place. Dramatic seasonal changes occur in the sea-surface temperature, salinity, and freshwater input due to the interaction between the cold and fresh Labrador Current and warm and salty North Atlantic Current (NAC) on the southeast Grand Banks. Due to this interaction, the biological productivity and seasonal stratification of the upper water masses are intensified. Such changes must have been more drastic during glacial times, due to the penetration of the Polar and Arctic fronts and the southward migration of the Gulf Stream/NAC. However, the extent to which such changes impacted the sea-surface characteristics in the Newfoundland Basin is poorly known. This study reports changes in the sea-surface characteristics using a sediment core (Hu9007-08) collected from the Milne seamount during the last 145,000 years. Sediment processing involved sample washing, ice-rafted debris (IRD) counts, and planktonic foraminifer census, as well as determination of oxygen and carbon isotopes, ¹⁴C-AMS dating, and age model construction. A total of 19 control points were used to construct the age model, in which linear sedimentation rates between the ¹⁴C-AMS date points were considered. Heinrich layers H1, H2, H4, and H5, as well as H11, were identified within MIS 3 and at the penultimate deglaciation by IRD and Neogloboquadrina pachyderma peaks, along with lighter oxygen isotopes. The rapid turnover of foraminiferal species with distinct depth habitats and ecological niches in the mixed layer and thermocline suggests an interplay between the polar and subpolar water masses during both Heinrich and non-Heinrich periods. Only two North Atlantic-wide cooling events, C24 and C21, in which the latter event is linked to the minor IRD peak during the marine isotope stage (MIS) 5 in Hu90-08, compared to eight cooling events in the eastern subpolar gyre (e.g., ODP Site 984). Millennial-scale N. pachyderma variability in the western subpolar gyre appears to be absent compared to the eastern subpolar gyre during the MIS 3, suggesting the occasional presence of the NAC-borne salty and warm water, implying a contrasting climate state between the western and eastern subpolar gyre. T. quinqueloba, a subpolar species, data are fragmentary; however, there are differences between the western and eastern subpolar gyre in addition to the differences within the western subpolar gyre during MIS 5 that imply a variable influence by the subpolar water. This finding suggests that the NAC influence outweighs the impact of cold and fresh polar water in the northern northwestern Atlantic during the MIS 5. The anti-covariation between N. pachyderma and N. incompta provides a proxy for sea-surface temperature, with the former thriving at temperatures below 8°C and the latter near 12°C. Overall, the data reflect rapid changes in sea-surface characteristics in the western subpolar gyre, driven by a dynamic balance between the Labrador Current and the NAC.

Persistent Organic Pollutants (POPs), Total Suspended Solids (TSS) and Sediment Composition in the Seawaters of Jakarta Bay

Edward — 2025-09-25

This research aimed to monitor water quality by observing total Persistent Organic Pollutants (PAH, OCP and PCB), total suspended solids (TSS) levels, and the percentage of sediment in Jakarta Bay. The study was carried out in March and May 2013. Surface seawater samples were taken with a water sampler at 16 research stations (8 in the west and 8 in the east). PAH, OCP, and PCB were analysed using chromatographic methods, and TSS was determined using the gravimetric method, while sediment composition was determined using the Wentworth and Shepard method. The stored procedure is used to evaluate the status of seawater quality. The results showed that in the west, PAH average concentration ranges from 7.852-36.518 ppb, in the east from 12.451-108.517 ppb, OCP from 7.660-7.852 ppt, in the east from 5.030-6.444 ppt, and PCBs from 3.680-18.183 ppt, in the east from 2.694-9.817 ppt. This concentration has passed the threshold value stated by the Ministry of Indonesia for marine life. TSS concentration in the west ranged from 20.05-30.414 mg/l, in the east from 23.90-34.55 mg/l, which also exceeds the threshold value for biota. Sediment percentage in the west ranged from 91.767-99.056% and in the east from 99.240-99.999%. All stations' water quality ranged from -1.5 to -10, or the Class B category (light polluted).

Growth Analysis of Lannea kerstingii (Anacardiaceae) for Sustainable Forest Management in Northeast Nigeria

Justus Eronmosele OMIJEH — 2025-09-25

Lannea kerstingii (Anacardiaceae) is found mainly in the Guinea and Sudan savannahs and is useful as an agroforestry species and in meeting health benefits. The objective of this study is to close existing gaps in data availability for the purpose of formulating forest policy and planning in the sub-region of the study area. Twenty trees were sampled from fifteen quadrats each measuring 100m*100m and using different approaches, were measured for Diameter at breast height, crown area, crown ratio, height and volume. Statistical analysis of the data generated was carried out using the coefficient of determination(r) and Pearson’s correlation (r²). There were strong positive correlations with basal area and volume, while weaker associations with crown ratio and crown area were observed. Biomass assessment provides relevant data which helps in biodiversity conservation, carbon sequestration, climate change mitigation, climate budgeting and financing, culminating in developing an appropriate framework for forest policy formulation, planning and development.

Estimation and Prediction of Biomass Carbon Stocks in India Using Remote Sensing: Implications for Emissions Reduction and Bioenergy Potential

Praveer Agrawal — 2025-09-25

As the global community transitions towards more sustainable energy sources, bioenergy has emerged as a promising solution, particularly for countries with substantial agricultural resources like India. With its vast reserves of organic waste and residues, India holds significant potential to transform biomass into clean, renewable energy. The objective of this study is to estimate the average availability of biomass in India in the year 2010 and predict it in the year 2025 with the help of high-resolution imagery through Google Earth Engine and GIS, also estimating the release of CO₂ into the atmosphere if the same biomass is not utilised. The analysis utilises NASA’s harmonised global maps of aboveground and belowground biomass carbon density for the year 2010 at a 300-m spatial resolution. The Moderate Resolution Imaging Spectroradiometer (MODIS) product provides information about annual Gross and Net Primary Productivity (GPP and NPP) at 500m pixel resolution. The range of average above-ground biomass (agb) in 2010 varies from 0.5338 - 93.644, below-ground biomass (bgb) 1.015- 22.474, and Total biomass (TBM) 1.5488- 116.118 kg*C/m² as computed from MODIS. Corresponding Total Biomass quantity in year 2010 is 4.39179 billion Ton and CO₂ release in atmosphere is 11.539218400000001 billion Ton. However, the Gross Primary Production is 4.79646005 billion tons. However, prediction was made with NASA imagery in conjunction with Vegetation indices, Land Cover and FPAR/LAI, the results obtained are in the range of average above ground bio-mass (agb) in 2010 varies from 0.000 – 79, below ground bio-mass (bgb) 0.000- 22, and Total bio-mass (TBM) 0- 101 mg/Ha. Corresponding Total Biomass quantity in the year 2010 is 4.112982692983341 billion tons and CO₂ release in the atmosphere is 13.25737496044534 billion tons. However, predicted figures in the year 2025: the above-ground biomass (agb) 85.73578643798828 mg/Ha, below-ground biomass (bgb) 22.05862045288086 mg/Ha, and Total biomass (TBM) 4.83646174936528 billion tons. Correlation and R-squared values are 0.9882423543764696 and 0.9766229509835477. The findings show that remote sensing, being an advanced technology, is quite useful for quick and reliable estimations of vegetation biomass and carbon over large areas. The study highlights that regions such as the Himalayas, North-East India, Eastern states, and the Western Ghats possess particularly high biomass potential. Future biomass research should focus on leveraging advanced technologies, addressing methodological gaps, improving data integration, and ensuring that outcomes are actionable for environmental and policy challenges.

Influence of Environmental Factors on the Seasonal Dynamics of Nitrogen and Phosphorus in Fresco Lagoon, Côte d’Ivoire

Yè Nicaise OUATTARA — 2025-09-25

The Fresco lagoon, one of the essential components of the Ivorian lagoon system and located in the southwest of Côte d'Ivoire, contributes to the economic and tourist development of the country. This study, conducted from June 2019 to May 2020, highlights the strong pressure that the Fresco lagoon is under due to human activities in its watershed. Pollutants from these activities, mainly consisting of organic matter, are released into the natural environment without prior treatment. Then, the mineralisation of organic matter, influenced by the physicochemical factors of the water, leads to a phenomenon of eutrophication, due to the enrichment of the water with nitrogen and phosphorus. Eutrophication is one of the causes of mortality of aquatic biodiversity due to low dissolved oxygen levels. The objective of this study is to monitor the seasonal dynamics of nitrogen and phosphorus nutrients in the waters of two locations in the Fresco lagoon, designated Zone I and Zone II. To do this, the physicochemical parameters were determined using a multiparameter and the ammonium (NH₄⁺), nitrite (NO₂^-), nitrate (NO₃^-) and phosphate (PO₄^3-) contents by spectrophotometric assay. The statistical components such as the mean (m), the standard deviation (s), the coefficient of variation (CV (%)), the minimum value (Min), the maximum value (Max) and the normalised principal component analysis (NPCA) were assessed. The results reveal high temperatures in the long dry season (32.04±0.52°C in zone I and 30.59±0.90°C in zone II), low dissolved oxygen contents in the short rainy season (1.40±0.43mg/L in zone I and 1.78±0.06 mg/L in zone II) and acidic waters in the long rainy season (pH = 6.25±0.08 in zone I and pH = 6.31±0.53 in zone II). Nitrate (16.77±9.82 mg/L) and phosphate (3.28±3.20 mg/L) levels in Zone II are relatively high during the short rainy season and the long dry season, respectively. These high levels characterise a eutrophic environment. Decontamination of wastewater before its discharge into nature, regular monitoring of the health of this ecosystem and public awareness of environmental protection could contribute to improving water quality.

Harnessing Carbon Markets for Climate Justice: A Pathway to Sustainable Development

Jane Munonye — 2025-09-25

As climate and environmental challenges grow increasingly severe, carbon markets have garnered significant attention in academic research. Carbon trading and offsetting are central to these mechanisms, with the primary objective of reducing greenhouse gas emissions. Climate change injustice is the situation where communities that contribute the least to climate change disproportionately bear the severe consequences. The aim of this review is to explore how carbon markets can be utilised as a mechanism to promote climate justice and contribute to sustainable development. By examining various policy approaches and their implications, the research seeks to shed light on how carbon markets can either advance or hinder climate justice goals. The findings indicate that carbon markets have the potential to encourage investments in clean energy and sustainable development projects, which can benefit communities disproportionately affected by pollution. It can provide opportunities for broader participation in climate action, allowing smaller emitters or developing countries to participate in emission trading. To maximise their positive impacts and minimise risks, carbon markets must be accompanied by complementary policies and measures that prioritise equity, inclusion, and community participation. Countries with greater capacity and responsibility for emissions need to take more drastic actions and provide financial and technical support to developing nations.

Geopolymer Composite Materials from Mining and Agricultural Residues for Engineering Applications: Red Mud and Rice Husk Ash

D. Sidibé — 2025-09-25

The transformation of raw materials into finished products generates residues and waste, whose management has become an environmental concern. With industrialisation and increasing material complexity, human activities have led to the exponential generation of waste. The more diverse and synthetic the materials involved, the more challenging it becomes to manage waste in ways that fulfil the dual objectives of protecting human health and the environment while conserving natural resources. In the Bayer process, the reaction of bauxite with sodium hydroxide to produce alumina results in the generation of red mud (RM), a highly alkaline waste that occupies land and poses environmental risks. In Guinea, rice is a staple food, and its processing produces large quantities of rice husk (RH), which also presents disposal challenges. RH contains about 20% silica, which becomes approximately 90% silica after combustion, forming rice husk ash (RHA) — a valuable material for various applications. Geopolymer technology offers a sustainable route for the valorisation of industrial residues. This study aimed to develop and analyse geopolymer composite materials using red mud and rice husk ash as alternatives to conventional construction materials. In this study, a composite geopolymer (GP) was synthesised using RM from a local alumina plant, RH from a local rice mill in Guinea, and water glass solution (WGS). For mechanical and microstructural characterisation, the geopolymer specimens were categorised into three main groups—GPA, GPB, and GPC—based on varying RM and RHA ratios while keeping the water glass solution (WGS) constant at 15%. Various mix ratios of RM, RHA, and WGS were tested. The resulting specimens were evaluated for compressive strength at different curing temperatures. Microstructural characterisation was conducted using X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The results revealed that the final product is predominantly composed of amorphous geopolymeric phases and that higher temperatures enhance the compressive strength of the material. The XRD of RM is characterised by the presence of sharp peaks mainly caused by hematite (Fe₂O₃), gibbsite (Al(OH)₃), akdalaite (4Al₂O₃·H₂O), lepidocrocite (FeO(OH)), and calcite (CaCO₃). There are no broad humps in the pattern; hence, amorphous phases are not present in large quantities. The greatest value of compressive strength was developed by the GPB1 specimen exhibited a strength: 36,31 MPa at ambient temperature and 66,97 MPa at 1000°C. Through geopolymerization, RM and RH are not stored in piles or dumped into nature; this is a considerable achievement for the circular economy and the zero waste principle.

Air Mycoflora in Traffic Zones of Siliguri, West Bengal- A Case Study

Chandra Ghosh — 2025-09-25

The present study deals with two objectives. The first objective deals with brief historical events of aerobiology around the world, functions of the International Association for Aerobiology (Wageningen, the Netherlands) and the national aerobiological network, composition of air spora, and sampling methods of the Municipality area. A portable volumetric bioaerosol sampler, Microbio MB1, was used to monitor the air mycoflora by exposing 10 cm diameter petri plates filled with Rose Bengal Chloramphenicol agar fitted in the sampler at a height of 1.5 meters above ground level. The sampler has an air flow rate of 10–100 l/min. and fixed at 100l/min. Culturable air-borne mycoflora varied among six sites, and the maximum (2090 cfu/M³) was recorded from site 6, while the minimum air mycoflora represented by 220 cfu/M³ at site 4. A mean aero mycoflora of 868.33 cfu/M³ was observed in the study. Species diversity of mycoflora varied among sites and was represented by six genera, Cladosporium, Rhodotorula spp (Pink yeast), Aspergillus flavus, Penicillium spp, Rhizopus spp, Trichoderma spp and sterile colony. Exposure of environmental air-borne mycoflora and their risk to human respiratory ailments was discussed in the light of available literature. Mitigation of roadside pollution by planting native, non-allergenic, non-poisonous plants has been suggested for Siliguri Town.The present study deals with two objectives. The first objective deals with brief historical events of aerobiology around the world, functions of the International Association for Aerobiology (Wageningen, the Netherlands) and the national aerobiological network, composition of air spora, and sampling methods of the Municipality area. A portable volumetric bioaerosol sampler, Microbio MB1, was used to monitor the air mycoflora by exposing 10 cm diameter petri plates filled with Rose Bengal Chloramphenicol agar fitted in the sampler at a height of 1.5 meters above ground level. The sampler has an air flow rate of 10–100 l/min. and fixed at 100l/min. Culturable air-borne mycoflora varied among six sites, and the maximum (2090 cfu/M³) was recorded from site 6, while the minimum air mycoflora represented by 220 cfu/M³ at site 4. A mean aero mycoflora of 868.33 cfu/M³ was observed in the study. Species diversity of mycoflora varied among sites and was represented by six genera, Cladosporium, Rhodotorula spp (Pink yeast), Aspergillus flavus, Penicillium spp, Rhizopus spp, Trichoderma spp and sterile colony. Exposure of environmental air-borne mycoflora and their risk to human respiratory ailments was discussed in the light of available literature. Mitigation of roadside pollution by planting native, non-allergenic, non-poisonous plants has been suggested for Siliguri Town.

Climate Change and Food Security: Whispers from a Developing Country

David Baaman Laar — 2025-09-25

The impacts of climate change represent an existential threat that disproportionately affects people and places. Some of these impacts are manifesting in several ways with regional variability, but most commonly in the form of seasonal erratic rainfall patterns, rise in surface temperatures, and flooding, among others. Ecologically fragile regions of sub-Saharan Africa, including Mali, Senegal, Niger, Chad, and Sudan, are becoming increasingly vulnerable to insufficient rainfall. To most peasant farmers in developing countries, some of these changes are immediately felt on a local scale as they face an immediate decline in crop yields owing largely to stochastic but sometimes long-lasting hydro-meteorological events. Drought has been a major problem confronting peasant farmers not only in the fragile ecological zones in the Sahel region, but also in some communities in the Sudan and Guinea savannah areas. Using mixed methods, the study has demonstrated how climate change-induced drought occurrences have led to a downward trend in crop yields and looming food insecurity issues among peasant farmers in Ghana’s northern savanna ecological belt. The study brings to light how available local adaptation and coping solutions merely represent a microcosm of a losing battle in sustaining livelihoods and eliminating poverty. Further research is needed to explore into access and feasibility of climate-smart strategies that favour the adoption and use of drought-resistant crops and improved crop varieties in the northern savanna ecosystem.