Maltese Islands Research Articles

Bioactive Potential of Olive Mill Waste Obtained from Cultivars Grown in the Island of Malta

This study explores the bioactive potential of olive mill waste derived from cultivars grown in the Maltese Islands through various analytical approaches. Cell culture, cell staining, allelopathic assays, shrimp brine lethality assays, and HPLC analysis were conducted to assess the efficacy and bioactivity of the extracts using different treatments, including methanolic extraction, acid, and alkaline hydrolysis. Notably, the results from cell lines revealed that NB4r2 cells exhibited high susceptibility to the tested extracts, with the lowest IC50 recorded after 72 h of exposure. Notably, the ‘Bajda’ cultivar displayed the most effectiveness, particularly with acid hydrolysis. In allelopathic assays, higher concentrations of ‘Malti’, ‘Bidni’, and ‘Bajda’ extracts significantly inhibited lettuce seed germination. Similarly, in the brine shrimp lethality assay, higher concentrations led to increased mortality rates of Artemia salina, though rates decreased at lower concentrations. The identification of phenolic compounds found in olive mill waste was conducted using high-performance liquid chromatography (HPLC) with the use of internal standards. The identification revealed a variety of compounds, with 3-hydroxytyrosol and oleacein being present in high abundance in nearly all hydrolyzed and methanolic extracts, whereas gallic acid was found to be the least abundant. These findings highlight the rich bioactive potential of olive mill waste and provide insights into its applications in pharmaceuticals, nutraceuticals, and agriculture, emphasizing the importance of further research to fully exploit these valuable resources.

Euxoa capsensis Chrétien, 1911 a new Noctuidae species for Europe and the Maltese Islands, including an updated Noctuoidea checklist for the Maltese Islands (Lepidoptera: Noctuidae, Noctuinae)

Euxoa capsensis Chrétien, 1911 is reported for the first time from Europe and the Maltese Islands. Notes on the distribution and habitat of the adult are included. A Maltese name is proposed for this new record.

Spodoptera frugiperda (Smith, 1797), an unwelcome visitor reaches the Maltese Islands (Lepidoptera: Noctuidae, Xyleninae)

Spodoptera frugiperda (Smith, 1797) is recorded from the Maltese Islands for the first time.

Flowpath 2023 Conference

The issue 175/1 of Acque Sotterranee – Italian Journal of Groundwater presents contributions from the Flowpath 2023 Conference which was held in Malta between the 14th and 16th of June. The scope of Flowpath focused on ensuring that hydrogeology can play an important role in supporting the development of groundwater management and protection policies; on strengthening the knowledge and research initiatives on emerging challenges to the groundwater environment and to highlight research initiatives undertaken in the Maltese islands, and improve technical cooperation between Maltese and Italian hydrogeologists. Flowpath brought together in Malta almost 200 hydrogeologists from Italy, Malta and six other countries who together contributed to 8 keynote speeches, 42 oral presentations and 45 posters. In fact this edition includes three papers from the Flowpath conference, two of which highlight joint work undertaken by researchers from Italy and Malta in the characterization of groundwater bodies.

Mapping saltwater intrusion via Electromagnetic Induction (EMI) for planning a Managed Aquifer Recharge (MAR) facility in Maltese Island

In coastal areas, saltwater intrusion causes a depletion of the resource by reducing potable and irrigation freshwater supplies and causing severe deterioration of groundwater quality. This trend is observed in Pwales Valley, in the North part of Malta where the management of water resources plays a crucial role for the environmental sustainability of the area, given the importance of intensive agricultural activity along this valley. In order to tackle such phenomenon, actions or adaptation measures against climate change are strongly required. For example, Managed Aquifer Recharge (MAR) is an increasingly important water management strategy to maintain, enhance and secure stressed groundwater systems and to protect and improve water quality. To accurately plan a Managed Aquifer Recharge scheme, it is crucial to define a hydrogeological model of the studied area, with the use of traditional hydrogeological measurements and innovative unconventional techniques. In recent years, Electromagnetic Induction measurements, based on induction of em fields, have been increasingly used for investigating the saltwater intrusion dynamics due to their high sensitivity to the salinity. In the study area of Pwales Valley, a Managed Aquifer Recharge scheme is being planned and, for this aim, a hydrogeological model has been developed through an Electromagnetic Induction survey. More than 20,000 apparent electrical conductivity (ECa) data were collected to generate a quasi 3D high-resolution model of electrical conductivity of the Pwales Valley. The results highlighted the spatial extension of the tongue-shape salt water intrusion from east to west along the valley, as well as some geological-hydrogeological peculiarities such as the thickness of the salt wedge and the irregular top surface of the bottom impermeable layer, otherwise undetectable with other direct techniques at the field scale resolution. The approach was confirmed to be a useful tool for an effective hydrogeological characterisation, essential for planning adaptation measures to a changing climate, such as the implementation of a Managed Aquifer Recharge scheme.

Attitudes Towards the Stress Created by Ever Increasing Traffic in the Maltese Islands

The relatively large and rapid increase in population in the Maltese Islands over the past decade has placed significant strain on the infrastructure of the country. These factors, together with the fact that issues with the public transport system have never been completely sorted, has led to an over-reliance on private cars as the main means of transport in most cases. Increased transport has been shown to increase stress and aggressive behaviour in drivers, amongst other possible negative consequences, leading to a negative effect on personal wellbeing. In order to assess the perceptions of the Maltese about the stress created by traffic, a cross-sectional study was conducted by means of telephone interviews with a stratified sample of 400 Maltese participants. A purposely designed questionnaire with twelve items scored on a seven-point Likert scale was used for this purpose. While more than four fifths of participants stated that they owned at least one car, and most agreed that traffic increases stress, both in the short and long term, less than one third of participants strongly agreed to preferring to use public transport rather than their private vehicle, even if public transport were more reliable. Females showed more anxiety than males with reference to the traffic situation and 18–29 year-olds showed the lowest level of agreement overall with the statements in the survey – a surprising result given this age group’s awareness of the negative effects of climate change on wellbeing.

Quantification of the size and distribution of the only known population of Crepis pusilla (Sommier) Merxm. (Asteraceae, Cichorieae) in Malta

Crepis pusilla (Asteraceae, Cichorieae) is “Critically Endangered” in the Maltese Islands, being restricted to a 60 metre country path. This study is the first to quantify the population and to precisely determine its distribution. Field surveys between February and May 2023 indicated a total of 27 confirmed individuals or close clusters of Crepis pusilla with a diameter ranging between 0.9 cm to 4.8 cm (mean 2.5 cm ± 0.9 cm). Flowering was observed during April and early May 2023, with each plant producing c. 150 achenes.

A Glimpse into the Genetic Heritage of the Olive Tree in Malta

The genetic diversity of the ancient autochthonous olive trees on the Maltese islands and the relationship with the wild forms growing in marginal areas of the island (57 samples), as well as with the most widespread cultivars in the Mediterranean region (150 references), were investigated by genetic analysis with 10 SSR markers. The analysis revealed a high genetic diversity of Maltese germplasm, totaling 84 alleles and a Shannon information index (I) of 1.08. All samples from the upper and the lower part of the crown of the Bidni trees belonged to the same genotype, suggesting that there was no secondary top-grafting of the branches. The Bidni trees showed close relationships with the local wild germplasm, suggesting that the oleaster population played a role in the selection of the Bidni variety. Genetic similarities were also found between Maltese cultivars and several Italian varieties including accessions putatively resistant to the bacterium Xylella fastidiosa, which has recently emerged in the Apulia region (Italy) and has caused severe epidemics on olive trees over the last decade.

Megachile parietina (Geoffroy, 1785), a new addition to the bee fauna of the Maltese Islands (Hymenoptera: Apoidea: Megachilidae)

Megachile parietina (Geoffroy, 1785), the black mud bee, is recorded from the Maltese Islands for the first time on the basis of two adult nesting females and four nests from Pembroke (north-east of Malta). This addition to the Maltese entomofauna brings the number of bees known from the archipelago to 106. The possibility that this species could be a suitable pollinator of the endemic orchid Ophrys melitensis (Salk.) Devillers-Terschuren & Devillers, 1994 is discussed, and further investigation is encouraged.

Trichoderma in the Maltese Islands

This study assessed presence of Trichoderma spp. in the Maltese Islands. Isolates were identified using dichotomous keys and DNA barcoding. Ten distinct isolates were obtained from different soils and other substrates, and were identified as T. virens, T. citrinoviride, T. gamsii, and, in the former T. harzianum species complex, T. breve, T. afroharzianum and T. atrobrunneum. Five out of these six fungi are reported for the first time in the Maltese Islands, and T. brevis is reported for the first time in Europe.

Conservation Genetics of the Loggerhead Sea Turtle, Caretta caretta, from the Central Mediterranean: An Insight into the Species' Reproductive Behaviour in Maltese Waters.

Loggerhead sea turtle, Caretta caretta (Linnaeus, 1758), nestlings were investigated through specimens found dead either after hatching or unhatched (n = 120) from eight nests around the Maltese islands (Central Mediterranean). Molecular genetics was used to conduct maternity and paternity tests of the collected specimens utilizing expanded mitochondrial DNA sequences from the control region (858 bp) and 25 microsatellite loci (12 dinucleotide loci and 13 tetranucleotide loci). Mitochondrial data produced two haplotypes, CC-A2.1 and CC-A3.1, with the most common haplotype being present in seven nests. Microsatellite data revealed the identity of six different females that were involved in the deposition of the eggs in the eight turtle nests analysed. This confirms that two females laid multiple nests. Additionally, microsatellite data allowed for the determination of multiple paternity, with one clutch being sired by two fathers. These results are useful for monitoring the genetic diversity of loggerhead sea turtle nestlings and of the turtle mothers and fathers contributing to future turtle offspring, which rely on Maltese sandy beaches for their successful start to life. Effective conservation management benefits from merging scientific knowledge with effective measures at potential nesting sites to avoid losses of nestlings caused by human negligence.

Abstract 17005: Brugada Syndrome: Is There a Difference Between Probands and Relatives?

Introduction: Brugada syndrome (BrS) is an inherited arrhythmic disease that is rarely linked to sudden cardiac death (SCD), often associated with SCN5A mutations. Hypothesis: The main objective of this study was to report the demographic, clinical findings and outcomes of a BrS registry in the Maltese Islands, comparing probands and relatives. Methods: Data was collected prospectively in all BrS patients. BrS was defined as per the latest European Society of Cardiology SCD guidelines published in 2022. Patients were placed in two groups (proband vs relative). Results: 120 individuals were included (2.7 per 10,000 individuals) (56.7% male, mean age 44.0±16.5 years at diagnosis, 7.5% athletes). 54 (45.0%) were probands. 61 (50.8%) reported cardiac symptoms. A relevant family history of SCD was present in 55 (46.6%). Follow up period of 49.8 ± 33.3 months. A spontaneous type 1 brugada pattern was the primary method of diagnosis in probands (71.1%), ajmaline provocation in relatives (71.6%) (p<0.001). Probands reported more symptoms (33.1% vs 17.8%, p<0.0001), documented arrhythmias during holter monitoring (29.0% vs 9.3%, p=0.028), and manifested J /ST elevation during stress testing (14.0% vs 5.3%, p=-0.039). The age at diagnosis was similar for probands and relatives. Similar proportions of atrioventricular block (15.7%), prolonged QRS (10.2%), early repolarisation (12.8%), QRS fragmentation (5.6%), low QRS voltages (5.6%) and pathological TWI (8.3%) were observed in both groups. 18 (20.4%) were identified with a SCN5A mutation (P, LP, VUS as per ACMG criteria). 5 patients (4.2%) had a novel variant. 17 (15.3%) were referred for a VT study. 20 (16.7%) had an ICD implanted, more frequent in probands (34.0% vs 3.1%) (p<0.001). 3 were implanted because of OHCA. 27 (22.5%) were implanted with an ILR, commoner in probands (33.3% vs 16.4%, p=0.047). Two patients (10% of ICD subgroup) had an appropriate ICD therapy. One patient is on quinidine because of refractory shocks. Conclusions: The prevalence of BrS in Malta is comparable to other studies. 20.4% (probands) had a SCN5A mutation. The higher incidence of symptoms, arrhythmias, abnormal response during exercise and ICD implantation in probands (vs relatives) may suggest they are a higher risk group.

Assessing the effect of Amphistegina lobifera invasion on infralittoral benthic foraminiferal assemblages in the Sicily Channel (Central Mediterranean)

This article documents, through a quantitative approach, the negative effect of the highly invasive species Amphistegina lobifera Larsen, 1976 on native benthic foraminiferal assemblages of coastal areas in the Sicily Channel (Central Mediterranean). A nested sampling design was applied through the comparison of benthic foraminiferal community structure across three areas that are known to be at different stages of invasion (i.e. Maltese Islands - advanced, southern Sicily – medium, and eastern Sicily - early). Results suggested that both diversity and richness of benthic foraminiferal community from the Maltese Islands were strongly modified by increased abundances of A. lobifera. In contrast, this phenomenon is less evident in southern and eastern Sicily, where the invader displayed lower abundances and the community structure was more diversified. Collected data also allowed for predicting what could happen in the near future in the whole Sicily Channel, as well as in the rest of the Mediterranean Sea.

Taxonomic survey on the genus Limonium in the Maltese islands, with description of a new species

The native species of the genus Limonium (Plumbaginaceae) occurring in the Maltese Islands are investigated. According to current literature, this genus is hitherto represented in this territory by L. virgatum, L. zeraphae and L. melitense, but recent field surveys led to the discovery of a new species growing exclusively on the islet of Cominotto and described as L. lanfrancoi. The latter, for some morphological features regarding the vegetative and reproductive traits, shows closer relationships with L. melitensis, from which, however, it differs in several diacritical characters. For each species, a detailed illustration and a new morphological description based on rich herbarium materials are provided, as well as information on their typification, synonymy, phenology, ecology, distribution, conservation status and a list of examined herbarium specimens is given. Besides, an updating analytical key has been elaborated.  

Maritimity in Stone: An Archaeology of Early Modern and Modern Ship Graffiti in the Maltese Islands (ca. 1530–1945)

Maritimity in Stone: An Archaeology of Early Modern and Modern Ship Graffiti in the Maltese Islands (ca. 1530–1945)

Axylia putris (Linnaeus, 1761) new to the Maltese Islands (Lepidoptera: Noctuidae)

Axylia putris (Linnaeus, 1761) is reported for the first time from the Maltese Islands. Distribution and habits of the adult are included. A Maltese name is proposed for this new record.

The Tubulifera (Hexapoda, Thysanoptera) of the Maltese Islands.

This work records the presence of 13 species of tubuliferan thrips from the Maltese Islands. Eleven of these species, namely Bolothripsdentipes, B.insularis, Priesneriellamavromoustakisi, Gynaikothripsuzeli, Haplothripsacanthoscelis, H.aculeatus, H.setiger, H.tritici, Karnyothripsflavipes, Liothripsreuteri and Neoheegeriadalmatica are new records for the Maltese Islands. Two species: Gynaikothripsficorum and Karnyothripsflavipes can be described as subcosmopolitan in distribution, another three species: Haplothripsaculeatus, H.setiger and H.tritici are distributed across the Holarctic and Palaearctic regions, while a further seven: Bolothripsdentipes, B.insularis, Haplothripsacanthoscelis, Liothripsoleae, L.reuteri, Neoheegeriadalmatica and Priesneriellamavromoustakisi have a European and/or Mediterranean distribution. Gynaikothripsficorum and G.uzeli are considered as alien species. A key to the Tubulifera of the Maltese Islands as well as chorological data for these recorded species are provided in this work.

A Review of Malta’s Pre-Temple Neolithic Pottery Wares

Abstract Sites from the earliest known phases of Maltese prehistory often consist of scatters of sherds for the Għar Dalam and Skorba phases (6000–4800 BCE), and tomb contexts for the Żebbuġ phase (3800–3600 BCE). Neolithic studies are, therefore, heavily reliant on the study of pottery. Although traditional typological and seriation-based analyses of the pottery record have substantially enhanced our knowledge of Early Neolithic Malta, there is a growing appreciation of the need to go beyond these approaches to gain new insights. This study reviews the accessible literature on fabric studies on assemblages found in the Maltese Islands, presenting the state of knowledge for the pottery of the Għar Dalam, Skorba (Early Neolithic), and Żebbuġ (Late Neolithic) phases. Microphotographs of pottery wares were selected from a compilation produced for an ongoing project (the MaltaPot project) to illustrate the descriptions found in the literature. The advances made by archaeologists in studying the Maltese Neolithic pottery are reviewed, and suggestions for building on them are proposed, as archaeometric and petrographic techniques have not been applied systematically to Neolithic pottery from Malta.

New Records and Updated Checklist of Bees (Hymenoptera: Apoidea) from the Maltese Islands

Between 2016 and 2021, several habitat sites in Malta were surveyed for wildbees by sweep netting patches with insect-pollinated flowering plants. These surveys haveled to an updated checklist of the bees of the Maltese Islands, which is provided in thisarticle. The species Andrena flavilabris Schenck 1874, Andrena florentina Magretti 1883,and Ceratina dentiventris Gerstaecker 1869 are recorded for the first time in the MalteseIslands (Central Mediterranean), and notes on the distribution of each species are alsoincluded. With the new additions to this checklist, the total number of species recordedin Malta is 105 species belonging to five families, namely Andrenidae (20 species), Apidae(35 species), Colletidae (6 species), Halictidae (19 species), and Megachilidae (25 species).

Restoration of the Church of St. Nicholas Fort Ricasoli: The Process of Conserving Our Heritage

Restoration programmes aid in preserving local building heritage for futuregenerations. Documentation of these restoration programmes is a fundamental taskin conserving and reserving significant cultural cultural buildings. Documenting anddeveloping a conservation strategy for a historical structure is quite a complex task andrequires not only planning the interventions required to conserve a building but also forfuture maintenance to enhance the effectiveness of such work. This paper is divided intofive sections. The first section, the introduction, gives a description and overview of thesubject being studied. In the second section, the existing literature study evaluates differentparadigms of protecting existing significant historic buildings. This is followed by anexplanation of the historical context and the history related to the subject studied. Finally,research on the documentation process is also reviewed. The third section describes themethodological approach that aided the analysis of this studys research questions in thefourth section. The fifth section gathers the primary and secondary data analysed and sumsup everything in accordance with the proposed research questions of this study. In order toconduct this research, the Church of St. Nicholas at Fort Ricasoli was used as the main casestudy. A detailed investigation of the church to identify the significance of conserving suchbuildings and an investigation of the existing conditions of the church were conducted. Thisaided in establishing the documentation process prior to the actual interventions on thefabric. In order to carry out such a process, different methods of documentation were used,such as laser scanning surveys, photogrammetry, and documentation of the existing stateof the building to aid in the process of deciding on future interventions. As a result of sucha process, considerations of appropriate uses of such methods and proposals were givenand, additionally, considerations of successful conservation after the actual conservation arehighlighted. The proposal for the conservation of the church of St. Nicholas at Fort Ricasolialso aims to set guidelines for other conservation programmes within the fort, amongstother local restoration projects. Conservation of abandoned structures will enhance thelocal context in various aspects. Finally, conservation programmes will give potentialbenefits to the Maltese islands. Giving back these historically significant monuments to thegeneral public will aid the Maltese islands economy.