Porto Santo Island Research Articles

Physical–Chemical and Thermal Properties of Clays from Porto Santo Island, Portugal

The use of clays for thermal treatments and cosmetic purposes continues to be a worldwide practice, whether through the preservation of native cultural traditions, pharmaceutical formulations or integrative health and well-being practices. Special clays, such as bentonites, are very common for healing applications due to their high cation exchange capacity (CEC), high specific surface area (SSA) and alkaline pH values and, therefore, are used in multiple therapeutic and dermocosmetic treatments. Numerous bentonitic deposits occur on Porto Santo Island with different chemical weathering degrees. This research evaluates which residual soils have the most suitable characteristics for pelotherapy. The texture of residual soils varies from silt loam to loamy sand and SSA between 39 and 90 m2/g. The pH is alkaline (8.7 to 9.6), electrical conductivity ranges from 242 to 972 µS/cm, and CEC from 50.4 to 86.8 µS/cm. The residual soils have a siliciclastic composition (41.36 to 54.02% SiO2), between 12.52 and 17.65% Al2O3 and between 52 and 82% smectite content, which are montmorillonite and nontronite. Specific heat capacity (0.5–0.9 J/g°C) and cooling kinetics (14.5–19 min) show that one residual soil has the potential to be suitable for pelotherapy according to the literature. Moreover, the residual soils have As, Cd, Co, Cr, Hg, Mn, Ni, Pb, Sb and V concentrations higher than the limits of guidelines for cosmetics and pharmaceutical products.

The Scarabaeoidea Latreille (Coleoptera) of the Madeiran Archipelago

We present an updated checklist for Madeira Archipelago's Scarabaeoidea Latreille, 1802, fauna. Considerable change has been observed over the last 15 years: four alien Cetoniidae (Cetonia aurataeformis, Protaetia cuprea brancoi, P. opaca and Oxythyrea funesta) have started to breed successfully in Madeira and Porto Santo islands. The following species (based on only a few specimens) are added as new records: Geotrupes spiniger (Geotrupidae) and Oryctes nasicornis grypus (Dynastidae). Both these families are also recorded for the first time.

Searching for the critically endangered European eel in oceanic islands: A pioneer study in the freshwater systems of Madeira, Macaronesia

Abstract The globally threatened European eel (Anguilla anguilla) is the only freshwater fish native to Macaronesia. Despite being a keystone species to freshwater habitats, little is known about its population, environmental associations and conservation requirements in oceanic islands. The density and geographical‐related factors influencing the distribution of A. anguilla in the subtropical Archipelago of Madeira (Portugal) were examined. Data on the species occurrence was initially collected using an online survey addressed to citizens. Eels were then sampled through electrofishing in 31 sampling sites along 11 streams on Madeira Island, and eel‐habitat associations were investigated using LMMs and GLMMs. One stream was also sampled in Porto Santo Island. The presence of A. anguilla was confirmed in the two islands of the archipelago with streams (Madeira and Porto Santo). Eels are distributed throughout Madeira Island, being more abundant – particularly small size individual– at lower altitudes (mostly below 150 m). The number of weirs was an important predictor of eel density, suggesting that these flood‐control structures limit their upstream migration. This study represents a pioneer sampling effort of the European eel in Madeira and results provide much‐needed baseline information on the species distribution and related environmental factors in oceanic islands. While most eel research has historically focused on mainland habitats where dams pose a significant threat to eel habitats, our study underscores the critical importance of addressing smaller, often overlooked barriers that may also cause habitat fragmentation. The European eel is a panmictic species, thus, the conservation of the Macaronesian subpopulations can have substantial benefits for its global recovery. A comprehensive investigation of the impact of man‐made obstacles on eel habitat is still needed. Similarly, other common threats such as interactions with non‐indigenous species and infection by Anguillicola crassus should be a research priority in future studies.

The Impact of the COVID-19 Pandemic on the Tourism Sector in the Autonomous Region of Madeira

The highly regarded and award-winning tourism destination that is the autonomous region of Madeira (ARM), in the Madeira and Porto Santo islands, has suffered the consequences that the COVID-19 pandemic has brought to tourism through the mobility limitations as well as the fear faced by travelers. From data collected on tourism, COVID-19, and demography in ARM from the years 2019 to 2020, this study makes use of data science techniques, including statistics, data mining, and data visualization, to analyze the direct and indirect effects of the coronavirus outbreak as well as the weight of population density in the propagation of the virus. The results validate a direct effect and show evidence of dense regions having aggravated virus propagation, but they do not corroborate the idea that an indirect effect was significant.

Electricity, Transportation, and Water Provision of 100% Renewable Energy for Remote Areas

The integration of variable renewable energy sources in islands has become crucial in reducing their dependency on imported fossil fuels. This study aimed to assess the energy transition of an island towards a 100% renewable energy system for power generation, inland transport, and potable water provision. Linking various fossil-fuel-consuming sectors, such as transport and potable water supply systems, may strongly assist in reducing the possible mismatch between renewable energy source production and demand and contribute to fulfilling other system requirements. The use of energy storage technologies is vital and unlike traditional power systems; as the number of components in the system increases, their proper capacity needs to be accurately determined. This work employs a multi-objective optimization assessment using a modified NSGA-II algorithm to depict the energy transition for Porto Santo Island. To evaluate the solutions, we considered the main criteria of energy cost, avoided environmental impacts (CO2-equivalent emissions) of the proposed system, and loss of power supply. The Pareto front contains various solutions under different system configurations. Results indicate that full inland transport electrification (introducing 3000 EVs) can account for 18% of the avoided CO2 emissions of the island while sharing 28–40% of the up-front cost of the system, depending on the proposed system’s components. The EV’s costs incorporate subsidies and their battery replacement. Another interesting finding from the optimization process is that the solution with the highest avoided CO2 emissions involves keeping a diesel generator for supplying 4% of the island’s total demand and using an underwater compressed air energy storage with a capacity of 280 MWh. This suggests that adding more installed wind turbines or PV panels may not necessarily contribute to reducing the emissions of the entire system.

Energetic Valorization of Bio-Waste from Municipal Solid Waste in Porto Santo Island

The valorization of bio-waste as a resource for green energy production will be beneficial at a social, economic, and environmental level in different regions. The scope of this research is to develop the energetic valorization of the bio-waste fraction from municipal solid waste, to produce biogas from the anaerobic digestion process and electricity in a biogas CHP process, to increase the penetration of renewables in the electricity production system, with an application of these technologies on islands instead of these waste fractions being transported to other regions. The methodologies developed included: 1. Identification and mapping of resources; 2. State-of-the-art of bio-waste parameters and process solutions; 3. Pilot initiative for separation, collection, and analysis of food waste fractions; 4. Development of process solutions according to resources and needs; 5. Determination of investment, production costs, and revenues of the solution created. The case study selected was Porto Santo Island, with the potential to reduce maritime transportation costs of these undifferentiated waste fractions to Madeira Island and contribute to developing an innovative solution for the energetic valorization of bio-waste, including the participation of the local community. The results demonstrated a production of 272,221 m3 of biogas for use as fuel in a cogeneration unit to transform chemical energy into electrical and thermal energies. Furthermore, the self-consumption of the cogeneration unit is 25% of the total electricity produced and 29% of the total thermal energy produced. In conclusion, this research and solution is in compliance with PNEC, the EU Green Deal, and the European Directive 2018/851, which will make mandatory from 2024: the selective collection of bio-waste, 60% by weight of urban waste to be recycled by 2030, and only 10% of waste to be landfilled by 2035.

Crossing the Atlantic: The tropical macroalga Caulerpa ashmeadii Harvey 1858 as a recent settler in Porto Santo Island (Madeira archipelago, North-eastern Atlantic)

The green macroalga Caulerpa ashmeadii was recently found in the North-eastern Atlantic Ocean, on the southern coast of Porto Santo Island (Madeira archipelago). Caulerpa ashmeadii was detected in a subtidal soft-bottom forming scattered patches, mostly among the green calcareous macroalgae Halimeda incrassata and Penicillus capitatus, within a depth range of 18–26 m. Some isolated patches were also observed in bare sand. The species is currently distributed over an estimated area of approximately 0.22 km2. Caulerpa ashmeadii may represent a recent settler (Nov. 2020), although the hypothesis of the species being present elsewhere in Porto Santo prior to our discovery cannot be discarded. Alternatively, the presence of C. ashmeadii in Porto Santo may indicate the influence of climate change on the composition and structure of benthic communities in the Webbnesia region, which further stresses the importance of conducting more intensive biological and environmental monitoring programmes. Overall, this new record constitutes an exceptional eastern expansion of this marine species by more than 4200 km, comprising its first register in the Eastern Atlantic Ocean.

Sewage Sludge Fertilization—A Case Study of Sweet Potato Yield and Heavy Metal Accumulation

Sewage sludge (SS) is derived from wastewater treatment plants and can be used as a biofertilizer when properly stabilized. This work aimed to evaluate SS application for agricultural production improvement. SS was tested on Porto Santo Island (Portugal). The experiment was randomly designed with three 25 m2 plots for each treatment (2 SS concentrations + control without SS) and performed in two consecutive cycles. For the first cycle, dehydrated sludge was mixed with soil, obtaining final concentrations of 0.8 kg/m2 (C1) and 1.6 kg/m2 (C2). Half of the concentration was used for the second cycle. Fifty-eight sweet potato plants were used in each plot. SS application boosted the agronomic parameters of biomass, productivity, and shoot biomass. Furthermore, improvements in soil properties were observed, mainly for pH, CEC, and NO3-N, with no significant increase in heavy metals. For the edible parts, heavy metal concentrations decreased, and Pb was the only one that still exceeded the maximum limits. The results demonstrated that SS application to low-fertility soil is effective in improving the agronomic parameters of sweet potato and enhancing soil features. Further studies considering other variables, i.e., SS origin, soil properties, and the crop, must be carried out to propose custom applications.

Morpho-stratigraphic characterization of the southern shelf of Porto Santo Island (Madeira Archipelago): Insights for small-scale instability processes and post-LGM sedimentary architecture

Shelves surrounding volcanic islands represent only a small portion of the entire submarine edifice that can extend to a few thousand meters below sea level. Despite their small areas, shelves show a significant morphologic imprint made by the erosional, depositional, tectonic and volcanic processes when compared to those left on slopes or the submarine bases of islands. Therefore, shelf morphology can be used to improve our knowledge about the island evolution, especially the more recent events. In this study, we use multibeam bathymetry, side scan sonar and seismic reflection profiles of the southern shelf of Porto Santo Island in Madeira Archipelago to map its seabed morphology and seismic stratigraphy from the nearshore to the shelf edge. Based on morphological and seismo-stratigraphic differences, the study area has been divided in three sectors (Western, Central and Eastern). In general, the shelf consists of an erosive rocky surface mostly covered by sediments, and locally outcropping on the seafloor, especially on the Western and Eastern sectors. On these sectors two sets of submerged erosional terraces have been mapped at different depths (35–45 m, 50–75 m). The depth range of the terraces and their absence in the Central sector suggests that these were formed/modified at least by the Marine Isotope Stages (MIS) 5a-5d stillstands or even by older relative sea-level stillstands. Dykes, which are more resistant to erosion than the surrounding outcrops, have orientations that are similar to the volcanic and structural features present on the island (NNE-SSW and NW-SE). The sedimentary cover on the shelf is highly varied both in thickness and internal architecture, mainly due to different onshore sediment supply and available accommodation space. Two main seismic units have been recognized: the lower one (U1) is interpreted as a transgressive deposit, formed during the sea level rise after the Last Glacial Maximum (LGM); the upper one (U2) is interpreted as a modern highstand deposit. The Western sector is practically sediment-starved, except for a local thin sedimentary cover of U2 on the inner and outer shelf. The Central sector shows U2 as a sigmoidal-oblique progradational clinoform characterized by inner prograding geometry on top of U1. The Eastern sector shows U2 as sigmoidal clinoform extending over a large area and having a more aggradational component. The shelf edge shows an overall arcuate shape that strongly matches the coastline configuration, suggesting the occurrence of an old large-scale landslide event (LS1) prior to the shelf formation. Further incisions in the shelf edge of the Central sector are interpreted as resulting from mass-movements, classified as LS2 and LS3. LS2 is at least older than seismic unit U1 and LS3 formed during the late Holocene. The volume of the LS2 event (0.6 km3) suggests that it might have caused a hazardous tsunami if it failed as a single event. The recent LS3 events, due to their small magnitude were probably not hazardous. These observations provided a more comprehensive understanding of the recent evolution of Porto Santo insular shelf in terms of mass-movement processes and post-LGM sedimentary architecture.

New taxa to the flora of Madeira archipelago islands (Portugal)

73 new references for 72 taxa of vascular plant are here reported for the Madeira archipelago. 55 not previously recorded for Desertas Islands, 12 to Porto Santo Island and 6 for Madeira Island. Of the 72 taxa, 28 are xenophytes, and 10 are new taxa to the flora of the archipelago (of these 9 are xenophytes). Their native status, taxonomy and distribution are briefly discussed.

Ascidian biodiversity in the shallow waters of the Madeira Archipelago: Fouling studies on artificial substrates and new records

Ascidians are recognized as major invaders on a global scale, found from the poles to the tropics and from shallow to deep sea waters with approximately 3000 known described species worldwide. However, to date only a few opportunistic studies focusing on the ascidian diversity colonizing natural and artificial substrates have been conducted in the Madeira Archipelago (NE Atlantic). Furthermore, little is known about the community composition and distribution of native and non-indigenous ascidians in the islands of the archipelago. In this context, we conducted a 3-phase study that allowed us to report an updated list of ascidian records found on artificial substrates in the Madeira Archipelago. First, to assess ascidian biodiversity colonizing artificial substrates present in the Madeira Archipelago, we conducted standardized monitoring campaigns in four marinas and hull vessel surveys during dry dock inspections. Second, we complemented this inventory with a comprehensive literature search and Museum collection focused on ascidians colonizing both artificial and natural substrates. Third, we investigated the temporal and spatial variability on the recruitment and succession of young vs mature ascidian assemblages. We found 24 ascidian species in all four marinas, from which 13 are NIS and 11 are new records for Madeira Archipelago. In addition, a literature survey found a total of 27 ascidians occurring on both artificial and natural substrates. This study now reveals a total of 39 ascidian species colonizing both artificial and natural substrates and comprises the most up-to-date list for all shallow-water ascidians in the Madeira Archipelago. A total of 15 NIS are now currently known, 9 exclusively from Madeira Island, 1 exclusively from Porto Santo Island and 5 on the two main islands of the archipelago. This study also shows that the spatial and temporal variability of fouling ascidian assemblages are driven by recruitment and succession of NIS rather than by presence of native species. Finally, total ascidian richness and cover was significantly higher in 4-month-old communities than in 8 to 16-month-old communities across all marinas, suggesting that “bare” artificial substrates are the main drivers of NIS success in the region.

Geotechnical Characterization of Marine Unconsolidated Sediments for Cable Routing between the Islands of Madeira and Porto Santo

Pombo, J.; Rodrigues, A., and Lapa, N., 2020. Geotechnical characterization of marine unconsolidated sediments for cable routing between the islands of Madeira and Porto Santo. In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 1245–1251. Coconut Creek (Florida), ISSN 0749-0208.The national economic sustainability strategy encourages the use of oceanic territory and resources for the reduction of dependency on fossil fuels. Submarine cables are subject to several risks, especially those associated with the seafloor stability processes, which are not described by the normal characterization of the marine sedimentary layer. As such, to ensure the safety and economic success of any new project it is essential to know the properties of the seabed, in particular, the geotechnical ones. Only in this way it will be possible to estimate and mitigate the natural hazards effects (e.g. submarine movements and landslides) or excessive burial of the electric power cable that could compromise the integrity of the infrastructure. If unavoidable, protection actions and measures should be taken, when submarine cables cross any rocky area, or highest slope area. In this paper, we will present the results of the geotechnical characterization of the marine soils along a corridor between Madeira and Porto Santo Islands. Unconsolidated sediments were collected in both islands and results of laboratory analysis (grain size, water content, carbonate content, Atterberg limits and triaxial tests) indicate the occurrence of frequent downslope mass movements in both islands.

Between Tradition and Taste: Fish Consumption Habits in a Small Portuguese Archipelago

ABSTRACTA survey of fish and seafood consumption habits was carried out in Madeira archipelago, in the Eastern Atlantic. A total of 465 valid questionnaires were obtained from all municipalities of Madeira and Porto Santo islands. Cod, an imported product, but a traditional Portuguese staple food, was the most frequently consumed species, surpassing locally caught species such as tunas and scabbardfish. In a GLM analysis, taste emerged as the most important factor conditioning fish consumption frequency, followed by fishing activity. The survey uncovered high participation in subsistence fishing and informal fish acquisition outside the commercial circuit.

Unforeseen diversity of quails (Galliformes: Phasianidae: Coturnix) in oceanic islands provided by the fossil record of Macaronesia

Abstract The original bird fauna of most oceanic islands has been affected by recent extinction processes associated with human arrival and its subsequent impacts. In the volcanic Macaronesian archipelagos (Azores, Madeira, Selvagens, Canary Islands and Cape Verde), in the North Atlantic, the Late Quaternary fossil record indicates that there was formerly a higher avian diversity, including a high number of now extinct endemic species. This assemblage of extinct birds includes endemic insular quails (Galliformes: Phasianidae). In this study, we describe three newly discovered extinct species of quails, two of which inhabited the archipelago of Madeira (Coturnix lignorum sp. nov. from Madeira Island and Coturnix alabrevis sp. nov. from Porto Santo Island) and one from Cape Verde (Coturnix centensis sp. nov.). The fossil record also indicates the presence of additional species of extinct endemic quails on other Macaronesian islands. These birds plus the extinct Canary Island quail (Coturnix gomerae) indicate a high former endemic diversity of this genus in Macaronesia, a feature unique among oceanic archipelagos. Anatomical traits show that the new taxa were flightless ground dwellers, making them vulnerable to human interference, with their extinction being linked to human arrival and subsequent habitat alterations and the introduction of invasive species.

Foreword to the special issue of the World Conference on Information Systems and Technologies (WorldCIST 2017)

Foreword to the special issue of the World Conference on Information Systems and Technologies (WorldCIST 2017)

Thalassotherapy in Porto Santo Island of the Madeira Archipelago: facts and prospects

Thalassotherapy in Porto Santo Island of the Madeira Archipelago: facts and prospects

Comparing the foraging strategies of a seabird predator when recovering from a drastic climatic event

Seabirds due to their status as sentinels of the marine environment can indicate qualitative changes at various levels of the food web. Furthermore, changes in marine productivity have been correlated with fluctuations in large-scale atmospheric conditions driven by global indices, such as the North Atlantic Oscillation (NAO) index. During the winter of 2009/2010, the second lowest NAO index in history was recorded leading to detrimental conditions that influenced productivity levels in the northeast Atlantic. The response of the Cory’s Shearwater Calonectris borealis, during the period of ameliorating climatic conditions from this drastic event, was monitored in two islands with contrasting productivity patterns: Berlenga, located on the rich upwelling area of the Portuguese shelf; and Cima Islet (Porto Santo Island), located in a poor oceanic environment in the Madeira Archipelago. We collected a multi-year GPS-tracking data set (2011–2015) from adult breeders during the chick-rearing season to examine their at-sea foraging distribution. During a year of low productivity, kernel estimations demonstrated that Cima Islet birds expanded their home ranges and core foraging areas all over the northeast Atlantic, whereas Berlenga birds maintained their distribution close to the breeding colony. Once oceanographic conditions ameliorated from 2012 to 2015, birds decreased significantly their foraging effort, and oceanic breeders concentrated their activity closer to the breeding colony. Analysis of habitat use by means of Maximum Entropy Modelling confirmed distance-to-colony as the most important predictor in the distribution of Cory’s Shearwater. Environmental variables describing sea surface temperature, bathymetry, and chlorophyll a were more influential in Porto Santo, indicating higher sensitivity of the oceanic population to marine productivity proxies. Our study confirms that the Cory’s Shearwater possesses enormous flexibility in its foraging tactics and that neither oceanic nor neritic populations disperse randomly from their breeding colonies to the open ocean even under conditions of environmental stochasticity. Instead, populations breeding in contrasting environments vary in their responses according to their strategies and to the changing levels of marine productivity in the surroundings of their colonies.

Preparation and characterization of novel clay/scleroglucan nanocomposites

In pursuit of integrating the use of clay/polymer nanocomposites (CPN) into mainstream applications, improvements made to the preparation process can be useful measures. One such measure involves taking advantage of the global prevalence of clay deposits via their use as primary sources for filler material, as opposed to expensive reference or commercial clay minerals. In this paper, a novel CPN was prepared using bentonite from Porto Santo Island, located in the Madeira archipelago, and was subsequently compared to a CPN prepared using the reference clay mineral SWy-2. According to an XRD characterization of both of the CPN materials, a monolayer intercalation of the biopolymer between the clay mineral layers had occurred. TEM results indicated that there was a mixture of exfoliated and intercalated structures in both cases, but in that of the CPN prepared using Porto Santo bentonite, a greater extent of disorder was observed. This was interpreted as having implications in the thermal stability of the CPN, since that of Porto Santo bentonite outperformed the SWy-2 based CPN when the temperatures of the 60% mass loss were compared. Nonetheless, TGA analysis of both nanocomposites indicated a thermal stability that surpassed that of the pristine polymer alone. This advantageous feature, in conjunction with the low-cost and high accessibility of filler material sourced directly from natural clay deposits, is a promising aspect towards improving the applicability of clay polymer nanocomposites.

Population-Scale Foraging Segregation in an Apex Predator of the North Atlantic.

In this work we investigated the between-colony spatial, behavioural and trophic segregation of two sub-populations of the elusive Macaronesian shearwaters Puffinus baroli breeding only ~340 km apart in Cima Islet (Porto Santo Island) and Selvagem Grande Island. Global location sensing (gls) loggers were used in combination with the trophic ecology of tracked individuals, inferred from the isotopic signatures of wing feathers. Results suggest that these two Macaronesian shearwater sub-populations do segregate during the non-breeding period in some ‘sub-population-specific’ regions, by responding to different oceanographic characteristics (habitat modelling). Within these disparate areas, both sub-populations behave differently (at-sea activity) and prey on disparate trophic niches (stable isotope analysis). One hypothesis would be that each sub-population have evolved and adapted to feed on particular and ‘sub-population-specific’ resources, and the segregation observed at the three different levels (spatial, behavioural and trophic) might be in fact a result of such adaptation, from the emergence of ‘cultural foraging patterns’. Finally, when comparing to the results of former studies reporting on the spatial, behavioural and trophic choices of Macaronesian shearwater populations breeding on Azores and Canary Islands, we realized the high ecological plasticity of this species inhabiting and foraging over the North-East Atlantic Ocean.

Advanced Control Solutions for Operating Isolated Power Systems: Examining the Portuguese islands

The operation of remote and isolated or islanded power systems is often very challenging because of their small system inertia. Moreover, economic and environmental pressure has led to an increasing renewable power penetration, particularly in wind generation and solar photovoltaics (PV). Simultaneously, significant technological progress has been made in terms of control capability of grid assets [generators, controllable loads such as electric vehicles (EVs), and energy storage systems], mostly exploiting the capabilities of power electronics. In this context, several advanced control solutions can be implemented, supporting and improving the robustness of the operation in terms of fast frequency and voltage control responses. In this article, the Portuguese islands are taken as a case study. Within the Madeira archipelago (Porto Santo and Madeira islands), two approaches were envisioned. For Porto Santo Island, the main goal is the sizing of a flywheel energy storage system (FESS) to avoid frequency stability problems. For Madeira Island, the objective relies on the exploitation of hydro resources through the quantification of the technical benefits resulting from variable speed hydro pumping stations that are able to provide primary frequency regulation services in the pump operation mode. In addition, this article also addresses the benefits of introducing EVs in Flores Island in the Azores Archipelago. Finally, to support the development of innovative technological solutions for this type of power system, a laboratory setup based on scaled test systems was also set up and is described. A set of applications was specifically developed for such autonomous power systems. The laboratorial infrastructure allowed the testing of solutions and prototypes for hardware and software modules related to those applications.