Rocky Island Research Articles

The application of UAV-derived SfM-MVS photogrammetry for the investigation of storm wave boulder deposits on a small rocky island in the semi-enclosed Northern Adriatic Sea

The inventory and categorization of an extensive coastal boulder assemblage originating from storm wave transport on the coastline of Fenoliga Island (Northern Adriatic Sea, southern Istria, Croatia) are presented and discussed herein. The study adopted the use of a commercial Uncrewed Aerial Vehicle (UAV) and Structure from Motion-MultiView Stereo (SfM-MVS) photogrammetry for the construction of a 3D model of the island. A Digital Elevation Model (DEM) and an orthomosaic were produced and employed for the mapping of the boulder assemblage in a GIS. In total, 592 boulders were identified and mapped. Using SfM-MVS-derived products allowed for the identified boulders to be categorized based on size classification. Amassed data relating to the boulder characteristics was inserted and stored in a GIS, including the results of a comparative assessment with historical Google Earth imagery which enabled the ‘quantification of boulder transport over a 9-year timeframe’. Field evidence indicates that boulders were created in-situ via the quarrying of bedrock strata by breaking waves causing increased water pressure within preexisting surfaces of weakness such as bedding planes and sub-vertical fractures. Once detached, the boulders were transported and deposited during storm wave events. Repeated storm events can further displace previously detached clasts.

Growth of the sandy isthmus of tyre and ensuing relocation of its harbors

The renowned Phoenician city of Tyre was settled on a small coastal island from which it resisted invasions and sieges for centuries. In 332 BCE, the city was taken when Alexander-the-Great built a 750 m-long causeway to seize the island. The causeway interrupted longshore sediment transport, forcing sand to accumulate along the causeway, creating a isthmus that today still connects the island to the mainland. This isthmus is no less than 530 m wide and 13 m high. We studied the impact of isthmus growth on city development during Antiquity, by combining archeological data, core stratigraphy, and multibeam bathymetry to track the paleogeographic evolution of the land-facing coast of Tyre, from the Holocene marine transgression up to today. In Phoenician time (900-300 BCE), sea-level markers indicate that relative sea level lied more than 2.5 m below current sea level, defining a 1500 × 600 m rocky island, 450 m longer in the south than the modern rocky headland. Between the island and the mainland, diffracted/refracted waves built a submerged sand bank that rests on eroded transgressive lagoonal clays. Along the mainland-facing coast of Tyre Island, Phoenician walls were built on the emerged end of the sand bank. Middle infrared spectroscopy (MIRS) shows that the sand of the bank and its successor isthmus is made of carbonate clasts (90–100%). 36Sr/37Sr ratios further indicate that these are modern bioclastic sands. Coeval, heterogeneous clay-rich sediments were deposited between the rocky island, and the sand bank. We interpret these as harbor sediments, deposited behind buried and/or submerged Phoenician breakwaters. The sand bank inflated dramatically after the building of Alexander's causeway, rising 5 m during the Hellenistic and Roman periods. It rose another 4 m–8 m in successive stages during Byzantine and Medieval times, up to the 19th century. The rapid growth of the sandy isthmus after 332 BCE led to the demise and burial of the harbors that had been developed along the mainland-facing coast. The Phoenician southern harbor of Tyre appears to have been buried in Roman times during the repurposing of the SE corner of the island for monumental baths. We interpret this repurposing as a response to the growth of the sandy isthmus, and suggest that the northern Phoenician harbor was then relocated to its present position. Subsequent relative sea level rise led to the erosion of the landfill overlying the southern harbor, exposing the formerly buried port on the seafloor.

О присвоении новых географических названий в оазисе Холмы Ларсеманн (Восточная Антарктида)

The author makes a summary for a series of geomorphometric, geological, and biological field studies by a complex team of the 68th Russian Antarctic Expedition performed at two areas of the Larsemann Hills oasis (Ingrid Christensen Coast, Princess Elizabeth Land, East Antarctica) in February 2023. The areas (a rocky island and a cape) are located to the south of the Stornes Peninsula, at the western border of the oasis with the Polararboken Glacier, on the Wilcock Bay coast. At the time of filed studies, both the areas were white spots on large scale topographic and geological maps, unexplored, and without any names given before. Guided by traditions of land explorers as well as considering the mapping practice of new territories, the 68th Russian Antarctic Expedition complex team assigned seven toponyms to the areas and their particular elements.

Climate and topography rather than tree species affect mite communities (Mesostigmata) in severe conditions—Studies from sandstone rocky islands of the Szczeliniec Wielki Plateau (Poland)

AbstractRelationships between certain plant species and soil fauna assemblages in severe climatic conditions require scientific attention due to reported climatic changes. We investigated density, diversity, and community structure of soil mites (Mesostigmata) in tree biogroups of Betula pendula, Picea abies, and Pinus sylvestris with microhabitats represented by Calluna vulgaris, Dicranum scoparium, Vaccinium myrtillus, and Vaccinium vitis‐idaea plant patches and accumulated litter in humid and cold rock crevices a few meters deep. We analyzed the effects of climatic (light availability, precipitation, temperature) and environmental (litter pH, organic matter thickness, microhabitat type) conditions on mite communities based on 1080 samples collected during two vegetation periods (2004–2005). Results revealed that litter pH was shaped by microhabitat type (plant patches and rock crevices) whereas organic matter thickness depended on tree species and microhabitat type. Also, light availability differed between tree biogroups and microhabitats. This study documented that Mesostigmata abundance was shaped by maximum daily temperature while species richness was also affected by total monthly precipitation, tree species (P. sylvestris) and microhabitat (rock crevices). Results revealed that mite density ranged from 3001 ± 213 ind./m2 in the P. abies biogroup to 3310 ± 350 ind./m2 in P. sylvestris. On the microhabitat level, mite density ranged from 2571 ± 170 ind./m2 in V. myrtillus patches to 4137 ± 463 ind./m2 in rock crevices. Total number of recorded species was highest in rock crevices (41 species), and lowest in C. vulgaris (19). In conclusion, results indicated that climatic conditions modulate mite communities on an isolated rocky island. This study documented that maximum daily temperature during the vegetation period affected Mesostigmata abundance, whereas species richness and diversity were also shaped by total monthly precipitation and tree species (P. sylvestris). In addition, the community was also affected by litter acidity, organic matter and tree species.

Historical Cartography (NE, Brazil): A Study of Coastal Geoforms Cartographed Post-Discovery

Geomorphological studies are crucial for understanding the evolution of relief, and when associated with cartography, they enhance the interpretation and knowledge of environmental dynamics. Hence, historical cartography is essential for the documental rescue of landscapes, which, based on the mapped geoforms, enhances post-discovery studies for the state of Ceará, Brazil. Historically, this state was intermittently mapped in the sixteenth and seventeenth centuries but gained greater attention from Portugal in the eighteenth and nineteenth centuries after its separation from Pernambuco. Despite this, cartographic studies on coastal geoforms are not typical for the Ceará coast over a given period, highlighting the importance of this investigation. Therefore, this article aimed to study the environmental history of the coastal geoforms mapped on the extreme west coast of Ceará in the seventeenth and eighteenth centuries. This research had a qualitative and exploratory basis, with cartographic documental surveys online and in loco, covering the municipalities of Jijoca de Jericoacoara, Camocim, and Barroquinha. Fifty maps of different origins were collected, three of which were used: a French sketch and two Portuguese maps. In the French material of 1615, geoforms in the Cape de la Tortue indicated the presence of a rocky island separated from the mainland. From the Portuguese map of 1629, a well-cut coastline was noted, identifying Buraco das Tartarugas, where there were two islands of different sizes. In the 1794 map, an island in the cove called Geri qua Coá was noted, differing in landscape from the previous ones, as it did not have tombolos connected to the continent. The cartographies presented particularities for revealing a possible advance in the local sea level. Thus, it is possible to motivate future research in the area of historical cartography as a tool for the analysis of the paleogeographic evolution of the coastal zones of Ceará.

Bird eggs

I once spent a summer studying gulls on Appledore Island in the Gulf of Maine, off the east coast of the United States. The rocky island is a breeding colony for herring gulls (Larus argentatus) and great black-backed gulls (Larus marinus), so I had a front-row seat to the dramas that unfolded as birds paired up, laid and incubated eggs, and raised chicks. I saw chicks hatch from large speckled eggs (Figure 1A), a Herculean feat that took over an hour. Eggs and chicks are extremely vulnerable, and many gull offspring do not survive. Now, when a gull soars past - or pilfers my sandwich at the beach - I appreciate the hurdles it overcame just to reach adulthood.

Skellig Michael, Co. Kerry: A Lonely Island Hermitage at the Edge of the World?

The spectacular monastic complex on the rocky island of Skellig off the south-west coast of Ireland is a UNESCO World Heritage site that has been subject to archaeological excavations and surveys since the 1980s. In recent years, it has been the location of episodes in the Star Wars films The Force Awakens and The Last Jedi which has led to some diminution of its cultural heritage and, in particular, its place in the history of universal monasticism. This article attempts to restore its significance to world monasticism by reading its location and landscape through the lens of monastic literature and monastic ideology.

The Mysteries of Lake Copais and the Island Fortress of Gla

The Bronze Age drainage of Lake Copais, Boeotia, is unique within Europe as the largest and most complex work of engineering of the period. Comprising large dams, polder dykes, canals, massive levees, cuttings and tunnels, it made at least 95km² of drained lake bed available for agricultural production. The first polders were established in the Middle Helladic period with great extensions in the Late Helladic. During the latter period the largest of all the Mycenaean citadels was constructed at Gla which had been a rocky island in the lake prior to the drainage. But exactly what type of settlement it was still remains something of a mystery. This paper draws together the history of research on the citadel of Gla.

Phylogeography and genetic diversity of the microbivalve Kidderia subquadrata, reveals new data from West Antarctic Peninsula

It is well established that Antarctic biodiversity has been strongly influenced by rapid climatic fluctuations during the Quaternary. Marine invertebrates from Antarctica constitute an interesting lens through which to study the impacts of the last glacial periods as glaciation impacted the distribution and intraspecific genetic variation of these animals. However, the impact on the spatial genetic distribution and historical demography of local processes in areas adjacent to the West Antarctic Peninsula (WAP) is less clear. Here we present new genetic information on the bivalve Kidderia subquadrata, a small mollusk that inhabits intertidal rocky island ecosystems throughout the WAP. Using a phylogeographical approach, we examined the spatial patterns of genetic diversity in this brooder species to test the hypothesis of strong genetic structure in incubating organisms and the hypothesis of glacial refugia in organisms with limited dispersion. We found evidence of strong genetic structure among populations of the WAP and a recent expansion in the South Shetland Islands. Our findings are concordant with the predictions that incubating organisms, abundant in Antarctica, present a strong genetic structure among their populations and also support the hypothesis of glacial refugia in organisms with limited dispersion. The effect of the coastal current pattern in the WAP is suggested as a driver to the local spatial dynamics of the genetic diversity distribution. Although genetic information about this microbivalve is still scarce, the knowledge reported here has increased our understanding of the evolutionary patterns of this organism that is endemic to the Southern Ocean.

Soil bacterial and fungal biomass are independent of aboveground plant communities in a rocky island system

Soil microbial communities and plants are intimately associated and each can regulate the growth and specific composition of the other through relationships such as competition and symbiosis. Such links between the above and belowground components of soil ecosystems are important as they determine the functioning of key ecosystem processes, including decomposition and nutrient cycling. In the present study, we used structural equation models to investigate the direct and indirect effects of plant community properties (richness, evenness and net primary productivity) and of soil nutrient pools (C, N and P) on the biomass of rhizosphere and non-rhizosphere bacteria and fungi. The biomass of rhizosphere and non-rhizosphere bacteria and fungi was mainly determined by the organic matter content. More importantly, nutrient pools were not modulated by plant communities and we did not find any evidence of a link between aboveground and belowground components of soil systems in this respect. The findings indicate that aboveground and belowground components of the soil system are not directly linked and that any potential relationships will be mediated by the effects of aboveground components in nutrient pools.

Wave climate and power distribution around a rocky island: Alcatrazes, Brazil

We investigate the distribution of the wave power around the Alcatrazes island, a protected marine reserve in southeastern Brazil, located at 20 nautical miles from the coast of São Sebastião/SP. A 14-year wave time series (2005-2018) extracted from the global WaveWatch III model, was used to obtain the offshore wave climate. Based on the wave climate, a wave propagation model (Delft3D) was applied in order to obtain nearshore information. The most frequent waves are from the east, southeast and south, with heights between 1.0 and 2.0 m and periods of 7 to 10 s. Due to dominant wave direction incidence, the wave power is higher at the more exposed eastern side of the island, with its lee side becoming shadowed from the main wave trains. Magnitudes vary seasonally, with winter and autumn presenting more energetic southerly waves and consequent higher wave power along the rocky island. The wave power distribution is a consequence of the incident wave characteristics and the geomorphology of the island. Our findings are the first assessment of the local wave climate and wave power distribution along the rocky shores of Alcatrazes island, providing important background information for understanding different aspects of its functioning and management.

Particle motion measurements near a rocky shore off Cabo Frio Island.

This paper describes the lessons learned from the experiment BIOCOM'19 carried out in January 2019, in a shallow water bay off the island of Cabo Frio (RJ, Brazil). A dual accelerometer vector sensor hydrophone was deployed for two days, near a rocky shore covered with a significant benthic fauna. The results show that the frequency band above approximately 1.5 kHz is mostly associated with invertebrate biological noise and that the acoustic and the particle motion fields have a similar behavior, following the usual dawn-dusk activity pattern, and a coherent directivity content. At low frequencies, below ∼300 Hz, the acoustic pressure and the particle acceleration fields have significantly different spectral content along time. Many of these differences are due to anthropogenic noise sources related with nearby boating activity, while during quiet periods, they may be attributed to the biological activity from the rocky shore.

ФРАКТАЛЬНІ ДОСЛІДЖЕННЯ РІЧКИ ДНІПРО

Розглядаються питання дослідження фрактальності стока р. Дніпро у 1818-1872 роках.

Place, Visibility and Perception: The materiality of Es Vedrà and its enfolding within New Age discourse and media-lore.

The rocky island of Es Vedra, off the south-western tip of Ibiza, in Spain’s Balearic Islands, features prominently in tourism materials and in related social media postings. Its scenic aspects have prompted a physical orientation of shoreline buildings around its vista and it has also been the subject of accounts detailing its allegedly mysterious attributes. The latter derive, in part, from regional histories and folklore but more fundamentally relate to recent New Age/counter-cultural perceptions of the various “energies” that have been perceived to flow around parts of Ibiza and the enfolding of Es Vedra, in particular, within a set of generic associations of mystical spatiality. Following a discussion of the latter, this article identifies the development of the area around Es Vedra and the rocky island’s representation as a specially “charged” location. Drawing on these aspects, the article identifies the manner in which the rarely visited island is, simultaneously, highly visible and overlaid by cultural associations that effectively “cloud” its materiality. In view of these aspects, the island is characterised as a distinct entity within international secular traveller pilgrimage circuits.

Marine geological researches in the greater bay of Navarino area, Southern Ionian sea

This paper examines the marine area of the Bay of Navarino and the Ionian sea sector to the west of the bay, based on a collection of shallow and intermediate penetration seismic profiles and on three gravity cores. The Bay has a smooth sea bottom morphology with maximum depth (75m) toward the south. Two minor reefs penetrate the sea bottom, one of them rising above the sea level forming a rocky island. In the open sea area the sea bottom is anomalous, especially after the shelf break, that is distinguished at a depth of approx. 160m. Beyond this depth deep valleys and ridges alternate and produce a rough morphology. The examination of the three gravity cores indicated that their sediment sand composition is mainly biogenic with minor amounts of terrigenous material. Increased shell fragments and terrigenous material was found at the bottom of one core taken at a depth of 116m, related probably to wave action at an earlier sea level position. The study of the seismic profiles collected within the bay and in the shelf area revealed,the presence of two distinct sedimentation units, un upper A filling with loose sediments the basins that are formed in the lower Y which is the basement. Within unit A two distinct subunits are recognized Al and A2, separated by an unconformity. In the sector to the west of the bay and beyond the shelf break, alternating opaque and transparent sediment packages are present, that are attributed to earlier sedimentation phases of low/high sea level stages. An older shelf break feature correlated with sea level stage 6 was distinguished at approx. 250m. sea depth. Thus subsidence rate in the area is estimated between 1 and 2 mm/year. The comparison of all data with the known sea level change curve indicated that unit AI was deposited during and after the latest transgression (stage 1) the unconformity between Al and A2 is related to the previous regression (stage 2), while the deposition of the unit A2 took place probably during stages 3 and/or 5. The morphology of the basement Y in the bay and the shelf area is thus attributed probably to stage 6 when the area was again subaerially exposed.

The High Price of Resettlement: The Proposed Environmental Relocation of Nauru to Australia

Most Australians today know the hot, rocky island of Nauru as a Pacific country to which Australia sends asylum seekers who have come by boat. Far fewer recall proposals 50 years ago to resettle the population of Nauru on an island off the Queensland coast. Extensive and lucrative phosphate mining on Nauru by Australia, the UK and New Zealand throughout the twentieth century devastated much of the 21 km2 island, and scientists believed it would be rendered uninhabitable by the mid-1990s. With the exorbitant cost of rehabilitating the land, wholesale relocation was considered the only option. But the Nauruans refused to go. They did not want to be assimilated into White Australia and lose their distinctive identity as a people. This episode adds further complexity to the fraught co-dependency of the Australian–Nauruan relationship, and an incongruous twist to the idea that Nauru might be able to resettle refugees today. In particular, it provides a cautionary tale for perennial discussions about the future relocation of Pacific island communities in the face of climate change.

Aerial photography based estimation of greenhouse gas emissions from penguins in Victoria Land, Antarctica

Marine animals are “bio-indicators” of climate change in the Antarctic. The abundance of nutrients in their excreta, such as carbon (C) and nitrogen (N), promotes the emission of greenhouse gases (GHGs), including methane (CH4) and nitrous oxide (N2O). Adelie penguins are important marine animals, and their colonies have therefore become potential “hotspots” of GHG emissions. Field observations have been conducted to study penguin excreta as a source of CH4 and N2O emissions in the Antarctic Peninsula. However, due to the lack of penguin population data, the total GHG emissions have not been estimated at the regional scale. With the development of remote sensing monitoring techniques in recent years, high-resolution satellite imagery and aerial photographs have made it possible to monitor penguin populations in the Antarctic, with the results used as a foundation to estimate GHG emissions. Inexpressible Island, a small, rocky island on the shore of the Ross Ice Shelf in Terra Nova Bay, Victoria Land, Antarctica, houses an important colony of Adelie penguins. This study extracted information about the penguins from aerial photographs using a pixel-oriented RGB (red, green, and blue) color space model of Victoria Land. Adelie penguin populations on Inexpressible Island could be estimated via a penguin shadow analysis in the RGB model. To validate the accuracy of the RGB model, we randomly selected several images and used the RGB method alongside an artificial visual interpretation method, with the results from both methods compared using the relative deviation index. In addition, a GHG model was developed to estimate CH4 and N2O emissions from Adelie penguins. The model included a variety of parameters, such as the CH4 and N2O fluxes from penguin excreta, the population number, the fresh weight of excreta produced by a penguin each day, and the duration of CH4 and N2O emissions from the excreta.

Pulau Ling: an important seabird hotspot on the east coast of Peninsular Malaysia

Pulau Ling is a small rocky island located to the south of Pulau Redang, forming with other southeast small islands, the Redang Archipelago, in the state of Terengganu, Malaysia. The island was highlighted in the early 1950s as an important seabird site, although little was then known on the status of seabirds on the island. Field visits were made between May 2015 and September 2015 to assess the importance of this small island to seabird species. Four tern species were identified: two of them, black-naped tern Sterna sumatrana and bridled tern Onychoprion anaethetus, were found to breed there, while the other two species, great crested tern Thalasseus bergii and roseate tern Sterna dougallii were found to use the island as a stopover site without any evidence of breeding. Furthermore, the Pacific Eastern Reef egret Egretta sacra (the black morph), was also found to breed on the island. Other species encountered included white-bellied sea eagle Haliaeetus leucogaster (recorded once in June 2015, soaring over the island). These preliminary data show the importance of such small rocky outcrops for tropical breeding and migrating seabirds, where food availability and lack of disturbance may be the two main drivers for diversity and survival.

Vertically-oriented trace fossil Macaronichnus segregatis from Neogene of Santa Maria Island (Azores; NE Atlantic) records vertical fluctuations of the coastal groundwater mixing zone on a small oceanic island

The trace fossil Macaronichnus segregatis is interpreted to be produced by opheliid polychaetes that feed on epigranular microbes and organic matter commonly abundant in shallow-marine foreshore sands. Resulting traces are horizontal and typically random in orientation, but sometimes perpendicular to the shoreline. However, M. segregatis in Neogene sandy sediments from Santa Maria Island in the Azores shows a vertical or sub-vertical orientation. This is explained by vertical flow of pore waters and oxygenation fluctuations within the mixing zone between interstitial marine and freshwater aquifers–where epigranular microbes and organic matter are most enriched. On reefless volcanic oceanic islands like the Azores, insular shelves are invariably steep, narrow, and exposed to strong swell. Aquifers in this setting respond rapidly to small changes on account of limited shelf space and a high potential differential that stimulates a vertical shift in habitats. Freshwater aquifers on small, low-relief oceanic islands form a thin lens, the edges of which are wedged against marine interstitial waters and migrate up and down in response to changes caused by tides, storm surges and precipitation. During the Late Miocene–Early Pliocene, Santa Maria was an island fitting this description. Due to a waning volcanism, intense marine erosion and gradual submersion, the island developed a wide shallow platform covered by sandy shoals, as exemplified by the Malbusca section with vertical Macaronichnus. The process, however, is more acute on small, reflective beaches perched on rocky island coasts. Here, sand blankets cover small ramps cut in the basaltic bedrock, resulting in very limited freshwater aquifers subject to strong changes due to the low permeability of basalts. The mixing zone is therefore forced to migrate chiefly up and down, mostly due to tides. The same response is dramatic in sandy fillings trapped in basalt fissures. As a consequence, the producer of Macaronichnus was tightly constrained in movement. Both situations occur in the “Pedra-que-pica” section on Santa Maria.

Model-based analysis of causes for habitat segregation in Idotea species (Crustacea, Isopoda).

On the shore of the rocky island of Helgoland (North Sea) two closely related isopod species, Idotea balthicaPallas, 1772, and Idotea granulosaRathke, 1843, share a similar fundamental niche but inhabit well-separated habitats. Idotea balthica inhabits floating algae at the sea surface and accumulations of decaying algae on the seafloor, whereas I. granulosa primarily occurs in intertidal macroalgal belts. In laboratory experiments on individually reared isopods I. balthica outperformed I. granulosa with regard to growth, reproduction, and mortality in both a fully inundated habitat and in a tidal habitat with 5 h of daily emergence. We hypothesized that habitat segregation in the two isopod species is driven by one or multiple types of biotic interactions: (1) no interaction, (2) cannibalism, (3) intraguild predation, and (4) terrestrial predation. In order to evaluate how habitat segregation can be explained by each of these interaction types we employed a size-structured population model to account for the body-size-dependent predation. Net population growth rates were fitted to the simulations as a measure of population fitness. Experimental results served as database for parameter and process identification. As predation rates were unknown, we performed a sensitivity analysis for these. We found that below 5 h of daily tidal emergence either cannibalism or terrestrial predation sufficed to explain habitat segregation. Intraguild predation, in contrast, advantaged I. balthica in any case. From linear extrapolation of the effects occurring under conditions of 5 h of daily tidal emergence, we predict that contrasting physiological responses in I. balthica and I. granulosa would cause segregation even without any interaction if emergence lasted long enough.Electronic supplementary materialThe online version of this article (doi:10.1007/s00227-016-2843-9) contains supplementary material, which is available to authorized users.