Coastal Sandy Beaches Research Articles

Salinity and Heavy Metal Tolerance, and Phytoextraction Potential of Ranunculus sceleratus Plants from a Sandy Coastal Beach.

The aim of the present study was to evaluate tolerance to salinity and different heavy metals as well as the phytoextraction potential of Ranunculus sceleratus plants from a brackish coastal sandy beach habitat. Four separate experiments were performed with R. sceleratus plants in controlled conditions: (1) the effect of NaCl gradient on growth and ion accumulation, (2) the effect of different Na+ and K+ salts on growth and ion accumulation, (3) heavy metal tolerance and metal accumulation potential, (4) the effect of different forms of Pb salts (nitrate and acetate) on plant growth and Pb accumulation. A negative effect of NaCl on plant biomass was evident at 0.5 g L-1 Na+ and growth was inhibited by 44% at 10 g L-1 Na+, and this was associated with changes in biomass allocation. The maximum Na+ accumulation (90.8 g kg-1) was found in the stems of plants treated with 10 g kg-1 Na+. The type of anion determined the salinity tolerance of R. sceleratus plants, as Na+ and K+ salts with an identical anion component had a comparable effect on plant growth: nitrates strongly stimulated plant growth, and chloride treatment resulted in slight but significant growth reduction, but plants treated with nitrites and carbonates died within 4 and 5 weeks after the full treatment, respectively. The shoot growth of R. sceleratus plants was relatively insensitive to treatment with Mn, Cd and Zn in the form of sulphate salts, but Pb nitrate increased it. Hyperaccumulation threshold concentration values in the leaves of R. sceleratus were reached for Cd, Pb and Zn. R. sceleratus can be characterized as a shoot accumulator of heavy metals and a hyperaccumulator of Na+. A relatively short life cycle together with a high biomass accumulation rate makes R. sceleratus useful for dynamic constructed wetland systems aiming for the purification of concentrated wastewaters.

The Formation of Late Pleistocene and Holocene Sand Dunes on Kikaijima Island, Nansei Islands

Coastal sand dunes dating to the latter part of the late Pleistocene were constructed at substantially lower sea levels on Kikaijima Island. They are preserved because of large-magnitude uplifts ascertained from occurrences of outstanding late Pleistocene and Holocene coral terraces. In addition, because Holocene sand dunes occur close to those of Marine Oxygen Isotope Stage 3 (MIS 3), the island is ideal for examining the environments of the formation of sand dunes, which were constructed under different climatic and sea-level conditions. Distributional and depositional features of sand dunes are clarified, and their chronology is constructed on the basis of tephrochronology, 14C dating, and chronological relationships of the sand dunes with marine terraces of known age. The environments of sand-dune formation on Kikaijima are examined in relation to climatic and sea-level records within regional and global contexts. Nine tephra layers are recognized. These include two widespread tephras, Kikai-Akahoya tephra (K-Ah) and Aira-Tn tephra (AT). The other seven tephras, consisting of fine ash layers, are newly recognized and named Kikaijima-1 tephra (Kj-1) to Kikaijima-7 tephra (Kj-7), of which the upper six, lying between K-Ah and AT, are aged from 13,000 to 30,000 cal BP. Holocene sand dunes began to form at c. 8,000 cal BP before the culmination of maximum Holocene sea-level rise. This is earlier than dune formation on other coasts of the Japanese Islands, where formation was generally after the culmination of maximum Holocene sea-level rise. The earlier formation on Kikaijima Island is probably due to coastal emergence caused by the conspicuous uplifts of Kikaijima and the high production of calcareous beach sands sourced from coral and foraminiferal and other materials. Late Pleistocene sand dunes, predominantly distributed at the southwestern part of Kikaijima Island, were formed in MIS 3. These dunes consist of longitudinal and parallel dunes. The largest longitudinal dunes on the lowest MIS 3 terraces, at the northern area of the southwestern part of Kikaijima Island, were formed in late MIS 3, c. 40 to 32 ka, while small and parallel sand dunes on the upper MIS 3 terraces were formed in early MIS 3. The occurrence and chronology of the Holocene and late Pleistocene sand dunes suggest that their formation on Kikaijima Island is mainly related to the occurrence of coastal sandy beaches during sea-level high stands. Although Holocene sand dunes are related to Holocene high stand, those of MIS 3 are related to high stands during cycles of sea-level fluctuations in MIS 3. The longitudinal landform of the sand dunes recognized in the late MIS 3 suggests that the prevailing winds in MIS 3 were stronger than in the Holocene. This study provides critical data for constructing a chronological framework that integrates various aspects of palaeoenvironments, as well as human interactions and responses in southern Kyushu.

Microplastic pollution on sandy beaches of Puerto Rico

Caribbean islands, including Puerto Rico, are biodiversity hotspots threatened by microplastics (<5 mm). Little is known about the extent of microplastic pollution in coastal sandy beaches of Puerto Rico. Sand from six northern beaches was collected in the high tide line to determine microplastic abundance (0.3–4.75 mm). Península La Esperanza, the most polluted beach, exhibited higher average abundance (17 items/kg dw) and diversity. High urbanization, industrial/port activities, and riverine input are likely sources of plastic debris on this beach. The other beaches showed lower and similar average abundance (3 to 7 items/kg dw) despite having distinct potential point and non-point sources. Overall, fibers (40%), fragments (28%) and foams (27%) predominated (n = 102 particles). Results showed comparable levels to other world beaches, some classified as highly contaminated, but only when transforming units to items/m2. Preliminary ATR-FTIR analysis identified mainly polyethylene. It is imperative to have plastics source reduction through waste management.

Wireless sensor networks and machine learning meet climate change prediction

SummaryClimate change is one of the main challenges faced by the development of every country. For countries producing agricultural commodities, the climate affects the quantity and quality of products. Many methods have been proposed to keep track of climate. One traditional method is the weather station model, which indicates the temperature, wind speed, and direction and extent of cloud cover. However, this method of predicting climate change has low accuracy due to geographical variation, for example, mountainous or forested areas. Recently, a combination of wireless sensor networks (WSN) and machine learning (ML) has been considered for prediction with the Internet of Things (IoT), for instance, through a wireless body area network. For climate change prediction, we design and develop a control system that uses node sensors to collect data in sandhills and beaches, with data management conducted via a web application with three components. The first component is designed to collect data from the node sensors. The second component is mainly used to control the system through a web application. The third component uses linear regression in ML to analyze the data to predict weight and volume. The complete system has been tried and tested in real time on a 10‐m2 area of a beach at Binh Thuan province, Vietnam, where sensor node data were wirelessly collected over a cloud using a web application. This enabled assessment of the current state of the land at a coastal sandy beach, as well as prediction of the risk level of desertification and natural disasters.

Indigenous microbial communities along the NW Portuguese Coast: Potential for hydrocarbons degradation and relation with sediment contamination

Hydrocarbon degradation (HD) potential by autochthonous microorganisms in the coastal sediments of the NW area of Portugal (coastal sandy beaches and estuaries of the rivers Minho and Douro) was evaluated, investigating if water and sediment contamination/characteristics influence it. Sediments were characterized for microbial abundance (by DAPI), HD microorganisms' abundance (by MPN), microbial community structure (by ARISA), hydrocarbons (by FTIR and SPME-GC–MS), hazardous and noxious substances (SPME-GC–MS) and metals (by AAS). To our knowledge, this is the first time all these pollutants, including the selected HNS, were measured simultaneously in sediments of the selected coastal area. Higher contaminants concentrations were, generally, registered in Douro samples. A clear differentiation of the microbial community structure between beaches and estuaries was observed, as well as, between Douro and Minho river estuaries. BIO-ENV analysis indicated both sediment characteristics (e.g. OM content) and contaminants presence/concentrations (e.g. tetrachloroethylene presence) affected the structure of the microbial community along the studied areas. In all the selected sites, the characterized autochthonous microbial communities showed potential for hydrocarbons degradation, with HD microorganisms being found in all collected sediments. These microorganisms can be a valuable asset to recover contaminated areas, but sediment characteristics and contaminants presence/levels need to be taken into account as they can affect their bioremediation potential and the success of their application as biotechnological tool.

Flying sand-dwelling spiders: aerial dispersal in Allocosa marindia and Allocosa senex (Araneae: Lycosidae)

Aerial dispersal in spiders or ballooning is typically considered to occur during the day by juvenile instars or small-sized adults. Allocosa marindia Simó, Lise, Pompozzi & Laborda, 2017 and Allocosa senex (Mello-Leitão, 1945) are two nocturnal wolf spiders that inhabit coastal sandy beaches of South America. As mothers of both species emerge from the burrows during the night to disperse the spiderlings, we expected that aerial dispersal of spiderlings could occur during that period. Our aim was to test ballooning occurrence in both species during day and night under laboratory conditions, using as a positive control, the wolf spider Schizocosa malitiosa (Tullgren, 1905). We examined ballooning behavior of once-molted spiderlings of A. marindia, A. senex and S. malitiosa, under diurnal and nocturnal conditions, recording observations in a container with grasses and sand as substrate. We exposed the spiderlings to air flow and recorded occurrences of climbing the grass, dropping on dragline and tip-toeing (pre-ballooning behaviors). The three species performed pre-ballooning behaviors during the day but also in the night, and the occurrences of these behaviors varied both within and among species. More events of pre-ballooning behavior were observed during the day than during the night. However, we found differences in the number of events of tip-toeing and dropping on dragline according to the time of the day. We discuss the possibility that microhabitat conditions could affect ballooning propensity particularly in the three coastal wolf spiders.

Statistical assessment of heavy metal distribution and contamination of beach sands of Antalya-Turkey: An approach to the multivariate analysis techniques

The distribution of heavy metal concentrations in the beach sand samples collected from 44 different locations along the Manavgat Alanya coastline of Antalya covering different coastal sandy beaches was studied. The average concentration level of these metals in the beach sand was calculated and compared to those of the Earth Crust, Sandstone, Ultrabasic Rock and the acceptable limit for Turkey in order to determine their anomalies. Heavy metal (Cr, Zn, Ni, As, Cu, Pb, Co, Mo, Sb and Cd; along with Al, Fe, Mg, Mn, Na, K, Ba, Ca and W) were determined. The elements occurred in abundance as Ca&gt;Na&gt;Mg&gt;Fe&gt;Al&gt;K&gt;Ti&gt;Mn&gt;Cr&gt;Ba&gt;V&gt;Zn&gt;Ni&gt;As&gt;Cu&gt;Pb&gt;Co&gt;Mo&gt;Sb&gt;W&gt;Cd. The sufficiency of the number of samples used from the study area is revealed by the high explanatory power R2 = 96:9 % of the ANOVA Model. Using the box plot, it was also noted that some heavy metals such as As (in samples 1, 19, 25, 28 and 29); Mn (in Samples 23 and 39); Na (in samples 23, 24 and 45); Cr (in Sample 33) and Ti (in Sample 15) had very high anomalies. Heavy metal contents show high anomaly concentrations when compared to some background values (Earth Crust, Sandstone, Ultrabasic and Turkey acceptable limit).

Foraging ecology of sanderlings Calidris alba wintering in estuarine and non-estuarine intertidal areas

Outside the breeding season, most shorebirds use either estuarine or non-estuarine intertidal areas as foraging grounds. The sanderling Calidris alba is mostly associated with coastal sandy beaches, a habitat which is currently at risk worldwide due to increasing coastal erosion, but may also use estuarine sites as alternative foraging areas.We aimed to compare the trophic conditions for sanderlings wintering in estuarine and non-estuarine sites within and around the Tejo estuary, Portugal, where these two alternative wintering options are available within a relatively small spatial scale. To achieve this, we analysed sanderling diet, prey availability, foraging behaviour, and time and energy budgets in the different substrates available in estuarine and non-estuarine sites.In terms of biomass, the most important sanderling prey in the estuarine sites were siphons of the bivalve Scrobicularia plana, polychaetes, staphylinids and the gastropod Hydrobia ulvae. In non-estuarine sites the main prey were polychaetes, the bivalve Donax trunculus and chironomid larvae. Both food availability and energetic intake rates were higher on estuarine sites, and sanderlings spent a higher proportion of time foraging on non-estuarine sites. In the estuary, sanderlings foraged in muddy-sand substrate whenever it was available, achieving higher intake rates than in sandy substrates. In the non-estuarine sites they used both sandy and rocky substrates throughout the tidal cycle but had higher intakes rates in sandy substrate.Estuarine sites seem to offer better foraging conditions for wintering sanderlings than non-estuarine sites. However, sanderlings only use muddy-sand and sandy substrates, which represent a small proportion of the intertidal area of the estuary. The extent of these substrates and the current sanderling density in the estuary suggest it is unlikely that the estuary could provide alternative wintering habitat for sanderlings if they face habitat loss and degradation in coastal sites.

어메니티요소를 활용한 백사장 가치평가의 기초적 연구

The sandy beach along the east coast of Korea offers beautiful scenery with high-quality sand for leisure, and is also famous for the white-sand and pine-tree which is an important scenic resource. Furthermore, the sandy beach helps to maintain natural environment of the costal area and functionates as a disaster prevention system against high waves. There are two major value evaluation methods, Travel Cost Method and Contingent Valuation Method, to assess the value of coastal sandy beach. Contingent Valuation Method is considered to be more appropriate for simultaneous evaluation on the usefulness and the uselessness of the beach. But in order to apply Contingent Valuation Method to coastal sandy beach evaluation, close examination and investigation on the potential bias, such as on questionnaires, surveys and replies, are required. In this study, the characteristic of primary amenity of sandy beach users is investigated, in prior to evaluating the usefulness and the uselessness of the beach measured by contingent valuation method. The characteristic of amenity on major sandy beaches on the east coast of Korea is studied and compared by diverse value evaluation methods.

Morphological and molecular characterization of Euplotes encysticus (Protozoa: Ciliophora: Euplotida)

The ciliate Euplotes encysticus Yonezawa, 1985 was insufficiently described so far regarding its living morphology, infraciliature and silverline system. Recently, a China population was isolated from brackish water (salinity 6‰) near a coastal sandy beach (114°32′E 22°43′N) of the Daya Bay, South China Sea and subsequent investigations were performed on it in detail. Based on data available, the morphology of this species was summarized and a new diagnosis is given which is characterized by: medium-sized body with consistently 9 frontoventral, 2 caudal and 2 left marginal cirri; 30–40 adoral membranelles; 7 dorsal kineties; dorsal silverline system consisting of complex type with irregular network; capable of encystment. Both the morphology and SSr RNA gene sequence show, with high support, a close relationship of E. encysticus and Euplotes muscorum.

Negative effects of oil spillage on beach microalgae in Nigeria

In a concerted effort to apply epipsammic microalgae indices as a biological indicator of crude oil pollution and natural remediation in a tropical estuarine environment, the direct effect of a recent oil spill on the abundance of microalgae in the coastal shore of the Qua Iboe Estuary was investigated. A significant negative effect of contamination on the salinity, acidity and nutritive salts (CO32−, Cl−, and SO42−) levels of the sandy beach soil was observed. The Biological Index of Pollution (BIP) of the beach soil was raised from the previous slightly polluted level (18%) to 75, 88, 45 and 41% after contamination, at sampling distances of 5.5, 9.5, 11.5 and 15 m from the barrier used for pollution control. These corresponded with increases in the density of microalgae with distance from the barrier. This implies that the effect of oil pollution was more severe on microalgal cells that are close to the barrier. The overall effect was a distance-influenced reduction in the regeneration capabilities of the epipsammic microalgae. Some microalgal species, particularly the cyanobacterial species of Aphanizomenon flos-aquae, Lyngbya majusculata,and a centric diatom Actinoptychus undulatus may have been exposed to contamination levels exceeding normal homeostasis and compensation. They lost their existence in the sandy beach, and their absence is recommended for use as an indicator of the short term effect of oil pollution in coastal sandy beaches in a tropical estuarine environment.

Mise évidence par l'analyse anthracologique de la stabilité de la végétation sur le littoral brésilien pendant l'Holocène supérieur [Anthracological evidence of vegetation stability in the Brazilian littoral during the Late Holocene

Anthracological studies earned out on six shell-mounds from Rio de Janeiro State (southeastern Brazilian coast) and one shell- mound from Santa Catanna State (southern Brazilian coast) showed that coastal vegetation present a marked resilience to climatic changes. In the southeastern Brazilian coast, the anthracological spectra is essentially the same between 5500 and 1400 yrs BP. Coastal sandy beach ridges were already colonized by the "restinga" (plant association charactenstic of the Brazilian coast) since at least the Middle Holocene. Depending on the site, the open restinga or the restinga forest were dominant. Forest and mangrove elements are present in all sites. In southern Brazil, no significant variation of the vegetal environment is recorded between 2500 and 1800 yrs BP. The studied site was established in the restinga environment, and the inland Atlantic Forest was probably situated quite far away. Mangrove vegetation was probably already absent from this region, which is presently under subtropical climatic conditions. No major changes of the vegetal ecosystem has taken place dunng the second part of the Holocene, notwithstanding many centuries of human occupation, pointing out to the fact that the vegetation was not greatly affected either by climatic or by anthropogenic perturbations. However, significant oscillations recorded in the mangrove vegetation from the Cabo Fno region (southeastern Brazil) might be related to climatic oscillations provoking lagoon salinity vanations. The stability of the mainland coastal vegetation is probably due to the edaphic character of coastal environments, particularly the restinga ecosystem, which is related to sandy soils and to the géomorphologie nature of sandy beach ndges. We propose that this environmental stability was a decisive factor in the sedentansation of the fisher-gatherer populations and in the maintenance of their sociocultural system.

Vegetation stability in the Brazilian littoral during the late holocene - anthracological evidence

Anthracological studies carried out on six sambaquis from Rio de Janeiro State (southeastern Brazilian coast) and one sambaqui from Santa Catarina State (southern Brazil) showed that coastal vegetation presents a marked resilience to climatic changes. Charcoal samples were collected from vertical profiles along the entire sambaqui height and examined under reflected light microscope. In the southeastern Brazilian coast, the anthracological spectra is essentially the same between 5500 and 1400 yrs BP. Coastal sandy beach ridges were already colonized by the resting vegetation since at least the Middle Holocene. Depending on the site, the open resting or the resting forest are dominant. Forest and mangrove elements are present in all sites. In southern Brazil, no significant variation of the vegetal environment is recorded between 2500 and 1800 yrs BP. The studied site was established in the resting environment, and the inland Atlantic Forest was probably situated quite far away. Mangrove vegetation was probably already absent from this region, which is presently under subtropical climatic conditions. No major changes of the vegetal ecosystem has taken place during the second part of the Holocene, notwithstanding many centuries of human occupation, pointing out to the fact that the vegetation was not greatly affected either by climatic or by anthropogenic perturbations. However, significant oscillations recorded in the mangrove vegetation from the Cabo Frio region (southeastern Brazil) might be related to climatic variations, is probably due to the edaphic character of coastal environments, particularly the resting ecosystem, which is related to sandy soils and to the geomorphologic nature of sandy beach ridges.

Multiple Autogeny and Burrow Oviposition by a Marine Horse Fly (Diptera: Tabanidae)

The pangoniine horse fly Apatolestes actites , whose immatures inhabit coastal sandy beaches in California, USA, was found to be bi-autogenous and to have much-reduced mouthparts. This is the first report of multiple autogeny in a wild-caught member of a predominantly bloodsucking brachycerous family; females of nearly all other known autogenous flies normally either require a blood meal to complete their 2nd gonotrophic cycle or are incapable of producing a 2nd batch of eggs. Gravid A. actites females search for, and oviposit in, subterranean burrows of amphipods or isopods. All other tabanids whose oviposition habits have been studied lay their eggs on objects aboveground. Mulitple autogeny and subterranean oviposition, plus other physiological and behavioral adaptations, have enabled this horse fly to colonize a generally inhospitable environment.