Coast Of Island Research Articles

Beach gold transport and aeolian concentration, southern New Zealand

ABSTRACT Aeolian concentration of iron-titanium oxides (black sand) is a common phenomenon on coasts around the world but associated aeolian detrital gold is relatively rare. In contrast, Holocene and active dunes at Waipapa beach on the coast of the southern South Island of New Zealand host aeolian black sand layers with locally abundant finely particulate (<200 µm) gold and platinum, some of which have been mined historically. Aeolian concentration of black sand, gold and platinum is driven by strong prevailing westerly winds (gusts >100 km/h) on annual or decadal time scales. Holocene fluvial recycling of aeolian sands has been important in upgrading the black sand, gold, and platinum contents. Surf concentration of black sand on the beach is minor and merely feeds the aeolian system, and this differs from other beach gold deposits around the world, which are surf-dominated. Most of the Waipapa beach gold (>90%) has flaky morphology with abundant superficial transport-related deformation reflective of fluvial transport, probably down the nearby Mataura River (∼200 km transport) between Miocene and Holocene. Minor distinctive wind-sculpted toroidal gold, and the platinum, arrived from the west (∼300 km transport) via the Waiau River and Foveaux Strait.

The Influence of Coral Reef Spur and Groove Morphology on Wave Energy Dissipation in Contrasting Reef Environments

AbstractCoral reefs protect coastlines from inundation and flooding and serve over 200 million people globally. Wave transformation has previously been studied on coral reef flats with limited focus on forereef zones where wave transformation is greatest during high‐energy conditions. This study investigates the role of forereef spur and groove (SaG) morphology in wave energy dissipation and transmission at the reef crest. Using XBeach on LiDAR‐derived bathymetry from One Tree Island in the southern Great Barrier Reef, we reproduced dissipation rates comparable to SaG field studies. We examined how wave energy dissipation differs between realistic bathymetry and those with SaG features removed, demonstrating an up to 40% decrease in dissipation when SaG features are absent. We then investigated changes to wave energy dissipation and wave transmission at the reef crest based on IPCC AR5 emission scenarios (RCP2.6 and RCP8.5) and a total disaster scenario (TD) for the year 2100. For RCP2.6, an increase in wave heights of 0.8 m and an increase in water level of 0.3 m resulted in a two‐fold increase in dissipation rates. For RCP8.5 and TD, with no increase in incident wave height, dissipation rates were 29% and 395% lower than RCP2.6. This resulted in increased wave transmission at the reef crest by 1.8 and 2.7 m for the RCP8.5‐ and TD based models, respectively, when compared to the RCP2.6‐based model. The results from our novel modeling approach of using long‐shore varying accurate bathymetry on forereefs show increased wave energy dissipation rates with implications for reducing coastal flooding and island inundation on reef‐lined coasts.

Impacts of coyote colonization on coastal mammalian predators

Extreme ecosystem modification by humans has caused drastic reductions in populations and ranges of top mammalian predators, while simultaneously allowing synanthropic mesopredator species to expand. These conditions often result in inflated local densities of highly adaptable mesopredators that disrupt trophic dynamics and place unsustainable predation pressure on native prey populations. Colonization of a dominant predator may lead to top-down control of mesopredators and restore trophic balance. Coyotes are a novel colonizer of some coastal barrier islands of eastern North America, offering an opportunity to test how the addition of an apex predator impacts an established guild of mesopredators. To assess their trophic impact, we conducted 75,576 camera trapping hours over an 18-month study period, capturing > 1.5 million images across 108 coastal camera sites. Using two-species occupancy and habitat use models, we found sizeable effects of coyote habitat use on that of red foxes and free-ranging domestic cats, suggesting that coyotes function as apex predators in barrier island ecosystems. In fact, the only factor that determined the spatial pattern of highly ubiquitous red foxes was the sympatric habitat use of the largest carnivore in the food web—coyotes. That ‘novel’ apex predators can become established in coastal food webs illustrates the highly dynamic nature of conservation challenges for habitats and species at the edge of the sea.

Epidemiological association between water salinity and blood pressure in coastal populations: ambient temperature’s role as a confounder

Due to global climate change and anthropogenic activities, many low-lying coastal communities experience high sodium in drinking water as a result of saltwater intrusion, an emerging environmental health problem in many coastal regions. Drinking saline water is associated with higher sodium intake and hypertension. Exposure to higher ambient temperatures is common in many regions affected by saltwater intrusion, particularly in tropical and subtropical regions. Little attention has been given to the role of ambient temperature in the epidemiological association between drinking saline water and population blood pressure. We argue that high ambient temperatures increase water salinity and influence communities' sodium intake, urinary sodium excretion, and blood pressure. Hence, we hypothesize that ambient temperature is a potential confounder for the relationship between drinking saline water and population blood pressure. Testing the hypothesis requires a detailed measurement of urinary, blood, and sweat biomarkers (e.g., sodium), the population's blood pressure, and their drinking water’s salinity. An increasing number of coastal regions and islands will face the dual burden of high ambient heat exposure and saltwater intrusion in the future. Future studies are needed to determine the association between drinking saline water and blood pressure after adjusting for ambient temperature in saltwater intrusion-affected regions.

Intrapopulation variation in reproduction of Lessonia variegata J. Agardh

ABSTRACT Lessonia variegata is an Aotearoa-New Zealand (A-NZ)-endemic kelp with significant commercial potential. Overseas, Lessonia spp. are harvested for use as human and animal food, cosmetics, and bioactives for biomedical applications. In A-NZ, interest in developing cultivation methodologies and commercial applications for L. variegata is growing, especially because it is an exposed-shore species which makes it an ideal candidate for exposed-coast or open-ocean aquaculture. However, establishing cultivation of L. variegata in A-NZ is currently challenging because essential knowledge about its reproduction and sporophyte development is generally unknown. This preliminary study investigated the intrapopulation variation in the reproductive output of L. variegata individuals collected from one population on the north-east coast of the South Island, A-NZ by quantifying the number of spores released, the percentage and number of spores settling, their germination, sex ratio, sporophyte production and growth. There were significant differences among individuals in the number of spores released and germinated, as well as the production of sporophytes and their growth. However, the sex ratio and the percentages and numbers of spores settling were similar among individuals. Evident differences reported in spores released and development can have possible implications for aquaculture including biobanks or sporophytes production.

Changing bryozoan fauna in Otago Harbour reflects growing urbanisation and globalisation

ABSTRACT A comparison between historic reports dating from 1884 (78 records of 35 species) to the bryozoan fauna present today (98 colonies of 14 species) reveals considerable faunal change in Otago Harbour / Te Wai Ōtākou (45° 50'S 170° 38'E) in Dunedin, east coast of South Island, Aotearoa New Zealand. This highly-modified urban port was once a rock-edged tidal inlet surrounded by bush and grassy hills, but changes to its flora and fauna are not limited to land and the intertidal. Our modern bryozoan surveys record predominantly ‘weedy’ invasive species which colonise anthropogenic surfaces, while previously-recorded larger, slower-growing native species are now missing. This study emphasises the importance of historical data and regular monitoring in determining baselines for conservation and restoration.

Seasonal and synoptic spatio-temporal variability on larval delivery mechanisms inferred from mussel settlement patterns in the Portuguese coast

Demographic connectivity is the process by which population persistence and growth are affected by the dispersal of individuals. In sessile marine species that disperse by planktonic larvae and form metapopulations, the interaction between oceanographic forcing and larval biology drives the spatial extent and magnitude of larval delivery to suitable habitat patches. The present study investigates the supply of Mytilus galloprovincialis larvae to rocky intertidal habitats located within and around two marine protected areas (MPA) in central Portugal, one located on the exposed coast and the other one in a sheltered bay, using time series of settlement intensity and oceanographic variables. The results indicate that larval delivery at short time scales (days) is strongly dependent on the interaction of upwelling circulation with coastline topography. In the exposed MPA, located on a coastal island, the magnitude of mussel larval delivery is limited by the dynamics of an upwelling front and filament that intercepts the island as upwelling increases and decreases. In the sheltered bay, under an upwelling shadow, the upwelling front promotes recirculation of the water mass, intensifying larval retention and settlement. The results are also consistent with larval transport distances of tens of kilometres and ongoing connectivity between the two MPA. This study highlights the relevance of coastal topography and its interaction with mesoscale hydrodynamics in the modulation of larval delivery, crucial for the persistence of populations and communities and in systematic conservation planning.

Tsunami Waves off the Southeastern Coast of Sakhalin Island Caused by the Eruption of the Hunga–Tonga–Hunga–Ha’apai Volcano on 15 January 2022 According to Observations by Bottom Devices of Waves

The observation of waves (sea level oscillations) in the coastal water area of the southeastern coast of Sakhalin Island was carried out from November 2021 to May 2022 using bottom-mounted high-precision ARW 14 K devices with one second discreteness. The analysis of the obtained time series revealed the presence of anomalous waves in the range of tsunami waves in January 2022. It is shown that the waves detected on 15 January 2022 with periods of 15 minutes–4 hours, significantly standing out above the background, are associated with volcanic tsunami waves. Spectral analysis of the time series showed that the maximum in the spectra of sea level oscillations found after the volcanic eruption is close to the period of the first mode of the shelf seiche. This indicates that incoming tsunami waves excite shelf seiches in the coastal zone and contribute to the generation of longshore and transverse seiches into Mordvinov Bay. Time series analysis made it possible to establish that the spectral density of sea level oscillations for the time interval of the beginning of the eruption of the Hunga–Tonga–Hunga–Ha’apai volcano from 21 December 2021 to 11 January 2022 significantly differs from the spectral density for the time of the Plinian volcanic eruption. An analysis of the statistical characteristics of sea level oscillations performed on two–day series in the range of periods 1 min–4 h for background waves and tsunamis showed an increase in the rms by 3.5 times for a time series containing tsunami waves. It has been established that for background time series containing tsunami waves, the coefficients of asymmetry and kurtosis differ little from“Gaussia” values. This indicates that the arrival of tsunami waves from distant sources does not significantly disrupt the stationarity of the wave field in the observation area.

Assessment of the concentration of some heavy metals in bottom sediments in the coastal and island areas of the southern region, Vietnam

Rivers, such as the Dong Nai, Saigon, and Mekong, are subject to urban, industrial, and agricultural pollution, leading to a high risk of heavy metal accumulation in bottom sediments. With the aid of a boat and bucket as tools, a survey was conducted to collect sediment samples from the coastal areas (downstream of Dong Nai, Saigon, Mekong Rivers) and islands (Con Dao, Tho Chu) in the Southern region of Vietnam during April and May 2023. Out of a total of 35 samples collected, preserved according to the guidelines of the Ministry of Natural Resources and Environment, the heavy metal indicators were analyzed by atomic absorption spectroscopy, and the average heavy metal concentrations were in the following order: Zn&gt;Cu&gt;Cd&gt;Pb&gt;As. Compared with the Vietnamese Technical Regulation (QCVN 43:2017/BTNMT) on sediment quality and the sediment quality of the Canadian Environment Ministry, the heavy metal concentrations in the research area have not exceeded the specified standards. However, compared with standards from the USA, the Russian Federation, and other regions in Vietnam, the levels are quite high. Moreover, the Igeo index indicates that the concentration of Pb, As, and Cd at many coastal locations downstream of the rivers is heavily polluted. This evidences that in addition to pollution from upstream sources, the activities of the local population significantly contribute to the accumulation of pollution. The research results provide a scientific basis for limiting pollution sources to ensure sustainable development of the studied areas, which is necessary today.

Pelestarian Pakaian Adat Melayu Riau Bagi Remaja di Provinsi Riau

Riau Province is an Indonesian province located on the east coast of the central island of Sumatra. Its coastal area borders the Strait of Malacca. Until 2004, the province also included the Riau Islands, a large group of small islands (the main islands include Batam Island and Bintan Island) located east of Sumatra and south of Singapore. The archipelago was split into its own province in July 2004. The capital and largest city in Riau province is Pekanbaru, and the other major city after Pekanbaru is Dumai. Riau is currently one of the richest provinces in Indonesia, and its resources are dominated by natural resources, especially petroleum, natural gas, rubber, oil palm and fiber plantations. along with the abundance of natural resources, Riau is also famous for its rich traditions and culture, both physical and non-physical that are inherent in the Riau people themselves. one of the physical cultures in Riau is Riau Malay traditional clothing. The people in Riau are dominated by the Malay tribe, where this tribe is also influenced by the Malay culture in Sumatra, Malaysia, Singapore. due to the close proximity of the region. characterized by similarities in dress or dress that has its own characteristics. the people of Riau usually wear their traditional clothes at major events, such as traditional ceremonies, holidays, official events.

A High-Resolution Digital Bathymetric Elevation Model Derived from ICESat-2 for Adam’s Bridge

This data descriptor elaborates the details of a high-resolution digital bathymetric elevation model generated for the region, namely, Adam’s Bridge, which encompasses a chain of shoals between Rameswaram Island, off the southeastern coast of Tamil Nadu, India, and Mannar Island, off the northwestern coast of Sri Lanka. The proposed dataset has taken advantage of the photon penetrability in the shallow waters by the green laser of ICESat-2 LiDAR to derive the seabed topography. Seafloor depths from ~0.2 million geolocated photons of ICESat-2 for the study area were accrued and interpolated to generate a 10 m digital bathymetric elevation model. Adam’s Bridge, an isthmus and submerged reefal assemblage in shallow and super-shallow waters, is a feature of scientific curiosity. Our dataset has the potential to enhance the understanding of Adam’s Bridge structure by providing substantial information to reconstruct its evolution.

Distribution of pacific herring off southeastern Sakhalin (sea of Okhotsk) in the summer and autumn period

The aim of the work is assessment of the spatial and density distribution of Pacific herring Clupea pallasii off the southeastern Sakhalin in June-October.Material and methods. It is based on the data of the 1989–2020 bottom trawl surveys.Novelty. For the first time long-term data on the spatial distribution of herring off the southeastern coast of Sakhalin Island are presented from the bottom trawl surveys.Results. Off the southeastern coast of Sakhalin Island herring is found in June in a pre-spawning state at depth of up to 140 m, concentrating abeam the spawning grounds. In July-October, during the feeding period and the initial period of wintering migration, herring spreads almost exclusively at depths of up to 50 m at a water temperature of more than 2–4 °C within the boundaries of the cold intermediate layer, forming the main accumulations in the Terpenya Bay at depths up to 30 m.Practical significance. The data complement the information on the spatial distribution of herring off the southeastern coast of Sakhalin Island in the summer and early autumn, and can be used for making decisions on the rational exploitation of the resource and organizations of trawl surveys.

Antibacterial activity of macroalgae crude extracts from Paraná coastal islands (Brazil) against marine isolate of Enterobacteriaceae

Antibacterial activity of macroalgae crude extracts from Paraná coastal islands (Brazil) against marine isolate of Enterobacteriaceae

Criteria for Building Residential Arrangement Models on the Coastal Island System of Vietnam

This research marks a significant milestone by proposing a set of comprehensive criteria for building residential arrangement models on Vietnam's coastal island system. The unique characteristics of these islands, such as their limited space and resources, pose complex challenges for population placement. Therefore, establishing the proper criteria for population placement is crucial and pivotal to ensure this area's sustainable and harmonious development. The author has meticulously derived 13 essential criteria from various data sources, including articles, project topics, field surveys, and expert consultations. These criteria are not just a theoretical framework but a practical tool to build a reasonable population arrangement model to bring sustainable, diverse, and harmonious development to the island community.

A Newly Discovered Ozone Formation Mechanism Observed in a Coastal Island of East China

A Newly Discovered Ozone Formation Mechanism Observed in a Coastal Island of East China

Abundance of Marine Debris on Satonda Island, West Nusa Tenggara, Indonesia

Abstract Macro-sized marine debris is found not only on the coasts of densely populated islands but also on the coasts of small islands. The presence of marine debris on this small island is because there are tourist attractions that attract people’s attention or because currents around it carry it away. Therefore, this research aims to determine the abundance of marine debris on Satonda Island (a small island in the eastern part of Sumbawa Island, West Nusa Tenggara Province, Indonesia). Even though it is small, this island is an attractive tourist destination because it has a lake formed from the eruption of Mount Tambora. Marine debris data was collected using the quadrant transect method, carried out randomly along the coastline. Data collection time was carried out at high and low tides, with the parameters recorded being the amount and type of waste, size and shape of rubbish, coordinate points, transect length, and data collection time. The research results show that the marine debris on Satonda Island is diverse (393 items), with a total weight of 16,665.45 g. At high tide, it is dominated by rubber marine debris, such as shoes and sandals weighing 1,457 g (33 items), while at low tide, it is dominated by hard plastic marine debris weighing 3,972 g (147 items).

Analysis of Seasonal Wind Energy Potential on Zanzibar Coastal Island

The main objectives of this research were to numerically analyze the potential for seasonal wind power (WP), assess wind direction, and select the most effective wind turbine (WT) for installation at the research site. Wind data were collected half-hourly from a branch of the Tanzania Meteorological Authority nearest to the research site. The collected data were analyzed using a double-parameter Weibull distribution (WD) model, where the standard deviation (SD) method was used to fit the WD. The results revealed that the site experienced strong winds within the range of 4.5–7 m/s between the hours of 05:00 - 20:00, with the most likely seasonal wind speed (WS) ranging from 5–7 m/s, while the mean seasonal WS was 9.07–12.14 m/s. The highest possible wind energy density (wED) of 23.3 GWh/m2 at a hub height of 10 m occurred during winter, followed by spring, autumn, and summer, with 6.39, 6.32, and 3.33 GWh/m2, respectively. The annual wED was &gt; 13.52 GWh/m2, with a typical month-to-month energy of 1.13 GWh/m2. Finally, the study concluded that the recommended WT model (POLARIS P62-1000) was the best choice for installation at the study site due to its sustainable WS and WP potential. Based on the findings of this research, which show that the site has sustainable seasonal wind resources, it is suggested that future wind research be carried out to extend the dataset to ensure the long-term seasonal wind pattern at the site. Doi: 10.28991/HIJ-2024-05-02-08 Full Text: PDF

Direct and Indirect Effects of Mountain Heights on Heavy Rainfall in the Hokitika Region of New Zealand

In the Hokitika region, on the west coast of the South Island of New Zealand on 18 June 2015, very heavy stratiform precipitation (&gt;200 mm/per day) occurred under north-westerlies with small CAPE (&lt;25 J/kg). Analyses of model simulations and observations showed that this heavy rainfall was due to cold-front lifting enhanced by orographic lifting over the Southern Alps. At 1.5 km grid-length, the model terrain underestimated the average height of the 103 tallest mountains over the South Island by ~800 m. This led to weaker orographic lifting and mountain blocking, and a faster-moving and stronger cold front in the Hokitika region. As a result, large errors in the heavy rainfall prediction occurred. By increasing either the resolved or the sub-grid mountain heights, the simulated rainfall errors were largely reduced through stronger orographic lifting and mountain blocking, and simulation of the cold front movement and strength was improved. All the experiments have the same “flow-over” regime with mountain waves and/or wave breaking (Fm ranges 0.61–1.21). However, the rainfall amount and distribution on the windward side of the mountains varied significantly. Our new findings were that the Southern Alps can have significant indirect effects on heavy rainfall by altering the speed and strength of the cold front, in addition to the well-known direct dynamical effects (i.e., orographic lifting and mountain blocking). A combination of these direct and indirect effects makes the heavy rainfall simulation sensitive to mountain heights even under the same “flow-over” regime.

Potential of Cold-Water Agriculture (ColdAg) in Mexico: Challenges and Opportunities for Sustainable Food Production

To guarantee sustainable development at a global level, humanity currently faces serious challenges related to a greater demand and better distribution of food to meet the needs of the growing population in environments affected by global climate change (GCC), and in limiting conditions with respect to natural, genetic, financial, and technological resources. Therefore, there is a dire need to implement technologies that can guarantee food security and sovereignty around the world, enabling sustainable development for all nations. Cold-Water Agriculture (ColdAg) is an available technology that offers an alternative to conventional food production in coastal areas and islands of the tropical and subtropical belts worldwide, making use of cold deep ocean water. Mexico has places with the optimal environmental conditions to adapt this technology, mainly in coastal areas and islands, which can contribute to ensuring access to food and drinking water. Initial tests have shown its viability, while production costs need to be adjusted to make this technology accessible to the poorest populations, so that it can contribute to their sustainable development and wealth. In this review article, we aimed to critically analyze some of the most salient literature on the ColdAg technology and outline the feasibility of this technology to be implemented and exploited in Mexico to contribute to alternative food production in a sustainable manner.

On the Fore-Shore Vegetation of Malacca Coast of the Car-Nicobar Island

In this paper, an account is given of the Fore-shore Vegetation of a part of E. Coast of Car-Nicobar along the Malacca Coast. The various types of plant species found on the shore above upper tidal limits are described, and the characteristic ones being Ipomoea pes-caprae (Linn.) Sweet., Panicum repens Linn., Vigna marina Mers., Ischaemum muticum Linn., Blainvillea acmella (Linn, f.) Philipson., Pandanus furcatus Roxb., Scaevola frutescens (Mill.) Krausse., Tournefortia argentea Linn., with Cocos nucifera Linn, occur behind, followed by Hibiscus tiliaceus Linn., Erythrina variegata Linn. var. orientalis (Linn.) Merr., Calophyllum inophyllum Linn., Thespesia populnea Corr., Guettarda speciosa Linn., Syzygium aqueum (Burm f.) Alston, and other trees in jungles. The various species met with are enumerated, in which 13 species and one variety would appear to be new records for the Andamans and Nicobars.