Big Island Research Articles

Francisella orientalis DNA detected in feral tilapia populations in Hawai'i.

Francisella orientalis is a bacterial pathogen that is responsible for substantial mortalities in warmwater fish, such as tilapia, and has negatively impacted the aquaculture industry globally. Starting in the mid-1990s, periodic F. orientalis outbreaks in Hawai'i led to severe mortalities in cultured and feral tilapia populations on Oahu. In an attempt to limit the outbreak's impact on tilapia aquaculture in Hawai'i, the Hawai'i Department of Agriculture Plant Quarantine Division issued a moratorium on the export of tilapia from Oahu to the other Hawaiian Islands. Despite reported high incidences of F. orientalis from cultured tilapia on Oahu and from around the world, the moratorium continues to remain in effect to this day. To assess the prevalence of F. orientalis in feral tilapia populations across the Hawaiian Islands, tilapia were collected from streams on Kauai, Oahu, Maui, Moloka'i, and the Big Island (Hawai'i) and were screened using a combination of molecular, bacteriological, and histological techniques. Although signs of infection (i.e., granulomas) were observed in fish on all five islands, molecular screening using quantitative polymerase chain reaction only detected the presence of F. orientalis on the islands of Oahu, Maui, and Kauai. These findings suggest that F. orientalis is prevalent in feral tilapia populations across the Hawaiian Islands.

Rb-Sr isochron method of sediment source fingerprinting reveals a fundamental shift in erosion in response to anthropogenic land use

Human alterations to landscapes can greatly influence watershed-scale sedimentary processes; therefore, in this study, we test the viability of a novel Rb-Sr isotope and elemental geochemical method for fingerprinting the impacts of human land use on sediment provenance. We analyzed a ∼1200-year sediment core record from Little Kennebago Lake, Maine, USA, that captures negligible anthropogenic activity pre-1900 CE, timber transport downstream during log drives (1900−1952 CE), and increased road construction and timber harvest (1952−2018 CE). 87Sr/86Sr data alone reveal several spikes, likely due to storm events, and variability but no systematic shift at the onset of logging. The pre-logging record Rb-Sr isotope data comprise an isochron corresponding to an age of 354 ± 16 Ma (two standard errors [2SE]; mean square of weighted deviates [MSWD] = 2.1, n = 33). None of the bedrock or glacial till sources that we analyzed fall along the pre-logging isochron, nor did any binary or ternary bulk rock mixtures. However, the linearity of all pre-logging samples and coincidence of the isochron age with Acadian metamorphism in the region suggests that sediment was derived from a single source in the undisturbed watershed, though that exact bedrock or glacial till source remains unclear. The onset of logging coincides with a shift toward generally lower sediment Rb-Sr isotope ratios that are offset from the pre-logging isochron. This logging data forms a scattered pseudo-isochron with an apparent Carboniferous age of 322 ± 32 Ma (2SE; MSWD = 4.5, n = 10). No rocks of this age exist in the region. Therefore, we interpret this age to have no geologic meaning and instead reflect the introduction of new sediment sources due to logging. Logging also coincides with subtle changes in elemental geochemistry. The Big Island Pond Pluton underlies most of the northern part of the watershed and is the only catchment lithology capable of producing each geochemical change; therefore, we conclude that it was the primary new source of sediment introduced by logging. We found little variation in sediment geochemistry between the period of early log drives and later road expansion, suggesting that sediment provenance was constant once altered by the initial onset of logging, which could reflect the same source being tapped by activities in each period. We established a framework for interpreting bulk sediment Rb-Sr isotope ratios and demonstrated their viability for identifying shifts in human impacts on geomorphic processes. Our findings suggest that relative changes in sediment Rb-Sr isotope ratios are a promising tool for investigating changes to sedimentary processes not identifiable by other commonly used fingerprints and that the method should be further tested in a range of other natural and anthropogenic settings globally.

Drifting long-lived. To the 50ʰᵗ anniversary of the opening of the “North Pole-22” station

The national drifting station “North Pole-22” (NP-22 or SP-22) had been opened on September 13, 1973 in the Arctic on the big ice island and operated for 3130 days. Now it is the longest operating observational station in the history of Arctic studies of the USSR and the Russian Federation. For eight and a half years, its total drift amounted 17,069 km. During that period a wide complex of scientific programs in oceanography, geophysics, meteorology, glaciology, hydrography, hydrobiology was carried out here. In addition, field tests and implementation of new types of scientific instruments and introduction of new expeditionary polar equipment into the observation practice were performed. For the first time in the practice of the drifting NP/SP stations, oblique sounding of the ionosphere, observations of fine thermohaline structure of waters of the active layer of the Arctic Ocean were carried out. Geographical coordinates of the station drift were determined using Soviet satellite navigation systems; a complex for recording satellite images of the ice cover was deployed; investigations of the arctic ecosystems were made. Specific experiments were conducted aimed at the natural decomposition of heavy hydrocarbons by the ultraviolet solar radiation. The ice airfield of this station received 1,511 flights of aircraft and helicopters, delivering 2,961 tons of expedition cargos. Landings on this airfield were provided by flight teams of the High-Latitude Air Expedition “Sever” of the Arctic and Antarctic Research Institute and the Hydrographic Service of the Northern Fleet. Foreign specialists repeatedly visited the station. For the nine rotations of polar explorers who worked at the NP/SP-22, its personnel amounted to 249 people, many of them several times worked at this drifting station in different years. The work of the NP/SP-22 team was appreciated by the government authorities of the USSR.

Persistence of widespread moderate Spinosad resistance among wild melon fly (Zeugodacus cucurbitae) and oriental fruit fly (Bactrocera dorsalis) populations on the major Hawaiian islands.

Insecticide resistance among invasive tephritid fruit flies poses a great risk to national food security and has the potential to disrupt quarantine and eradication programs, which rely on the efficacy of Spinosad to prevent widespread establishment in North America. During 2022 to 2023 we surveyed the extent of Spinosad resistance of two key species, oriental fruit fly Bactrocera dorsalis, and melon fly Zeugodacus cucurbitae, from 20 sites across five Hawaiian Islands including Kaua'i, O'ahu, Maui, Molokai and the "Big Island" (Hawai'i). We used topical thoracic applications of eight concentrations of Spinosad ranging from 0.028 to 3.6 mg/mL to evaluate the lethal concentration (LC50 and LC99) required to kill wild-caught males. Resistance ratios (RR) were calculated by comparing the LC50 of wild flies to laboratory susceptible lines maintained in colony. Our results identified at least two new sites of concern for melon fly resistance on the Big Island, and at least four sites of concern for oriental fruit fly, all of which were located on the Big Island. At these locations RRs were >5. On O'ahu, melon fly RRs were >10. The persistence of Spinosad resistance is concerning, yet it is a reduction compared to the values reported previously and before changes to Spinosad use recommendations by local extension agents beginning in 2017. For oriental fruit fly, these RR values are the highest levels that have been detected in wild Hawai'i populations. These data suggest that expanded Spinosad reduction and replacement programs are warranted given the ongoing issues with Spinosad resistance in Hawai'i and expansion in the number of species affected. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Climate research on big ocean islands

Climate research on big ocean islands

Greener pasture in the government sector? A factor structure on public service motivation among government employees in the Philippines

Working in the government is both a dream of securing a greener pasture and the opportunity to serve society with a noble intention and values. The main purpose of this study is to establish the factor structure of PSM in the Philippine context. A total of 456 randomly selected government employees from different agencies representing the three big islands of the country, namely Luzon, Visayas, and Mindanao, willingly participated in the survey. Data were analyzed using Exploratory Factor Analysis and Confirmatory Factor Analysis. The results of the Exploratory Factor Analysis validated the original 40-item and four-indicator-PSM but with a shorter version with only three underlying factors comprising 11 items, namely, Self-Sacrifice with six items, Commitment to Public Interest with two items, and Attraction to Policy Making with three items. Furthermore, Confirmatory Factor Analysis validated the model's goodness of fit and established a significant relationship among the latent variables, signifying the ability to measure public service motivation in the Philippine context. Hence, aside from the lure of a greener pasture, the results highlight the higher public service values as motivating factors. The findings can help the Philippine government tailor the agencies’ respective human resource development programs while maximizing the identified motivation factors to propel individual productivity and effectiveness in public service.

Prediction of two-neutron halos in the N = 28 isotones 40Mg and 39Na

The ground states of the nuclei Mg40 and Na39 are investigated using the hyperspherical formalism. Since they are located at the edge of the “big island of inversion”, we concentrate on whether we are likely to find two-neutron Borromean halos in these nuclei. A three-body model with effective n-n and Mg38+n interactions is built for Mg40 based on the available data. We also give predictions for the low-lying spectrum of Na38=37Na+n and two-neutron separation energy of the Na39 nucleus. Depending on parameter choice, we report an increase in the matter radii in the range 0.1-0.5 fm relative to those of the core nuclei. The results suggest a two-neutron halo structure in Mg40 for a subset of parameters, reinforcing the prediction of a Borromean halo nucleus. The calculations indicate that a two-neutron halo is even more likely for Na39. As expected, the halo is linked to the disappearance of the shell gap in these nuclei due to the inversion of the 2p3/2 and 1f7/2 orbitals. We study the total cross section for scattering of these nuclei from a carbon target using a Glauber model and show that these provide a clear signal to assess the halo structure.

Estimating fish production in wetlands

Fish production integrates changes in biomass from growth, reproduction, and mortality, and is a useful indicator for fisheries management. However, calculation of fish production has been limited by the intensive requirements for data on abundance, biomass, age structure, and vital rates, and so it is uncommon to find estimates of fish production for wetlands. We developed an approach to directly estimate production that is suitable for data-limited systems: a continuous time model of production describing individual growth over short time intervals with continuous time models of abundance and biomass over longer timescales. We applied this model for 18 Great Lakes coastal wetlands (GLCWs) on Lake Ontario, including Big Island Wetland (BIW). In BIW, most species were dominated in abundance and biomass by younger cohorts and, as a result, these young, fast-growing individuals contributed disproportionately to fish production. In total, BIW produced 336.1 kg·ha·year of fish and the other 17 neighbouring ranged between 447.7 and 1119.9 kg·ha·year. These are some of the first estimates of fish production for GLCWs, highlighting their value for managing Great Lakes fisheries.

Groundwater microbial communities reflect geothermal activity on volcanic island.

Studies of the effects of volcanic activity on the Hawaiian Islands are extremely relevant due to the past and current co-eruptions at both Mauna Loa and Kīlauea. The Big Island of Hawai'i is one of the most seismically monitored volcanic systems in the world, and recent investigations of the Big Island suggest a widespread subsurface connectivity between volcanoes. Volcanic activity has the potential to add mineral contaminants into groundwater ecosystems, thus affecting water quality, and making inhabitants of volcanic islands particularly vulnerable due to dependence on groundwater aquifers. As part of an interdisciplinary study on groundwater aquifers in Kona, Hawai'i, over 40 groundwater wells were sampled quarterly from August 2017 through March 2019, before and after the destructive eruption of the Kīlauea East Rift Zone in May 2018. Sample sites occurred at great distance (~80 km) from Kīlauea, allowing us to pose questions of how volcanic groundwater aquifers might be influenced by volcanic subsurface activity. Approximately 400 water samples were analyzed and temporally split by pre-eruption and post-eruption for biogeochemical analysis. While most geochemical constituents did not differ across quarterly sampling, microbial communities varied temporally (pre- and post-eruption). When a salinity threshold amongst samples was set, the greatest microbial community differences were observed in the freshest groundwater samples. Differential analysis indicated bacterial families with sulfur (S) metabolisms (sulfate reducers, sulfide oxidation, and disproportionation of S-intermediates) were enriched post-eruption. The diversity in S-cyclers without a corresponding change in sulfate geochemistry suggests cryptic cycling may occur in groundwater aquifers as a result of distant volcanic subsurface activity. Microbial communities, including taxa that cycle S, may be superior tracers to changes in groundwater quality, especially from direct inputs of subsurface volcanic activity.

Modeling and simulation of absorption solar air conditioning to reduce energy consumption: A case of some cities in tropical region

Buildings are one of the most important infrastructure sectors in today’s society. However, in Madagascar, most hotels, malls, hospitals use fossil fuels to meet energy needs, especially in the traditional air conditioning system. they consume a considerable amount of energy that has negative effects on the environment. The emergence of solar cooling systems is a very interesting solution to this problem because the use of renewable energies in this sector contributes to a significant reduction of greenhouse gas emissions in the environment. Madagascar is one of the countries with high renewable energy potential, notably solar energy estimated at 2000kWh/m².an.At present, the rate of exploitation of this potential for the operation of the solar absorption cooling system coupled with the building is still non-existent. This energy is clean, sustainable, profitable and environmentally friendly. This is the main objective of this work which uses this energy source to ensure thermal comfort in a building in Madagascar and contributes to the development of this system. The TRNSYS software helped us to model and simulate this system. To do this, first we will select 4 big cities of the big island, a building of total surface 80 m² was used. Then, the hourly thermal loads of this building for the whole year were simulated using the TRNbuild sub-program using meteorological data for a typical year of the selected cities. The dimensions of the components of the solar absorption air conditioning system were obtained using the maximum loads of the building. The results of the simulations show, the system meets the cooling load needs of the building with the climatic conditions of each selected city.

Travel Behavior Changes during the COVID-19 Pandemic in Indonesia: Present, Past and Future

COVID-19 (Coronavirus Pandemic2019) brought major changes to the behavior and mobility of people all over the world. This change is mainly a consequence of the lockdownand social distancing taken by governments in most countries around the world. This article presents an analysis of a survey conducted in major cities from 6 big islands in Indonesia (Java, Bali, Sumatera, Kalimantan, Maluku, Papua) where citizens were asked about their mobility preferences before, during, and after the lockdown due to the virus and about factors that influence the decision in choosing a mode. The surveyors distributed the closed questionnaireusing Googleformsto reduce the contact time with the respondents. The data is processed through a comparative test with the Friedman Test revealed that there is an average difference in the choice of transportation mode before, during,and after the pandemic and there is also a difference about the main travel purpose of the community before, during, and after the pandemic. The main purpose of respondents' travel before the pandemic was work/school, during the pandemic it was shopping the daily needs (except those working in the essential sector) and after the pandemic returning to work/school as the main purpose of travel.The resultsof the influence test on ninesocio-demographic conditions revealed that before the pandemic there were 6 factors that influenced the mode choice, which is: gender, type of job, working in the essential sector or not, the number of people in the family, vehicle ownership and marital status influenced the modal choice, during pandemic COVID-19there was 5 influential factors, which is: age, occupation, working in the essential sector/not, number of family members and vehicle ownership, after the pandemic are the same as before the pandemic except working in the essential sector/not.

Coupling and de-coupling of the El Niño Southern Oscillation to the supply of larval fishes to benthic populations in the Hawaiian Islands.

Several recent high intensity ENSO events have caused strong negative impacts on the adult phases of foundational species in coral reef ecosystems, but comparatively little is known about how climatic variables related to recent ENSOs are impacting the supply of larvae to benthic populations. In marine fishes and invertebrates, reproductive adults and planktonic larvae are generally more sensitive to environmental variability than older, non-reproductive adults. Further, the transport of larvae in ocean currents may also be strongly ENSO dependent. The interactions between the dynamics of larval survivorship and larval transport could lead to population bottlenecks as stronger ENSO events become more common. We tested the predictions of this hypothesis around the Main Hawaiian Islands (MHI) by constructing a correlation matrix of physical and biological time series variables that spanned 11 years (2007-2017) and multiple ENSO events. Our correlation matrix included four types of variables: i. published ENSO indices, ii. satellite-derived sea surface temperature (SST) and chlorophyll variables, iii. abundance and diversity of larval fishes sampled during the late winter spawning season off Oahu, and iv. abundance and diversity of coral reef fish recruits sampled on the western shore of the Big Island of Hawaii. We found that the abundance and diversity of larval fishes was negatively correlated with the Multivariate El Niño Index (MEI), and that larval variables were positively correlated with measures of fall recruitment (September & November), but not correlated with spring-summer recruitment (May & July). In the MHI, SST variables were not correlated with the MEI, but two successive El Niño events of 2014-15 and 2015-2016 were characterized by SST maxima approaching 30°C. Two large pulses of benthic recruitment occurred in the 2009 and 2014 recruitment seasons, with > 8000 recruits observed by divers over the summer and fall months. Both events were characterized by either neutral or negative MEI indices measured during the preceding winter months. These patterns suggest that La Niña and the neutral phases of the ENSO cycle are generally favorable for adult reproduction and larval development in the spring and summer, while El Niño phases may limit recruitment in the late summer and fall. We hypothesize that episodic recruitment during non-El Niño phases is related to favorable survivorship and transport dynamics that are associated with the formation of pairs of anticyclonic and cyclonic eddies on the leeward sides (western shores) of the Main Hawaiian Islands.

Empowerment of Women Farmer Groups in Utilization of Idle Land

Unused land in Indonesia can be found everywhere, especially on the big islands. Unutilized land is also found in rural areas. In fact, idle land should not be wasted land. If handled properly, it will be able to improve the community's economy. On the other hand, women in rural areas have a lot of free time because they are usually not tied to a permanent job. Utilizing idle land by empowering women who are members of the Women Farmer Group, is the strategy that will be applied in this research. The purpose of this study is to describe the use of unused land in the surrounding environment through community empowerment, namely a group of women. The Farmer Women's Group in Gadog Cianjur Village is the empowered community in this study. The research method used is descriptive with a qualitative approach. How women are empowered to cultivate idle land to produce benefits for people's lives, will be described step by step. The women's spare time (Women Farmers Group) is put to good use by cultivating idle land in their village. Unused land that initially did not produce anything, can eventually be used as a place to grow vegetables. The results of cultivating on unused land which were worked on by these women, had an impact on increasing the family's economy and better social relations.

Archaeoseismological study in northeastern Bulgaria: Islands in Durankulak Lake

The most northeastern part of the territory of Bulgaria is characterized by high seismicity. In 2019, archeoseismological studies of traces of strong earthquakes were carried out in the oldest architectural monument in Europe – Durankulak. There are reports of earthquakes in these places in the Middle Ages and in Аntiquity, but the data on the location of their foci is unspecified. Therefore, a team of scientists from Bulgaria and Russia carried out special scientific research on the islands in Lake Durankulak. A large number of artifacts have been found on the Big Island. The ruins located there are very old and have fixed traces of seismic impacts that have occurred over a long period of time. As a result of paleoseismological and archaeoseismological studies, three major earthquakes have been identified. Most likely, the focus of the first is connected to the Intramysian fault, and the focus of the second and third to the Shabla-Kaliakra seismic zone. The first was between VIII and IX degree on the scale of MSK 64, the second between IX and X, the third also between VIII and IX degree on the same scale.

Forest Bird Populations at the Big Island National Wildlife Refuge Complex, Hawai‘i

Abstract Endemic Hawaiian forest birds have experienced dramatic population declines. The Big Island National Wildlife Refuge Complex (Refuge Complex) was established for the conservation of endangered forest birds and their habitats. Surveys have been conducted at two units of the Refuge Complex to monitor forest bird populations and their response to management actions. We analyzed survey data from 1987 to 2019 at the Hakalau Forest Unit (HFU) and from 1995 to 2019 at the Kona Forest Unit (KFU). We analyzed three strata at HFU: open-forest, closed-forest, and afforested-pasture, and two strata at KFU: upper (>1,524 m elevation) and lower (<1,524 m). In all years, ‘i‘iwi Vestiaria coccinea, ‘apapane Himatione sanguinea, and Hawai‘i ‘amakihi Chlorodrepanis virens virens were the most abundant species at HFU. Three endangered forest bird species, Hawai‘i ‘ākepa Loxops coccineus, ‘alawī Loxops mana (also known as Hawai‘i creeper) and ‘akiapōlā‘au Hemignathus wilsoni, had much lower densities. The most abundant species at KFU was ‘apapane, followed by Hawai‘i ‘amakihi at much lower densities. We found a continuation of several trends observed in previous analyses at HFU up to 2012, with most species’ trends upward in afforested-pasture stratum, stable in the open-forest stratum, and downward in the closed-forest stratum. However, more species were showing downward trends in all three strata during the most recent decade. Results were mixed at KFU, with most species’ trends downward in the upper stratum and upward in the lower stratum. Populations of endangered species were either locally extirpated at KFU or in numbers too low to reliably estimate population abundance. The Refuge Complex is important for conservation of forest birds on Hawai‘i Island. Our results show that HFU supports the majority of three endangered forest bird species. Threats to forest birds at the Refuge Complex appear to be having a negative impact. These threats include habitat loss, disease, feral ungulates, and nonnative predators. Continuing and enhancing management actions, such as forest restoration and removal of invasive species, could help mitigate these impacts and allow the Refuge Complex to remain a key site for forest bird conservation in Hawai‘i.

Sosialisasi dan Pelatihan Pemanfaatan Sampah Anorganik Menjadi Media Tanam Vertikultur pada Masyarakat di Gili Air

Gili Air as one of the Small Islands in West Nusa Tenggara (NTB) has various geographical limitations and even has economic dependence on the tourism industry. The large number of tourists has an impact on the amount of waste generated every day. This is not balanced with optimal waste management in Gili Air, where waste from each household and tourism supporting facilities is just piled up, then taken by the transportation service (Gili Care) and disposed of in the TPA (Final Disposal Site) in Lombok Big Island. Waste management on Gili Air requires a large amount of money because you have to pay for transportation by boat. Some local people and owners of tourism-supporting facilities manage their waste by dumping it in pits or burning it. Some of them who know the economic value of inorganic waste sell directly cardboard, used bottles, iron and others to collectors or scavengers themselves. The waste bank in Gili Air has not run optimally, so the reduction in waste generation only comes from selling used goods individually. Based on these various problems, the service team carried out community service activities through outreach and training on the use of inorganic waste to become verticultural planting media which indirectly contributed to household-scale greening in Gili Air. The goal of this activity is to generate enthusiasm and participation from Karang Taruna Gili Air (KTGA) in terms of waste management. This service activity took place enthusiastically and actively involved KTGA, where the evaluation results showed that there was an increase in knowledge of 47%. The community's activeness in providing questions and responses is an asset for participatory community empowerment in Gili Air.

The Potential of The Big Island of Melaka and the Tomb of Sultan al-Ariffin Sheikh Ismail as a Visitor-Friendly Religious Tourism Destination

Abstract: Big Island Melaka is one of Malaysia's historical and religious tourist destinations. However, many people are unaware of the island's historical and religious significance. The purpose of this research is to explore and describe the current state and history of Melaka Big Island as an Islamic tourist destination through content analysis methodology. The results of the study found that the Big Island is a historical island that contributed greatly to the effective spread of Islam in Melaka and its surroundings. The existence of the tomb of Sultan al-Ariffin and other figures is the main attraction for many religious tourists to come to the Big Island to get to know more about the historical side of this Big Island. However, some tourists continue to engage in khurafat activities and violate Islamic restrictions. The Big Island should adopt the idea of Islamic tourism to make it free from aspects of shirk and khurafat as well as cosy and welcoming to visitors. Local authorities need to be concerned about monitoring the activities carried out by visitors to this Big Island. With various studies on programmes and activities that have been carried out, it is hoped that the management of Pulau Besar will be better for the purpose of being recognised as an Islamic tourist destination that is visited by tourists at the local and global levels. Abstrak: Pulau Besar Melaka merupakan antara destinasi pelancongan bersejarah dan keagamaan di Malaysia. Walau bagaimanapun, ramai orang tidak menyedari tentang pentingnya nilai sejarah dan aspek agama di pulau ini. Penulisan ini bertujuan bagi meneroka dan menghuraikan keadaan semasa dan sejarah Pulau Besar Melaka sebagai destinasi pelancongan Islam melalui metodologi kualitatif analisis dokumen. Hasil kajian mendapati bahawa Pulau Besar merupakan sebuah pulau bersejarah yang memberi sumbangan besar kepada kejayaan penyebaran Islam di Melaka dan sekitarnya. Keberadaan makam Sultan al-Ariffin serta tokoh lainnya merupakan tarikan utama pelancong keagamaan ramai datang ke Pulau Besar bagi mengenal lebih dalam sisi sejarah Pulau Besar ini. Namun demikian masih terdapat aktiviti khurafat serta dilarang agama yang dilakukan oleh sesetengah pengunjung. Konsep pelancongan Islam perlu diaplikasikan di Pulau Besar bagi menjadikan tempat pelancongan tersebut bebas daripada unsur syirik dan khurafat serta selesa dan mesra pengunjung. Pihak kerajaan tempatan perlu mengambil berat terhadap pengawasan aktiviti yang dijalankan pengunjung Pulau Besar ini. Dengan pelbagai kajian berkenaan program dan aktiviti yang telah dijalankan diharapkan pengurusan Pulau Besar ditambah baik bagi tujuan ianya diiktiraf sebagai destinasi pelancongan Islam yang ramai dikunjungi oleh pelancong di peringkat tempatan mahupun antarabangsa.

Why river islands are formed after every big city

The perennial rivers have high and wide catchment areas that supply water continuously to the rivers. So, all through the year, they get water for their activities. Large cities emerge around such rivers and congregate as huge urban clusters like Delhi, Varanasi, and Patna. It was quite interesting to note that in all the big rivers like the Ganges, after crossing all big cities are invariably present, big river islands. The perceived cause of this is the heavy deposits by the people, or the slowing down of the river as it flattens up. The cause of the river islands is only partly the dirt thrown into the river by the people but largely because of the soap detergents and acids that produce large amounts of salts leading to precipitate and coagulation through a process called Cataphoresis of the colloidal impurities while crossing the cities. Since the river is slender in the cities due to concertized/solid embankment the flow is fairly fast. So, the whole material is pushed beyond the precincts of the cities. But as the river meanders beyond the city's ambit it spreads wider and slows down. So it gives enough opportunity to the colloids to settle down over some time the same enlarges to form River Island.

The dynamic of sea level anomaly in the Papua coastal area and its associated response to the climate indices

With thousands of islands and a vast coastline, Indonesia is expected to suffer from severe and drastic impacts of sea level rise, not only to coastal urban areas and small islands but also to big islands with wetland ecosystems, such as Papua. Because the coastal areas are very sensitive to climatic and sea level changes, it is important to quantify the trends in sea level and the influences of climate variability in this region. This study aims to analyse the seasonal and interannual sea level anomaly in Papua coastal areas and investigate its associated response to climate indices. This study is performed based on the reprocessed satellite models of sea level height anomaly (SSHA) and Sea Surface Temperature (SST), climate index of Southern Oscillation Index (SOI), Dipole Mode Index (DMI), and Pacific Decadal Oscillation (PDO), from 1993–2021. The results showed that the rate of sea level rise in Papua is accelerating and significantly higher than the global trend by 0.54–1.03 cm/year. By performing statistical analyses, this study indicates that sea level in the northern waters is more sensitive to climatic phenomena, while sea levels in the southern waters are more responsive to seasonal drivers that influence the SST variability.

Two-dimensional mapping of impulsive ambient sound on a coral reef using vector sensors

Coral reef health is an important focus of tropical marine park management. Evidence exists that passive acoustic measurements of reef sound are associated with reef health and ecodiversity, but its utility would be enhanced by an ability to localize and map source distributions. Since much reef noise is impulsive, arising from both fish and crustaceans, localization could be achieved by collecting relative time-of-arrival information across synchronized spatially separated hydrophones. However, the sheer number of bioacoustic pulses in many reef environments can overwhelm attempts to associate sounds between sensors, Here we discuss how directional acoustic vector sensors sidestep these issues and permit 2-D mapping of thousands of pulses an hour, using data collected from two locations off the Big Island of Hawaii in 2020. At one location, three sensors spaced 20 m apart found acoustic activity was only present along the current-facing side of a 100 m long block reef. A second location set in the middle of more complex topography found several acoustic “hotspots” that remained stable over a month’s worth of measurements. A new generation of vector instrumentation is permitting this approach to be extended to crustacean noise in the kilohertz range. [Work sponsored by ONR and DARPA.]