Banda Sea Research Articles

Seasonal and interannual variability of water mass sources of Indonesian throughflow in the Maluku Sea and the Halmahera Sea

So far, large uncertainties of the Indonesian throughflow (ITF) reside in the eastern Indonesian seas, such as the Maluku Sea and the Halmahera Sea. In this study, the water sources of the Maluku Sea and the Halmahera Sea are diagnosed at seasonal and interannual timescales and at different vertical layers, using the state-of-the-art simulations of the Ocean General Circulation Model (OGCM) for Earth Simulator (OFES). Asian monsoon leaves clear seasonal footprints on the eastern Indonesian seas. Consequently, the subsurface waters (around 24.5σθ and at ~150 m) in both the Maluku Sea and the Halmahera Sea stem from the South Pacific (SP) during winter monsoon, but during summer monsoon the Maluku Sea is from the North Pacific (NP), and the Halmahera Sea is a mixture of waters originating from the NP and the SP. The monsoon impact decreases with depth, so that in the Maluku Sea, the intermediate water (around 26.8σθ and at ~480 m) is always from the northern Banda Sea and the Halmahera Sea water is mainly from the SP in winter and the Banda Sea in summer. The deep waters (around 27.2σθ and at ~1 040 m) in both seas are from the SP, with weak seasonal variability. At the interannual timescale, the subsurface water in the Maluku Sea originates from the NP/SP during El Nino/La Nina, while the subsurface water in the Halmahera Sea always originates from the SP. Similar to the seasonal variability, the intermediate water in Maluku Sea mainly comes from the Banda Sea and the Halmahera Sea always originates from the SP. The deep waters in both seas are from the SP. Our findings are helpful for drawing a comprehensive picture of the water properties in the Indonesian seas and will contribute to a better understanding of the ocean-atmosphere interaction over the maritime continent.

Madden\u2013Julian Oscillation Enhances Phytoplankton Biomass in the Maritime Continent

In addition to monsoon-driven rainfall, the Maritime Continent (MC) is subject to heavy precipitation caused by the Madden–Julian Oscillation (MJO), a tropical convection-coupled circulation that propagates eastward from the Indian to the Pacific Ocean. This study shows that riverine runoff from MJO-driven rainfall in the western MC significantly enhances phytoplankton biomass not only in the coastal regions but as far as the nutrient-poor Banda Sea, located 1,000 km downstream of the riverine source. We present observational estimates of the chlorophyll-a concentration in the Banda Sea increasing by 20% over the winter average within an MJO life cycle. The enhancement of phytoplankton in the central Banda Sea is attributed to two coinciding MJO-triggered mechanisms: enhanced sediment loading and eastward advection of waters with high sediment and chlorophyll concentrations. Our results highlight an unexpected effect of MJO-driven rainfall on the downstream oceanic region. This finding has significant implications for the marine food chain and biogeochemical processes in the MC, given the increasing deforestation rate and projections that global warming will intensify both the frequency and strength of MJO-driven rainfall in the MC.

Study of Seasonal Variation of Sea Surface Salinity in Java Sea and its Surrounding Seas using SMAP Satellite

This research was conducted in The Java Sea and Surrounding Seas. This study uses satellite data with the period in 2015 - 2017, which composed of the main data of sea surface salinity and supporting data of rainfall, evaporation, wind, and current. The entire data processed into monthly climatology data and analyzed by using Pearson correlation. The salinity of Java Sea is generally in the range of 30.0 to 35.0 ‰. However, we found some phenomena in four areas, that is the significant decrease of salinity reach up to 30.919 ‰ in April in south waters of Borneo. Those influenced by river run off from the high precipitation reach up to 0.689 mm/hr in Borneo land. In south waters of Sulawesi, there is the highest increase of salinity in October to November reach up to 34.45 ‰ which affected by Banda Sea’s water mass entering the area. Salinity fluctuation in Natuna Sea is inversely proportional to other study areas, influenced by the geographical condition in the Northern Hemisphere which was crossed east monsoon and by the minimum salinity of water mass from the Java Sea which moved by the current which has correlation around of -0.717 between salinity and current. Negative of the high value shown big inverse relation. While the phenomenon of decreasing salinity is occurring in West Sulawesi waters in June, it is influenced by mass input from Banda Sea that depresses Java Sea waters and ARLINDO (Indonesia cross flow) which had minimum salinity from the west season.

THE ANALYSIS OF SEISMOTECTONICS, PERIODICITY, AND CHANGING OF QUAKES LEVEL IN WEST NUSA TENGGARA AREA BASED ON 1973 – 2015 DATA

This research was conducted as one of the earthquake disaster mitigation efforts in Nusa Tenggara Barat region, because this region is one of the regions in Indonesia which has a relatively high level of seismicity. The purpose of this research is to determine seismotectonic parameter, earthquake periodicity along with the average of seismicity rate changes in Nusa Tenggara Barat region. The data used in this research is the data sourced from the United States Geological Survey (USGS) and Badan Meteorologi Klimatologi dan Geofisika (BMKG) from Januari 1973 until February 2015 for Bali Strait region up to Banda Sea with coordinate boundaries of 1140–1300 East Longitude and 40-130 South Latitude. This research was conducted using the maximum likelihood method with second party of software Zmap ver 6.0 also software ArcGis ver 10 to map seismotectonic parameter, periodicity and the average velocity of seismicity rate changes. Variation b value range between 0.972–1.44, a low value of b are associated with high stress levels, and vice versa. The a value range between 6.67- 9.1, its show that the regions with high a value experience a relatively high earthquake incidence rate, and vice versa. The density of earthquake is about -2.63 to -2.01 logN/km2 or the occurrence of earthquakes in the area is very rare. Earthquake periodicity with magnitude (M) 6 SR is 5 to 18 year, M 6.5 SR is 16 to 67 year, M 7 SR is 54 to 304 year, and M 7.5 SR is 178 to 1.386 year. The average of seismicity rate changes on a case that occurred in Sumbawa in 1982 is more than 125%, meanwhile the earthquake that occurred in 2009 is more than 75%.Copyright © 2019IPR. All rights reserved.

Water mass exchange at Ambon Bay based on trajectory model: a preliminary study

Ambon Bay is divided into two parts, Inner Ambon Bay (IAB) and Outer Ambon Bay (OAB) which separated by 10 m narrow canal called sill. It causes IAB and OAB has different water dynamics. Generally, circulation dynamics at Ambon Bay affected by upwelling process in Banda Sea during southeast monsoon. During that period, tidal upwelling brought high density water from thermocline layer in OAB to surface and enter the IAB. The mechanism of water mass exchange can be describe using three-dimensional trajectory model which evaluate the origin and movement of water particles. This preliminary study shows the particle movement during one tidal cycle based on trajectory model results. Verification result shows that model error is 2.32%. Preliminary results show that after one tidal cycle, particles predominantly move to OAB rather than enter IAB through western side of the sill.

SAMPLING DESIGN FOR WATER QUALITY MONITORING IN MARINE RESERVE: A STUDY CASE AT BANDA SEA CONSERVATION PARK

Design of sampling site water quality monitoring at marine reserve is critical, to optimize the effectiveness of periodic assessment. A simple stratified systematic design, that been usually used in most of monitoring anlaysis, may not maximize the information of spatial data in marine hydrology. The present work applied a multivariate statistical analysis and spatial autocorrelation methods to develop an optimal sampling design for water quality assessment in tropical marine reserve, Banda Sea Conservation Park, Indonesia. Seasonal (west, intermediate, and east monsoon season in Indonesia) and spatial (38 stations) water quality analysis (Salinity, Dissolved Oxygen, pH, and nutrient) in 3 zones of Marine Reserve were conducted. Principal Component Analysis (PCA) showed Dissolved Oxygen (DO) was the principal variable for the sampling design criterion. Spatial DO Variograms showed relocation of the sampling stations, to optimize the design of water quality monitoring. Therefore, even the principal variable may vary at other locations, depends on hydrology and other area specific characteristics, the proposed technique could be applied in sampling design concerning hydrology monitoring.

Designating Spatial Priorities for Marine Biodiversity Conservation in the Coral Triangle

To date, most Marine Protected Areas (MPA) have been designated on an ad hoc basis. However, a comprehensive regional and global network should be designed to be representative of all aspects of biodiversity, including populations, species, and biogenic habitats. A good exemplar would be the Coral Triangle (CT) because it is the most species rich area in the ocean but only 2% of its area is in any kind of MPA. Our analysis consisted of five different groups of layers of biodiversity features: biogenic habitat, species richness, species of special conservation concern, restricted range species, and areas of importance for sea turtles. We utilized the systematic conservation planning software Zonation as a decision-support tool to ensure representation of biodiversity features while balancing selection of protected areas based on the likelihood of threats. Our results indicated that the average representation of biodiversity features within the existing MPA system is currently about 5%. By systematically increasing MPA coverage to 10% of the total area of the CT, the average representation of biodiversity features within the MPA system would increase to over 37%. Marine areas in the Halmahera Sea, the outer island arc of the Banda Sea, the Sulu Archipelago, the Bismarck Archipelago, and the Malaita Islands were identified as priority areas for the designation of new MPAs. Moreover, we recommended that several existing MPAs be expanded to cover additional biodiversity features within their adjacent areas, including MPAs in Indonesia (e.g., in the Birds Head of Papua), the Philippines (e.g., in the northwestern part of the Sibuyan Sea), Malaysia (e.g., in the northern part of Sabah), Papua New Guinea (e.g., in the Milne Bay Province), and the Solomon Islands (e.g., around Santa Isabel Island). An MPA system that covered 30% of the CT would include 65% of the biodiversity features. That just two-thirds of biodiversity was represented by one-third of the study area supports calls for at least 30% of the ocean to be in no-fishing MPA. This assessment provides a blueprint for efficient gains in marine conservation through the extension of the current MPA system in the Coral Triangle region.

SONIC LAYER DEPTH VARIATION ANALYSIS UTILIZING BIDE (BANDA ITF DYNAMIC EXPERIMENT) ARGO FLOAT IN SITU OBSERVATION FOR UNDERSEA WARFARE TACTICAL ENVIRONMENT SUPPORT

ABSTRACT
 Sonic Layer Depth is the vertical distance from surface to the depth where the speed of sound reach it’s local maximum. Global Navy as well as Indonesan Navy operates in this kind of layers on a daily basis, wether it be in an anti submarine warfare operation through its ships and aircrafts or in an anti-surface warfare operation waged by its submarines. For the navy, the importance of knowing the exact value of the SLD is because it determines the minimum cut off frequency and sound wave propagation above which sound tends to be trapped and below which a shadow zone exist. This has a direct impact on where the navy operates its sensors and places its platforms in the water column. The best way to estimate SLD is by performing own measurement on the ocean using instrument such as expendable bathytermographs, which can be relatively expensive and time consuming for an operational navy ships, furthermore such measurement may be impractical in the case of mission planning or emergencies. Dedicated oceanography survey for the purpose of science and defense is relatively scarce due to prioritization concerning to the budget available resulting lack of time series in situ CTD observation which cover full annual cycle variation in Indonesia waters. Banda Indonesia Through Flow Dynamic Experiment (BIDE) is multi institution and bilateral oceanography experiment led by Indonesian scientist which utilizes argo float to perform in situ CTD measurement in Banda Sea to get an adequate time series data that cover full annual cycle variation. The dataset is publicly available so defense community as well may utilize the data for defense interest such as sonic layer depth variation analysis in Banda Sea. 
 Keyword : sonic layer depth, BIDE, argo float, undersea warfare, tactical environment

Deglacial Warming and Hydroclimate Variability in the Central Indonesian Archipelago

AbstractWe present centennial‐scale records of sea surface temperature and oxygen isotopes from the Celebes Sea, Makassar Strait, Flores Sea, and northwestern Banda Sea, which provide new insights into the variability of Indonesian hydroclimate over the past 25 kyr. Deglacial warming was generally gradual with an amplitude of 3–4 °C. Statistical evaluation of the temperature data suggests that the onset of deglacial sea surface temperatures warming in the tropical Indonesian Sea occurred earlier than the global atmospheric CO2 rise. In contrast to previous terrestrial precipitation records, our ice volume‐corrected δ18O of seawater (δ18Osw) does not support widespread aridity in central Indonesia during the last glacial period. While δ18Osw was substantially enriched during Heinrich Stadial 1 and the Younger Dryas, δ18Osw values were only ~0.2‰ heavier during the Last Glacial Maximum than during the Holocene. Heavier δ18Osw during Heinrich Stadial 1 and the Younger Dryas either reflects a decline in precipitation amount and/or increased δ18O of rainfall in central Indonesia, both likely caused by a southward displacement of the tropical rain belt. Comparison of the Celebes Sea, Makassar Strait, Flores Sea, and Banda Sea records suggests that rainfall isotope and/or amount changes were comparable over Borneo and Sulawesi during the last termination.

POPULATION DYNAMIC AND EXPLOITATION RATE OF THE BLUE SWIMMING CRAB (Portunus pelagicus) IN THE KENDARI BAY WATERS

Kendari Bay waters consitute a potential blue swimming crab (BSC) fishing ground in WPP NRI 714 (the Banda Sea). The intensive fishing activities have been increasing from year to year that raised concern to the fishing that will disturb resource sustainability. Therefore, an alternative sustainable management is advisable. The purpose of this research was to examine the population dynamics and exploitation rate of BSC in the Kendari Bay waters conducted between January and November 2016. The results show the isometric of BSC growth pattern and balance of male and female ratio. The length at first capture (L c ) of BSC was 116.65 mm (carapace width),smaller than the length at first maturity (L m ) at 119.7 mm (carapace width). The von Bertalanffy growth equation for the blue swimming crab was L(t) = 182.0[1-e -0.91 (t - 0) ] and the fishing mortality rate (F) was higher than the natural mortality rate (M). The blue swimming crab exploitation rate calculated BSC from Kendari Bay has exceeded the optimum rate of 0.73 per year and is indicating a category “overfishing”. Therefore, to maintain the BSC stock sustainability, a management measure is needed to reduce the current fishing effort of approximately 46 % from the current effort and regulation of net mesh size.

USING DNA BARCODE TO IMPROVE THE IDENTIFICATION OF MARINE FISH LARVAE, CASE STUDY COASTAL WATER NEAR JAKARTA AND BANDA SEA, INDONESIA

The sustainability of the exploitation of the Indonesian fishes depends heavily on many of fish’s basic information including both larvae distribution and dispersal. However, the identification of fish larvae and juvenile to species is very limited. In this study, we employed DNA barcoding techniques to identify marine fish larvae to a species level in Jakarta Bay and Banda Sea by comparing the querries with sequences from adult stage as reference library to contribute on biodiversity information on that particular area. The result revealed that in Jakarta Bay, the molecular marker of a 471 bp region of the mitchondrial cyctochrome c oxidase I gene (COI) has been successfully found to be species-specific, genetic distance within species (0.0 - 1.30 percent). There are total of 8 families, 5 genera and 5 species from a total 15 successful PCR that could be used to calculate the accuracy of larval fish identification in three taxonomic categories. Meanwhile in Banda Sea, for the adult specimens, after some of PCR experiment, we have successfully amplified 27 individuals, only 8 sequences available. There are a total 326 eggs and larvae which been collected from 19 stations, of the 28 successfully amplified PCR samples, 11 sequences were available for DNA analysis and at least 10 species used Banda Sea and surrounding area as their spawning ground. We prove the ability of COI barcodes to identify species level resolution from query sequences and to classify species from distinct geographical origins and determine of how the data retrieved give important information for proposing plans for conserving and managing of fisheries in the sea waters.

Physical properties and nutrients distribution of seawater in the Banda Sea - Indonesia

The Banda Sea is a sea in the eastern part of the Indonesian archipelago, connected directly to the Pacific Ocean and surrounded by hundreds of small islands that create its unique characteristics. A large portion of Pacific seawater is passed through the Banda Sea to the Indian Ocean forming an Indonesian through flow (ITF), an ocean current with importance for global climate. The ITF provides a low-latitude pathway for warm, fresh water to move from the Pacific to the Indian Ocean and serves as the upper branch of the global heat conveyor belt. Despite its importance in the global ocean and climate system, detail study and discussion of the Banda Sea are scarce. Here, we discuss the physical properties in term of temperature, salinity and density in conjunction with nutrients distribution in seawater from 17 stations of the Banda Sea using the direct observation data of the research cruises that were gathered by Reid and Mantyla. The available numerical data of the Banda Sea were then visualized using Ocean Data View software. To the best of our knowledge, it is the first report for a detailed discussion of this kind in the Banda Sea. The results show that nutrients concentration depleted in surface water (0 – 500 m) and enriched in deep water (500 m – bottom). The concentrations ranges of phosphate, nitrate and silicate were 0.3 – 3.1, 0.5 – 40 and 1 – 147 μmol l−1, respectively. As shown from temperature, salinity and density profiles, it is known that the inflowing seawater from the Pacific Ocean into the Banda Sea is gradually modified which change the upper water masses (0 – 250 m) characteristics that eventually outflows into the Indian Ocean.

The importance of the Banda Sea for tuna conservation area: A review of studies on the biology and the ecology of tuna

Tuna exploitation in the Banda Sea was started when the Indonesian government gave access to the Japanese fleet under the bilateral cooperation of the Banda Sea Agreement (BSA) in 1975-1980. Several studies were conducted afterward in revealing the magnitude of tuna resources in the Banda Sea. In this paper, we reviewed the tuna studies that were done in the Banda Sea over the periods of 1980-2017 to improve our understanding on the biology and ecology of tuna in the region as the basis for future studies. Overall, we reviewed 29 publications consisted of eight research themes; biodiversity (5), catch composition (8), fish aggregating device (FAD) (2), fishing ground (2), growth-population (3), harvest-effort strategy (4), reproduction (4), and tagging (1). The Snellius II expedition in 1984-1985 was a remarkable study covering almost whole area of the Banda Sea. The study of catch composition and biodiversity were dominant in recent decade indicating there was urgent need to manage the tuna fisheries in the Banda Sea to preserve the tuna stock. Since the Banda Sea is considered as a tuna conservation area, the future studies should be focussed on the scientific findings to support the regulation.

Reef fish stocks assessment around the islands in the Banda Sea for supporting local community livelihood

Located in the Indonesian fisheries management area (WPP) 714, the Banda Sea has a high potential of fisheries resources. However, information about reef fish resources is limited. This study aims to assess the Banda Sea reef fish diversity, abundance, and stocks. The diversity, abundance, and density of three reef fish groups (indicator, target, and major) were assessed using underwater visual census (UVC) from 287 sites. A stock assessment was done by multiplying fish habitat areas and fish density. There were 287, 42, and 301 species of target, indicator, and major groups recorded respectively. High abundances were found in Banda Islands and the Southeast region, while the lowest abundance was in the Kendari waters. The average density of indicator and major groups were 0.251 and 4.519 individuals.m−2, with estimated stocks of 2,883 × 106 and 51,899 × 106 individuals (ind.) respectively. The density of target group fish which has economic values was 1.976 ind.m−2, equivalent to the biomass of 599.6 ton.km−2 with stocks of 4,214,468 tons. Despite huge reef fish resources supporting the local livelihood, the stock tended to decrease in 2009-2012 and 2015-2016 in Flores and Banda Islands. Therefore, conservation and sustainable use of reef fishes of the Banda Sea is required.

Current Status and Future Prospect of Marine Pollution Research in the Banda Sea

Anthropogenic pressure can cause serious problem in the marine environment, such as marine pollution. In this paper the existing scientific literatures related to marine pollution study that had been conducted at the Banda Sea were reviewed. There were in total 22 publications found that specifically addressed the marine pollution at the Banda Sea. The majority of case studies were conducted in shallow coastal waters. Few data discussed about deep-sea waters. We highlighted knowledge gaps regarding the information on data from Banda Islands coastal area. The final goal of this paper is to recommend the future studies that need to be conducted in the Banda Sea waters.

A review of studies on bacteria in the Banda Sea over the past seven decades (1950-2017)

Studies on marine bacteriology in the Banda Sea were started from the 1950s. This paper is an attempt to review all works carried out in the last seven decades. Literature reviews indicated that there was not much research done on marine bacteria in the Banda Sea and adjacent waters such as Ambon Bay. Studies on bacterial biomass, indicator bacteria on water quality monitoring as well as bacteria potential as a producer of secondary metabolites were carried out. However, considering Banda Sea ecosystem that is mostly consisted of deep environments, it would be interesting to prioritize research activities on piezophiles or at least piezotolerant marine bacteria. There is thus an urgent need to determine the priorities in studying marine bacteria in this ecosystem, which should be focused on deep-sea ones.

Banda deep-sea research: history, mission and strategic plan

Attention to the deep-sea ecosystem research in order to achieve blue economy goals is low. The Banda Sea is important deep-sea ecosystem in Indonesia and it was identified as a global marine mega-biodiversity site. The objectives of this paper are 1) to document the history, achievements, and challenges of deep-sea research development and 2) to develop a grand design and innovative strategic plan for deep-sea research. Literature reviews and questionnaire survey for scientists across Indonesia were carried out. The literature reviews indicated that deep-sea ecosystem is not well documented. Few articles on deep-sea were published (mean 0.8 article y−1) which were mainly focused on geological (45%) and physical oceanography (32%), less research on biological (16%) and chemical oceanography (8%). Deep-sea ecosystem faced tremendous threats due to ecosystem degradation, pollution, and climate change. The questionnaire survey showed that research infrastructure/facilities (Ranking 1) and institutional management systems (Ranking 2) were the main obstacles to Indonesian deep-sea research development. A grand design named Indonesian Deep-sea Research and Monitoring (I-DREAM) and its strategic plan were developed to achieve blue economy goals. Strengthening research infrastructure and institutional management systems are the top priories that should be achieved in the short-term period to support deep-sea research in Indonesia. Scientific pursuit in long-term period should be focused on biodiversity and deep-sea ecology including chemical oceanography (24%) and its interaction with other ecosystems and atmosphere (18%) were identified as the top priorities to be implemented for future research (Ranking 1 and 2). The Banda Sea was identified as a suitable core study area of the I-DREAM’s pilot project. The grand-design and its innovative strategic plan are essential to fulfilling high demand on a guideline for deep-sea research to achieve blue economic development goals.

Geological aspects of Banda Sea ecosystems and how they shape the oceanographical profile

The Banda Sea is a collage of young oceanic basins and fragmented Australian continental crust located at the heart of the Australia–SE Asia collision zone where Australian and Asian biogeographic regions converge. The formation of the sea was governed by the southeastward rollback of the Banda Slab since c. 16 Ma, which in its wake opened new oceanic basins and extended and fragmented Australian crust. These Australian crustal fragments are today either stranded within the Banda Sea where they form the prominent submarine ‘Banda Ridges’, or now reside as thrust-sheets on the NW Australian shelf after being transported all the way to the southern Banda Arc. The deepest part of the Banda Sea, the 7.2 km Weber Deep, was formed by extreme lithospheric extension that occured in the latter stages of Banda Slab rollback. This extension was accommodated by the vast low-angle ‘Banda Detachment’, which operated above the subducted fringes of the Australian continental margin.

Fish larval composition and distribution assessment in the northern waters of Ambon Island

The Banda Sea ecosystem has been highlighted in the past decade for its potential role in providing economically important fish stock for human consumption. However, literature studies indicated lack of references regarding fish larvae abundance and composition in coastal areas of islands impacted directly by the Banda Sea. The study covers fish larval survey carried out at the northern waters of Ambon Island in April 2017. The composition, distribution, and abundance of fish larvae were described based on five horizontal and one vertical sampling stations. Twenty-eight families were identified and two of them were the most abundant: Atherinidae (23% of the total larvae) and Apogonidae (21% of the total larvae). Most of the other families were known to be neritic and in particular were fishes commonly found to be associated with coral reef ecosystems. This finding indicated the profile of the northern waters area, which has extensive coral reef coverage, as well as estuary and mangrove area.

The Banda Sea: a hotspot of deep-sea echinoderms diversity in Indonesia

A list of Echinodermata fauna recorded from the Banda Sea has been compiled from the literature published between 1889-1995 as well as from the LIPI-RCO reference collection. To date, 44 species from five extant classes (Asteroidea, Ophiuroidea, Crinoidea, Echinoidea, and Holothuroidea) have been recorded from this area that consisting of the epipelagic (< 200 m depth), mesopelagic (200-1000 m depths) and bathypelagic (> 1000 m depth) species. Research history, taxonomy, and depth distribution are briefly discussed here. However, deep-sea habitats all over the world remain unexplored, including the Banda trench. The opportunity to discover both new records and new species for science from this trench is still wide open since the hitherto record of its marine biodiversity is still a few compared to the discovery on the shallow water. More deep-sea exploration will be needed to improve our knowledge of marine biodiversity.