Celebes Sea Research Articles

Morphological discoveries in the genus Diploneis (Bacillariophyceae) from the tropical west Pacific, including the description of new taxa

Epiphytic diatoms on seaweeds and seagrasses were collected from tropical regions in the western Pacific Ocean (i.e., Siladen Island, Celebes Sea, Indonesia; Guam; Palau). Fifteen species of Diploneis are described in detail with light and scanning electron microscopy including six species new to science, D. cerebrum, D. claustra, D. craticula, D. crispa, D. rimosa and D. weissflogiopsis. Valve structure in Diploneis is particularly complicated, and two new distinctive structures are described for the first time: (1) central external raphe endings with flaps or rolled flaps and (2) internal globular papillae near the marginal ends of the virgae. In addition, we confirm that openings on the inner surface of the longitudinal canals are of taxonomic value. The structural complexities encountered in Diploneis require the study of a great many more taxa before a meaningful revision of the genus can be undertaken. Its diversity in warm waters is a rich resource for new Diploneis taxa to further our understanding of the genus.

A new species of clausophyid calycophoran siphonophore (Cnidaria: Hydrozoa), Kephyes hiulcus sp. nov., widely distributed throughout the world's oceans.

A new species of clausophyid siphonophore, Kephyes hiulcus sp. nov. is described. It can most easily be differentiated from its congener Kephyes ovata by the shape of the hydroecium in the anterior nectophore of the polygastric stage. This is open over the entire height of the nectophore in K. hiulcus sp. nov., and it is this character from which its specific name is derived. This species was found in the eastern and western Pacific Ocean, as well as the Celebes and Mediterranean Seas, indicating that this species is both relatively common and geographically widespread.

Macroglossia

A study was carried out on the distribution and enrichment of trace elements in the core marine sediments of East Malaysia from three stations at South China Sea and one station each at Sulu Sea and Sulawesi Sea. Five stations of sediment cores were recovered and the vertical concentration profiles of six elements namely Br, Cs, Hf, Rb, Ta, and V were determined using the instrumental neutron activation analysis. The enrichment factor, geoaccumulation index and the modified degree of contamination were used to calculate the anthropogenic and pollution status of the elements in the samples. Except for Cs and Hf, which by the enrichment factor are categorized from minimum enrichment to moderate enrichment in all stations and for V and Rb in Sulu Sea and Sulawesi Sea, which are categorized minimum enrichment, other elements are found to be no enrichment at all stations. The geoaccumulation index of Hf in one station shows moderately polluted and for other elements are unpolluted. However, the modified degree values of all samples are less than 1, suggesting very low contamination of elements found in all the stations.

Distribution of Trace Elements in Core Marine Sediments of Coastal East Malaysia by Instrumental Neutron Activation Analysis

A study was carried out on the distribution and enrichment of trace elements in the core marine sediments of East Malaysia from three stations at South China Sea and one station each at Sulu Sea and Sulawesi Sea. Five stations of sediment cores were recovered and the vertical concentration profiles of six elements namely Br, Cs, Hf, Rb, Ta, and V were determined using the instrumental neutron activation analysis. The enrichment factor, geoaccumulation index and the modified degree of contamination were used to calculate the anthropogenic and pollution status of the elements in the samples. Except for Cs and Hf, which by the enrichment factor are categorized from minimum enrichment to moderate enrichment in all stations and for V and Rb in Sulu Sea and Sulawesi Sea, which are categorized minimum enrichment, other elements are found to be no enrichment at all stations. The geoaccumulation index of Hf in one station shows moderately polluted and for other elements are unpolluted. However, the modified degree values of all samples are less than 1, suggesting very low contamination of elements found in all the stations.

First Record of the anchovy Stolephorus teguhi (Engraulidae) from the Philippines

A single Philippines specimen (59.7 mm standard length) of Stolephorus teguhi Kimura, Hori & Allen, 2009 (Engraulidae), previously recorded only from North Sulawesi, Indonesia, was recently discovered in the fish collection of the National Museum of Natural History, Smithsonian Institution, USA. A full description is given of the specimen, which constitutes the first record of the species from the Philippines and supports the view that S. teguhi is widely distributed in the Celebes Sea to the eastern part of the South China Sea.

Seasonal and Inter Annual Variation of Sea Surface Temperature in the Indonesian Waters

Sea surface temperature plays an important role in air-sea interactions. This research was conducted to understand seasonal and interannual variations of sea surface temperature in the Indonesian waters. The data used in this research was daily sea surface temperature in 1986 to 2015 which was obtained from the Physical Oceanography Distributed Active Archive Center - National Aeronautics and Space Administration. Method used in this study was the anomaly analysis. The result showed that the seasonal and interannual variations of sea surface temperature in the Indonesian waters varied. Seasonal variations of SST in the Makasar Strait, Sulawesi Sea, and Halmahera Sea were low. High seasonal variations of sea surface temperature occurred in the southern waters of Java, Timor Sea, Arafura Sea, and Banda Sea, which were allegedly due to the upwelling process. In addition, interannual variation of sea surface temperature in the Indonesian waters fluctuated. From 1986 to 2000, it showed a negative anomaly dominant. Meanwhile, from 2001 to 2015, it showed a positive anomaly dominant. The effect of Indian Ocean Dipole on the fluctuation of sea surface temperature in the Indonesian waters was stronger than ENSO. Within the last 30 years, the sea surface temperature in the Indonesian water indicated a rising trend. The highest sea surface temperature rise occurred in the Halmahera Sea that reached 0.66 OC/30 years and the lowest was in the Timor Sea of 0.36 OC/30 years.

Siliceous sponge spicule dissolution: In field experimental evidences from temperate and tropical waters

Sponge siliceous spicules are considered a sink in the silica balance of the oceans as their dissolution rate seems to be negligible, but no field data are available about this process. The aim of this study was a first evaluation of the quantitative dissolution rates of some demosponge and hexactinellid spicules (collected in different localities at different latitudes), left at sea for six months in two localities characterised by different water average temperatures: Mediterranean Sea and Celebes Sea. The effects of silica dissolution on the experimented spicules, studied by SEM analysis, produced an enlargement of the axial canal sometimes resulting in empty spicules. While in demosponges the axial canal wall of eroded spicules was perfectly smooth or slightly rough, the hexactinellid Rossella racovitzae showed a cavernous, well recognisable pattern of dissolution. The dissolution rates were determined evaluating the decrease in outer diameter and in the expansion of the axial channel of about 300 spicules for each considered species and locality. The spicules from the Mediterranean Geodia cydonium did not show any detectable dissolution in both localities, while those from Tethya citrina showed a loose of silica of about 23% in the Mediterranean and 47% in the Celebes Sea. Paratetilla bacca from the Red Sea decreased the silica content of about 30% in both the localities. Tetilla leptoderma from Mar del Plata lost about 8% and 42% of silica respectively in Mediterranean and Celebes Sea. Finally, the hexactinellid spicules from the Antarctic Rossella racovitzae showed highest dissolution rates in both experimental sites (37% and 66% in the Mediterranean and Celebes Sea, respectively). The different levels of dissolution can be related to the different taxonomic position in terms of specular structures as well as to the temperatures at which the spicules have been deposited and exposed. In fact, spicules from the same species showed a dissolution rate generally higher in tropical waters than in Mediterranean.

Opposite Variability of Indonesian Throughflow and South China Sea Throughflow in the Sulawesi Sea

AbstractBased on a high-resolution (0.1° × 0.1°) regional ocean model covering the entire northern Pacific, this study investigated the seasonal and interannual variability of the Indonesian Throughflow (ITF) and the South China Sea Throughflow (SCSTF) as well as their interactions in the Sulawesi Sea. The model efficiency in simulating the general circulations of the western Pacific boundary currents and the ITF/SCSTF through the major Indonesian seas/straits was first validated against the International Nusantara Stratification and Transport (INSTANT) data, the OFES reanalysis, and results from previous studies. The model simulations of 2004–12 were then analyzed, corresponding to the period of the INSTANT program. The results showed that, derived from the North Equatorial Current (NEC)–Mindanao Current (MC)–Kuroshio variability, the Luzon–Mindoro–Sibutu flow and the Mindanao–Sulawesi flow demonstrate opposite variability before flowing into the Sulawesi Sea. Although the total transport of the Mindanao–Sulawesi flow is much larger than that of the Luzon–Mindoro–Sibutu flow, their variability amplitudes are comparable but out of phase and therefore counteract each other in the Sulawesi Sea. Budget analysis of the two major inflows revealed that the Luzon–Mindoro–Sibutu flow is enhanced southward during winter months and El Niño years, when more Kuroshio water intrudes into the SCS. This flow brings more buoyant SCS water into the western Sulawesi Sea through the Sibutu Strait, building up a west-to-east pressure head anomaly against the Mindanao–Sulawesi inflow and therefore resulting in a reduced outflow into the Makassar Strait. The situation is reversed in the summer months and La Niña years, and this process is shown to be more crucially important to modulate the Makassar ITF’s interannual variability than the Luzon–Karimata flow that is primarily driven by seasonal monsoons.

High biodiversity of leptocephali in Tomini Bay Indonesia in the center of the Coral Triangle

The Indonesian Seas in the center of the Coral Triangle have high marine biodiversity, and a unique area is Sulawesi Island that has the large semi-enclosed Tomini Bay, including the Togian Islands, formed within the island. A sampling survey for leptocephali was conducted in March 2010 at 48 stations in the southern Celebes Sea and in Tomini Bay that collected 2056 leptocephali (6.0–319 mm) of at least 11 anguilliform and 3 elopomorph families and ∼126 species. About 44 Muraenidae, 26 Ophichthidae, 25 Congridae, and 11 Chlopsidae species and < 5 species of each of the other families were collected. The congrid, Ariosoma scheelei, the chlopsid, Kaupichthys, serrivomerids, Nemichthys and an ophichthid species of Neenchelys were the most abundant species/taxa. Comparisons of the two sampling areas found that ∼105 species were among the 1090 leptocephali from 21 tows in Tomini Bay and ∼78 species were among the 966 leptocephali from 30 Celebes Sea tows. Species such as chlopsids (25% of leptocephali in Tomini Bay), some muraenids, congrids, moringuids, and serrivomerids were more abundant in Tomini Bay than in the Celebes Sea, and some rare species were only collected there. The wide size range of most taxa indicated that many species spawn in the bay and their larvae are likely retained there. Large eddies in the Celebes Sea appeared to have transported leptocephali offshore. The high biodiversity of marine eel larvae suggest the unique semi-enclosed Tomini Bay may offer a good environment for spawning and self-recruitment, which may partly explain the high number of species of some families. More research is needed to evaluate the species composition of eels in Tomini bay and the wider region and to facilitate understanding and conservation of the diverse marine habitats of the Indonesian Seas.

The Dependency of Probabilistic Tsunami Hazard Assessment on Magnitude Limits of Seismic Sources in the South China Sea and Adjoining Basins

The South China Sea (SCS) and its adjacent small basins including Sulu Sea and Celebes Sea are commonly identified as tsunami-prone region by its historical records on seismicity and tsunamis. However, quantification of tsunami hazard in the SCS region remained an intractable issue due to highly complex tectonic setting and multiple seismic sources within and surrounding this area. Probabilistic Tsunami Hazard Assessment (PTHA) is performed in the present study to evaluate tsunami hazard in the SCS region based on a brief review on seismological and tsunami records. 5 regional and local potential tsunami sources are tentatively identified, and earthquake catalogs are generated using Monte Carlo simulation following the Tapered Gutenberg–Richter relationship for each zone. Considering a lack of consensus on magnitude upper bound on each seismic source, as well as its critical role in PTHA, the major concern of the present study is to define the upper and lower limits of tsunami hazard in the SCS region comprehensively by adopting different corner magnitudes that could be derived by multiple principles and approaches, including TGR regression of historical catalog, fault-length scaling, tectonic and seismic moment balance, and repetition of historical largest event. The results show that tsunami hazard in the SCS and adjoining basins is subject to large variations when adopting different corner magnitudes, with the upper bounds 2–6 times of the lower. The probabilistic tsunami hazard maps for specified return periods reveal much higher threat from Cotabato Trench and Sulawesi Trench in the Celebes Sea, whereas tsunami hazard received by the coasts of the SCS and Sulu Sea is relatively moderate, yet non-negligible. By combining empirical method with numerical study of historical tsunami events, the present PTHA results are tentatively validated. The correspondence lends confidence to our study. Considering the proximity of major sources to population-laden cities around the SCS region, the tsunami hazard and risk should be further highlighted in the future.

Seagrass biodiversity at three marine ecoregions of Indonesia: Sunda Shelf, Sulawesi Sea, and Banda Sea

Kawaroe M, Nugraha AD, Juraij, Tasabaramo IA. 2016. Identification of soybean genotypes adaptive and productive to acid soil agro-ecosystem. Biodiversitas 17: 585-591. Seagrass is one of the coastal ecosystems in marine ecoregions of Indonesia that has very important ecological and economical functions. This study aimed to illustrate the diversity of seagrass ecosystems through its distribution, coverage, and density, in three marine ecoregions of Indonesia, namely Sunda Shelf/SHS (Bintan Island/SHS-B and the Seribu Islands/SHS-S), Sulawesi Sea/SS (Talaud Island), and Banda Sea/BS (Tanimbar Islands). The study was conducted at 16 stations in SHS, 20 stations in SS, and 30 stations in BS. A line transect method was used. Three line transects (length 50m) were deployed ineach station perpendicular to the shoreline towards the sea with a distance of 20 meters between transect lines. In each line transect, quadrate transects were placed (0.5mx0.5m) along the line, alternating left and right line up to the edge. Species identification and seagrass density were calculated in each quadrate transect. Similarity indexes were calculated and analyzed between ecoregion on seagrass coverage and abundance through dendrogram graphic. Results showed that 10 species of seagrass were found in three marineecoregions. In SHS-B, 10 species with a coverage cover of 61% were found and Thalassia hemprichii was of the highest abundance. In ShS-S, 6 species with a coverage cover of 37% were found and Enhalus acoroides species was of the highest abundance. In SS, 5 species with a coverage cover of 43% were found and Cymodocea rotundata was of the highest abundance. Finally, in BS, 7 species with coverage of 60% were found and Thalassia hemprichii was of the highest abundance. These results indicated that seagrass biodiversity found in 3 Indonesia marine ecoregions were still in a healthy condition. One of the implications of this healthy condition of seagrass was that the very important functions of seagrass as a habitat for economically important organisms and a food source for herbivores, particularly Dugong dugong, living in seagrass was still secured.

Gambierdiscus balechii sp. nov (Dinophyceae), a new benthic toxic dinoflagellate from the Celebes Sea (SW Pacific Ocean)

A new benthic toxic dinoflagellate is described from the Celebes Sea. Gambierdiscus balechii sp. nov. was isolated from seaweeds growing in tidal ponds. Its morphology was studied by means of LM and SEM; G. balechii has a very ornamented theca, a hatchet shaped second apical plate, a narrow second antapical plate and an asymmetrical third precigular plate, a unique combination of characters among Gambierdiscus species. It has a very wide size range with widths from 36 to 88μm. Phylogenetic analyses of two G. balechii strains, based on LSU rRNA (D8–D10) and partial SSUrRNA sequences confirmed that these clustererd in its’ own group, separated from the rest of Gambierdiscus species and with G. pacificus, G. belizeanus and G. scabrosus as its closest relatives. Thecate cysts are described from culture as non motile vegetative-like cells which germinated after being isolated and transferred to fresh medium. Mouse tests showed that this species is toxic and hence it is a potential cause of ciguatera in the Celebes Sea.

Phylogeography of the planktonic shrimp Lucifer hanseni Nobili 1905 in the Indo-Malayan Archipelago

Using partial sequences of two mitochondrial genes, cytochrome c oxidase subunit I (COI) and 12S ribosomal RNA (12S rRNA), and one nuclear gene, 28S ribosomal RNA (28S rRNA), we investigated population genetics of the holoplanktonic shrimp Lucifer hanseni Nobili, 1905 in the Indo-Malayan Archipelago (IMA), encompassing Andaman Sea, Malacca Strait, Gulf of Thailand, Borneo Island, Philippines (hereafter collectively referred to as the Thailand-Malaysia-Philippine area: TMP), Celebes Sea (CS), and the waters near islands in the Western Pacific (WP) including Palau, Papua New Guinea and Solomon Islands. The samples from the TMP showed the highest number of haplotypes. Significant phylogeographic structure was found in the L. hanseni populations (ΦST = 0.832 for COI, 0.159 for 12S rRNA, 0.783 for 28S rRNA). The total number of haplotypes was 46 in COI, 28 in 12S rRNA and 23 in 28S rRNA. The haplotype network analyses revealed two major clades for COI (subgroups: TMP + CS, WP) and for 12S rRNA and 28S rRNA (TMP, CS + WP). The CS and WP populations appeared isolated from the TMP populations. The samples from the CS showed low genetic diversity compared with the other samples at both haplotype and nucleotide levels, suggesting that the population CS experienced bottleneck events. This is the first demonstration of significant genetic structure of a holoplanktonic metazoan in IMA, which is suggested to be synergistically influenced by historical events (vicariance) and contemporary oceanographic circulations and corroborates the results of previous studies on other benthic/demersal animals with mero-planktonic phases.

The effect of contrasting threat mitigation objectives on spatial conservation priorities

The primary role of marine protected areas (MPAs) is marine conservation, however policy and practice around MPAs have not reflected this. The focus on cost-effectiveness by spatial conservation prioritization has led to a bias towards placing MPAs in areas that are least threatened. This study investigates how conservation priorities differ between two management strategies of either targeting or avoiding high threat areas for protection, using the case of the Sulu Sulawesi Seas in the Coral Triangle. For both strategies, the target of protecting 20% of habitat could not be achieved solely by protecting low threat areas. A high proportion of the region had large differences in conservation outcomes between the two strategies; majority of these areas were highly prioritized in the threat avoidance strategy but had low or zero importance in the threat selection strategy. Selecting for highly threatened areas required less habitat area to be protected to achieve the same conservation target and resulted in a more equitable distribution of priority sites per country and sub-region. This demonstrates the importance of deciding on the objectives of conservation and management policies up-front. The results suggest that, contrary to the common practice of avoiding threats in spatial planning, a threat selection strategy should be part of the management toolbox, particularly in transboundary planning for regions with high overall threat levels, where it may be important to achieve shared conservation targets equitably.

Growth, Morphology and Growth Related Hormone Level in Kappaphycus alvarezii Produced by Mass Selection in Gorontalo Waters, Indonesia

The use of high quality seed can support the success of the seaweed cultivation. This study was conducted to evaluate the growth performance, morphology and growth related hormone level of brown strain seaweed Kappaphycus alvarezii seed produced by mass selection. Selection was performed in the Tomini Gulf, Gorontalo, based on mass selection of seaweed seed protocol with a slight modification in cut-off 10% of the highest daily growth rate. Selection was carried out for four generations. The selected 4th generation of seed was then used in cultivation performance test in the Celebes Sea, North Gorontalo, for three production cycles. The results showed that the selected K. alvarezii has higher clump weight and daily growth rate, longer thallus, more number of branches, and shorter internodes compared to the unselected control and seaweed from the farmer as external control. Furthermore, total sugar content, levels of kinetin hormone and kinetin:indole-3-acetic acid ratio were higher in selected seaweeds than that of unselected control and external control. Thus, mass selection method could be used to produce high growth of seed, and kinetin and indole-3-acetic acid play an important role in growth of K. alvarezii.

Intraseasonal Sea Surface Temperature Variability across the Indonesian Seas*

Abstract Sea surface temperature (SST) variability at intraseasonal time scales across the Indonesian Seas during January 1998–mid-2012 is examined. The intraseasonal variability is most energetic in the Banda and Timor Seas, with a standard deviation of 0.4°–0.5°C, representing 55%–60% of total nonseasonal SST variance. A slab ocean model demonstrates that intraseasonal air–sea heat flux variability, largely attributed to the Madden–Julian oscillation (MJO), accounts for 69%–78% intraseasonal SST variability in the Banda and Timor Seas. While the slab ocean model accurately reproduces the observed intraseasonal SST variations during the northern winter months, it underestimates the summer variability. The authors posit that this is a consequence of a more vigorous cooling effect induced by ocean processes during the summer. Two strong MJO cycles occurred in late 2007–early 2008, and their imprints were clearly evident in the SST of the Banda and Timor Seas. The passive phase of the MJO [enhanced outgoing longwave radiation (OLR) and weak zonal wind stress) projects on SST as a warming period, while the active phase (suppressed OLR and westerly wind bursts) projects on SST as a cooling phase. SST also displays significant intraseasonal variations in the Sulawesi Sea, but these differ in characteristics from those of the Banda and Timor Seas and are attributed to ocean eddies and atmospheric processes independent from the MJO.

Rare earth elements in core marine sediments of coastal East Malaysia by instrumental neutron activation analysis

A study was carried out on the concentration of REEs (Dy, Sm, Eu,Yb, Lu, La and Ce) that are present in the core marine sediments of East Malaysia from three locations at South China Sea and one location each at Sulu Sea and Sulawesi Sea. The sediment samples were collected at a depth of between 49 and 109m, dried, and crushed to powdery form. The entire core sediments prepared for Instrumental Neutron Activation Analysis (INAA) were weighted approximately 0.0500g to 0.1000g for short irradiation and 0.1500g to 0.2000g for long irradiation. The samples were irradiated with a thermal neutron flux of 4.0×1012cm−2s−1 in a TRIGA Mark II research reactor operated at 750kW. Blank samples and standard reference materials SL-1 were also irradiated for calibration and quality control purposes. It was found that the concentration of REEs varies in the range from 0.11 to 36.84mg/kg. The chondrite-normalized REEs for different stations suggest that all the REEs are from similar origins. There was no significant REEs contamination as the enrichment factors normalized for Fe fall in the range of 0.42–2.82.

The stalked crinoid fauna (Echinodermata) of the Molucca and Celebes Seas, Indonesia: taxonomic diversity and observations from remotely operated vehicle imagery

The seafloor of the Molucca and Celebes Seas, Indonesia, was investigated using a remotely operated vehicle with high-definition video during 18 dives to depths of 280 to 3200 m. Irregular slopes and rocky substrata supported abundant megabenthos, including stalked crinoids. Video zoomed on many individuals provided enough details to assign 770 stalked crinoids to major taxa and many to species level. These taxa included Guillecrinus neocaledonicus, Ptilocrinus cf. amezianeae, three species of Hyocrinus, an unknown phrynocrinid, Naumachocrinus hawaiiensis, Proisocrinus ruberrimus, Endoxocrinus alternicirrus, seven phenotypes in the Subfamily Metacrininae and one taxon of unknown affiliation. A novel observation of a juvenile Endoxocrinus included the attachment disk to a rocky surface. Taxa usually considered rare were well represented on hard substrata, thus expanding knowledge of their depth distributions. Mostly, stalked crinoids were sparsely distributed in low densities (to 186 individuals per km), except for occasional single-species clusters. Metacrinins and P. cf. amezianeae dominated at depths of 250–600 m, while E. alternicirrus and G. neocaledonicus were the most abundant species at a depth range of 1000–1400 m. The largest peak of species richness (with nine of the 17 taxa identified) occurred at 1000 to 2000 m. Many specimens altered their feeding posture with current intensity, but a balloon-like crown posture is common in low or non-existent currents. The postures of several mobile metacrinin individuals suggest an active role of arms and cirri in slow crawling movements. The possible origin of some taxa from either Gondwanaland or Eurasian margins is discussed using biogeographical and paleontological data. The location of the Wallace line cannot be delimited only using extant stalked crinoid distribution.

Diversity and community structure of pelagic cnidarians in the Celebes and Sulu Seas, southeast Asian tropical marginal seas

The Sulu Sea is a semi-isolated, marginal basin surrounded by high sills that greatly reduce water inflow at mesopelagic depths. For this reason, the entire water column below 400m is stable and homogeneous with respect to salinity (ca. 34.00) and temperature (ca. 10°C). The neighbouring Celebes Sea is more open, and highly influenced by Pacific waters at comparable depths. The abundance, diversity, and community structure of pelagic cnidarians was investigated in both seas in February 2000. Cnidarian abundance was similar in both sampling locations, but species diversity was lower in the Sulu Sea, especially at mesopelagic depths. At the surface, the cnidarian community was similar in both marginal seas, but, at depth, community structure was dependent first on sampling location and then on depth within each Sea. Cnidarians showed different patterns of dominance at the two sampling locations, with Sulu Sea communities often dominated by species that are rare elsewhere in the Indo-Pacific. Mesopelagic and bathypelagic species recorded in the Sulu Sea did not have significantly different vertical distributions in the Celebes Sea. However, some deep mesopelagic genera were absent from the Sulu Sea in the sampled depth range. These results suggest that a combination of environmental and physiological parameters determine the distribution and dominance of pelagic cnidarians.

WATER MASSES CHARACTERISTICS AT THE SANGHIE TALAUD ENTRY PASSAGE OF INDONESIAN THROUGHFLOW USING INDEX SATAL DATA 2010

ABSTRACT Measurement of ocean physical parameters using the CTD was conducted by deep water expedition INDEX-SATAL 2010 (Indonesian Expedition Sangihe-Talaud) in July-August 2010. The aim of this study was to determine the characteristics of water masses around the Sangihe Talaud Water where there was an entry passage of Indonesian throughflow (ITF) at the west pathway that passed through the primary pathway i.e., the Sulawesi Sea and Makassar Strait and the secondary pathway (east pathway) that passed through the Halmahera Sea. The analyses were performed by the method of the core layer and was processed with software Ocean Data View (ODV). The results showed that in the Sangihe Talaud waters there was a meeting water masses from the North Pacific and the South Pacific. The water mass characteristics in main pathway through the Sulawesi Sea was dominated by surface and intermediate North Pacific water masses and carried by the Mindanao Currents. While the Halmahera Sea water mass was dominated by surface and intermediate South Pacific water masses carried by the New Guinea Coastal Current that moved along the Papua New Guinea and Papua coast enters to the Halmahera Sea. Keywords: Index-Satal 2010, Northern Pacific Water Masses, Southern Pacific Water Masses, Sangihe Talaud