Marine Research in Indonesia (MRI - E-Journal)
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A PRELIMINARY STUDY ON THE RESPONSE OF AMPHIPHOD GRANDIDIERELLA SP. TO CONTAMINATED SEDIMENT OF JAKARTA BAY
No full textA preliminary study on the response of amphipod exposed to contaminated sediments of Jakarta Bay was carried out in October 2009. The objective of the study was to determine the mortality rate of amphipod in response to exposure of contaminated sediments. Seven sediment samples were taken from the bay, i.e, reference site (St. A), and six-contaminated sites (St. B3, B5, C3, C5, D3, and D5). Amphipod (Grandidierella sp.) was collected from reference site. The study showed that average of mortality rate of amphipod ranged between 50.0 and 76.3% at contaminated sediments and 38.3% at reference sediments. There was significant difference on mortality rate of amphipod exposed to sediments of reference site and that of contaminated sites. The mortality of Grandidierella sp. was not strongly correlated with the concentration of Pb and Cu in contaminated sediments. The critical mortality factor of amphipod in this study might be due to variation in grain size of sediments and short period of acclimatization
THE DISTRIBUTION OF BENTHIC FORAMINIFERA IN DAMAR ISLAND AND JUKUNG ISLAND, SERIBU ISLANDS
No full textSeribu Islands are archipelago within Jakarta Bay built upon the pleistocene coral formation of the Sunda Shelf. The islands are characterized by unique and high biodiversity such as coral reefs. Since coral reef degradation would lead to a decrease of human prosperity, the determination of the coral reef quality is of high importance. Foraminifera offers an early warning system for the coral reef condition, as exemplified by the FORAM Index, i.e. Foraminifera in Reef Assessment and Monitoring Index. This study compared the foraminiferal community structure and the FORAM Index of two islands between the Damar Besar and Jukung. Both islands were dominated by symbiont-bearing foraminifera of the genera Amphistegina, Calcarina, Heterostegina, Marginophora, and Operculina. However, the number of benthic foraminifers at Jukung Island was higher than that at Damar Besar Island, having 17 individuals per species on average. Jukung Island was a conducive site to reef growth, as indicated by a FORAM Index (between 6,48 and 6,57), and Damar Besar Island was liable to environmental change
GROWTH OF MANGROVE COCKLE (Anandara antiquata) CULTURED IN CAGES
No full textStudy on growth of mangrove cockle (Anadara antiquata) was conducted in the intertidal area of Passo, Inner Ambon Bay. Three size-classes of 25 individual cockles were cultured in 1 m3 cage. Length increment data was collected every two weeks for seven periods of observation. Relative growth rate, length-weight relationship and condition factor were estimated using formula proposed by Effendie, Pauly and King, respectively. The results showed that the small size had the highest length increment and relative growth rates while the large size had the best condition factor. Length-weight relationship showed isometric growth for all categories
DISSOLVED AND PARTICULATE CARBON IN JAKARTA BAY, INDONESIA
No full textIn order to investigate spatial and temporal variability of dissolved organic carbon (DOC) and particulate organic carbon (POC), several samples were collected from five estuaries, inner part and outer part of Jakarta Bay. The samples were collected on 15 and 16 February 2007, a week after heavy flood in Jakarta Area, and on 16 May 2007. DOC concentration in February and May in Jakarta Bay ranged between 100-950 µg-C/l and between 0-850 µg-C/l respectively. POC concentrations ranged between 50-650 µg-C /l and 50-900 µg-C /1 in February and May 2007, respectively. Even though the concentrations between both periods were similar, the load of organic carbon from the land to Jakarta Bay showed a large contrast due to the different amount of freshwater input. The Total organic carbon fluxes from the rivers to the bay in February and May 2007 were 107.6 t d-' C-(ton per day Carbon) and 42.7 t d-1 C, respectively
FIRST RECORD OF Thamnaconus modestoides (Barnard, 1927) (Tetraodontiformes: Monacanthidae) in Indonesia
No full textThis paper gave evidence of the occurrence of Thamnaconus modestoides in Indonesian waters. A specimen (271.15 mm SL) was collected from the Winenet fish market at Bitung, North Sulawesi in March 2008. It was reported being caught in the depth of 20-30 m, in association with other coral-reef fishes, despite the fact that member of Thamnaconus has been known as deep water species. The morphological features of this new record species were discussed and illustrated
PREDICTION OF SOUTHERN OSCILLATION USING THE INDONESIAN THROUGHFLOW VARIABILITY
No full textAtmospheric boundary layer derived from NCEP/NCAR reanalyses for the period of 1974 to 2002 has been used as boundary forcings for the global ocean model Max Planck Institute Ocean Model (MPIOM). The ocean model is a curvilinear grid model, whose poles are located over mainland China and over the Australian continent, thus focusing on the maritime continent. The model simulates major Indonesian throughflow passages that focus on six cannels representing three inlets and three outlets (the Makassar, Lifamatola, Halmahera, Lombok, Ombai and Timor Straits). The model results have been validated using the Arlindo observation Project over the Makassar Strait in the period of January 1997 to February 1998, which fortunately was during a strong El Niño episode. The model simulation results were then investigated for their prediction capabilities of any of those channels in foreseeing the incoming southern oscillation events. Temporal correlation analysis with lag and advance time correlation methods were performed against simulated data at all levels on those channels. Variabilities in depth of 74 to 200m (thermocline depth) show the strongest correlation with SOI index (Darwin minus Tahiti mean sea level pressure). The temperature and salinity correlations with SOI are the highest with one-month in advance over Lifamatola Strait (0.77) and two-month in advance over the Makassar Straits (0.74). These significant correlations highlight the important of those two straits in prediction of incoming southern oscillation that usually leads to ENSO episode which brings most of the time devastating impact to economy, agriculture and ecosystem
ANOMALOUS OCEANIC CONDITIONS IN THE TROPICAL INDIAN OCEAN DURING 2006 AS REVEALED BY MULTI-SATELLITE SENSORS
No full textA positive Indian Ocean Dipole (IOD) took place in the tropical Indian Ocean during 2006. The evolution of this event started in July 2006 and intensified during August 2006. It was indicated by negative sea surface temperature anomalies, lower than normal sea level and supressed convection in the southeastern equatorial Indian Ocean in contrast to western counterpart. Peak negative SST anomalies exceeding 1°C were observed in the eastern basin during September-November coinciding with anomaous easterly winds along the equator and strong southeasterly winds along the coast of Sumatra and Java. The expression of this positive IOD was also seen in other physical variables: negative sea surface height anomalies about 30 cm and negative rainfall anomalies exceeding 8 mm/day were observed in the eastern basin. The events was terminated in December 2006 mainly due to warming of the eastern pole. The magnitude of this event determined by the east-west temperature gradient across the tropical Indian Ocean was the third largest in the last 30 years, after 1997 and 1994 events
CRYPTIC MARINE BIODIVERSITY OF RAJA AMPAT ISLANDS
No full textDuring a marine field survey in Raja Ampat as part of Ekspedisi Widya Nusantara (E-win), 21 scientists, studied the area's cryptic biota on coral reefs and in marine lakes. Cryptic species lead hidden lives due to their small size, successful camouflage or mimicry, or because they live in habitats that are easily overlooked or hard to access. Hundreds of species were sampled, many of which still have to be identified. The species richness of Raja Ampat appears to be very high, even among other areas within the centre of maximum marine biodiversity, the so-called Coral Triangle
OOCYTES OF HOLOTHURIA LEUCOSPILOTA (ECHINODERMATA: HOLOTHUROIDEA): AN ULTRA STRUCTURAL STUDY
No full textOvaries of Holothuria leucospilota consist of simple tubules, within which oocytes grew and reached maturity. The oocytes development started at the tubule lining and as the development proceeded, the oocytes increased in size and moved to the tubule lumen. An ultra-section-method was applied to describe ultrastructural changes in the oocytes during their development, leading to the knowledge on gametogenesis of sea encumber H.leucospiota. Primary previtellogenic oocytes embedded in tubule lining was the earliest stage, which were characterized by the presence of nuage. Prior to yolk formation, clusters of mitochondria appeared in the ooplasm. This may indicate the need for energy to produce yolk substance. When yolk bodies were common in vitellogenic oocytes, nuage became invisible and mitochondria were no longer in groups. As development progressed, abundant microvilli appeared on the surface of vitellogenic oocytes, but less common on postvitellogenic oocytes when maximum growth had been attained. This structure was suggested to facilitate size increase and functional efficiency of oocyte surface
MANGROVES FOR NATIONAL DEVELOPMENT AND CONSERVATION IN INDONESIA: CHALLENGES FOR THE FUTURE
No full textIndonesia's mangrove resources (soils and waters, flora and fauna, and as an ecosystem all are called as mangrove biodiversity) are growing in importance. As a consequence of past and present human utilization the mangrove resources have been depleted. Keen competition for use of the mangrove resources is apparent and is likely to intensify in the future. This policy document stresses the importance of mangroves for the Nation and the need for the Government to manage and protect them. A set of basic principles for the management and protection of mangroves is provided, together with an outline of some actions which local and central governments (Pemerintah Pusat dan Daerah) should take up in order to achieve a balance between the use of mangrove resources, their conservation and long term national development