Jurnal Ilmu dan Teknologi Kelautan Tropis
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PLANNING ON HATCHING TIME OF GROUPER EGGS THROUGH DIFFERENT INCUBATION TEMPERATURES
Groupers were known as a high economically marine commodity and in order to support groupers production, the seed availability was the most important. Eggs are still as limited factor in hatchery production, for this reason the success of eggs transportation is one as base of successful production of seed. Planning on hatching time of eggs through different incubation temperature was an option to solve that problem. This experiment was aimed to find out the optimum temperature for groupers eggs and the minimum temperature to arrange incubation time and to plan the hatching time. Fertilized eggs were incubated into three beaker glasses of 1 liter in volume with the density of ± 250 eggs/liter. The incubation was done under laboratory condition at controlled temperature, i.e. (A) 21-22 ºC, (B) 24-25 ºC, (C) 27-28 ºC and (D) 30-31 ºC. The eggs that used were including orange spotted grouper (Epinephelus coiodes), brown marbled grouper (E. microdon), tiger grouper (E. fuscoguttatus) and humpback grouper (Cromileptes altivelis). Investigated variables were embryonic development pattern, incubation time and hatching rate. The result showed that the eggs incubated in temperature range of 24-31°C had the normal sequence of embryonic development pattern, but in temperature of 21-22°C performed irregular sequence and the embryonic development stopped at blastula or gastrula stage or even the eggs could still develop but the body of hatched larvae were abnormal. In lower temperature incubation, the incubation time was longer and the hatching rate of eggs was lower than those in higher temperature. Therefore the optimum temperature for incubation of orange spotted grouper, marbled grouper, tiger grouper and humpback grouper eggs ranged between 24-31 ºC, while the lowest possible temperature was 24 ºC.Keywords: incubation temperature, embryonic development pattern, grouper eggs, hatching rat
ACCUMULATION OF HEAVY METALS PB, CU, AND ZN IN THE MANGROVE FOREST OF MUARA ANGKE, NORTH JAKARTA
In this study, the concentrations of three kinds of heavy metals, namely Pb, Zn, and Cu from 3 species of mangrove that grow in Muara Angke were measured and analyzed. Our result showed that substrate of mangrove ecosystem in Muara Angke was dominated by clay (30.5% - 62.4%), silt (21.7% -35.6%), and sand (2% -39.5%). The heavy metals accumulation in roots is higher than in sediment, water and leaves with concentration of Zn as the highest. Bioconcentration Factor (BCF; content ratio of heavy metal concentrations in roots or leaves and sediment) and Translocation Factor (TF; ratio of heavy metal concentrations in leaves and roots) of non-essential heavy metals (Pb) is higher in leaves than in roots, but for essential heavy metals (Zn and Cu), the BCF and TF was higher in roots than in leaves. TF values for heavy metals Pb, Cu, and Zn were 0.98-2.59, 0.17-0.51, and 0.52-0.86, respectively. The values of root BCF of those three heavy metals were 0.71-3.17, 0.27-0.74, and 0.95-1.53, while the values of leaf BCF were 1.84-3.45, 0.07-0.34, and 0.72-1.19, respectively. Furthermore, by calculating the phytoremediation (FTD), i.e. the difference between BCF and TF, it is obtained that Sonneratia caseolaris and Avicennia marina can be used in phytoremidiation, with leaves and roots FTD of 1.93 and 2.09, respectively for Sonneratia caseolaris and 1.93 and 1.98 for Avicennia marina.Keywords: heavy metals, mangroves, phytoremidiation, Muara Angke, bioconcentration factor, translocation facto
FISH COMMUNITY STRUCTURE IN DIFFERENT SEAGRASS BEDS OF BARRANG LOMPO ISLAND
The importance of seagrass meadows as a habitat for fishes, including several of economic importance, is widely acknowledged. The complexity of seagrass beds might offer a different condition of habitat for fishes. The physical nature of the seagrass canopy is thought to play a major role, potentially influencing available shelter, food, and protection from predators. Structural complexity of seagrass such as shoot and leaf density is also an important factor in determining ecological function of seagrass in the marine environment. The objective of the research is to assess the ecological function of different seagrass beds (in terms of spesies and density) in supporting fish community. The study found 28 species of fish originating from 14 families and Pomacentridae were dominantly found. Abundance of fish found to be higher in seagrass beds with high densities both composed by one species of seagrass (monospesific) or by more than one species of seagrass (multispesific), compared to the seagrass beds with low density and bare areas. Fish community diversity index was found higher in dense seagrass beds composed of many species of seagrass compared to the rare and consists of only one species of seagrass. The presence of epiphytes as nutrients for the fish that live in seagrass beds may contribute to the finding.Keywords: Seagrass, fish, Barrang Lompo Islan
SUBTROPICAL WATER MASSES IN HALMAHERA WATERS
Research of water masses by using conductivity temperature depth (CTD), are conducted in the eastern path of the Indonesia Throughflow (ITF) in the Halmahera, Seram and Banda seas during March-April 2007 under the Expedition of Widya Nusantara (EWIN). The objective of this research is to see maximum salinity spread of South Pacific Subtropical Water (SPSW) water masses enter the eastern Indonesia Waters. The temperature and salinity profiles show the presence of the presence of SPSW have been very much confined to the Halmahera Sea only. Little of this water masses have been detected in the eastern Seram Sea, but none in Banda Sea. Early data of Arlindo Mixing (ARMIX) experiment in southeast monsoon 1993 indicated that this water masses SPSW may entered the southern most part of the Moluccas Sea. Type of South Pacific Subtropical Water (SPSW) water masses appears in the Halmahera Sea at an average depth of 200m and the dominant flows between Halmahera and Obi Islands (Moluccas Sea continues to the east). Type of South Pacific Intermediate Water (SPIW) water mass appeared on average Halmahera Sea at a depth of 750m and the dominant flows between Halmahera and Obi Islands (Moluccas Sea continues to the east). Type of North Pacific Subtropical Water (NPSW) water masses at an average depth of ~ 150m found in the northern part of Halmahera, the dominant flow to the Celebes Sea, Makassar Strait, Flores Sea and partly flows into Lombok Straits. Type of minimum salinity water mass of North Pacific Intermediate Water (NPIW) obtained at an average depth of ~ 400m dominant flow towards the Celebes Sea, Makassar Strait and Flores Sea.Keywords: maximum salinity, SPSW, Halmahera, Seram, and Banda Sea
VARIABILITY OF CHLOROPHYLL-a CONCENTRATION OF THE NORTHERN SUMBAWA WATERS BASED ON Sea WiFS SATELLITE DATA
Variability of chlorophyll-a concentrations of the northern Sumbawa waters was investigated based on SeaWiFS satellite data for the period of January 1998-December 2007. Chlorophyll-aconcentration was estimated employing OC4v4 algorithm. Chlorophyll-a concentrations of,SeaWiFS satellite data were obtained from the Goddard Space Flight Center, NASA archieve data. In general, fluctuations of chlorophyll-a concentration of the northern Sumbawa waters had three patterns i.e., the maximum with a range of 0,21-0,74 mg/m3 occurred during the West Season (November-February), the minimum with a range of 0.12-0.15 mg/m3 occurred during Transition Season I (March-April), and relatively high (second peak) with a range of 0.21-0.36 mg/m3 occurred during the mid-East Season until the beginning of Transition Season II (July-September).High chlorophyll-a concentration occurred during the West Season was closely related to the high rainfall, the possibility of vertical water mass mixing,and upwelling process in the northern coastal waters of Sumbawa. Meanwhile, the relatively high (second peak) of chlorophyll-aconcentration occurred in July-September was caused by the movement of water masses from the South of Makassar Strait containing relatively high chlorophyll-a concentrations and relatively low temperatures since upwelling processes occurred at this location in the same period. Keywords:Chlorophyll-a,northern Sumbawa waters, SeaWiFS, OC4v4, upwelling
KINETIC STUDY OF PHOSPHOR DAN NITROGEN COMPOUNDS FROM SEDIMENTARY RE-SUSPENSION
Kinetic study of phosphor and nitrogen compounds through resuspension sediment has been carried out to determine their time release from sediment to the water column. This laboratory study was performed by stirring the sediment within the seawater at an equal current speed of 1 m/sec. Nutrients were observed at several intervals of 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes and 40 minutes by sampling 25 ml water mixture with 3 time as replicates. The increase of nutrient occurred significantly during 5 minutes. Their average contribution of nutrient per gram sediment reached 1.827 μg phosphate, 0.292 mg ammonia, 0.276 mg ammonium, 1.776 μg nitrite and 9.059 μg nitrate. The extent of nutrient increase was probably depended upon characteristic of sediment (composition of nutrient availability) and resuspension speed.Keywords: kinetic, nutrient, resuspension, sediment, Jakarta Bay
ISLAND S IDENTIFICATION IN LINGGA COUNTY RIAU ARCHIPELAGO PROVINCE BASE D ON TOPONY MY METHOD
The Survey of Islands Toponymy has been conducted in Lingga County Riau Archipelago Province on March-April 2004. The data were collected by field survey : by interviews andGlobal Positioning System (GPS) measurement. The result of the survey identified 455 islands apart of 223 islands have not been listed at DEPDAGRI (Ministry of Internal Affairs) and 232 islands have been named. Some of 244 islands from Dishidros TNI-Al Sea Map can be updated and 211 islands have been identified from filed survey. Keywords: GPS, Island, Lingga County, Toponym
INTEPOLATOR DALAM PEMBUATAN KONTUR PETA BATIMETRI
Suatu model batimetri digital dapat dibangun melalui interpolasi sejumlah besar titik kedalaman hasil pemeruman. Studi ini menggunakan dua skenario pengolahan yaitu menggunakan keseluruhan data perum dan menggunakan data perum terpilih. Pada setiap skenario pengolahan data, ada tiga metode interpolasi yang dibandingkan yaitu metode inverse distance to power, kriging dan minimum curvature.Nilai RMSE yang didapatkan dari masing-masing interpolator pada setiap skenario tersebut ternyata cukup bervariasi. Secara umum metode Kriging lebih efektif digunakan untuk menghasilkan gambar kontur kedalaman perairan dibandingkan dengan metode lainnya. Hasil studi ini memperlihatkan perlunya penanganan data agar pola suatu unsur spasial (kontur kedalaman) dapat ditampilkan secara lebih baik.Kata Kunci: interpolasi, kriging, inverse distance to power, minimum curvature,batimetr
THE PATTERN OF WAVE TRANSFORMATION USING RCPW ave MODEL AT BAU - BAU COAST, SOUTHEAST SULAWESI PROVINCE
When wind-wave generated on deep water propagates into shallow water they will be transformed into several processes such as refraction, shoaling, reflection, diffraction, and finally collapsing. This research has objective to analyze the pattern of wave transformation which pro pagate into Bau-Bau coastal waters by using RCPWave Model as a numerical model solution to predict wave condition within the surf zone. The model showed that the wave transformation at Bau -Bau Coastal waters was influenced by coastal morphology and characteristic that was more open to the west (to the opensea) than to the east coast (bordered by Buton Strait). Wave transformation occurred from both sides, either from west or east side. When wave were broken at the western coast the wave high from west and east were 1.9 m and 0.5 respectively. At the eastern coast were 1.0 m and 0.7 m. The highest wave high occurred at head land or peninsula. Keywords: wave transformation, RCPWave, Bau-Bau Coast, refraction, shoaling,reflection, diffraction and collapsin
POTENSIAL FISHING GROUND MAPPING OF SKIPJACK AND FRIGATE TUNA IN NORTH NANGGROE ACEH DARUSSALAM WATERS
Potential fishing ground mapping of skipjack and frigate tuna was determined based on sea surface temperature (SST) and chlorophyll-a concentration. The objectives of study were to analyze the temporal and spatial variability of SST and chlorophyll-a and it’s relationship on potential fishing ground. Chlorophyll-a concentration and SST were derived from Moderate Imaging Spectroradiometer (MODIS) sensors using SeaDAS image processing software. Catch data of skipjack and frigate tuna collected from Lampulo fishing base, Banda Aceh from January 2006 until November 2007. Linier regression was used to analysis relationship between catch perunit effort (CPUE) of fish and oceanographic parameters. The analysis of SST and chlorophyll-a concentration showed the temporal and spatial variations in northern part of Aceh seawaters. Both of Chlorophyll-a concentration and SST have positive relationship on CPUE of skipjack and frigate tuna.Keywords: Mapping, potential fishing ground, skipjack and frigate tuna, North Nanggroe Aceh Darussalam Waters, chlorophyll-a, SST