ILMU KELAUTAN: Indonesian Journal of Marine Sciences 

About: ILMU KELAUTAN: Indonesian Journal of Marine Sciences is an academic journal published by Diponegoro University; Association of Indonesian Coastal Management Experts. The journal publishes majorly in the area(s): Population & Environmental science. It has an ISSN identifier of 0853-7291. Over the lifetime, 485 publications have been published receiving 2068 citations. The journal is also known as: Majalah ilmiah pengembangan ilmu-ilmu kelautan & Indonesian journal of marine sciences.

Variabilitas Suhu dan Klorofil-a di Daerah Upwelling pada Variasi Kejadian ENSO dan IOD di Perairan Selatan Jawa sampai Timor

Abstract: Informasi mengenai variabilitas spasial suhu dan klorofil-a permukaan laut memiliki peran penting sebagai sarana pendugaan daerah potensi ikan tuna. Penelitian ini bertujuan untuk mengkaji dan menggambarkan variabilitas suhu dan klorofil-a permukaan laut baik secara spasial maupun temporal di daerah upwelling pada variasi kejadian El Nino Southern Oscilation (ENSO) dan Indian Oscillation Dipole Mode (IOD) di perairan Selatan Jawa hingga Timor. Variabilitas suhu dan klorofil-a permukaan laut dikaji berdasarkan data-data MODIS (Moderate-Resolution Imaging Spektroradiometer) bulanan Level 3 dari satelit Aqua dan Terra. Nilai suhu dan klorofil-a permukaan laut bervariasi menurut waktu (bulan), wilayah (provinsi) dan variasi antar tahunan iklim global (El Nino-IOD(-), El Nino-IOD(+), La Nina-IOD(-) dan La Nina-IOD(+). Secara umum kisaran suhu permukaan laut (SPL) di daerah upwelling pada variasi ENSO dan IOD berkisar 26,18 -28,35°C dengan rerata 27,04±0,93°C. Kisaran klorofil-a sebesar 0,3-0,95 mg/M³ dengan rerata 0,69±0,28mg/M³. Mulai bulan Juni umumnya nilai suhu permukaan laut (SPL) semakin turun dan klorofil-a semakin meningkat hingga mencapai puncak bulan Agustus atau September, kemudian berangsur normal kembali. Nilai suhu permukaan laut terendah ditemukan berkembang dari timur (Bali) pada bulan Juni bergerak ke barat hingga Jawa Barat di bulan Oktober. Nilai klorofil-a tinggi berkembang sesuai dengan perkembangan suhu terendah, namun nilai klorofil-a tertinggi umumnya bergerak tidak sesuai dengan perkembangan SPL terendah. Klorofil-a tertinggi umumnya terjadi di perairan selatan Provinsi Bali. Jauh dekatnya pergerakan SPL terendah dan klorofil-a tinggi tampak dipengaruhi nilai IOD-nya, semakin besar nilai IOD maka semakin jauh gerakannya ke barat. Kata Kunci : Variabilitas, suhu, klorofil-a, upwelling, perairan selatan Jawa The information of spatial variabilities of sea surface temperature and chlorophyll-a are important for predicting potential fishing ground of tuna. The aims of the reseach are to describe and study the spatial and temporal variabilities of sea surface temperature and chlorophyll-a at upwelling area during the variabilities of El Nino Southern Oscilation (ENSO) and Indian Oscillation Dipole Mode (IOD) event at southern waters of Jawa until Timor Island. They were studied based on monthly MODIS (Moderate-Resolution Imaging Spektroradiometer) data Level 3 from Aqua and Terra satelite. The values of sea surface temperature and chlorophyll-a are variable in the times (month), areas (province) and annually global climate (El Nino-IOD(-), El Nino-IOD(+), La Nina-IOD(-) dan La Nina-IOD(+). Commonly range of the seawater surface temperature (SST) at upwelling area on the variabilities of ENSO and IOD are about 26.18-28.35°C with average 27.04±0,93°C, whereas average of chlorophyll-a are about 0.3-0.95 mg/m³ with average 0.69±0,28mg/M³. From June, sea surface temperature starts to decrease but clhorophyl-a is increasing and back to normal after reaching peak in August or September. The lowest sea surface temperature was found developing from east (Bali) in June and then moving to west until southern west Java in October. The development of high chlorophyll-a values are suitable with that of low sea surface temperature. However the development of highest chlorophyll-a generally move inconsistent with that of lowest sea surface temperature. The highest chlorophyll-a generally happen at the southern of Bali Province. The distance movement of the low sea surface temperature and high chlorophyll-a distributions are affected by IOD value, the higher IOD value the further they move to the west. Key words: Variability, temperature, khlorophyll-a, upwelling, southern waters of Jawa

Substrat Dasar dan Parameter Oseanografi Sebagai Penentu Keberadaan Gastropoda dan Bivalvia di Pantai Sluke Kabupaten Rembang

Abstract: Gastropod and bivalve have broad distribution in time and space, and mostly abundance as individual. Generally, their habit was the sea, live along the shore or in shallow waters. The aims of this research were to examine the effect of bottom substrate texture and organic material content as a detector in the present of gastropod and bivalve in Sluke beach. Research location were divided into five stations, each 100 meters a part along the shore. Each location were divided into 5 sub stations which space 100 meters each to the sea. Sampling were done by using 1 x 1 m quadrant transects, then sample were cleaned and restore for further identification. The result showed that most gastropod and bivalve found at station B2 while in stations A3, A5, C3, D3 and E2 there was no bivalve or gastropod found. The most abundant species was Nassarius siquijorensis of gastropod class as much as 62 species while Trachycardium rugosum of bivalve class was the smallest in amount to be found. Organic material content in Sluke Beach has a distinct range. The highest was 22.38% of high organic material in C5 while the lowest was 2.65% of low organic material in E1. Bottom substrate texture in station 1 mainly was sand, station 2 mainly silty sand. While station 3, 4 and 5 mainly were sandy silt.

Exploited but Unevaluated: DNA Barcoding Reveals Skates and Stingrays (Chordata, Chondrichthyes) Species Landed in the Indonesian Fish Market

Abstract: Reliable and precise species identification is important to fisheries management and conservation. However, many rays and skates in Indonesia are currently being exploited and landed into traditional fish market without a proper identification. Therefore, this study was conducted to identify species of skates and stingrays that were landed and traded in three fish markets in Indonesia (Palabuhanratu, Muara Saban, and Lampung) using molecular techniques and to determine the conservation status of the identified species based on IUCN (International Union for Conservation of Nature and Natural Resources) as well as defined by CITES (Convention on International Trade in Endangered Species). The mitochondrial cytochrome oxidase I (COI) gene was amplified by polymerase chain reaction (PCR) using a pair of primer, fish-BCL and fish-BCH. Of 29 tissue samples collected from the study sites, a total of five species were successfully identified: Dipturus chilensis (4), Himantura walga (1), Neotrygon kuhlii (11), Taeniura lymma (9) and Rhinoptera javanica (4). The Neighbor Joining phylogeny of mitochondrial lineages, based on partial COI gene sequences, the ingroup haplotypes were clustered into five main clades representing each species. The identified stingrays were being listed as vulnerable (D. chilensis and R. javanica), near threatened (H. walga and T. lymma), and data deficient (N. kuhlii) by IUCN, with two species (D. chilensis and H. walga) population were indicated decreased. Unfortunately, all of identified species have not been evaluated by CITES regarding their trade status. As a consequences, a valuable effort should be placed to create a scientific network for monitoring programmes not only on a local scale, and to make pressure on governments for adopting molecular techniques as tools for controlling and avoiding misidentification. Keywords : Mitochondrial DNA, Phylogeny, Coral Triangle, Taxonomy, Fisheries

Kajian Zat Hara Fosfat, Nitrit, Nitrat dan Silikat di Perairan Kepulauan Matasiri, Kalimantan Selatan

Abstract: Penelitian zat hara fosfat, nitrit, nitrat dan silikat telah dilakukan di perairan Kepulauan Matasiri, Kalimantan Selatan pada 12 stasiun pengamatan. Penelitian bertujuan untuk mengetahui kondisi perairan berdasarkan ketersediaan dan distribusi spasial zat hara di perairan tersebut. Pengambilan sampel air menggunakan botol Niskin pada lapisan permukaan dan dekat dasar perairan, sedangkan pengukuran konsentrasi zat hara menggunakan Spektrofometer Shimadzu UV-1201V. Hasil penelitian menunjukkan bahwa perairan Kepulauan Matasiri termasuk perairan yang subur. Rata-rata konsentrasi fosfat di permukaan dan di dekat dasar perairan relatif sama, sedangkan konsentrasi nitrit, nitrat dan silikat lebih tinggi di dekat dasar perairan dari pada di permukaan. Kata kunci: Fosfat, Nitrit, Nitrat, Silikat, Kepulauan Matasiri. A research on marine nutrients including phosphate, nitrite, nitrate and silicate was conducted in the Matasiri Islands waters, South Kalimantan, on 12 observation stations. The aim of the research is to understand and assess the waters condition based on the availability and the spatial distribution of nutrients in these waters. Water sampling used Niskin bottles in the surface and near bottom layers, whereas the measurement of nutrients concentration used spectrophotometer Shimadzu UV-1201V. The results showed that Matasiri Islands waters is categorized as fertile waters. The average concentration of phosphate in surface and near bottom layers were relatively similar, whereas the average concentration of nitrite, nitrate and silicate were higher in near bottom layer than in the surface. Key words: phosphate, nitrite, nitrate, silicate, Matasiri Islands.

Oksigen Terlarut dan Apparent Oxygen Utilizationdi Perairan Teluk Klabat, Pulau Bangka

Abstract: Pengamatan kadar oksigen terlarut dan Apparent Oxygen Utilization (AOU) di perairan Teluk Klabat, Pulau Bangka telah dilakukan pada bulan Juni-Juli 2003. Tujuan penelitian ini adalah untuk mengetahui kondisi lingkungan dan distribusi oksigen terlarut serta Apparent Oxygen Utilization (AOU) perairan Teluk Klabat, Pulau Bangka. Contoh air laut diambil dari 20 stasiun penelitian dengan menggunakan Botol Nansen di perahu nelayan dan Botol Niskin di Kapal Riset Baruna Jaya VII pada 3 kedalaman yaitu pada lapisan penvukaan (0 m); 5 meter dan dekat dasar. Kadar oksigen terlarut ditentukan dengan titrasi jodometri berdasarkan metode Winkler. Has/7 analisa oksigen terlarut menunjukkan kadar oksigen terlarut di lapisan permukaan (0 m); 5 m dan dekat dasar masing-masing berkisar antara 3,54 - 4,08 ml/1; 3,22 - 3,58 ml/I ; 2,97 - 3,30 ml/ I. Kadar ini terus menu run dengan bertambahnya kedalaman. Berdasarkan nilalsuhu dan salinitas yang diperoleh telah dihitung daya larut "apparent oxygen utilization" (AOU) dan derajat kejenuhan oksigen pada lapisan permukaan. Di lapisan permukaan sampai dekat dasar diperoleh kisaran nilai AOU yaitu - 1,07 sampai 0,09 ml/1 dengan nilai AOU yang negatip diperoleh sebanyak 4 % sedangkan positip 96 % di lapisan permukaan. Dari hasil penelitian diperoleh konsentrasi oksigen terlarut yang belum menunjukkan dampak negatif terhadap lingkungan perairan. Kata kunci : Apparent Oxygen Utilization (AOU), oksigen terlarut, Teluk Klabat Observation of dissolved oxygen concentration in Klabat Bay Waters Bangka Island was carried out on June-July 2003. The aim of research was to know environment condition and dissolved oxygen distribution and Apparent Oxygen Utilization (AOU) values in the Klabat Bay Waters. Water samples from 3 depths (0, 5, bottom depth) were collected from 20 stations by using Nansen bottles on the boat and Niskin Bottles on the Research Vessel Baruna Jaya VII. The dissolved oxygen was analyzed with Iodometric titration by Winkler method. The results showed that the concentrations of dissolved oxygen ranged 3.54 – 4.08 ml/l ; 3.22–3.58 ml/l; 2.97 – 3.30 ml/l were found in surface layer (0 m), 5 m and near bottom depth respectively. These concentrations decreased by depth. The highest concentration was found on the offshore area, while the lowest concentration was found at near coastal. In the surface layer till near bottom depth were found AOU values varied between -1.07 to 0.09 ml/l with the AOU negative values was found 4 % and positive 96 % in the surface layer. The result indicated that dissolved oxygen concentration did not show negative impact in the Klabat Bay Waters, Bangka Island. Key words : Apparent Oxygen Utilization (AOU), dissolved oxygen, Klabat Bay