KONSENTRASI MERKURI (Hg) DI SEDIMEN PERAIRAN CIREBON, JAWA BARAT PADA MUSIM PERALIHAN TIMUR

Cirebon waters are one of the areas with dense fishing, industrial and human activities can cause heavy metal pollution in these waters. This study aims to analyze the Hg content in sediments and their relationship with environmental characteristics in three research sites on the Cirebon coast: i.e., Bondet, Sukalila, and Kejawanan. Nine research points were selected at each location. In situ analysis was carried out for temperature, salinity, pH, and DO variables. In addition, surface sediment samples were taken at variations in water depth between 1–6 m. Grain fraction, organic carbon, and heavy metal Hg were analyzed from each of the sediment samples. The results showed that the surface temperature, salinity, pH, and DO of Cirebon waters ranged from 31.09–32.30 oC; 26.4–30.10‰; 7.66–8.56; and 4.50–6.87 mg/L. Cirebon waters are dominated by silt and clay about 1% organic carbon. Mercury in sediments is still considered safe for aquatic life with a concentration of 29.36–68.55 µg/kg-dw. Principal Component Analysis shows that the three study sites have different water characteristics and hence, influence the Hg deposition. Overall, although Hg accumulation occurs, it is ecologically safe for biota life. Sedimentary accumulation of Hg was probably due to the terrestrial input and the condition of environmental deposition such as riverine flow and coastal current.  Perairan Cirebon merupakan salah satu wilayah dengan aktivitas perikanan, industri, dan manusia yang padat, sehingga dapat menyebabkan pencemaran logam berat di perairan tersebut. Penelitian ini bertujuan untuk menganalisis kandungan Hg di sedimen dan hubungannya dengan karakteristik lingkungan di beberapa lokasi penelitian pada beberapa wilayah pesisir Cirebon: Bondet, Sukalila, dan Kejawanan. Sembilan titik penelitian dipilih pada setiap lokasi. Analisis in situ dilakukan untuk variabel suhu, salinitas, pH, dan DO. Selain itu, sampel sedimen permukaan diambil pada variasi kedalaman perairan antara 1-6 m. Fraksi butir, karbon organik, serta logam berat Hg dianalisis dari setiap sampel sedimen. Hasil yang diperoleh memperlihatkan bahwa suhu permukaan, salinitas, pH, dan DO Perairan Cirebon berkisar 31,09–32,30 oC; 26,4–30,10‰; 7,66–8,56; dan 4,50–6,87 mg/L. Sedimen Perairan Cirebon didominasi oleh lanau lempungan serta karbon organik sekitar 1%. Kandungan merkuri pada sedimen masih tergolong aman untuk kehidupan akuatik dengan konsentrasi 29,36–68,55 µg/kg–bk. Analisis komponen utama menunjukkan bahwa ketiga lokasi penelitian memiliki karakteristik perairan berbeda dan selanjutnya memengaruhi pola akumulasi Hg di sedimen. Secara keseluruhan, walaupun terdapat akumulasi Hg di sedimen, namun kondisi masih tergolong aman untuk kehidupan biota. Akumulasi diduga dipengaruhi oleh sumber dari daratan dan kondisi lingkungan pengendapan seperti aliran air sungai dan arus pantai

Distribution of Sediment Fractions and Organic Matter in Lampung Bay

Deposisi sedimen di perairan sangat dipengaruhi oleh proses-proses pantai yang menyebabkan variasi karakteristik fisik dan kimiawinya. Penelitian ini mengungkap komposisi ukuran sedimen dan bahan organik di sedimen Teluk Lampung untuk menduga proses deposisi. Analisis fraksi sedimen dilakukan berdasarkan pada American Society for Testing and Materials (ASTM) standards D422-63, sedangkan bahan organik dilakukan dengan menggunakan metode loss on ignition (LOI). Fraksi pasir lanau (75,95-78,73%) dan fraksi lempung (18,27-20,28%) memiliki persentase yang lebih tinggi dibandingkan dengan fraksi pasir (3,00-3,81%). Kandungan organik di sedimen perairan Teluk Lampung berkisar antara 10,67-13,48%. Distribusi fraksi sedimen dan bahan organik di perairan Teluk Lampung tidak berbeda signifikan antar stasiun, yang artinya stasiun yang berada di dekat kepala teluk (TL 1 dan TL 2) memiliki persentase fraksi sedimen dan bahan organik yang tidak berbeda signifikan dengan stasiun yang berada di tengah atau ke arah mulut teluk (TL 3-TL5).Sediment deposition in waters is considerably influenced by coastal processes causing variations in their physical and chemical characteristics. This study reveals the size composition of sediments and organic matter in Lampung Bay sediments how deposition processes occurAnalysis of the sediment fraction was carried out based on the American Society for Testing and Materials (ASTM) standards D422-63, while the organic matter was carried out using the loss on ignition (LOI) method. The silt sand fraction (75.95-78.73%) and clay fraction (18.27-20.28%) have a higher percentage than the sand fraction (3.00-3.81%). Then, the organic content in the sediments of Lampung Bay waters ranges from 10.67-13.48%. The distribution of sediment and organic matter fractions in the waters of Lampung Bay was not significantly different between stations, which means that stations near the head of the bay (TL 1 and TL 2) had a percentage of sediment and organic matter fractions that were not significantly different from stations in the middle or towards the mouth of the bay (TL 3-TL5)

Investigasi Kontaminasi Minyak Melalui Fingerprint Kimia di Estuari Muara Angke, Cimandiri dan Cilintang

Polycyclic aromatic hydrocarbons (PAHs) and hopanes are one of the biomarker components that can be used in petroleum contamination tracing. The study was conducted with the objective of assessing petroleum contamination in sediment based on Polycyclic Aromatic Hydrocarbon (PAH) and Hopana components in Estuari Muara Angke, Cimandiri and Cilintang. Sediment samples were collected to a depth of ± 10 cm. Sediment samples were dried by freeze-dryer then extracted and fractionated. The fractionated sample was analyzed by gas chromatography-mass spectrometry. Estuary Muara Angke and Cimandiri showed the presence of petroleum contamination while Cilintang was not detected.     Polisiklik aromatik hidrokarbon (PAH) dan hopana merupakan salah satu komponen biomarker yang dapat digunakan dalam penelusuran kontaminasi petroleum. Penelitian dilaksanakan dengan tujuan mengkaji kontaminasi petroleum dalam sedimen berdasarkan komponen Polisiklik Aromatik Hidrokarbon (PAH) dan Hopana di Estuari Muara Angke, Teluk Jakarta, Cimandiri-Teluk Pelabuhan Ratu dan Cilintang, Ujung Kulon. Contoh sedimen dikumpulkan hingga kedalaman ± 10 cm. Contoh sedimen dikeringkan dengan alat freeze-dryer kemudian dilakukan ekstraksi dan fraksinasi. Sampel yang telah terfraksinasi dianalisis dengan alat kromatografi gas–spektrometri massa. Estuari Muara Angke dan Cimandiri menunjukkan adanya kontaminasi petroleum sedangkan Cilintang tidak terdeteksi

Kontribusi Massa Air Tawar dari Estuari Banyuasin ke Perairan Selat Bangka pada Musim Peralihan II

Perairan Selat Bangka banyak mendapat pasokan air tawar dari sungai-sungai di pesisir timur Provinsi Sumatera Selatan, termasuk estuari Banyuasin.  Percampuran air tawar dan air laut menentukan kondisi lingkungan estuaria, khususnya pola salinitas, termasuk pembentukan habitat yang kompleks untuk komunitas tumbuhan dan hewan yang khas di dalamnya.  Tujuan penelitian ini adalah mengestimasi besarnya masukan air tawar dari empat muara sungai di estuari Banyuasin ke Perairan Selat Bangka pada bulan Oktober (musim peralihan II).  Pengukuran data lapangan dilakukan di 23 lokasi pada bulan Oktober 2018 menggunakan Valeport Midas CTD+ Model 606.  Selanjutnya, data salinitas digunakan untuk mengetahui kisaran nilai salinitas, menganalisis nilai anomali, fraksi air tawar dan stabilitas massa air dari masing-masing sungai.  Kisaran salinitas massa air di perairan Selat Bangka pada musim peralihan II adalah 2,19 sampai 31,42 psu dengan nilai anomali salinitas sebesar -30,23 sampai -1,00 psu. Masukan massa air tawar dari empat sungai adalah berbeda satu sama lain sehingga terbentuk kontur lidah salinitas di mulut estuari dan nilai salinitas bervariasi secara spasial di Selat Bangka.  Fraksi air tawar yang paling dominan berasal dari Sungai Musi dengan kontribusi sebesar 31,2 %, selanjutnya diikuti Sungai Air Saleh (21,9%), Sungai Banyuasin (20,5%) dan Sungai Upang (20,3%)

ASSOCIATION OF LOKAN SHELL Geloina erosa, SOLANDER 1786 AND MANGROVE AT KAHYAPU COASTAL AREA OF ENGGANO ISLAND, BENGKULU PROVINCE

Lokan shell Geloina erosa closely related to mangrove ecosystem in Enggano island. Mangrove is one supplier of organic materials required by Lokan shell. The research conducted in September 2015 - January 2016 at mangrove ecosystems in Kahyapu coastal area, aims to analyse lokan shells Geloina erosa conditions and its association with mangrove ecosystems. Sampling of mangrove vegetation was taken using line transect and lokan shell sampling using plot in mangrove ecosystem. The results show that mangrove condition of the Kahyapu coastal area was in healthy condition for the growth of lokan shell. Lokan shell are significantly assosiated with mangrove in Kahyapu coastal area of Enggano Island

Komposisi Isotop Stabil dan Trofik Level Kerang Kipas (Pectenidae: Chlamydinae sp.) dan Produsen Primer di Pulau Pari, Kepulauan Seribu, DKI Jakarta

Scallop (Pectenidae: Chlamydinae sp.) is fauna habitat in seashore ecosystem and had commercial value commudity. The aims this study were to identify the main composition of stable isotopes, food sources, and trophic level from scallop and potential food sources to comparing isotopic signatures of different primary producers and fauna, and to estimate qualitatively the importance of material in ecosystem seashore. The researched conducted in Pari islands, Seribu Islands, DKI Jakarta, we analyzed the stable isotopes δ13C and δ15N. The composition signature of stable isotopes (δ13C and δ15N) scallop, seagrasses, macroalgae, and sponge showed significant differents (ANOVA; p < 0.05). Fractionation signature δ13C scallop with potential food sources is had not range. In addition, signature δ13C from scallop is not assimilated seagrass, macrolagae, and sponge. The signature δ15N from species, scallop had value riched than seagrass, macroalgae, and spong. The function scallop in trophic level had consumer and seagrass, macrolagae, and sponge is primary producer. Stable isotopes composition scallop is first study conducted in habitat Seribu islands

Placement of Floating Net Cages Cultivation System Based on Current Dynamics Model in the Semak Lagoon, Indonesia

This research examines the dynamics of 3-dimensional flow and the placement of floating cages in the Semak Daun Lagoon (SDL). The research was carried out using 3-dimensional current modeling process, which is designed in four tidal conditions model in accordance with the wind and tidal pressure generation. Furthermore, this research used the discretization method to vertically determine the finite volume and sigma coordinates, therefore, the whole domain was 43,575 triangular elements. The acuration of model showed by a MAPE value of 9.9%, its shows model is a very good category. The results of the model showed that the monsoons do not have a significant effect on the current pattern and velocity in SDL, however, the dominant current dynamics are influenced by tides. In addition, the current pattern in SDL waters generally moves from the Southwest to the Northeast at low tides and vice versa. In all tidal conditions, downwelling and upwelling occurred in the middle of the lagoon, with the current pattern and velocity significantly affected by Bathymetry. Surface and vertical current velocities range from 0.002 - 0.600 m/s. However, the current velocities of 0.10 - 0.20 m/s were only found at -2 m depth. Meanwhile, the optimum current velocity for marine cultivation activities is 0.10 - 0.50 m/s, therefore the utilization of SDL waters for floating net cage system cultivation is more optimal at a depth of -2.3 m

Association of Lokan Shell Geloina Erosa, Solander 1786 and Mangrove at Kahyapu Coastal Area of Enggano Island, Bengkulu Province

Lokan shell Geloina erosa closely related to mangrove ecosystem in Enggano island. Mangrove is one supplier of organic materials required by Lokan shell. The research conducted in September 2015 - January 2016 at mangrove ecosystems in Kahyapu coastal area, aims to analyse lokan shells Geloina erosa conditions and its association with mangrove ecosystems. Sampling of mangrove vegetation was taken using line transect and lokan shell sampling using plot in mangrove ecosystem. The results show that mangrove condition of the Kahyapu coastal area was in healthy condition for the growth of lokan shell. Lokan shell are significantly assosiated with mangrove in Kahyapu coastal area of Enggano Island