This research examines the eutrophication process mainly by considering the chlorophyll-a concentration. A simple linear model was used to determine the correlation between Chlorophyll-a and dissolved inorganic phosphate (DIP). The research was carried out on river mouths in the north coast of Central Java. The results of the linear model show that the relationship between chlorophyll-a and DIP follows the logarithmic model with the log [Chloa] = 1.52 + 1.60 log [DIP], R 2 = 0.55. The model suggests that the high concentration of chlorophyll-a is related to dissolved inorganic phosphate concentrations. On the basis of the sufficient of conclusive evidence for these variables, the study sites with high stresses from several anthropogenic sources had higher chlorophyll-a than the sites that are relatively far from river mouths and lands.

No abstract

Disposal of waste and mud into Porong River is expected to have an impact to the surrounding environment, particularly the increasing concentration of suspended solids (TSS) and affect the distribution of phytoplankton in the region. The purpose of this study was to determine the correlation between the concentration of TSS and abundance of phytoplankton as an indicator for determinate condition of Porong River Estuary. Determining the location of sampling by purposive sampling method. The data were then analyzed with statistical methods and spatially using ArcGIS 10 program. The concentration of suspended solids charge 542-885 mg/L. concentration of 3.7-20.5 NTU turbidity. The abundance of phytoplankton 153-238 ind/L with a diversity index ranged from 0.4 to 0.62. Hydrodynamic modeling simulated using ADCIRC module of SMS 8.1 software with a current velocity in the range of 0 to 0.04 m.s-1. Distribution of TSS and turbidity linked to the abundance of phytoplankton at low tide, although the quantity is not always the same, based on the diversity index and the condition of the Porong River estuary is in category of lightly polluted.

Gracllaria sp. merupakan rumput laut yang memiliki nilai ekonomis tinggi karena menghasilkan agar. Agar banyak dimanfaatkan dalam bidang industri maupun pangan. Kualitas Gracilaria sp. ditentukan oleh kadar agar, pigmen serta  proksimatnya. Penelitian ini bertujuan untuk mengkaji pengaruh parameter kualitas media tumbuh Gracilaria sp. terhadap biosintesis agar, klorofil a, karoten dan kadar proksimat (protein, karbohidrat, lemak, abu, dan air). Lokasi pengambilan sampel di reservoir dan biofilter tambak udang Vaname (Litopenaeus vannamei). Kondisi lingkungan perairan yang diukur adalah kandungan nitrat dan fosfat, suhu air, salinitas, DO (oksigen terlarut), serta pH (Derajat keasaman). Ekstraksi agar dilakukan dengan metode alkali. Karakterisasi agar menggunakan analisis Fourier Transform Infra Red. Hasil penelitian menunjukkan kandungan agar (31,4 ± 0,42%) pada reservoir lebih baik dibandingkan biofilter. Begitu pula dengan konsentrasi klorofil a (19,61 ± 0,04 mg/g), karotenoid (7,42 ± 0,21 µmol/g) serta kadar protein (15,38 ± 0,27%). Kadar lemak, karbohidrat, air dan abu pada kedua lokasi tidak berbeda nyata. Hasil karakterisasi agar menujukkan keberadaan gugus galaktosa 3,6-anhydro-L-galaktosa. Gracilaria sp. is well known as to has a high economically value, due to the application of the agar content that is used in various industries especially in food industry. The quality of Gracilaria sp. depends on agar and pigment content as well as proximate analysis. This study aimed to investigate the effect of water quality parameter on Gracilaria sp habitats to agar, chlorophyl a, carotene and proximate analysis (protein, carbohydrate, total lipid, ash, water content). Samples were collected from reservoir and biofilter from Litopenaeus vannamei’s waste pond. Water quality parameter measured were nitrate and phosphate, water temperature, salinity, dissolved oxygen (DO) and pH. Agar extraction was done by alkali methods. Agar and its chemical structure were characterized by FT-IR analysis. Results showed that agar content (31.4 ± 0.42%) on reservoir was better than biofilter. Higher results from reservoir samples were also found in chlorophyl a (19.61 ± 0.04 mg/g), carotenoids (7.42 ± 0.21 µmol/g) and protein level (15.38 ± 0.27 %). On the other hand, total lipid, carbohydrate, water and ash content were similar. Based on FT-IR analysis shows that the galactose 3,6-anhydro-L-galactose was present.

Perairan Karangsong mendapat pengaruh sangat besar dari aktivitas manusia yang berada di sepanjang maupun di hulu kawasan perairan tersebut. Aktivitas yang ada meliputi aktivitas rumah tangga, industri, tambak, lalu lintas kapal dan vegetasi mangrove. Padatnya aktivitas manusia tersebut dapat menyebabkan menurunnya kualitas perairan dan berpengaruh terhadap konsentrasi zat hara di perairan Karangsong. Tujuan penelitian ini adalah untuk mengetahui konsentrasi dan pola sebaran nitrat dan fosfat di perairan Karangsong, Kabupaten Indramayu. Penelitian ini dilaksanakan pada bulan Agustus 2015, dengan menggunakan metode kuantitatif dan untuk penentuan lokasi pengambilan sampel air menggunakan metode purposive sampling. Data yang dikaji adalah konsentrasi nitrat dan fosfat, suhu, oksigen terlarut, salinitas, kecerahan, pH dan arus permukaan. Untuk menggambarkan pola sebaran nitrat dan fosfat serta pola arus menggunakan softwareArcGIS 10.0. Hasil penelitian menunjukkan bahwa konsentrasi nitrat berkisar 0,4148–2,4541 mgL-1 dan konsentrasi fosfat berkisar 0,0253 – 0,6261 mgL-1. Pola sebaran konsentrasi nitrat dan fosfat mengikuti pola arah arus yang terjadi yaitu ke arah Timur Laut. Kata kunci: Sebaran, Nitrat, Fosfat, Perairan Karangsong