Judul: Pola Suksesi Fitoplankton Pada Perairan Waduk Jatigede, Sumedang, Jawa Barat
Abstrak: Kegiatan antropogenik baik secara eksternal maupun internal di sekitar Waduk Jatigede dapat berpengaruh terhadap keberadaan bahan organik. Bahan organik yang masuk ke dalam perairan berpotensi menjadi nutrien, yang kemudian dimanfaatkan oleh plankton. Perubahan parameter kualitas air dapat memimbulkan adanya pola suksesi plankton. Penelitian ini bertujuan menganalisis keterkaitan suksesi fitoplankton dengan kualitas air di perairan Waduk Jatigede, Sumedang, Jawa Barat. Penelitian ini dilaksanakan pada bulan Februari–April 2021 di perairan Waduk Jatigede, Sumedang, Jawa Barat. Data yang digunakan pada penelitian ini yaitu data primer dan data skunder. Data primer yang diambil terdiri dari data pH, Amonia, nitit, nitrat, ortofosfat, suhu perairan, kedalaman perairan, kekeruhan, daya hantar listrik, kecerahan, dan data plankton. Pengambilan contoh dilakukan dengan metode purposive sampling. Data sekunder merupakan data curah hujan. Analisis pola suksesi dilakukan dengan penentuan stadia melalui pendekatan grafik suksesi Frontier. Kesamaan waktu penelitian ditentukan melalui Stander’s Similarity Index (SIMI), sedangkan laju suksesi ditentukan melalui Summed Difference Index (SDI). Kelimpahan plankton didominasi oleh kelompok Cyanophyceae dan Rotifera. Komposisi jenis tertinggi di dominansi oleh kelompok Chlorophyceae dan Rotifera. Secara umum komunitas fitoplankton di perairan Waduk Jatigede berada pada stadia 1 dan 2. Stadia 1 suksesi fitoplankton tidak berkorelasi dengan parameter nitir dan ortofosfat dan stadia 2 tidak berkorelasi dengan nitrat, suhu, dan DHL (p < 0,2). Secara umum kualitas air yang berkorelasi positif dengan suksesi fitoplankton yaitu nitrat, amonia, kecerahan, dan DHL., Anthropogenic activities both externally and internally around Jatigede Reservoir can affect the presence of organic matter. Organic matter that enters the water has the potential to become nutrients which are utilized by plankton. Changes in water quality parameters can cause a pattern of plankton succession. This study aims to analyze the relationship between phytoplankton succession and water quality in the water of Jatigede Reservoir, Sumedang, West Java. This research was carried out in February–April 2021 in the water of Jatigede Reservoir, Sumedang, West Java. The data used in this study are primary data and secondary data. Primary data consisted of data on pH, ammonia, nitrite, nitrate, orthophosphate, water temperature, water depth, turbidity, conductivity, brightness, and plankton data. Sampling was done by purposive sampling method. Secondary data is rainfall. Succession pattern analysis is done by determining stadia through the Frontier succession graph approach. Similarity of the research time was determined by Stander’s Similarity Index (SIMI), while the succession rate was determined by Summed Difference Index (SDI). Plankton abundance is dominated by Cyanophyceae and Rotifera. The highest species composition was dominated by Chlorophyceae and Rotifera. In general, phytoplankton community in Jatigede Reservoir was at stages 1 and 2. Stage 1 of phytoplankton succession did not correlate with nirite and orthophosphate and stage 2 did not correlate with nitrate, temperatur, and DHL (p < 0,2). In general, water quality is positively correlated with phytoplankton succession is nirate, ammonia, brightness, and DHL.
Keyword: Jatigede Reservoir, plankton, succession, succession rate, water quality

Judul: Relationship Model of Phosphorus Load and Phytoplankton Abundance and Diversity
Abstrak: Waduk Jatigede merupakan waduk yang terletak di Kabupaten Sumedang yang dibangun pada tahun 2008 dengan membendung Sungai Cimanuk. Pembangunan waduk ini dilatarbelakangi defisit air di hilir Sungai Cimanuk untuk kegiatan domestik dan industri. Aktivitas Keramba Jaring Apung di Waduk Jatigede tidak diperbolehkan karena dapat memicu terjadinya eutrofikasi. Eutrofikasi dipicu oleh peningkatan ortofosfat di perairan dan memicu blooming fitoplankton. Fitoplankton dapat dijadikan sebagai parameter dalam menentuka kondisi lingkungan perairan. Penelitian ini dilakukan pada musim kemarau 2018. Pengambilan sampel dilakukan di inlet dan outlet waduk dan sembilan titik di badan waduk. Parameter yang dianalisis adalah ortfosfat, nitrit, nitrat, amonium dan kelimpahan fitoplankton. Titik sampling di badan waduk di kelompokkan menjadi zona riverine transisi dan lakustrin. Hasil penelitian menunjukkan adanya keterkaitan antara masukan fosfor dengan kelimpahan dan diversitas plankton. Fitoplankton dari Kelas Cyanophyceae dan Dinophyceae dan nutrien memiliki korelasi yang kuat dengan nutrien yang berada di perairan Waduk Jatigede. Model dibangun menggunakan submodel masukan fosfor, kelimpahan dan komposisi fitoplankton. Sub model kelimpahan dipengaruhi konsentrasi fosfor di dalam air di badan air, sedangkan sub model kelimpahan dipengaruhi olen N:P Rasio.Model keterkaitan menunjukkan kelimpahan maksimum fitoplankton berada pada konsentrasi fosfor terntentu. Simulasi kelimpahan menunjukkan kelas Chlorophyceae dan Cyanophyceae merupakan kelas dengan kelimpahan tertinggi. Staurastrum dan Mictocystis dari Kelas Cyanophyceae merupakan genus dengan kelimpahan tertinggi., Jatigede Reservoir is a reservoir located in Sumedang Regency which built in 2008 by damming Cimanuk River. The construction of this reservoir caused by water deficit in Downstream of Cimanuk River for domestic and industry activities. Fisheris activity such as cage culture in Jatigede Reservoir has been banned because it can trigger eutrophication. Eutrophication is consequences of enchancement of orthophospate and trigger phytoplankton bloom. Phytoplankton could be a parameter to determine aquatic ecosystem. The research conducted in dry season 2018. Sample was taken in inlet, outlet and reservoir body. Parameters analyzed is orthophosphate, nitrate, nitrite ammonium and the abundance of phytoplankton. Reservoir was classified to riverine, transition and lacustrine zone. The result of this research shows the relationship between phosphorus loads with abundance and diversity of phytoplankton. Phytoplankton from Cyanophyceae and Dinophyceae shoe a strong correlation with nutrient in Jatigede Reservoir. The model was constructed using phosphorus loading, abundance and composition of phytoplankton submodel. Abundance submodel was influenced by phosphorus concentration while composition submodel influenced by N:P ratio. The Relationship model shows that phytoplankton reach maximum abundance in particular phosphorus consentration. Abundance simulation shows Chlorophyceae and Cyanophyceae is the highest abundance in this study. Staurastrum and Microcystis is a genus which reach maximum abundance.
Keyword: Cyanophyceae, Microcystis, Fitoplankton, Ortofosfat, Fitoplankton, Waduk Jatigede

Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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