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Manajemen persediaan sangat penting bagi suatu usaha dalam menjalankan aktivitas perusahaannya. Apabila manajemen persediaan tidak dilakukan dan dikontrol dengan baik, maka dapat menimbulkan selisih stok barang pada usaha tersebut. Serba 8000 Aviari memiliki kendala dalam perhitungan stok fisik dengan stok sistem. Oleh karena itu, penulis akan membantu mitra dalam mengatasi kendala tersebut. Pengumpulan data yang dilakukan oleh penulis adalah dengan menggunakan metode observasi dan wawancara. Hasil implementasi manajemen persediaan di Serba 8000 Aviari adalah dengan melakukan stock opname dengan menggunakan Google sheet untuk merapikan stok yang kemudian di opname sesuai dengan jumlah barang yang sudah dihitung sebelumnya ke dalam sistem GF-Akuntansi pada mitra. Kegiatan ini dilakukan untuk mempermudah Serba 8000 Aviari dalam menyeimbangkan stock on hand dan stok pada sistem agar tidak terjadi selisih stok barang.

Lake Siombak is a tidal lake that is an estuary around the lake covered with various mangrove trees. It is interesting to study the fish's spatial and temporal distribution as a unique and distinctive tidal lake ecosystem. This research was conducted for a year (from September 2018 to August 2019). Fish sampling was performed by installing gill nets (mesh size 1 inch) and cast nets (mesh size 0.5 inch). Gill nets and cast nets were installed at high and low tides during the full moon. This research showed that there were 27 species of 20 families. Tilapia, Mudskipper, Indo-pacific tarpon, and mainly Rice Fish are always found in Lake Siombak. The fish group at Lake Siombak consists of freshwater fish (mainly: Tilapia, Catfish, and Snakehead), brackish fish (mainly: Mudskipper, Rice fish, and Indo-pacific tarpon), and marine fish (mainly: Milkfish, Kanda mullet, and John's snapper). The actual resident in Lake Siombak consists of Oryziidae, Tilapia, and mudskipper. Other fish are temporary resident fish except for Lutjanidae and Scatophagidae as visitor fish during high tide and high salinity periods (dry season) and Synbranchidae during low salinity (rainy season).

The utilization of the gambier plant in Gunungsitoli City is still limited to produce dried gambier leaves as a raw material for betel nut chewing, so it has the potential to be processed into gambier which has high economic value. The study was aimed to determine the quality of gambier produced from gambier plants that grow in Mado Laoli Village, Gunungsitoli City with different drying methods. This study used a completely randomized design (CRD) consisting of 2 treatments, that were P1 (sun drying) and P2 (oven drying) with 3 replications. The results showed that the gambier plant in Mado Laoli Village had a high potential to be processed into gambier because it has produced gambier which have good quality and met the SNI quality requirements. Sun drying produced gambir second quality (15.48% of water content, 2.37% of ash content, 59.36% of catechin content, 12.17% of tannin content, 5.54% of water insoluble material, 3,29% of alcohol insoluble material). Oven drying produced gambir first quality (11.30% of moisture content, 2.18% of ash content, 68.15% of catechin content, 12.24% of tannin content, 6.32% of water insoluble material, 3.77% of insoluble alcohol). Different drying methods had a significant effect on the yield, moisture content, catechin content, water insoluble material and alcohol insoluble material content.

Porang plants are widely cultivated in Indonesia as a potential source of glucomannan. Glucomannan is obtained by separating impurity components such as starch, cellulose, protein, fat, and the rest of the flour bag from porang flour. The purpose of this study was to determine the effect of the isolation method on porang flour to produce high purity glucomannan. In this study, the extraction of glucomannan was carried out by a modified simple centrifugation method with the addition of aluminum sulfate (EAS), sodium metabisulfite (ENM), both (ENMAS), and no treatment (EK). All of the glucomannan obtained was then analyzed for composition, color, transparency, degree of acetylation and viscosity. The characteristics of porang glucomannan were then compared with konjac glucomannan (PKG). The results showed that ENMAS showed the highest value with a purity value of 93.71%, WHC 55.06 g water/g glucomannan, whiteness degree 79.16, and gel viscosity 73000 cps.

Tea talua is a traditional Minangkabau drink made from tea mixed with egg yolks and beaten with sugar and some other additives. Currently there are no instant talua tea drinks available. Instant drinks are usually in powder form served in airtight packages. Powdered drinks are prepared by quick drying with the addition of coating agents. This study aims to determine the effect of different types of eggs on the physicochemical quality of instant egg tea produced. This research method used a completely randomized design (CRD) which consisted of 3 types of treatment and 3 repetitions. This study used a completely randomized design (CRD) with 3 treatments and 3 replications. The treatment given was the difference between egg yolks as raw material for talua tea, including: R = chicken eggs, B = duck eggs, and K = native chicken eggs, so that 9 treatment units were obtained. Data were analyzed using Analysis of Variance (ANOVA) and Duncan's Multiple Range Test (DMRT) at 95% confidence level. The use of different types of eggs did not differ significantly in the proximate test, namely moisture content (2.17+0.40 - 2.41+0.26%), ash content (1.02 + 0.02 - 1.05 + 0.06%), fat content (6.43 + 3.86 - 7.98 +2.10%), protein content (7.74+1.34 - 8.3+0.53%), carbohydrate content (80.48+2.78 - 82.39 +4.47 %) and the yield (6.70 +0.55 - 8.61 +2.15 % )of instant talua tea produced Keywords: instan drink, egg, tea, teh talua.

Limbah cair industri pembekuan udang merupakan salah satu sumber mikroorganisme pendegradasi kitin yang potensial. Tulisan ini melaporkan pencarian sumber enzim kitinolitik dari limbah industri perikanan. Tujuan dari riset ini adalah mengisolasi bakteri kitinolitik dari instalasi pengolahan limbah cair pembekuan udang dan mengidentifikasi bakteri terbaik penghasil kitinase. Skrining isolat bakteri dilakukan dengan mengevaluasi indeks kitinolitik (IK) pada medium kitin agar (koloidal kitin 2%). Terdapat 5 bakteri dengan indeks kitinolitik terbesar pada medium agar, yakni AR 17 dengan nilai IK 2,59 diikuti isolat bakteri AR 15; AR 18; AR 16 dan IL 08 secara berturut turut dengan nilai IK 2,55; 2,43; 2,32 dan 2,17. Lima isolat ini kemudian diukur nilai aktivitas kitinolitik pada medium kitin cair yang diperkaya koloidal kitin 1% pada suhu 30ºC. Berdasarkan pengujian didapatkan hasil bahwa Isolat AR 18 memiliki aktivitas enzim kitinolitik terbesar. Hasil identifikasi bakteri yang dilakukan secara biokimia menunjukkan bahwa isolat AR18 memiliki kemiripan 83,33% dengan Corynebacterium striatumKata Kunci: bakteri kitinolitik, isolasi, identifikasi, kitinase, Limbah cair pembekuan udang

Saat ini kelompok budidaya ikan koi di Desa Perbarakan masih terfokus pada proses pemijahan alami sehingga perlu penerapan teknologi pemijahan semi alami yang dinilai dapat meningkatkan kuantitas dan kualitas produksi ikan koi. Metode eksperimen lapangan yang dilakukan dengan melakukan perbandingan pemijahan alami dengan pemijahan semi alami menggunakan induk ikan koi yang siap dipijahkan dengan perbandingan 2 : 1 yaitu 2 ekor jantan (Kohaku dan Shiro) dan 1 betina (Tancho sanke doitsu) dengan melalui parameter pengamatan fekunditas, derajat pembuahan, daya tetas telur dan sitasan larva. Hasil variasi nilai fekunditas pemijahan alami adalah 7000 butir dan pemijahan semi alami adalah 14.000 butir, derajat pembuhan telur (FR) pemijahan alami adalah 71,42% dan pemijahan semi alami sebesar 85,71%, selanjutnya persentase daya tetas telur ikan koi pada pemijahan alami adalah 90% dan pemijahan semi alami sebesar 95% , sintasan larva tertinggi pada pemijahan semi alami 78,26% sedangkan pada pemijahan alami 44,44%. Sehingga penggunaan bantuan hormon ovaprim dinilai dapat menghemat waktu proses pemijahan dan tingkat keberhasilan lebih tinggi dibandingkan dengan teknik pemijahan alami

Pada pengoperasian sistem tenaga listrik diperlukan kualitas dan tingkat keandalan yang baik, salah satunya adalah tegangan yang sampai ke pelanggan tidak mengalami drop tegangan. Salah satu cara agar perencanaan dan pengoperasian tenaga listrik tersebut baik adalah dengan analisis load flow. Analisis load flow bertujuan untuk mengetahui karakteristik aliran daya yang berupa pengaruh dari variasi beban dan rugi-rugi pada aliran daya dan juga mempelajari adanya tegangan jatuh di sisi beban. Tujuan penulisan paper ini adalah untuk melihat dan menganalisa load flow sistem saat kondisi eksisting, hubung singkat (Short Circuit) dan pada saat adanya penambahan DG (Distributed Generation) yang mana pada penelitian ini DG yang dipakai adalah PV (photovoltaic). Analisa dilakukan pada GI (Gardu Induk) Kentungan feeder 3 (KTN07) yang terdiri dari 23 area (KTN07-A sampai KTN07-W) dengan total 106 busbar. Penelitian menggunakan ETAP (Electrical Transient Analyser Program) 12.6.0.

Sawang duck is one of Indonesia's local dual-purpose type ducks due to the offspring of Tsaiya ducks originating from Taiwan. Tsaiya ducks enter the Sawangarea, brought by residents from Singapore around 1955 and subsequently bred in the Sawang Village, adapting to the environment and the local farming. This research was conducted in August-December 2018. Primary data on the qualitative, morphometric, and potential feed were taken in Sawang Village, Karimun Regency, Riau Islands Province. Currently, Sawang duck is only found in Sawang Village, maintained by two farmers. Secondary data of potential areas and poultry populations were obtained from the Department of Food and Agriculture of Karimun Regency, and proximate analysis was carried out at the Ruminant Nutrition Laboratory, Faculty of Animal Husbandry, Andalas University. The research method was conducted by survey with census sampling techniques. The Sawang duck has a diversity of colors for feather, skin, beak, and shank. The morphometric decrease was indicated by bodyweight of 1,450 ± 119.52 grams, femur length of 7.41 ± 1.62 cm, tibia length of 9.94 ± 0.51 cm, length of shank 4.38 ± 0.25 cm, third finger length 6.36 ± 0.90 cm, maxilla length 5.21 ± 0.16 cm, backbone length 20.13 ± 1.13 cm, wing bone length 26.65 ± 1.70 cm, bone length chest 10.63 ± 0.80 cm, and shank circumference 1.24 ± 0.10 cm. Efforts to preserve ducks Sawangneed to be considered so that their existence is not destroyed by exploiting the existing area's potential.

The background of this research was that the classroom atmosphere was very calm, no one responded to the teacher's explanation, even though the teacher had repeatedly given the opportunity to ask questions. The questions given were sufficient, but in the final results of the formative test given by the teacher, the results were still far from what was expected. This study aims to describe the learning achievement of the second semester students of SDN 88 / II Sungai Mengkuang, Bungo Regency, academic year 2016/2017 in Indonesian through the assignment method. This type of research is a classroom action research (PTK) with a qualitative descriptive approach carried out in three cycles. The results showed that the use of the assignment method in class II students can improve student achievement in pre-cycle only 38.7%, 38.7% first cycle, 61.29% cycle, and 87.09% third cycle

Dersita, Rambey R, Muhtadi A, Onrizal O, Mamurung VR, Hasibuan JS, Tamba IS. 2022. Biodiversity of nekton in the Barumun Watershed, Labuhanbatu District, Indonesia. Biodiversitas 23: 2426-2432. Biodiversity is a very valuable source of germplasm for science and sustainable development. Therefore, research on freshwater biodiversity is very important to support the sustainability of this development. The research investigated three rivers in South Labuhanbatu District, North Sumatra, Indonesia: Barumun, Tasik, and Titi Kembar rivers. This investigation aims to ascertain the composition, distribution, and variety of nekton. From April to August 2020, the trial lasted five months. Nekton samples were collected with the aid of nets and fishing nets. While installed in the afternoon, the nets are removed the following day. Additionally, at each observation point, stocking nets were operated three times. The investigation discovered 38 fish species and one shrimp species. Two species of fish discovered, are protected by the government of the Republic of Indonesia. Both fish species are Tenualosa terubuk, a fish with little protection, and Fluvitrygon signifer, a ray fish with complete protection. The study site's sole shrimp species was the gigantic prawn Macrobrachium rosenbergii in the Barumun river. The index of nekton diversity discovered in the three rivers was not identical. Compared to other rivers, the Tasik river station has a high diversity. This makes the Tasik river rich in fish compared to the Barumun and Titi Kembar rivers. The Tasik river is recommended as water suitable for fish life from these results.

Pembangkitan listrik dengan menggunakan bahan bakar fosil dapat meningkatkan pemanasan global. Untuk mengurangi penggunaan bahan bakar fosil tersebut dapat diatasi dengan pengembangan dan pemanfaatan Energi Baru Terbarukan (EBT). Salah satu contoh dari EBT tersebut adalah Photovoltaic (PV). Penambahan PV dengan penetrasi dan penempatan yang bervariasi memiliki pengaruh yang berbeda-beda terhadap aliran daya. Disisi lain, ketidakseimbangan beban mengakibatkan munculnya arus di netral trafo. Arus yang mengalir di netral trafo ini menyebabkan terjadinya losses (rugi-rugi), yaitu losses akibat adanya arus netral pada penghantar netral trafo dan losses akibat arus netral yang mengalir ke tanah. Tujuan penelitian ini adalah untuk melihat pengaruh masuknya PV ke sistem dengan penetrasi yang berbeda-beda. Penambahan PV di ujung dekat beban dengan penetrasi 10 %, 20% dan 30 % pada tegangan 0,38 kV menyebabkan losses naik sebesar 3,5 kW, 30,8 kW dan 101,6 kW, sedangkan Penambahan PV di tengah saluran dengan penetrasi 10 %, 20% dan 30 % pada tegangan 20 kV membantu mengurangi losses sebesar 9,4 kW, 11,4 kW dan 13 kW. Selain itu, untuk melihat load flow sistem saat terjadi ketidakseimbangan beban pada Wirobrajan substation feeder 1 yang terdiri dari 4 area penyaluran yaitu Ngestiharjo-pakuncen, Tegalrejo, Bumijo A dan Bumijo B dengan menggunakan ETAP (Electrical Transient Analyzer Program) 12.6.0.

Red dragon fruit is one of the agricultural commodities in Simpang Sugiran Village. Dragon fruit has many functions and properties for health. Based on monitoring in the field, farmers do not have the knowledge and skills in processing dragon fruit into various processed dragon fruit products to increase their selling value. In addition, the price of dragon fruit and farmer acceptance continues to decline while the number of farmers cultivating is increasing. The purpose of this activity was to increase community knowledge and skills in processing dragon fruit, and business management to increase the added value of dragon fruit cultivation. The results of community service activities indicated that the diversification of dragon fruit processing is one of the most effective ways to increase community income in the Simpang Sugiran village. Dragon fruit can be processed into various processed products using simple technology and can be done as a home industry. This community service activity can motivate and encourage the entrepreneurial spirit of the Farmer Group of Simpang Sugiran, Guguak Sub District, Lima Puluh Kota, West Sumatra.

The purpose of this study was to describe the relationship between the role of parents in the implementation of learning from home mathematics subjects to the mathematics learning outcomes of 5th graders at SD Negeri 04 Silungkang 3, Silungkang District, Sawahlunto City. This type of research is correlative research. The population in this study were 5th-grade students of SD Negeri 04 Silungkang 3 for the 2020/2021 academic year, totaling 25 people. The sampling technique is total sampling. The instrument in this study is a questionnaire on the role of parents in the implementation of learning from home in mathematics. Based on the calculation, the calculated r-value is 0.86 and the r table value is 0.382. Because of the value of r arithmetic > r table, it can be concluded that there is a significant relationship between the role of parents in the implementation of learning from home mathematics subjects to the mathematics learning outcomes of grade 5 students at SD Negeri 04 Silungkang 3 because the value of r count is 0.86 which means that the level of the relationship between the role of parents in the implementation of learning from home mathematics is very strong. So it can be concluded from this study that there is a significant and very strong relationship between the role of parents in the implementation of learning from home mathematics subjects to the mathematics learning outcomes of 5th graders at SD Negeri 04 Silungkang 3, Silungkang District, Sawahlunto City.

Oyster mushrooms are widely cultivated by Saraso farmer group Kenagarian Batu Balang, Harau District, Lima Puluh Kota Regency. The purpose of the activity was to increase knowledge and skills and empower the women of the Saraso Farmers Group, in the diversification of processed oyster mushroom products in order to increase the selling value. So far, the oyster mushrooms they cultivate are sold in fresh mushrooms, and only a few sell in processed food. The hope is that with this activity, the community can make various processed oyster mushrooms to add value to the sale which is expected to raise the family economy. The activity method was carried out by demonstration and hands-on practice. The results of community service activities showed that the women of the Saraso farmer group are able to process oyster mushrooms into various ready-to-consume products. Various processed mushrooms are made, namely Dendeng oyster mushroom, oyster mushroom beef, oyster mushroom satay, oyster mushroom shredded and additional materials, namely making sauces and chili sauce. This activity succeeded in arousing the motivation of the Saraso farmer groups in making variations of processed oyster mushrooms.

Based on statistical analysis from Dinas Kelautan Perikanan, Deli Serdang Regency in 2018, The capacity for freshwater aquaculture output was recorded at 1328.9 tons / year with a land area of 65.9 ha , which is a problem for the aquaculture community with the decreasing quantity of seed production, limited infrastructure and development management which is still conventional in Desa Perbarakan, Deli Serdang Regency, therefore it is important to implement the required application of science and technology, namely the implementation of semi-natural methods of spawning techniques of koi fish (Cyprinus carpio). Counseling, seminars and practices are the methods of tasks carried out. Extension activities were carried out by illustrating the conceptual awareness of the development of koi fish spawning strategies, the distribution of leaflets, the application of recognition technology, as well as tools and resources, including the dose of gonadotropin hormone (GnH) in broodfish and fish anaesthetic techniques. For female fish, the injected hormone level is 0.5 ml / kg and 0.1 ml / kg for male fish. The weight of the female fish is 1 kg tancho sanke doitsu, 0.5 ml/gr, and the weight of the male fish is 1 kg. At a dose of 0.1 ml / gr and 900 g of shiro, kohaku at a level of 0.09 ml / gr. The result is that the number of eggs is estimated at 10,000, and then the eggs hatch within 2-4 days. Boiled egg yolks are fed to the eggs which hatch into the larvae, then the larvae are transferred to the nursery pon after 10 days of age.

Rambey R, Susilowati A, Rangkuti AB, Onrizal O, Desrita, Ardhi R, Hartanto A. 2021. Plant diversity, structure and composition of vegetation around Barumun Watershed, North Sumatra, Indonesia. Biodiversitas 22: 3250-3256. Watershed ecosystem plays an important role in water and soil conservation which is supported by vegetation around watershed. As such, vegetation analysis is beneficial to assess the current state of watershed vegetation and monitor future changes. Barumun Watershed, located in South Labuhanbatu District, North Sumatra Province, Indonesia, is under threat due to habitat degradation and land conversion for plantation and agriculture. This research aimed to investigate the diversity, structure and composition of vegetation in the Barumun River including its smaller streams (rivulets). Data were collected using a combination of line transect and quadratic plots arranged systematically. The total observation plots were 48 plots, consisting of 24 plots in Barumun River, 12 plots in Tasik Rivulet and 12 plots in Titi Kembar Rivulet. The results documented a total of 51 plants in the studied sites in Barumun Watershed in which 37 species were found in Barumun River, 20 species in Tasik Rivulet and 17 species in the Titi Kembar Rivulet. Plant species consisted of several habitus including herbs, palms, shrubs, climbers and trees. The trees consisted of 22 species (43.13%), herbs 22 species (43.13%), climbers 3 species (5.88%), shrubs two species (3.92%), and palm two species (3.92%). The highest Importance Value Index (IVI) for tree community was recorded in the Barumun River from Hevea brasiliensis (108.28), followed by Cryptocarya sp. (123.24) in the Titi Kembar Rivulet. In addition, the highest IVI for pole, sapling, seedling, and shrub was recorded from Muntingia calabura (Barumun River), Nauclea orientalis (Tasik Rivulet), Psychotria viridiflora (Tasik Rivulet), and Calamus axillaris (Titi Kembar Rivulet), respectively. The plant diversity in Barumun Watershed was categorized from low to moderate level of richness.

Desrita, Hasugian FK, Yusni E, Manurung VR, Rambey R. 2021. Feeding habits of Tinfoil barb Barbonymus schwenenfeldii in the Tasik River, South Labuhanbatu, North Sumatra, Indonesia. Biodiversitas 22: 2131-2135. Research on feeding habits of Tinfoil barb, Barbonymus schwanenfeldii was carried out in the Tasik River from July to August 2020. This study aims to determine the composition of foods consumed by Tinfoil barb fish, and the availability of natural food in the Tasik River from 3 sampling stations. Fishes were caught using a gillnet with a mesh size of 3.18 cm, then the fish samples were dissected, and the digestive tract was taken and preserved with 10% formalin. A total of 138 Tinfoil bars were caught for this study. Analysis of stomach contents found that Tinfoil barb ate phytoplankton (41-48%) as the primary food, moss (25-38%), plant pieces (13-17%), worms (2-11%) as a complementary food and few of insects (0-4%), zooplankton (0-1%) as other foods. Based on analysis of food item values, all types of food and ratio within the intestine length and the total length showed that Tinfoil Barb was classified as omnivorous. The availability of natural foods for Tinfoil Barb in the Tasik River consists of the genera Asteroinella, Bacillaria, Bidulphia, Cestom, Gyrosigma, Gonatozygon, Oscillatoria, and Thalassiora.

Stingrays are a group of fish that have high economic potential landed at TPI Tanjung Beringin. The dominant type of stingray landed at TPI Tanjung Beringin is the Dwarf Whipray (Brevitrygon heterura) or commonly called Tuka-Tuka by the local community. This research wa carried out during July and September of 2021 at TPI Tanjung Beringin, survey method with a census technique, namely a method by seeking various information and various facts regarding the biological aspects. This study aims to determine the growth and exploitation rate of the dwarf whipray. There were 82 dwarf whipray, which were then measured for length and weight. The results of the study concluded that dwarf whipray (Brevitrygon heterura) which landed in TPI Tanjung Beringin had a negative allometric growth pattern, namely length growth was greater than weight growth. The exploitation status of the dwarf whipray (Brevitrygon heterura) in the waters of the Malacca Strait is classified as overfishing.

Indian Mackerel (Rastrelliger kanagurta) is one of the main catch fishery at Tanjung Beringin’s Auction Place, Serdang Bedagai, Sumatera Utara. The purpose of this research is to analyze the stock status of indian mackerel landed at Tanjung Beringin. This research was conduted in July – September 2021. The method of research used purposive sampling method. The total sample fish of indian mackerel were 272 individuals. The research showed Indian mackerel’s sex ratio was 1: 1.060. Indian mackerel’s growth pattern was negative allometric. Value estimation of male and female’s L∞ was 268.80 mm and 295.05 mm. Value K of male mackerel was bigger than female. But value of Lc and Lm male mackerel were smaller than female. The total rate of mortality was 2.466/year, natural mortality was 0.684/year and fishing mortality (F) was 1.782/year. The rate of exploitation was 0,723 classified as high exploitation level (overfishing).

Percut Sei Tuan is a coastal area on the east coast of North Sumatra which has a lot of natural resource potential, one of them which is green mussels (Perna viridis). Green mussels have many benefits, namely for consumption, cultivation and bioindicator. This study aimed to determine the density, habitat location, growth pattern, frequency distribution of green mussels, physical-chemical parameters of water, a substrate of the bottom waters, and the relationship of green clams density to water and substrate parameters. The study was conducted in July-September 2020. Data analysis included density, the relationship of total length and weight of green mussels, the frequency distribution of shell lengths, and Principal Component Analysis (PCA). The results showed that the density of green mussels at stations I, II, and III were 352 ind/m2, 3 ind/m2, and 1 ind/m2, respectively. The relationship between the length and weight of green shells shows that the growth was negative allometric. The water condition, seen from the physical, chemical, and substrate parameters, was still suitable for P. viridis. Water and substrate parameters that were positively related to the density of green mussels were water temperature, nitrate, phosphate, C-organic, percentage of silt and clay. Parameters that were negatively related were salinity, pH, and percentage of sand in the bottom substrate. The present study suggested that Station I was an appropriate area for the growth and reproduction of green mussels.

Desrita, Muhtadi A, Leidonald R, Sibagaring RD, Nurfadillah 2020. Biodiversity of nekton in Batangtoru River and its tributaries in North Sumatra, Indonesia. Biodiversitas 21: 2344-2352. Batangtoru River which flows from the Tapanuli highlands (i.e., Sipirok, Tarutung, Siborong-borong, and Silangit) to the southwestern Indian Ocean is an important habitat for aquatic organisms in the western region of North Sumatra. This research was done to provide basic data on biodiversity of aquatic organisms in Indonesia, especially North Sumatra. The study was conducted in July-August 2019. Nekton was captured using backpack electrofishing units (12 volts and 9 Amperes), traps, nets, and bamboo trap. This study found 68 nekton species, consisting of fish (57 species), crab (3), shrimp (6), lobster (1), and 1 freshwater turtle (1). In general, nekton found in the Batangtoru River and its tributaries are native and economically valuable fish (Tor and eel), including the newly discovered species, which was, Hemibagrus caveatus. Invasive fish found consisted of 6 species, i.e., Cyprinus carpio, Oreochromis mossambicus, Oreochromis niloticus, Xiphophorus helleri, Hypostomus plecostomus, and Trichogaster pectoralis. The only invasive crustacean found was freshwater crayfish (Cherax quadricarinatus).

Meningkatkan hasil belajar siswa pada meteri ikatan kimia menggunakan model pembelajaran flipped classroom learning tipe peer instruction flip

The ongoing COVID-19 pandemic, as a result of the SARS-CoV-2 virus, since December 2019, is a major health problem and concern worldwide. The pandemic has impacted various fields, from the social to the development of health science and technology. The virus has been mutating and thus producing several new variants, rushing research in the field of molecular biology to develop rapidly to overcome the problems that occur. Vaccine clinical studies are developing promptly with the aim of obtaining vaccines that are effective in suppressing the spread of the virus; however, the development of viral mutations raises concerns about the decreasing effectiveness of the resulting vaccine, which also results in the need for more in-depth studies. There have been 330 vaccines developed, including 136 clinical developments and 194 pre-clinical developments. The SARS-CoV-2 variant continues to evolve today, and it poses a challenge in testing the effectiveness of existing vaccines. This is a narrative review describing the emergence of the COVID-19 pandemic, development of vaccine platforms, identification of concerning mutations and virus variants in various countries of the world, and real-world monitoring of post-vaccination effectiveness and surveillance.

The role of plankton as natural food affects the potential of fish in the waters. The structure of the plankton community in the Aneuk Laot Lake can provide an overview of the stability of these waters. This study aims to determine the plankton biomass and the structure of the plankton community of Aneuk Laot Lake Sabang. This research was conducted in September 2019 in the waters of Aneuk Laot Lake. Determination of observation stations using the stratified random sampling method, identification of plankton using the census method and analysis of chlorophyll-a using the Trichomatic method. The results showed that the plankton composition consisted of 27 phytoplankton and 4 zooplankton genera which were divided into Bacillarophyceae (36%), Chlorophyceae (19%), Cyanophyceae (16%), Zygnematophyceae (10%), Dinophyceae (3%), Euglenophyceae (3%) and Crustacean class (13%). The abundance of plankton was 21,333 ind/l, the most abundant type is Navicula sp. Diversity index value (2.97) is category high, eveness index (0.87) and low dominance index (0.07). Chlorophyll-a values ranged from 2.84 to 4.84 mg/l including the medium nutrient category. Aneuk Laot Lake has a high level of community stability with trophic status of mesotrophic-eutrophic.

Coral reefs are one of the typical ecosystems in coastal areas that have ecological and economicvalue. There are many cases of coral reef damage in Salah Nama Island caused by natural andhuman factors. Coral reefs damage is mostly caused by human activities such as water pollution,destructive fishing and using of ship anchors. Activity of devotion society aims to provideinformation and skills to fishermen groups in Salah Nama Island about coral transplantationtechniques, as well as conducting coral transplantation activities as one of the efforts to preservethe ecosystem of coral reefs. Based on the description of the problems and objectives of devotionsociety, the activities that have been done are counseling to the partner fishermen abouttransplantation and coral benefits in ecosystem, transplantation practice and coral transplantationmonitoring.

Desrita, Muhtadi A, Tamba IS, Ariyanti J, Sibagariang RD. 2018. Community structure of nekton in the upstream of Wampu Watershed, North Sumatra, Indonesia. Biodiversitas 19: 1366-1374. River is a habitat for many aquatic organisms. Water quality is the main river characteristic that strongly influences distribution pattern, biodiversity, and abundance of aquatic organisms. Nekton is aquatic organism that swims and moves actively on their desire, for example, fish, shrimp, amphibian and also big aquatic insects. The purpose of this research was to know the habitat condition and biodiversity of nekton in the upstream of Wampu watershed. The habitat condition was measured by examining the temperature, visibility, flow velocity, depth of waters, dissolved oxygen, pH, kind of substrate, the width of the river, body width of river and rate of flow of the river. The type of nekton was determined by catching the nekton using a backpack of electrofishing unit with an electric flow of 12 Volt and 9 Ampere. The upstream habitat condition of Wampu watershed was characterized by big stone, pebble, sandy type of substrate with moderate to strong current flow, and the clear aquatic. Physical and chemical parameters in upstream of Wampu watershed were still sustainable and appropriate as habitat for fish and shrimp. The result of this research showed a variety of nekton collected, comprised of 27 species of fish, five species of shrimp of inland water. Two species of fish from Tor genera, i.e., T. soro and T. tambroides were also found in this study. The highest diversity (H´) in this research site was the Bahorok River (2.12), followed by Landak River (1.93) at the second, and the lowest was Berkail River with only about 1.50 diversity index.

Highly Utilization of Mangrove field as cultivation field of fish and recreation and tour site by people have big posses to the abundance of Mangrove crab (Scylla serrata) because of mangrove play role as habitats of mangrove crabs. The research was conducted for two months from December 2016 to January 2017. This study aims to see the structure of mangrove vegetation, the abundance of Mangrove Crab and the influence of mangrove vegetation structure on the abundance of Mangrove Crab in Kampung Nipah. The results of this research are Vegetation structure of Mangrove in the station I and II show high density, whereas density in station III wide apart. The abundance of mangrove crab in the station I and II showed the higher result from station III. The Influence of Vegetation Structure of Mangrove and Abundance of Mangrove Crab can be related by using regression analysis Y = 0.0241x + 113.6. The correlation coefficient (r) that value obtained as 0.79 have a meaning the connection between mangrove density and abundance of mangrove crab are rated in the strong category that has a value 79%. The density of Mangrove to 1000 units will rise up the abundance of mangrove crab to 43.5 an individual. Tingginya pemanfaatan mangrove sebagai lahan budidaya ikan dan sebagai wisata rekreasi oleh masyarakat sangat mempengaruhi kelimpahan Kepiting Bakau (Scylla serrata) karena hutan mangrove merupakan habitat bagi Kepiting Bakau. Penelitian ini dilaksanakan selama dua bulan yaitu bulan Desember 2016 sampai Januari 2017. Penelitian ini bertujuan untuk melihat struktur vegetasi mangrove, kelimpahan Kepiting Bakau dan pengaruh struktur vegetasi mangrove terhadap kelimpahan Kepiting Bakau di Kampung Nipah. Hasil dari penelitian struktur vegetasi mangrove di stasiun I dan II memiliki kerapatan sangat padat, sedangkaan kerapatan di stasiun III jarang. Kelimpahan Kepiting Bakau di Stasiun I dan II lebih tinggi dari kelimpahan di stasiun III. Pengaruh kerapatan mangrove dan kelimpahan Kepiting Bakau diperoleh persamaan regresi yaitu Y = 43,521 + 0,2061x. Koefisien korelasi (r) yang diperoleh 0,79 yang artinya hubungan kerapatan mangrove dan kelimpahan Kepiting Bakau tergolong kuat yaitu sebesar 79%. Kerapatan mangrove sebanyak 1000 satuan akan meningkatkan kelimpahan Kepiting Bakau sebesar 43,5 individu.

Susetya IE, Desrita, Ginting EDD, Fauzan M, Yusni E, Saridu SA. 2018. Diversity of bivalves in Tanjung Balai Asahan Waters, North Sumatra, Indonesia. Biodiversitas 19: 1147-1153. Local and regional market demands for bivalves increase outside Tanjung Balai City and Asahan District Waters, North Sumatra, Indonesia. As a result, high exploitation of bivalves occurred. In the other hand, there were less comprehensive information and studies on the diversity of bivalves in this area. This study aimed to determine the diversity of bivalves and water quality of Tanjung Balai Asahan Waters; was conducted between July 2016 and November 2017. Sampling of bivalves was conducted monthly. Several physical and chemical parameters were quantified. Data analysis included community structure analysis and Principal Component Analysis (PCA). The result showed that there were 16 species of bivalves from 7 families in Tanjung Balai Asahan Waters. Station 2 had the highest composition of bivalves, while the lowest was noted at Station 1. The mean abundance of bivalves at stations 1, 2 and 3 were 352±22 ind/m2, 222±14 ind/m2 and 388±30,2 ind/m2, respectively. In general, the index of diversity was categorized as low to moderate. The evenness index was categorized as low to high, while the dominance index indicated the absence of dominant species at almost all stations except station 1. Water quality of the waters was still in capacity to support the life of bivalves. Based on PCA analysis, it was obtained that the abundance of bivalves was positively correlated with nitrite, nitrate, phosphate, salinity, and pH.

Bandeng ( Chanos chanos ) adalah ikan ekonomi penting yang dibudidayakan di tambak air payau. Bandeng relatif tahan terhadap penyakit yang mungkin disebabkan oleh bakteri usus terkait untuk meningkatkan kesehatan dan mencegah penyakit. Di usus bandeng dilakukan pengamatan untuk mendapatkan bakteri probiotik potensial untuk dikembangkan sebagai probiotik. Beberapa pengamatan morfologi seperti bentuk dan warna sel dan uji biokimia seperti pati, hidrolisis kasein dilakukan. Uji antagonistik dari isolat bakteri potensial dilakukan pada Aeromonas hydrophila . Penelitian ini dilakukan dari bulan Juni hingga September 2017 di Balai Karantina Ikan dan Pengendalian Mutu dan Keamanan Hasil Perikanan Kelas 1 Medan, Kuala Namu. Hasilnya menunjukkan bahwa bakteri probiotik potensial dalam saluran pencernaan ikan bandeng adalah Staphylococcus spp. (UIM01), Micrococcus sadentarius (UIM02), Lactobacillus acidophillus (LIM01) dan Micrococcus lylae (LIM02). Bakteri ini menunjukkan aktivitas menghambat pertumbuhan Aeromonas hydrophila hingga rendah meluas. Milkfish ( Chanos chanos ) is an important economic fish that is cultured in brackish water ponds. Milkfish is relatively resistant to diseases that may be caused by associated gut bacteria to improve health and prevent from disease. In the gut of milkfish was screened to obtain potential probiotic bacteria to be developed as probiotic. Some morphological observation such as shape and color of cell and biochemical test such as starch, casein hidrolysis were conducted. Antagonistic test of the potential bacteria isolate was done to A eromonas hydrophila . This study was conducted from June to September 2017 in Balai Karantina Ikan dan Pengendalian Mutu dan Keamanan Hasil Perikanan Kelas 1 Medan, Kuala Namu. The result indicated that potential probiotic bacteria in the digestive tract of milkfish were Staphylococcus spp. (UIM01), Micrococcus sadentarius (UIM02), Lactobacillus acidophillus (LIM01) and Micrococcus lylae (LIM02). These bacteria showed to inhibiting growth of Aeromonas hydrophila for low extend.

Leidong river flow is deriving from the Kualuh river basin as the largest river in Labuhanbatu District. The Leidong stream is possibly a water space with changed human exercises which has the potential to cause contamination and disturbance of oceanic biota. The purposes of this study were to figure out fish abundances and the growth of tarpon fish (Megalops cyprinoides) in the Leidong River, North Labuhanbatu District. The highest fish abundance was at station one which was 6 ind/m2, followed by stations 3 and 2 which were 5 and 4 ind/m2. The length and weight estimation of the catched angle at each station demonstrated the development of the tarpon fish with the esteem of b> 3 which is a positive allometric and the value of the condition factor of each K> 1, where this indicates that the condition of the fish in the estuary of the Leidong river morphologically can be said to have good plumpness.

Serdang Bedagai Regency has fisheries and marine potential demersal species of stingray in TPI Tanjung Beringin. The current study used a survey and descriptive method, accompanied by sample collection and morphology identification, as well as determining the rate explotation of fish landed in TPI Tanjung Beringin. A total of five species were successfully identified: Neotrygon kuhlii, Brevitrygon heterura, Aetoplatea zonura, Maculabatis macrura and Rhynchobatus australiae. The most dominant stingray species landed in TPI Tanjung Beringin namely of Neotrygon kuhlii, so that condition was an analysis of Neotrygon kuhlii weight length relationship of fish and body weight is negative allometric growth is more dominant than weight gain. The growth rate Von Bertalanffy is L ∞ (infinity) value is 300.30 mm, K value is 0.42 and t0 value is -0.68, the fish growth can be influenced by internal and external factors. Mortality and exploitation rate of Neotrygon kuhlii total mortality (Z) value is 1.01, natural mortality (M) value is 0.59408, fishing mortality (F) value is 0.4192 and exploitation rate is 0.7105 as long as indicators high fishing mortality and decreasing natural mortality indicate a state of growth overfishing.

Program Pengabdian Kepada Masyarakat ini merupakan kegiatan melatih masyarakat membuat produk Belanak Presto “Beluker” yang sehat, higienis serta layak dijual sebagai produk olahan ikan. Kontribusi mendasar yang diperoleh dengan adanya pelatihan ini adalah ikan belanak yang merupakan ikan hasil tangkapan di wilayah perairan muara sungai ekosistem mangrove, akan mempunyai masa simpan yang lebih panjang dalam bentuk belanak presto. Selain itu juga dapat memberikan nilai tambah pada harga jual ikan, serta menyediakan sumber pendapatan yang berkelanjutan pada masyarakat. Mitra sasaran adalah ibu-ibu rumah tangga yang tinggal di desa Lubuk Kertang. Berdasarkan penelusuran awal ibu-ibu tersebut belum mempunyai pengetahuan dan ketrampilan membuat produk olahan belanak presto. Kegiatan yang dilaksanakan meliputi survey, penyuluhan, pemberian leaflet serta alat pendukung pengolahan belanak presto dan dilanjutkan dengan praktek pembuatan produk belanak presto. Hasil yang diperoleh dari kegiatan ini adalah peningkatan pengetahuan dan keterampilan mitra pengabdian tentang bentuk olahan berbahan dasar ikan belanak yang selama ini belum dimanfaatkan secara optimal.

Biologi reproduksi meliputi distribusi frekuensi panjang, hubungan berat-panjang tubuh, rasio jenis kelamin, tingkat kematangan gonad (TKG), indeks somatic gonad (IKG), diameter telur. Data primer yang digunakan adalah panjang dan berat tubuh, bobot dan gonad Ikan yang diperoleh dari 360 ekor sampel. Data sekunder dikumpulkan dari Laporan Statistik Perikanan PPS Belawan berupa jumlah produksi, dan jumlah tangkapan ikan tahun 2011-2016. Hasil penelitian menunjukkan distribusi frekuensi panjang ikan berkisar antara 110 mm - 163 mm. pola pertumbuhan ikan adalah alometrik negatif dengan koefisien korelasi jantan dan betina mendekati 1 yaitu 0,812 dan 0,733. Indeks kematangan gonad untuk ikan betina adalah lebih besar dibanding ikan jantan. Tingkat kematangan gonad diperoleh dari tingkat I, II, III, dan IV . Reproductive biology including length frequency distribution, long weight relationship, sex ratio, g onadal maturity level, gonad al somatic index and egg diameters. Primary data used is lenght and body weight. Weighting obtained as many as 360 samples . Secondary data was collected from Fishing Statistical Report of PPS Belawan, which were the amount of production, and fishing effort of the year 2011-2016. The results showed the frequency distribution of fish length of 110 mm – 163 mm. Character growth negative allometric with a correlation coefficient males and females approximate to 1 whereas 0.812 and 0.733. Gonadal maturity index for females fish than large from males fish. Gonadal maturity index obtained by the I, II, III, and IV.

The aims of the research was to examine the lenght weight relationships, growth pattern and condition factor of mudskipper (Family: Gobiidae) at the mangrove ecosystem. The research was conducted for two months from March to April 2016 at the mangrove ecosystem in the Sembilan Island village. The result showed that there are three species of mudskipper found in study area, namely Periophthalmus chrysospilos, Periophthalmus gracilis, and Boleophthalmus boddarti. The growth pattern of mudskipper with a value b < 3, indicate a allometrik negative growth pattern and the condition factor was between 1-2. Penelitian ini bertujuan untuk menganalisis hubungan panjang bobot, pola pertumbuhan dan faktor kondisi ikan belodok (Famili: Gobiidae) pada ekosistem mangrove di di desa Pulau Sembilan Langkat. Penelitian dilaksanakan selama dua bulan yaitu Maret sampai April 2016. Penelitian ini menggunakan metode purposive random sampling. Hasil penelitian ditemukan 3 spesies ikan belodok di lokasi penelitian yaitu Periophthalmus chrysospilos, Periophthalmu sgracilis, dan Boleophthalmus boddarti. Pola pertumbuhan ikan belodok dengan nilai b < 3, mengindikasikan pola pertumbuhan allometrik negatif. Faktor kondisi dari Ikan Belodok berkisar 1 – 2.

The study was conducted to determine the condition of the habitat and the diversity of fish in the watershed of Wampu. The habitat conditions was determined by measuring parameters of temperature, brightness, current velocity, depth, DO, pH, type of substrate, the width and the width of the river. Nekton was sampled using electrofishing units at voltage of 15 volt and 9 amperes. The characteristic of upstream watershed was large stones substrate, gravel, and sand with a fast flow and clear waters. Physical-chemical parameters of waters in the upper watersheds Wampu is still suitable for fish, crabs, and shrimp to live in good condition. A total of 1 5 species of fishes and one species of freshwater crab and one species of freshwater prawns were recorded during the study. There were two species of mahseer were recorded, namely; Tor soro and T. tambra. The higher diversity index (H ') was recorded in the Bahorok River with a value of 4.5 followed by Berkail River (3.45) and Landak River with a value of 2.46 . Penelitian ini dilakukan untuk mengetahui kondisi habitat dan keragaman ikan di DAS Wampu. Pengukuran kondisi habitat dengan mengukur parameter suhu, kecerahan, kecepatan arus, kedalaman, DO, pH, jenis substrat, lebar dan lebar badan sungai. Jenis nekton ditangkap dengan alat backpack electrofishing units dimana arus listrik yang dihasilkan bersumber dari batere 15 volt dan 9 ampere. Kondisi habitat pada bagian hulu DAS Wampu yaitu bertipe substrat batu besar, kerikil, dan pasir dengan arus yang sedang - besar serta perairan yang jernih. Parameter fisika-kimia perairan di hulu DAS Wampu masih layak dan cocok untuk habitat ikan, kepiting dan udang. Selama penelitian nekton yang terkoleksi sebanyak 15 jenis ikan dan 1 jenis kepiting air tawar serta 1 jenis udang air tawar. Pada survei ini ditemukan dua jenis ikan Tor yakni T . soro , dan T. Tambra. Keanekaragaman (H') tertinggi terdapat pada Sungai Bahorok dengan nilai 4,5 diikuti Sungai Berkail dengan nilai 3,45, dan Sungai Landak dengan nilai 2,46.

Tilapia is fish consumption with some excess, that is has a high protein, non-cholesterol, the taste is delicious, affordable and easily cultivated. One of the problems in cultivating them is a disease because it can cause the death of the fish. Disease-causing factors can be derived from the bacterium Aeromonas hydrophila . The bacteria A. hydrophila can cause the death of fish until 80%-100% within 1-2 week and even many that are already resistant to several types of commercial antibiotics, so that the need to look for a new antibiotics source. The source of these antibiotics can be derived from nature because it is cheaper, safer and environmentally friendly. Mangrove Excoecaria agallocha has been known to have potential as an antibacterial, larvacide, and antifungal. This can be used as a source of antibiotics. The purpose of this research is to analyze the potential of the mangrove leaves infusion E. agallocha in preventing the spread of disease in tilapia infected the bacteria and identify the compounds of secondary metabolite. This research was carried out from March-August 2018 and use approach posttest-only control group design (by comparing the treatment with the control group). The amount of treatment is five with three replicates. The dose used, namely 0%, 2.5%, 5%, 7.5% and 10%. The results showed that there was no difference in the influence of the mangrove leaves infusion E. agallocha against weight gain and survival rate of tilapia juveniles. The result of phytochemical screening indicates that E. agallocha leaves infusion contains tannins and flavonoids. Keywords: Excoecaria agallocha ; phytochemical; tilapia Abstrak Ikan nila merupakan ikan konsumsi dengan beberapa kelebihan yaitu memiliki kandungan protein yang tinggi, non-kolesterol, rasa enak, harga terjangkau dan mudah dibudidayakan. Salah satu masalah yang dihadapi dalam membudidayakannya adalah penyakit, karena dapat menyebabkan kematian pada ikan. Faktor penyebab penyakit dapat berasal dari golongan bakteri yaitu Aeromonas hydrophila . Bakteri A. hydrophila dapat menyebabkan kematian ikan dengan kisaran 80%-100% dalam jangka waktu 1-2 minggu dan bahkan banyak yang sudah resisten terhadap beberapa jenis antibiotik komersil sehingga perlu dicari sumber antibiotik baru. Sumber antibiotik tersebut dapat berasal dari alam karena lebih murah, aman dan ramah lingkungan. Mangrove jenis Excoecaria agallocha telah diketahui memiliki potensi sebagai antibakteri. Hal ini dapat dijadikan referensi sebagai bahan antibiotik baru. Tujuan dari penelitian ini adalah menganalisa potensi infusa daun mangrove jenis E. agallocha dalam mencegah penyebaran penyakit pada Ikan Nila yang terinfeksi bakteri dan mengidentifikasi kandungan golongan senyawa metabolit sekundernya. Penelitian ini dilaksanakan dari bulan Maret - Agustus 2018. Penelitian ini menggunakan pendekatan posttest only control group design (dengan membandingkan antara kelompok perlakuan dengan kelompok kontrol). Jumlah perlakuan adalah 5 dengan 3 kali ulangan. Dosis yang digunakan yaitu 0%, 2,5 %, 5 %, 7,5 % dan 10 %. Hasil penelitian menunjukkan bahwa tidak terdapat perbedaan pengaruh infusa daun mangrove jenis E. agallocha terhadap bobot tubuh dan kelangsungan hidup dari benih Ikan Nila. Hasil skrining fitokimia menunjukkan bahwa pada infusa daun E. agallocha mengandung senyawa tanin dan flavonoid. Kata kunci: Excoecaria agallocha; fitokimia; ikan nila

Metabolit sekunder merupakan senyawa yang digunakan untuk menunjang kehidupan organisme, akan tetapi tidak vital dan memiliki aktifitas dibidang farmakologi dan biologi. Mangrove jenis E. agallocha memiliki banyak manfaat yang berhubungan dengan bidang farmakologi seperti antibakteri, antijamur dan antioksidan. Hal ini disebabkan karena memiliki senyawa metabolit sekunder. Tujuan dari penelitian ini adalah untuk mengetahui jenis senyawa bioaktif yang dimiliki oleh daun mangrove jenis E. agallocha setelah mengalami proses perebusan. Penelitian ini dilaksanakan pada bulan Maret sampai April 2018. Pengambilan sampel dilakukan secara purposif sampling. Sampel daun mangrove jenis E. agallocha dibagi menjadi dua, yaitu sampel kering (daun E. agallocha dikeringkan menggunakan oven pada suhu 45 0C) dan sampel basah (daun E. agallocha direbus sampai mendidih). Skrining fitokimia dilakukan terhadap kedua sampel daun mangrove jenis E. agallocha. Hasil skrining fitokimia menunjukkan bahwa terdapat perubahan kandungan senyawa bioaktifnya. Senyawa bioaktif sampel kering yaitu alkaloid, flavonoid, tanin dan saponin, sedangkan senyawa bioaktif pada sampel basah yaitu alkaloid dan tannin. Kata kunci: Excoecaria agallocha; fitokimia; perebusan Abstract Secondary metabolites are compounds that are used to support organism life but are not vital and have activities in the field of pharmacology and biology. E. agallocha mangroves have many benefits related to pharmacology such as antibacterial, antifungal and antioxidant. This is due to having secondary metabolites. The purpose of this study was to determine the types of bioactive compounds possessed by E. agallocha mangrove leaves after undergoing a boiling process. This research was conducted from March to April 2018. Sampling was conducted purposively. Samples of E. agallocha mangrove leaves were divided into two, namely dry samples (E. agallocha leaves were dried using an oven at 45 0C) and wet samples (E. agallocha leaves boiled until boiling). Phytochemical screening was carried out on both samples of E. agallocha mangrove leaves. Phytochemical screening results showed that there was a change in the content of the bioactive compounds. Dry sample bioactive compounds are alkaloids, flavonoids, tannins, and saponins, while bioactive compounds in wet samples are alkaloids and tannins. Keywords: Excoecaria agallocha; phytochemical; boiling

Makarel India adalah ikan air laut yang umum dikonsumsi. Keunggulan ikan tenggiri adalah memiliki cita rasa yang enak, harga yang terjangkau, dan dapat diolah menjadi berbagai macam masakan. Kelemahan dari ikan kembung India adalah mudah untuk mengalami penurunan kualitas. Salah satu cara untuk memperpendek umur simpan adalah dengan penambahan es. Cara pengawetan lainnya adalah dengan memanfaatkan bakteri asam laktat hasil fermentasi kubis. Kubis digunakan sebagai bahan starter fermentasi karena memiliki harga yang terjangkau dan mudah didapatkan. Tujuan penelitian ini adalah untuk mengetahui umur simpan ikan tenggiri yang direndam menggunakan larutan fermentasi kubis dengan lama waktu 1 jam, 2 jam, dan 3 jam. Sampel ikan kembung India berasal dari pasar ikan. Ikan dicuci menggunakan air bersih, kemudian direndam menggunakan larutan fermentasi kubis dengan lama waktu perendaman 1 jam, 2 jam, dan 3 jam. Parameter yang diamati adalah kenampakan mata, insang, lendir pada permukaan tubuh, daging, bau, dan tekstur. Hasil penelitian menunjukkan umur simpan ikan tenggiri pada suhu ruang adalah 11 jam (untuk kontrol), sedangkan umur simpan ikan tenggiri direndam selama 1 jam, 2 jam, dan 3 jam adalah 14 jam. Pengujian menggunakan Anova menunjukkan nilai signifikan sebesar 0,351. Artinya lama perendaman menggunakan larutan fermentasi kubis tidak mempengaruhi umur simpan ikan tenggiri. Hasil penelitian menunjukkan umur simpan ikan tenggiri pada suhu ruang adalah 11 jam (untuk kontrol), sedangkan umur simpan ikan tenggiri direndam selama 1 jam, 2 jam, dan 3 jam adalah 14 jam. Pengujian menggunakan Anova menunjukkan nilai signifikan sebesar 0,351. Artinya lama perendaman menggunakan larutan fermentasi kubis tidak mempengaruhi umur simpan ikan tenggiri. Hasil penelitian menunjukkan umur simpan ikan tenggiri pada suhu ruang adalah 11 jam (untuk kontrol), sedangkan umur simpan ikan tenggiri direndam selama 1 jam, 2 jam, dan 3 jam adalah 14 jam. Pengujian menggunakan Anova menunjukkan nilai signifikan sebesar 0,351. Artinya lama perendaman menggunakan larutan fermentasi kubis tidak mempengaruhi umur simpan ikan tenggiri.

Sucker barb fish is one of the potential of fish resources in Tasik river. This study aimed to determine the morphometric and meristic characteristics of the growth of sucker barb fish in the Tasik River. The method used in this study is a survey method using the fishing net and gillnet with mesh size 1,5 inches. The nets are placed in the afternoon, then lifted in the morning. This is done 3 times with a span of 2 weeks in the three research stations. The number of samples collected were 135 fish. The morphometric characteristics of sucker barb fish are bodyweight (BT) ranging from 9-85 g, total length (PT) ranging from 100-230 mm, standard length (PS) ranging from 75-176 mm, head length (PK) of 20-42 mm, snout length (PM) of 30 mm, the height of dorsal fin (TSP) of 40 mm, length of the base of dorsal fin (PPSP) of 15-30 mm, eye diameter (DM) of 10 mm, caudal peduncle (TBE) of 8-22 mm, body height (TB) of 17-40 mm, pectoral fin length (PSD) of 30 mm and pelvic fin length (PSP) of 25 mm. Meristic characteristics are the characteristics of counting the scales and fins of sucker barb fish. The number of scales in the lateral lines (LL) is 35-38, the body coiled scales (SMB) are 6, the scales around the pectoral fin (PF) P 10-14, anal fin (AF) A 8 and caudal fin (CF) C 18. The growth pattern of sucker barb fish in the Tasik River is allometric negative

South Labuhanbatu Regency has quite large water resources with the Barumun River which crosses Pasir Tuntung Village, Asamjawa Village, Kotapinang Village and Sisumut Village. This study aims to determine the factors that influence the income of fishermen in Asamjawa Village, South Labuhanbatu Regency. This research method is a descriptive method with a questionnaire tool and the data obtained were analyzed using SPSS software. The variables observed were fisherman’s income, fisherman’s education, length of time working as a fisherman, area of fishing location, daily working time, number of fishing gear and number of fisherman catches. The linear regression model of fishermen’s income in Asamjawa Village was obtained as follows: Y = -19.344,10 + 392.699,10 X1 - 5.024,53 X2 + 73.255,48 X3 + 16.349,29 X4 + 135.819,41 X5 + 12.465,72 X6. The regression analysis results obtained three variables that significantly affect the income of fishermen in Asamjawa Village, Torgamba District, South Labuhanbatu Regency. Where the variables that have a significant effect are the education variable, the number of catches, and daily working time.

Chengham (Scphyphora hydrophyllacea Gaertn. f., Rubiaceae) is a mangrove shrub or tree commonly in landward mangrove zones having some biological activities. All parts of S. hydrophyllacea have shown some components benefits to biological and pharmaceutical properties. This present study aimed to analyze the distribution and composition of polyisorenoid in senesnece leaves, fruits and branches of S. hydrophyllacea. Polyisoprenid patter was evaluated by two-dimensional thin layer chromatography (2D-TLC) approach. The total lipid (TL) content of five samples ranged from 5.7 mg/g in branches to 10.0 mg/g in the old leaves. Additionally, the percentage of polyprenol of senescence leaves slightly abundance compare to dolichol in the polyisoprenoid presence. Overall, polyprenol was found in higher content than dolichol in the yellow leaves. Results of this study found the type-II of S. hydrophyllacea fruits was in line with earlier reports on the plant fruits. The present study provided the occurrence of polyprenols and dolichols in S. hydrophyllacea tested organs.

Waduk Koto Panjang dibangun dengan membendung Sungai Batang Mahat dan Sungai Kampar Kanan. Waduk ini selesai dibangun pada tahun 1996 dan terdapat di Kabupaten Kampar Provinsi Riau. Banyak biodiversitas jenis nekton ditemui baik di perairan mengalir yang menjadi inlet maupun waduknya sendiri. Salah satu nekton yang ditemui di Perairan Inlet Waduk Koto Panjang adalah Ikan Bunga Air. Penelitian ini bertujuan untuk mengidentifikasi dan mengetaui sebaran ukuran Ikan Bunga Air. Pengambilan sampel ikan dilakukan selama empat bulan yaitu dari April – Juli 2010 dengan mengambil 5 lokasi penelitian. Stasiun I Muara Takus, Stasiun II Gunung Bungsu I, Stasiun III Gunung Bungsu II, Stasiun IV Tanjung I dan Stasiun V Tanjung II. Dari hasil penelitian didapatkan bahwa Ikan Bunga Air kedalam Kelas Actinopterygii Ordo Clupeiformes Famili Clupeidae Genus Clupeichtyhs dan Spesies Clupeichthys goniognathus Bleeker, 1855. Sedangkan distribusi ukuran yang dominan secara keseluruhan, ikan jantan dan betina adalah 30 – 47 mm dan 30 – 48 mm.Koto Panjang reservoir built with dam of Batang Mahat and Kampar Kanan river. This reservoir finishing built at 1996 and location in Kampar regency province Riau. Many biodiversity species of necton that finded in this aquatic, in river stream and in reservoir. One of necton that finded in Inlet Koto Panjang reservoir is Sumatran River Sprat. This research aims are for identified and to know distributed size of Bunga Air fish. Take the fish sample during 4 months, from April until July 2010 with five location research, namely Muara Takus, Gunung Bungsu I, Gunung Bungsu II, Tanjung I and the Tanjung II. The result research show Bunga Air fish include Class Actinopterigii Order Clupeiformes Family Clupeidae Genus Clupeichthys and Species Clupeichthys goniognathus Bleeker, 1855. While for the size distributed that dominant for all of it, male fish and female fish are 30 – 47 mm and 30 – 48 mm.

In fishing activity, the success is indicated by the number of catches that extremely influenced by the conditions of fishing ground. Information of the potential fishing ground is needed for fishermen to increase the effectiveness and efficiency in fishing activity. Sea Surface Temperature (SST) and chlorophyll-a in waters are two things that can affect the potential of fishing ground. The research aims to create distribution map of SST and chlorophyll-a and to presume the potentials of fishing ground in Malacca Strait based on distribution of SST and chlorophyll-a in Malacca Strait (2015-2019). The data of SST and chlorophyll-a distribution in Malacca Strait were using Aqua MODIS satellite imagery. Based on the result of SST and chlorophyll-a analysis, potential fishing ground in Malacca Strait is expected located around East Aceh in Western season, Malaysian waters in the Transition I season, between Asahan and Malaysian waters in Eastern season and between Deli Serdang and East Aceh in the Transition II season.

The purpose of this study was to determine the morphometric and meristic characteristics, growth of Signal barb fish in the Tasik river. The method used in this research is a survey method. Morphometric characteristics of Signal barb fish Bodyweight (BW) ranges from 4-73 gr, Total Length (TL), Standard Length 6.3-15.5 mm (SL), Head Length (HL) 1.8-2.5, Snout Length (SL) 0.5, Dorsal Fin Height (DFH) 2.3, Dorsal Fin Length (DFL) 3-7, Eye Diameter (EM) 0.8, Tail Trunk Height (TTH) 0.8-1.8, Body Height (BH) 2-4.5, Pectoral Fin Length (PFL) 2 cm and Belly Fin Length (BFL) 2 cm. The meristic characteristics of Signal barb fish are the number of Linnea Literalis (LL) as many as 35-38 scale, 13 Circular Body Scales (CBS), 11-13 Front Fin Dorsal Scales (FFDS), the Scales Around the Tail (SAT) a total of 5, Dorsal Fin (DF) of DI. 23-26 fin radii, Ventral Fin (VF) of 9 fin radii, Pectoral Fin (PF) of 11-14, Anal Fin (AF) a total of 7 fin radii and a Caudal Fin (CF) a total of 20-22 fin radii. The growth pattern of signal barb fish in the Tasik River is negative allometric with the condition factor value an average value of 0.42

The research was conducted in Percut Sei Tuan Aquatic with goblinfish (Neovespicula depressifrons) as the main object. Goblinfish was caught at a brackish aquatic which is mangroves are grown. This study aimed to analyse the relationship between weight-length, growth pattern, length-frequency distribution, and condition factors of goblin fish. Danish seines with mesh size net of 1 inch, ½ inch, and ¼ inch was used for fishing. After the fish caught, then measured the total length and weighed, measurements were conducted in the laboratory. The total length of fish caught is in the range of 24-65 mm and a weight of 0.2 - 3 g. The resulting group size consisted of 7 groups with class intervals of 42-47 mm is the mode group size. From the analysis of the length-weight relationship, the constant value of b = 0.972 and the value of the condition factor ranges from 0.90 to 1.37 with an average value of CF > 1.

Tinfoil barb is one of the fish caught in the Tasik river. The purpose of this study was to determine the morphology and weight-length relationship of tinfoil barb. This research was conducted in July-August 2020 in the Tasik river using a net with a mesh size of 1.25 inches. The number of fish caught was 96 fish with a total weight (TW) of 2-47 g and a total length (TL) of 60-125 mm. Meristic characteristics of tinfoil barb consecutively are as follows: 31-33 Linnea Literalis (LL), 24-26 Body Circular Scales (BCS), 12-14 Dorsal Front Scales (DFS), 12-14 Tail Scales (TS) a total of 12 pieces, the dorsal fin formula (DF) is DI. 8-9, the ventral fin formula (VF) is V8-10, the pectoral fin formula (PF) is P12-14, the anal fin formula (AF) is AI. 5-6 and the caudal fin formula is (CF) C14. The results of the length-weight relationship indicate that the growth pattern of fish is negative allometric (b =3.221) where the weight gain is faster than the length gain.

Microgrid testbed is a prototype of a large scale microgrid system. This paper discusses a microgrid testbed simulation consisting of one synchronous generator, two induction generators, three induction motors, busbar, and load. The induction motor is used as prime mover which controlled by inverter. The operation of microgrid testbed, both in stand-alone as well as parallel operation, can affect frequency. The speed of prime mover is used to maintain the frequency of the system at 50 Hz (±1 %). The method used to control the speed of prime mover is by changing the frequency of the power source. The best stand-alone operation frequency (50 Hz) of induction generator is achieved by setting the power source frequency to 46 Hz to get the motor speed of 0.85 pu, while synchronous generator operation achieved with setting the power source frequency to 45 Hz and the motor speed of 0.9 pu. The oscillation occurred shortly when induction generator 1 and 2 connected to the system in parallel operation. This happens because the induction generator not only acts as an active power supply, but also absorbs reactive power from the system, so it affects the changes of frequency. The synchronous generator as the primary generator can reduce oscillation because it acts as both active and reactive power supply to the system, so it can stabilize the frequency.