Judul: Tangkapan Maksimum Lestari Ikan Kembung Lelaki (Rastrelliger kanagurta Cuvier, 1816) di Perairan Utara Jawa (WPPNRI 712)
Abstrak: WPP 712 merupakan wilayah dengan potensi sumberdaya ikan pelagis kecil yang tinggi. Ikan kembung lelaki (Rastrelliger kanagurta) merupakan ikan pelagis kecil yang bernilai ekonomis penting dan banyak ditangkap di perairan WPP 712 sehingga dikhawatirkan dapat menyebabkan overfishing. Penelitian ini bertujuan menentukan jumlah tangkapan maksimum lestari (MSY), upaya penangkapan maksimum lestari (fMSY), dan jumlah tangkapan yang diperbolehkan (TAC) untuk ikan kembung lelaki (R. kanagurta) di perairan Utara Jawa (WPPNRI 712). Penelitian ini menggunakan data sekunder yang diperoleh dari data e-logbook penangkapan ikan tahun 2018–2022 dalam aplikasi database Sistem Informasi Logbook Penangkapan Ikan (SILOPI). Model produksi surplus menggunakan model Schaefer menunjukkan nilai MSY dan fMSY ikan kembung lelaki masing-masing sebesar 147,66 ton/tahun dan 478,89 trip/tahun dengan jumlah tangkapan yang diperbolehkan (TAC) sebesar 118,12 ton/tahun. Hasil tangkapan dan upaya penangkapan aktual lebih kecil dari nilai MSY dan fMSY yang mengindikasikan bahwa ikan kembung lelaki di WPP 712 dalam kondisi underfishing., FMA 712 is an area with a high potential for small pelagic fish resources. The Indian mackerel (Rastrelliger kanagurta) is a small pelagic fish species of significant economic value and is widely caught in the waters of FMA 712, raising concerns about overfishing. This study aims to determine the maximum sustainable yield (MSY), maximum sustainable fishing effort (fMSY), and total allowable catch of Indian mackerel (R. kanagurta) in Northern Java Waters (FMA 712). This study uses secondary data obtained from e-logbook records of fish catches from 2018–2022 within the database application known as the Fisheries Logbook Information System (SILOPI). The surplus production model, using the Schaefer model, indicates that the MSY and fMSY for Indian mackerel are 147,66 tons/year and 478,89 trips/year, with a total allowable catch (TAC) of 118,12 tons/year. The actual catch and fishing effort is lower than MSY and fMSY indicating that Indian mackerel resources in FMA 712 are in an underfishing condition.
Keyword: CPUE, surplus production model, sustainable potential, total allowable catch

Judul: Spatial Temporal Distribution of Female  Short Mackerel (Rastrelliger brachysoma, Bleeker, 1851) in WPP 712 Based on e Logbook
Abstrak: Ikan kembung perempuan (Rastrelliger branhyosoma) merupakan salah satu jenis ikan ekonomis penting yang umum ditangkap di Wilayah Pengelolaan Perikanan Republik Indonesia (WPPNRI) 712. Penelitian ini berfokus pada wilayah WPP 712 dengan menggunakan data sekunder yang diperoleh dari e-logbook Sistem Informasi Logbook Penangkapan Ikan (SILOPI) Kementerian Kelautan dan Perikanan Republik Indonesia. Penangkapan ikan kembung yang dilakukan nelayan menggunakan 12 jenis alat tangkap dengan alat tangkap dominan yang digunakan adalah pukat cincin. Catch per unit effort (CPUE) ikan kembung perempuan di WPP 712 selama 5 tahun terakhir memiliki nilai yang fluktuatif dan cenderung menurun. Analisis model produksi surplus (MPS) yang dilakukan dengan 5 macam model menujukan model Clarke Yhosimoto Pooley dengan koefisien determinasi (R2) sebesar 81,55% sebagai model yang paling menggambarkan kondisi sesungguhnya. Status stok ikan kembung perempuan dalam kurun waktu 5 tahun terakhir tergolong underfishing. Distribusi daerah penangkapan secara spasial dan temporal selalu mengalami perubahan dengan dominasi lokasi penangkapan berada di bagian utara pekalongan., The female Indian mackerel (Rastrelliger branhyosoma) is one of the economically important fish species commonly caught in the Republic of Indonesia Fisheries Management Area (WPPNRI) 712. This study focuses on the WPP 712 area using secondary data obtained from the e-logbook of the Fishing Logbook Information System (SILOPI) of the Ministry of Maritime Affairs and Fisheries of the Republic of Indonesia. Mackerel fishing by fishermen uses 12 types of fishing gear with the dominant gear used is purse seine. Catch per unit effort (CPUE) of female mackerel in WPP 712 for the last 5 years has a fluctuating value and tends to decrease. Analysis of the production surplus model (MPS) conducted with 5 different models showed the Clarke Yhosimoto Pooley model with a coefficient of determination (R2) of 81.55% as the model that best describes the real conditions. The stock status of female mackerel in the last 5 years is classified as underfishing. The spatial and temporal distribution of fishing areas always changes with the dominance of fishing locations in the northern part of Pekalongan.
Keyword: fishing grounds, fishing gear, stock status, female mackerel, WPP 712

Judul: Sintesis BaTiO3 dari BaCl2 dan TiCl4 dengan Metode Hidrotermal
Abstrak: Increasing technology has lead to proliferating electronic equipments. One component of electronic equipment is capacitor, which can be made of barium titanate (BaTiO3). This study aims to synthesize and to characterize BaTiO3 from a mixture of BaCl2 and TiCl4 by observing changes in temperature and the stage of the reaction. This study was carried out in several stages, i.e synthesis of BaTiO3 by hydrothermal method, changes in the reaction steps, changes in pH, compared the results by nonhydrothermal method and characterization by X-ray diffraction (XRD). Based on XRD results, synthesis of BaTiO3, using the method of hydrothermal (T = 120-150 °C), changes in the reaction steps, also in pH, had not been able to produced pure BaTiO3. It can be seen from low intensity of BaTiO3 and presence of other impurities in the form of TiO2 as can be found in all methods including non-hydrothermal method (T = 600 °C).
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