Judul: Analysis of the Fishing System for Hairtail Fish (Trichiurus sp.) at the Cikidang Fish Landing Base, Pangandaran Regency
Abstrak: Penurunan sumberdaya ikan layur di perairan Pangandaran dikhawatirkan akan berdampak kepada kegiatan perikanan layur di Pangkalan Pendaratan Ikan Cikidang, Namun informasi mengenai kegiatan perikanan layur masih belum banyak dikaji secara ilmiah. Penelitian ini bertujuan untuk mengetahui kondisi perikanan layur saat ini, menganalisis faktor-faktor penurunan hasil tangkapan layur, menyusun strategi pengembangan perikanan layur di kawasan Pangkalan Pendaratan Ikan Cikidang, Kabupaten Pangandaran. Metode pengumpulan data yang digunakan adalah pengumpulan data statistik dan wawancara dengan teknik purposive sampling. Analisis data yang digunakan berupa analisis deskriptif, pendekatan sistem, dan SWOT. Hasil penelitian menunjukan bahwa nelayan menggunakan gillnet dan pancing ulur dengan kapal berukuran ≤ 5 GT untuk menangkap ikan layur. Mesh size badan pada gillnet yang digunakan berukuran 0,5 – 1 inci, The decline in hairtail fish (Trichiurus sp.) resources in Pangandaran waters is feared to have an impact on hairtail fish activities at the Cikidang Fish Landing Base, but information about hairtail fish activities is still not widely studied scientifically. This study aims to determine the current condition of hairtail fish, analyze the factors of decreasing hairtail fish catches, develop strategies for the development of hairtail fish in at the Cikidang Fish Landing Base area, Pangandaran Regency. The data collection method used is statistical data collection and interviews with purposive sampling techniques. Data analysis used in the form of descriptive analysis, system approach, and SWOT. The results showed that fishermen used gillnets and hand lines with vessels measuring ≤ 5 GT to catch hairtail fish. The body mesh size of the gillnet used is 0.5 – 1 inch
Keyword: Analisis, sistem, perikanan layur

Judul: Fishing Season and Allowable Catch Size of Hairtail Fish (Trichiurus sp.) in Cikidang Fishing Port
Abstrak: Ikan layur (Trichiurus sp.) merupakan ikan demersal ekonomis penting yang sering dimanfaatkan untuk tujuan ekspor. Tingginya permintaan ekspor menyebabkan meningkatnya upaya penangkapan. Sifat ikan layur yang mempunyai ruaya rendah serta kecenderungan menetap, sehingga memiliki daya tahan yang rendah terhadap tekanan penangkapan. Produksi ikan layur di PPI Cikidang mengalami penurunan sebesar 27.846 kg tahun 2020 menjadi 21.925 kg tahun 2021. Penentuan pola musim penangkapan dan menentukan ukuran ikan layak tangkap dengan mengestimasi ukuran ikan pertama kali matang gonad (length at first maturity) penting dalam upaya penangkapan yang lebih efektif dan berkelanjutan. Hasil penelitian menunjukan bahwa 82% ikan layur di lokasi studi layak tangkap, yakni dengan length at first maturity (Lm) sebesar 50,6 cm. Catch Per Unit Effort (CPUE) tertinggi dari alat tangkap drift gillnet tahun 2017-2021 terjadi pada tahun 2018 dengan musim puncak penangkapan ikan layur terjadi selama 6 bulan yaitu pada musim timur (Juli, Agustus, dan September) musim peralihan (Oktober, dan November) dan musim barat (Desember)., The hairtail fish (Trichiurus sp.) is an economically important demersal fish targeted for the export market. The high demand for exports has led to an increase in fishing efforts. The hairtail fish is a demersal fish with behaviour of low fecundity and is relatively sedentary, resulting in being subject to fishing pressure. The hairtail fish landing in PPI Cikidang tend to decline from 27,846 kg in 2020 to 21,925 kg in 2021. Determining the seasonal fishing pattern and establishing the allowable capture size of the fish by estimating the length at first maturity (Lm) is biologically important to as basic information in achieving more effective and sustainable fishing management. The research results showed that 82% of the hairtail fish sample from the study location exceeded the Lm, and biologically allowable to sustainable catch, with a length at first maturity (Lm) of 50.6 cm. The highest Catch Per Unit Effort (CPUE) from drift gillnet fishing gear from the year 2017 to 2021 was recorded in the year 2018, with the peak fishing season for the fish occurring for six months, specifically during the eastern season (July, August, and September), the transitional season (October and November), and the western season (December).
Keyword: drift gillnet, allowable catch size, hairtail fish, seasonal fishing patterns, trichiurus sp., ikan layur

Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology