Judul: Mikrodebris pada Tripneustes gratilla (Echinodermata) dan Polycarpa aurata (Tunikata) di kepulauanSpermonde, Sulawesi Selatan
Abstrak: Microdebris in the ocean has been considerable concern and becomes a pollution for marine biota, including Echinodermata as a detritivore and Tunicates as a filter feeder. The study aims to measure microdebris contamination and to determine the different type and size of the microdebris in Tripneustes gratilla and Polycarpa aurata digestives. This research was conducted at four different islands in Spermonde including Kayangan, Barrang Lompo, Badi, and Kondong Bali. Ten individuals were collected in each island. It will takes digestives tracks, added H2O2 for destructives and NaCl for flotation. Our results that microdebris was contamined for all samples with form Fiber and Fragment. Average abundance of microdebris range 3.4 to 14.8 particle/individual. Fiber were the most common types microdebris, and 0.05-1mm mostly found in all samples. Observed microdebris with FTIR-Microscope showed that are the Cotton at T. gratilla and degradation of PE at P. aurata. The high abundance of microdebris in T. gratilla and P. aurata could negatively affect these organisms.
Keyword: Echinodermata, Tunikata, mikrodebris, polimer, spermonde

Judul: Komposisi dan Densitas Marine Debris di Pantai Pulau Tidung Besar, Kepulauan Seribu
Abstrak: Pulau Tidung Besar sebagai salah satu dari wilayah pesisir dan pulau kecil tidak terlepas dari permasalahan marine debris. Penelitian ini bertujuan mengetahui komposisi, densitas, dan keterkaitan antara jenis-jenis marine debris serta menganalisis perbedaan densitas marine debris dari tiga stasiun di Pulau Tidung Besar, Kepulauan Seribu. Hasil menunjukkan plastik merupakan jenis makro debris yang paling banyak ditemukan dengan rata-rata komposisi 89,35%. Fiber merupakan jenis mikroplastik yang paling mendominasi di antara jenis mikroplastik lainnya baik pada sedimen maupun gastropoda dengan nilai rata-rata komposisi 51,67% untuk mikroplastik pada sedimen dan 44,31% untuk mikroplastik pada gastropoda. Uji non-Metric Multidimensional Scaling menunjukkan kepadatan makro debris dari jenis plastik memiliki asosiasi dengan kelimpahan mikroplastik jenis fiber, fragment, dan pellet pada sedimen dan kelimpahan mikroplastik jenis fiber dan pellet pada gastropoda. Terdapat perbedaan densitas marine debris antar stasiun pengamatan secara statistik menggunakan Uji Kruskal-Wallis dengan stasiun pengamatan kesatu (area wisata) merupakan area dengan densitas marine debris tertinggi di Pantai Pulau Tidung Besar., Tidung Besar Island, as one of the coastal and small island areas, is not exempt from marine debris issues. This research aimed to know the composition, density, and interrelationships among various types of marine debris, and to analyze differences among three stations Tidung Besar Island, Seribu Archipelago. The results indicated that plastic is the most commonly found type of macro debris, with an average composition of 89,35%. Fiber is the predominant type of microplastic among others, observesed in sediment and gastropods, with average compositions of 51,67% and 44,31% respectively. Non-Metric Multidimensional Scaling analysis showed that the density of plastic macro debris is associated with the abundance of microplastics such as fibers, fragments, and pellets in sediment, as well as fibers and pellets in gastropods. Marine debris density showed significant difference among stations. The first observation station (tourist area) exhibited the highest marine debris density on the beaches of Tidung Besar Island.
Keyword: abundance, density, gastropods, microplastics, sedimen

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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