Judul: Sumberdaya Ikan Karang pada Berbagai Kondisi Kerapatan Lamun di Perairan Pulau Pasi Kabupaten Kepulauan Selayar Provinsi Sulawesi Selatan
Abstrak: Seagrasses are marine angiosperms, distributed in both tropical and temperate coastal waters creating one of the most productive aquatic ecosystems on earth. Due to the high primary production and a complex habitat structure, meadows formed by seagrasses support a variety of benthic, demersal and pelagic organisms. Many fish species are attracted to seagrass habitats for foraging and shelter, especially during their juvenile life stages. Thus, seagrass meadows are valuable resources for fisheries at both local and regional scales. The study presented the community structure, size distribution, species composition and spatial distribution of reef fish in seagrass habitats at Pasi Island waters. Sampling of fish was conducted in daylight and night using a small trawl. The total abundance and biomass of the reef fish in this research was 431 individual (13129 gram). Out of 55 different reef fish species from 24 families were recorded during the study, only one species accounted for more than 25% of the total abundance and biomass is Siganus canaliculatus. The study showed that the diversity and dominant indices of fish were generally significantly higher at station V with sand and reef fraction substrate dominated by Thalassodendron ciliatum and Cymodocea serrulata. Seagrass species with high density and percent cover value as Syringodium isoetifolium, Cymodocea serrulata and Thalassodendron ciliatum has a high fish diversity value. Seagrass species that has large and long leaves such as Thalassia hemprichii and Enhalus acoroides favored by reef fish planteater (herbivore) i.e. Siganus canaliculatus (Siganidae), Apogon melas (Apogonidae) and Scarus forsteni (Scaridae).
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Judul: Design for sustainable management of seagrass ecosystems for supporting fisheries in the Spermonde Archipelago, South Sulawesi
Abstrak: Seagrasses have been well known as important habitat for various fauna, including numbers of economic important fishes, especially in the nursery stage. Therefore, seagrass ecosystems management is an important part of managing the marine fisheries. Spermonde Archipelago, a hotspot of coral and seagrass, consist of ± 120 small islands and have dense population (most of them depends on subsistence and small scale fisheries), especially in the south east of the archipelago implements an increased pressure to the seagrass ecosystems. The pressure to the ecosystems will affect the fisheries productivity. By knowing the sustainability status of the seagrass ecosystems, it will facilitate an assessment of the effectiveness of fisheries management and it will provide a valuable information to policy makers about the best policy option for the sustainability management of seagrass ecosystems in the future. Based on that, the main goal of this study was to determine the sustainability status of seagrass ecosystems in Barrang Lompo Island (BL) and Kapoposang Island (KP) for supporting fisheries. In order to achieve the main goal, there are three specific objectives were performed, namely 1). to analyze fish community structure in the seagrass beds, 2). to analyze the fishing activities and their status in the seagrass beds, 3). to design the sustainable management of seagrass ecosystems. Fish community structure was analyzed using non-metric multidimensional scaling technique and Bray-Curtis cluster analysis, while the most contributed species to difference of fish community structure was analyzed using SIMPER (similarity of percentages) procedure. All statistics analysis were carried out using PRIMER v6 software. The difference between fish distribution in both seagrass beds was analyzed with t-test and Bonferroni post-test using PRISM v5 software. Fishing activities were analyzed through fisher recognition based on the latest census data from village office and by interviews, observation of fisher’s behaviour during fishing in the seagrass beds, classification of their catches, analysis of maturity size of their catches based on life stage classification using fish maximum length. Status of fishing in the seagrass beds were determined based on FAO-like exploitation status scale and analyzed through measurement of catch per unit effort (CPUE), total catch in one year (Y), natural mortality as weight-dependence of mortality (Mw), estimated biomass in the same year (B), and maximum sustainable yield (MSY). RAPSECS (rapid appraisal technique for evaluating seagrass ecosystems sustainability) analysis using multidimensional scaling (MDS) was applied to analyze the sustainability status of seagrass ecosystems for each dimension (ecology, economic, social, technology, institution). A combination of pairwase comparison and geomean was used to determine the general sustainability status of each seagrass fisheries. Leverage analysis was applied to identify the most influence attributes to the sustainability status of each dimension. Strategy intervention was formulated based on the most influence attributes within each dimension. The results of non-metric multidimensional scaling technique and Bray- Curtis cluster analysis revealed that overall, there were significant differences of fish community structure and distribution pattern in the seagrass beds dominated by Thalassia hemprichii (TH) and Enhalus acoroides (EA). Fish abundance was higher in TH- than in EA-dominated beds, but fish biomass and species richness were lower in
Keyword: management strategy, sustainability, seagrass ecosystems, fishing, Spermonde Archipelago, RAPSECS, Thalassia hemprichii, Enhalus acoroides

Judul: Dynamical System of Hepatitis B in Three Groups with Vaccination
Abstrak: The aim of this study is to modify the hepatitis B transmission model in three age groups involving vaccination from the model conducted by Zhoe and Zhang.The method used is to analyze the stability of the fixed point and its basic reproduction number (R_0). Performed stability analysis and numerical simulation to see population dynamics. Next, a sensitivity analysis of the parameters was carried out to see its effect on R_0. From the analysis obtained two fixed points, namely non-endemic and endemic fixed points. Non-endemic fixed points are locally asymptotically stable if R_0 <1 Meanwhile, the endemic fixed point is locally asymptotically stable if R_0 > 1. Hepatitis vaccination affects the number of susceptible population, because the more successful the vaccination, the smaller the number of susceptible populations so that the smaller the population will be infected.
Keyword: Dynamic, Hepatitis B, Vaccine, Mathematical model