Mangrove forests have the potential to export carbon to adjacent ecosystems but whether mangrove-derived organic carbon (OC) would enhance the soil OC storage in seagrass meadows adjacent to mangroves is unclear. In this study we examine the potential for the contribution of mangrove OC to seagrass soils on the coast of North Sulawesi, Indonesia. We found that seagrass meadows adjacent to mangroves had significantly higher soil OC concentrations, soil OC with lower δ 13C, and lower bulk density than those at the non-mangrove adjacent meadows. Soil OC storage to 30 cm depth ranged from 3.21 to 6.82 kg C m−2, and was also significantly higher at the mangrove adjacent meadows than those non-adjacent meadows. δ13C analyses revealed that mangrove OC contributed 34 to 83% to soil OC at the mangrove adjacent meadows. The δ13C value of seagrass plants was also different between the seagrasses adjacent to mangroves and those which were not, with lower values measured at the seagrasses adjacent to mangroves. Moreover, we found significant spatial variation in both soil OC concentration and storage, with values decreasing toward sea, and the contribution of mangrove-derived carbon also reduced with distance from the forest.

Mangrove plays the importance of roles for the small island sustainability, both physically and ecologically. In the high-risk Pacific Ocean’s islands, small islands in Biak face typhoons, earthquakes, high waves, and tsunami effects. The study was conducted at 100 10mx10m-quadratic-plots scattered on seven small islands in Biak-Numfor Regency. Research objectives were to investigate the mangrove community structure of each island, i.e., canopy coverage, density, and morphological size, and to analyze the correlation among those parameters. The result found that mangrove was in pristine condition, large individual size with low anthropogenic threats. They were covered by a medium and dense canopy from 61.32±3.04% in Pasi to 93.88±0.14% in Meos Mangguandi. Substrate significantly influenced the level of canopy coverage and the MDS ordination of species composition. Sonneratia alba tended to be dominant in rocky sand in Pasi, Owi, Padaidori, and Wundi, while Ceriops and Rhizophora were mostly occupied the muddy sand, or Bruguiera gymnorrhiza has the highest domination in sandy mud substrate in Auki, Pai, and Meos. The canopy coverage had a significant correlation only with total density but none with the others. The height of the tree (up to 21.2 m) was found highly related to the diameter size (max: 124 cm).

Keberadaan mikroplastik di perairan dapat berpotensi masuk pada organisme perairan termasuk ikan. Penelitian ini bertujuan untuk mengungkap keberadaan mikroplastik pada 12 ikan terumbu karang yang ditangkap dari perairan di tiga pulau kecil dan terluar Papua (Pulau Liki, Befondi dan Miossu) dan menganalisis perbedaan mikroplastik yang ditemukan pada insang dan saluran pencernaannya. Ikan ditangkap dengan alat pancing dan dipisahkan organ insang dan saluran pencernaannya untuk dianalisis jenis mikroplastiknya. Destruksi bahan organik dilakukan dengan menggunakan larutan H2O2 30% dan identifikasi mikroplastik dilakukan menggunakan mikroskop. Diantara jenis mikroplastik, hanya jenis fiber yang ditemukan di semua spesies ikan dengan kisaran 1,60-28,30 partikel/g berat kering. Mikroplastik yang ditemukan pada ikan yang ditangkap dari Pulau Liki lebih tinggi jika dibandingkan dengan di Pulau Befondi dan Miossu. Penelitian ini menemukan bahwa ukuran ikan tidak mempengaruhi keberadaan mikroplastik pada ikan. Ikan-ikan yang ditangkap dari Pulau Liki berukuran lebih kecil jika dibandingkan dengan ikan yang ditangkap dari Pulau Befondi dan Miossu. Sebagian besar ikan yang ditemukan, mengandung fiber pada insang dan saluran pencernaan dengan ukuran yang dominan adalah >1000 µm. Kelimpahan mikroplastik jenis fiber lebih tinggi pada insang dibandingkan pada saluran pencernaan dan hal ini diduga karena perbedaan fungsi antar organ dan proses masuknya mikroplastik dari perairan ke organ-organ tersebut.

Papua shoreline has been considered as the most extensive mangrove area in Indonesia and great size of their trees. It implies that the forest could be a perfect habitat for biota food web due to its high productivity. Wondama mangrove, part of Cendrawasih National Park -West Papua, had a promising mangrove forest to be discovered. Nevertheless, the forest was rarely studied due to limited access and costly, so that the scientific data was difficult to be found scientifically. A preliminary study was carried out to identify the condition of mangrove in this area. The objectives of this study was to analyze mangrove community health and structure. Canopy coverage and vegetation structure data were collected from 107 circular plots included three plot areas (radian: 5 m, 2.5 m and 1 m) which were distributed to determine three plant classes i.e. tree, sapling and seedling, respectively. Present study showed that Wondama mangrove is a pristine mangrove community. It had large size of tree trunk diameter by 19.77± 6.55 cm averagely. Its diameter size affected on low tree density which was less than 1000 tree/ha. Those two parameters were strongly negative-correlated each other. On the other hand, community canopy was highly covered mangrove area by 82.46±6.43%. Rhizophora has mostly dominated in the forest. Mangrove regeneration in Wondama was excellent referring to density and species composition of sapling-seedling levels.

Mangrove menjadi salah satu ekosistem lahan basah yang berperan penting dalam menyerap karbon. Namun, secara alami ekosistem mangrove juga mampu mengemisikan gas rumah kaca kedalam atmosfer. Metana merupakan salah satu gas rumah kaca yang berdampak signifikan terhadap perubahan iklim. Penelitian tentang siklus metana telah dilakukan di ekosistem mangrove TAHURA Ngurah Rai Bali. Penelitian ini bertujuan untuk mengukur konsentrasi gas metana pada tiga zona ekosistem mangrove. Metode chamber tertutup digunakan dalam pengambilan sampel gas yang kemudian dianalisis dalam gas kromatografi dengan sensor flame ionization detector (FID). Karakter ekologi mangrove yang terdiri dari parameter struktur komunitas mangrove dan lingkungan diukur dari setiap plot kuadrat pengambilan sampel gas. Hasil penelitian menunjukkan konsentrasi gas metana tertinggi ditemukan pada zona darat dengan rata-rata 3,698 ± 0,986 mg. L-1. Walaupun demikian, konsentrasi gas metana pada dua zona lainnya tidak menunjukkan perbedaan yang signifikan dengan zona darat. Variabilitas konsentrasi gas metana tidak berbeda signifikan dengan kondisi struktur komunitas mangrove yang berbeda antar zona. Penelitian ini hanya menemukan variasi nilai potensial redoks (ORP) yang berhubungan signifikan dengan konsentrasi gas metana. Hasil penelitian mengindikasikan bahwa karakter ekologi mangrove yang cukup seragam di kawasan sehingga, tidak menimbulkan perbedaan yang signifikan pada konsentrasi gas metana antar zona. Namun, parameter kondisi substrat lainnya perlu dilibatkan dalam penelitian berikutnya.AbstractMangrove is one of the wetland ecosystems that play an important role in carbon sequestration and storage. However, the ecosystem also emits greenhouse gas into the atmosphere naturally. Methane has been considered as a significant effect on global warming. A preliminary study in a part of the carbon cycle was conducted on the mangrove ecosystem in Ngurah Rai Forest Park Bali. This study was aimed to determine methane gas concentration in three different mangrove zones. Gas samples were collected by closed chamber method and they were analyzed using gas chromatography embedded with the flame ionization detector (FID) sensor. Mangrove ecological parameters i.e. community structure and environmental condition were determined on each quadratic plot where gas samples were collected. The result showed that the highest methane concentration was found in the landward zone at 3,698 ± 0,986 mg. L-1. Even though, the methane concentration of the other zones had not significantly different from the landward zone. In addition, the mangrove community structure among the three zones was not different significantly. The oxidation-reduction potential was the only factor that had a significant correlation with methane concentration. Those results indicated that mangrove ecological conditions among zones were similar to each other,  hence the variation of methane concentration was not significant. Nevertheless, substrate abiotic characters need to be involved in greenhouse gas studies in the future.