<strong>Mangrove Community in Coastal Area of Tidore Islands.</strong> Indonesia has the most extensive area of mangrove ecosystem in the world. It bring many direct and indirect benefits for the coastal community. Research on the condition of mangrove communities in Tidore, Halmahera, Ternate Island and surrounding areas was conducted in August 2015, to determine the current condition of mangrove communities in the region. Assessment condition mangrove forest was done by means of analyze the percentage covering canopy with the hemispherical photography methods (photography toward) vertical and analyze the percentage pixels from a photograph obtained by using software image J and Microsoft Excel. The species Sonneratia alba in the Maitara, Tidore, and Kaiyasa Island West Halmahera is the most dominant.

ABSTRAK Sebaran suhu, salinitas, kekeruhan dan kecerahan di suatu perairan sangat berpengaruh pada berbagai aspek parameter lain, seperti reaksi kimia dan proses biologi. Penelitian mengenai kondisi suhu, salinitas, kekeruhan dan kecerahan air laut di perairan Tumbak-Bentenan, Minahasa Tenggara dilakukan pada bulan Pebruari 2018. Hasilnya menunjukkan suhu air berkisar antara 28,8-30,5 o C; salinitas antara 25,0-34,0 o / oo ; kekeruhan 0,21-6,31 NTU dan kecerahan 4,5-31,5 meter. Sebaran nilai suhu, salinitas, kekeruhan dan kecerahan air cukup bervariasi. Bervariasinya suhu, salinitas, kekeruhan dan kecerahan air laut di perairan ini dipengruhi oleh fakktor eksternal antara lain cuaca, angin dan arus. Kondisi suhu, salinitas, kekeruhan dan kecerahan air masih tergolong normal dan baik untuk kehidupan biota laut.

Indonesian mangrove declined significantly in the last two decades which has been considered to deliver a negative impact for adjacent communities in small islands. Mangrove quality monitoring was conducted during Nusa Manggala Expedition in 2018, which was aimed to analyze forest structure and healthiness using spatial-temporal investigation in Liki island, Papua. Field data were collected from 10m-×-10m quadratic plots which were distributed following stratified purposive sampling method. Spatial and temporal was implemented using Sentinel 2 imagery on this area from 2016 to 2021. The result of this field study had considered that mangrove in Liki island was in moderate healthiness since the MHI value was between 33.33%-66.67%. It was supported by remote sensing analysis in 2018 which showed that the moderate MHI area was dominant by approximately 42% compared to the excellent area in about 33%. Liki’s mangrove had experienced a declining trend of excellent category from 2016 and reached the lowest area of its category in 2018. In the last four-year observation, excellent areas gradually increased which was covering 57.68% of forest MHI. The dynamic of mangrove healthiness on this island tended to be delivered by natural events.

Ekosistem mangrove memiliki peranan penting bagi eksistensi dan penyediaan jasa ekosistem kepada masyarakat di pulau kecil. Fungsionalitas mangrove sangat tergantung dari ukuran, struktur komunitas dan kualitas ekosistem. Penelitian tentang penilaian kualitas struktur komunitas mangrove pulau kecil telah dilakukan di Pulau Middleburg-Miossu sebagai rangkaian dari Ekspedisi Nusa Manggala 2018. Penelitian ini bertujuan untuk menganalisis struktur komunitas dan indeks kesehatan mangrove (MHI) mangrove di pulau tersebut yang dihubungkan dengan indeks-indeks vegetasi berbasis penginderaan jauh. Lokasi penelitian dibagi menjadi empat zona, dimana hasil penelitian menunjukkan bahwa zona terdepan didominasi oleh jenis Sonneratia alba (INP 263,32%) dengan persentase tutupan kanopi < 50%, ukuran diameter > 20 cm dan ketinggian tegakan yang lebih rendah. Sementara itu, tiga zona lainnya ke arah darat, didominasi oleh jenis Ceriops tagal dengan persentase tutupan kanopi >80%, serta kerapatan pancang yang cukup tinggi. Secara keseluruhan, kondisi kesehatan mangrove di lokasi penelitian termasuk dalam kategori sedang/cukup baik dengan rentang nilai MHI 38,7-60,7%. Kombinasi indeks vegetasi NBR, GCI, SIPI dan ARVI menunjukkan nilai koefisien regresi yang paling tinggi untuk memprediksi nilai MHI, yaitu 0,831, berdasarkan analisis AIC. Interpolasi nilai MHI berdasarkan model regresi linier terbaik menunjukkan bahwa 6,56 ha mangrove di lokasi penelitian atau 40.74% termasuk dalam kategori sehat.

Large seagrass meadows in Indonesia are predicted to have a significant ability in capturing and storing carbon and are useful to mitigate global climate change. However, most of the available data are derived from short-term carbon storage of living biomass, whereas data on long-term carbon storage in the soil is still limited. This study, therefore, aims to measure soil carbon storage in mono-specific Enhalus acoroides meadows in Pari Island. A total of nine soil cores was collected in a 100×100 m2 area. The parameters were soil depth, dry bulk density (DBD), and Corg content. We applied a PVC corer with 7.4 cm in diameter and 80 cm in length to collect the soil. The length of the soil core varied between 8 and 67 cm. The mean (±SE) of soil dry bulk density is 0.98±0.04 gr/cm3 and the median is 1.1 gr/cm3, while Corg content is 2.1±0.1% soil DW (mean±SE) and 1.9% (median). E. acoroides vegetation in Pari Island stores around 63 Mg Corg/ha organic carbon in 8-67cm or 34cm (mean depth) of topsoil. Carbon storage of these mono-specific meadows is comparable to soil carbon storage in the seagrass ecosystems per hectare areas on national, regional, and global levels.