The mangroves' aboveground biomass significantly contributes to the global carbon cycle or economic and ecological values. This makes knowledge about the spatial extent of the mangroves indispensable for policymakers. The sequence of mangroves’ condition range also requires remote sensing data to update the geographical information and synthesize carbon stock in Bengkulu. Therefore, this study aims to create a spatial distrribution of mangroves and evaluate their carbon stock in Bengkulu City using Sentinel-2 imagery. The semi-empirical method uses Sentinel-2 imagery through NDVI to appraise and picture the mangroves' aboveground carbon stock. An allometric equation was used to compute the mangroves' aboveground carbon stock from field measurements. Non-linear regression was used to establish a connection between the NDVI calculated from the Sentinel-2 imagery and the mangroves' aboveground biomass measured in the field, which was subsequently used for aboveground carbon estimation. The results showed that mangroves mapping could derive overall accuracy of 89.09%, where the high-density class existed in 135.12 Ha of total area. It was also discovered that Sentinel-2 imagery could estimate mangroves carbon stock up to 61%. The carbon stock estimation based on the imagery has a value of 16.3992 – 115.134 t C/ha, while that of field survey data ranges from 19.69 to 326.06 t C/ha. These results showed that Sentinel-2B spectral data is functional and has a good chance of being able to predict carbon stock.   Keywords : Carbon; mangroves; NDVI; remote sensing; sentinel-2B   Copyright (c) 2022 Geosfera Indonesia and Department of Geography Education, University of Jember This work is licensed under a Creative Commons Attribution-Share A like 4.0 International License

Kota Sibolga merupakan salah satu kota yang berada di Provinsi Sumatera Utara. Kota ini terletak di Pantai Barat Sumatera yang berhadapan langsung dengan Samudera Hindia dan merupakan daerah penangkapan ikan (Fishing Ground) bagi nelayan di Sibolga. Tujuan dari penelitian ini untuk mengetahui hasil tangkapan dan menentukan potensi Maksimum Lestari (MSY) Ikan Tongkol pada alat tangkap Purse Seine di pelabuhan perikanan Sibolga. Berdasarkan produksi tertinggi yang mengunakan alat tangkap purse seine yaitu sebesar 134.016 kg sedangkan jumlah produksi terendah 27.456 kg pada kurun waktu satu bulan penelitian yang digunakan adalah metode Deskriptif. Ruang lingkup yaitu Pelabuhan perikanan Sibolga dan analisis data. Hasil produksi sumberdaya Ikan Tongkol dengan alat tangkap purse seine di peroleh melalui data dari pelabuhan perikanaan nusantara Sibolga. Berdasarkan produksi tertinggi yang mengunakan alat tangkap purse seinse yaitu sebesar 134.016 kg Ikan Tongkol Krai (Auxis thazard) sedangkan jumlah produksi terendah 27.456 kg Ikan Tongkol Komo (Euthynnus affinis) pada kurun waktu satu bulan.

Moluska memiliki cara unik dalam mempertahankan dirinya pada daerah intertidal, selain itu moluska di daerah ini memiliki keanekaragaman yang berbeda dibandingkan zona lainnya. Oleh karena itu, perlu kajian mendalam terkait keanekaragaman dan cara adaptasi moluska pada daerah tersebut. Tujuan dari penelitian ini adalah untuk mengetahui jenis dan keanekaragaman moluska, cara adaptasi moluska pada gelombang tinggi, potensi ekonomis moluska, serta menentukan klaster komunitas moluska di Pantai Pamengpeuk, Jawa Barat. Penelitian ini berlokasi di Pantai Bubujung, Pantai Karang Paranje, Pantai Santolo Indah, Pantai Karang Papak, Pantai Taman Manalusu, Pantai Cicalobak, Pantai Karang Wangi, Pantai Ranca Buaya 2 dan Pantai Ranca Buaya 1 dengan menggunakan metode purposive sampling. Hasil pengamatan ditemukan 37 spesies moluska yang terdiri dari 33 jenis gastropoda dan 4 jenis bivalvia. Moluska di daerah ini beradaptasi dengan cara bersembunyi pada bebatuan dan mencari daerah yang lembab untuk mempertahankan kadar air di dalam tubuhnya. Famili dengan jumlah individu dan penyebaran tertinggi adalah Nodilittorina, Trochoides, dan Littorinidae. Indeks keanekaragaman (H') moluska tertinggi yaitu Pantai Ranca Buaya 1 dengan indeks keanekaragaman 2,8, sedangkan indeks kemerataan tertinggi (e) yaitu Pantai Parenje (0,92). Moluska yang berpotensi ekonomis untuk dikembangkan di Pantai Pamengpeuk, Garut Selatan antara lain Planaxis sulcata, Nerita polita, Nerita picea, Cerithium eburneum, dan Turbo setosus. Pantai Pemengpeuk memiliki tingkat keanekaragaman yang tinggi sehingga berpotensi untuk dikembangkan dalam rangka meningkatkan kelestarian dan perekonomian masyarakat di wilayah tersebut.

Coral reefs are one of the important ecosystems that need data inventory in order to manage marine resources both spatially and temporally. Remote sensing with drone technology is one of the vehicles for collecting data related to coral reef ecosystems in real time. Along with the times, drones are widely used in research both in terrestrial and in coastal areas. This research was conducted on December 4 – 10, 2018 in the Karang Lebar, Seribu Islands, Jakarta. The purpose of this research was to explored the ability of drones as a vehicle to complement field survey data for coral reef mapping. In addition, conducting a pixel-based analysis for coral reef classification based on WorldView-2 satellite imagery using field survey data and additional data from drone data. Based on the results of the study, information was obtained that drone imagery can help visual interpretation in detecting coral reefs. Thus, field survey data that are not covered in the research area can be assisted by the use of drones as a complementary vehicle for field survey data. The coral reef classification process using WorldView-2 imagery can be mapped well. Drone imagery has proven to be an alternative in field data collection as a training area in identifying coral reef objects, such as with massive coral lifeforms that can be clearly seen from drone images. It's just that visual interpretation is limited because of the water column, making it difficult to identify objects.

This research was carried out in September 2022 at Muara Jenggalu, Bengkulu City. The mangrove vegetation in Muara Jenggalu, Bengkulu City consists of 8 (eight) true mangrove species : Avicennia alba, Avicennia marina, Bruguiera gymnorrhiza,Lumnitzera littorea, Rhizophora apiculata, Sonneratia alba, Sonneratia caseolaris and Xylocarpus granatum. Associated mangrove species consist of 3 (three) species, namely Nypa Fruticans, Hibiscus tiliaceus L, and Pandanus tectorius.The most common types of mangroves found in the Jenggalu Estuary, Bengkulu City, are Rhizophora apiculata and Sonneratia alba. The density of mangrove species in Muara Jenggalu, Bengkulu City, is categorized as rare, with a density value of mangrove species ≤ 1,000 ind/ha. Coverage of mangrove species in Muara Jenggalu is 69.59-86.27%. The lowest type of closure is 0.18-49.68%. The type of mangrove with the highest IVI in Muara Jenggalu, namely Sonneratia alba, plays an important role in the mangrove area of Muara Jenggalu with an IVI range of ≥ 121.55-163.28. The dominance index ranged from 0.45-0.78, and the diversity index (H') ranged from 0.34-0.93.