Heavy metal is one source of pollution from industrial waste. The presence of heavy metals can cause health problems and environmental problems. This research was conducted to determine the ability of floating plant islands to absorb heavy metals. This floating plant island consists of 3 different types of aquatic plants namely Hydrilla verticilata, Limnocharis flava and Echinodorus palifolius. The heavy metals measured were Pb, Cr, Cd, Zn, Cu and Fe. Measurement of heavy metals is carried out at 15 and 30 days interval. The results showed that the highest rate of absorption of heavy metals was Fe. In Hydrilla verticilata the absorption rate is 17,39 μg / g per day, Limnocharis flava is 2.22 mg / kg per day and Echinodorus palifolius is 2.63 mg / kg per day.

Riau Province has the Koto Panjang reservoir which is generated from the damming of the Kampar River flow for hydroelectric power generation and other utilization activities. The increase in community activities in reservoir waters and on land causes water quality dynamics that can affect fish farming activities. The purpose of this study was to determine the dynamics of reservoir water quality. The survey was conducted in March – August 2021 at seven sampling points, where water samples at each sampling point were taken at a depth of 1 m as much as 1 liter using a van dorn water sampler and preserved and analyzed according to standard methods. Data from measurement and analysis were tabulated and analyzed descriptively including temperature, pH, turbidity, TSS, TDS, DO, nitrate, ammonia, total nitrogen, BOD5, COD, and total phosphate. The results obtained indicate that the values of temperature, turbidity, TDS, TSS, pH, DO, ammonia, nitrate, and phosphate are still below the quality standard, except in the range of BOD values of 4.30 – 5.75 mg/L and COD of 17.90. – 23.73 mg/L is an indication of organic matter originating from other activities on the reservoir land, such as plantations, agriculture, settlements, tourism, apart from floating net cage cultivation activities.

Seaweed is a significant economic product that should be promoted. A transparent trading system, which is intended to support the growth and development of seaweed production on a greater scale, is one of the main criteria for providing stronger value to cultivators. This is a benefit that the Indonesian people, in general, can take advantage of to their fullest potential. In June 2021, a survey will be conducted in Alor Regency, Nusa Tenggara Timur Province, to map market potential and market chains. Seaweed farmers and traders interested in seaweed marketing made up the study’s population. The sampling method used the snowball sampling method, namely the first level sampling, in this case, was seaweed farmers determined by simple random sampling, while the next sample, in this case, was traders determined by farmers where farmer s who had selected are identified (excavated data). The goal of doing a market chain research and business strategy for seaweed commodities is to have a more complete picture of the potential, obstacles, and restrictions of developing seaweed production in the Alor Regency. Based on observations and interviews with farmers, it appears that the seaweed marketing chain begins with producers as seaweed farmers, followed by middleman traders (village collectors), i. e. traders who buy directly from village farmers. Also, there are inter-island collectors/collectors (PAP), who are traders who purchase seaweed from middlemen/seaweed collector traders and also farmers, most of whom are based in Alor, the sub-district capital. Collector traders have a great deal of money, so they can keep seaweed temporarily as they wait for a reasonable price or a better price.

Mangrove ecosystems naturally function as trap of waste produced from anthropogenic activities including marine debris. This study aims to analyze marine debris and density of mangrove forests in the Purnama Village. The survey research method was carried out in two stations: Station I (Estuary of Sungai Masjid) and Station II (coastal waters of the Unri Marine Station), which was held from April to July 2021. Marine debris was collected in five plots in a quadrant transect measuring 100 x 50 meter. Identification results of mangrove species in Station I found 3 species of mangrove (Xylocarpus granatum, Rhizophora apiculata and Bruguiera gymnorriza), while at Station II found 3 species of mangroves (Rhizophora apiculata, Xylocarpus granatum and Avecennia alba). This research results obtained the release of marine debris at Station II is more than that of Station I. While in Station II there are 172 items (marine debris density of 0.172 item/m2), weight of marine debris 12.665 grams/m2 and mangrove density 2222 individu/ha (category very close). At Station I there are 35 items (the density of marine debris is 0.035 item/m2), the total weight of marine debris is 3.194 grams/m2 and the density of mangroves is 1678 individu/ha (category very close).

Hutan mangrove merupakan salah satu ekosistem pesisir yang berperan penting dalam mendukung kehidupan biota laut. Keberadaan hutan mangrove di Kabupaten Kepulauan Meranti saat ini terus mengalami degradasi yang berimplikasi terhadap menurunnya fungsi ekologis, sosial dan ekonomi masyarakat lokal. Upaya meminimalisir kerusakan hutan mangrove terus dilakukan oleh pemerintah daerah dan masyarakat lokal hingga saat ini. Salah satu upaya yang dapat dilakukan melalui budidaya kepiting bakau dengan sistem sylvofishery. Metode penelitian yang digunakan adalah eksperimen dan wawancara yang dilakukan di Kelurahan Teluk Belitung dan Desa Bandul Kabupaten Meranti. Data dan informasi dihimpun dari penelusuran, dan penelahaan data dan informasi hasil penelitian serta laporan kegiatan yang terkait dengan budidaya kepiting bakau dengan sistem silvofishery. Hasil kajian menunjukkan potensi pengembangan budidaya laut di Kabupaten Kepulauan Meranti tersebar di beberapa pulau seperti Pulau Padang, Tebing Tinggi dan Pulau Rangsang dengan luas lahan sebesar 438 ha. Luasnya lokasi budidaya didukung pula dengan kualitas perairan yang cukup bagus dan cocok untuk dikembangkan budidaya kepiting dengan sistem sylvofishery. Ujicoba penerapan sylvofishery kepiting bakau model kurungan tancap diperoleh tingkat survival rate mencapai 70 % dan pertumbuhan rata-rata berkisar 100 – 140 g per bulan. Pemeliharaan kepiting bakau dengan sistem sylvofishery selama 3 bulan dapat memberikan keuntungan dan tambahan penghasilan per bulan sebesar Rp. 1.070.150. Dalam satu siklus pembesaran jika kondisi normal dapat mengembalikan investasinya sehingga sylvofishery kepiting bakau layak dijadi usaha alternatif bagi masyarakat pesisir.Mangrove forest is one of the coastal ecosystems were plays a role in supporting marine life. Existence of mangrove forests in the Meranti Kepulauan district is experiencing degradation which has implications for the decline to ecological, social and economic functions of the local community. The efforts for minimize damage of mangrove forests have been carried out by local governments and local communities. One of the effort could be done through the cultivation of mud crabs with sylvofishery system. Experiment method was applied and interview was done in Teluk Belitung and Bandul villages, Meranti Regency. Data and information were collected and had been analyzed and activities reported that related to mud crab culture using the silvofishery system. The resut of the study showed that potential development of marine culture in the Kepulauan Meranti district is spread across several islands such as Padang Island, Tebing Tinggi and Pulau Rangsang with an area of 438 ha. The extent of the aquaculture site is also supported by good waters quality and suitable for developing mud crab culture with the sylvofishery system. The trial application of the mud crab silvofishery model of fixed confinement obtained a survival rate of up to 70% and an average growth of around 100-140 g per month. Maintenance of mangrove crabs with the sylvofishery system for 3 months can provide benefits and additional income per month of IDR. 1,070,150. In one cycle of enlargement if normal conditions, it’s can return the investment so the mangrove crab sylvofishery deserves to be an alternative effort for coastal communities.