No abstract

Several studies have suggested Indonesia to be among the top plastic polluting countries globally. Data on the presence and amounts of plastic pollution are required to help design effective plastic reduction and mitigation strategies. Research quantifying plastic pollution in Indonesia has picked up in recent years. However, a lack of central coordination in this research has led to research output with different goals, methods, and data formats. In this study we present a meta-analysis of studies published on plastic pollution in Indonesia to uncover gaps and biases in current research, and to use these insights to suggest ways to improve future research to fill these gaps. Research gaps and biases identified include a clear preference for marine research, and a bias toward certain environmental compartments within the marine, riverine, and terrestrial systems that have easy to apply methods. Units of measurement used to express results vary greatly between studies, making it difficult to compare data effectively. Nevertheless, we identify polypropylene (PP) and polyethylene variants (PE, HDPE, LDPE) to be among the most frequently found polymers in both macro- and microplastic pollution in Indonesia, though polymer identification is lacking in a large part of the studies. Plastic research is mostly done on Java (59% of the studies). We recommend research methods used to quantify plastic pollution to be harmonized. Moreover, we recommend a shift in focus of research toward the riverine and terrestrial environments and a shift of focus of environmental compartments analyzed within these systems, an increase in spatial coverage of research across Indonesia, and lastly, a larger focus on polymer characterization. With these changes we envision future research which can aid with the design of more effective and targeted reduction and mitigation strategies.

Tujuan penelitian ini untuk mendapatkan informasi tentang nilai penting, simpanan karbon vegetasi dan estimasi nilai ekonomi simpanan karbon mangrove di Kecamatan Kema, Kabupaten Minahasa Utara, Sulawesi Utara. Pengambilan data dilakukan di tujuh stasiun dengan menggunakan metode transek kuadrat 100 m2 yang diletakkan secara vertikal terhadap garis pantai. Identifikasi spesies mangrove berdasarkan ciri-ciri morfologi akar, daun, buah dan bunga. Pengukuran DBH untuk mengetahui biomassa dan simpanan karbon sedangkan estimasi nilai ekonomi simpanan karbon menggunakan pendekatan harga dari pasar bebas dan pasar wajib Clean Development Mechanism (CDM). Sebanyak delapan species teridentifikasi yaitu Avicennia alba, Avicennia officinalis, Bruguiera gymnorhiza, Ceriops tagal, Lumnitzera littorea, Rhizophora apiculata, Rhizophora mucronata dan Sonneratia alba. Spesies R. mucronata teridentifikasi di semua stasiun. Hasil analisa struktur komunitas terlihat bahwa spesies R. mucronata dan  S. alba memiliki tingkat kerapatan relatif spesies yang lebih tinggi dibandingkan spesies yang lain. Penutupan relatif spesies (Rci) menunjukkan bahwa S. alba mendominasi spesies yang lain sebesar 62% dan R. mucronata sebesar 26,34%. Analisa INP menunjukkan S. alba dan R. mucronata memiliki peran yang penting dalam keberlangsungan ekosistem ini. Nilai rata-rata simpanan karbon di kawasan Kema sebesar 133,76±25,70 MgCha-1.  Nilai rerata estimasi ekonomi simpanan karbon yang dihasilkan adalah sebesar Rp. 6.955.123.566 (pasar bebas) atau US$ 519.310,56 dan Rp. 18.176.056.252 (CDM) atau US$ 1.357.131,6 untuk simpanan rerata karbon sebesar 23.397±4.495 MgC (85.865,72±16.496,15  Mg CO2e) pada luasan mangrove sebesar 174,92 ha. Nilai ekologis dan ekonomis yang dihasilkan dari penelitian ini, dapat dijadikan sebagai informasi awal perumusan kebijakan pengelolaan ekosistem mangrove yang lestari dan berkelanjutan.

Mangrove ecosystem provides important services for coastal communities. Unfortunately, this ecosystem has undergone physical pressures for decades, including land conversion for shrimp aquaculture. Rehabilitation of the degraded mangroves offers an effective solution for bringing back mangrove functions, including carbon sequestration capacity. This study aims to quantify carbon stock (CS) and sequestration rate of a rehabilitated mangrove ecosystem in Indonesia, particularly in Banten Province. We compared sediment CS and carbon accumulation rate (CAR) of a rehabilitated mangrove in Ciseukeut, Panimbang, with a natural mangrove in Cilintang, the Ujung Kulon National Park. The sediment CS to a depth of 1 m in a rehabilitated mangrove in Ciseukeut was higher than in a natural mangrove in Cilintang, constituting 364 Mg C ha À1 and 126 Mg C ha À1 , respectively. However, CAR showed the opposite pattern, in which a natural mangrove showed an almost two-fold higher rate (0.50 ± 0.42 Mg C ha À1 year À1 ) than that of a rehabilitated mangrove (0.27 ± 0.20 Mg C ha À1 year À1 ). Local hydrogeomorphological conditions play a role in affecting sediment CS and CAR in both sites. Enhancing hydrological modification can promote CAR, especially in an abandoned pond like in Ciseukeut. This study provided a knowledge base for suitable mangrove rehabilitation in the future that supports the Indonesian government's commitment to rehabilitating ca. 600,000 ha of degraded mangroves in Indonesia. Furthermore, the study also provides the first investigation of potential blue carbon for the world's natural heritage of the Ujung Kulon National Park.

Sampah plastic merupakan ancaman bagi keberlanjutan sumber daya alam hayati saat ini. Berbagai upaya telah dilakukan oleh Pemerintah daerah baik pusat dan daerah dalam mengelola sampah ini. Salah satunya adalah Pemerinntah Provinsi DKI Jakarta yang memiliki cakupan wilayah dari darat hingga Periaran kepulauan Seribu. Sampah plastic dapat berimplikasi terhadap ekosistem di pesisir DKI Jakarta, salah satunya adalah menutup tunas-tunas mangrove saat air surut, sehingga apabila berlanjut dapat menghambat pertumbuhan mangrove.