The Ecological and Economic Value of Seagrass Ecosystems in Kemujan Island, Karimun Jawa National Park (TNKJ), Central Java Province, Indonesia

The seagrass ecosystem is one of the most critical ecosystems in the sea. It supports a variety of marine life, just like coral reefs and mangroves. Seagrasses are commonly found in the Atlantic and Indo-Pacific seas of tropical waters. In Indonesia, there are 60 seagrass species, and 12 of them are found in the country. The seagrass ecosystem is linked to local economic activities, which means that the livelihoods of coastal communities depend on seagrass beds. A research study examined the economic value of the seagrass ecosystem on Kemujan Island, Karimunjawa National Park (TNKJ), from March to June 2021. The method used was purposive sampling, which involved taking four observation stations. The study found seven types of seagrass on Kemujan Island, with the C. serrulata seagrass type having the highest Importance Value Index (INP) value. This indicates that the presence of this seagrass type is crucial to the condition of the seagrass community in the waters of Kemujan Island. The water quality conditions in the area meet the quality standards to support seagrass growth based on Minister of Environment Decree No. 51 of 2004. The economic value of the seagrass ecosystem on Kemujan Island was calculated to be IDR 28,261,235,060.00 per year. This value includes a direct use value of IDR 12,778,630,000.00/year (45.22%), an indirect use value of IDR 12,343,071,477.00/year (43.67%), an option value of IDR 1,672,082,583.00/year (5.92%), an existence value of IDR 189,588,000.00/year (0.67%), and bequest value of IDR 1,277,863,000.00/year (4.52%).