KARAKTERISTIK DAN KESESUAIAN PERAIRAN UNTUK BUDIDAYA RUMPUT LAUT DI KABUPATEN KEPULAUAN SANGIHE, SULAWESI UTARA

Kabupaten Kepulauan Sangihe dengantiga pulau terdepannya memiliki potensi untuk pengembangan budidaya rumput laut (Kappaphycus alvarezii), namun belum tersedia data kondisi perairannya.  Kajian bertujuan untuk mengetahui karakteristik, kesesuaian, dan daya dukung perairan untuk budidaya rumput laut di kawasan pesisir Kabupaten Kepulauan Sangihe.  Data  kondisi perairan yang dikumpulkan berupa lingkungan fisik dan kualitas air.  Analisis dengan weighted linear combinationdalam SIG dilakukan untuk penentuan kesesuaian perairan danbesarnya kapasitas perairan digunakan untuk penentuan daya dukung perairan. Hasil kajian menunjukkan bahwa, karakteristik perairan Kabupaten Kepulauan Sangihe dapat mendukung usaha budidaya rumput laut, namun kedalaman perairan yang relatif dangkal dan adanya alur pelayaran yang menjadi faktor pembatas dalam kesesuaian lahan untuk budidaya rumput laut. Dari 4.839,36 ha kawasan pesisir yang dikaji di Teluk Talengen (Kecamatan Tabukan Tengah), Teluk Manalu (Kecamatan Tabukan Selatan), dan Teluk Dagho dan sekitarnya (Kecamatan Tamako dan Manganitu Selatan) dijumpai kawasan pesisir seluas 181,80 ha yang tergolong sangat sesuai; 852,82 ha yang tergolong cukup sesuai; 3.633,75 ha yang tergolong kurang sesuai; dan 179,99 ha yang tergolong tidak sesuai untuk budidaya rumput laut metoda tali panjang.  Budidaya rumput laut metoda tali panjang di Kabupaten Kepulauan Sangihe dapat dilakukan di Teluk Talengen, Teluk Manalu, dan Teluk Dagho dan sekitarnya  dengan pengembangan kawasan maksimal masing-masing seluas 324; 559; dan 1.171 ha yang dapat digunakan untuk masing-masing 1.296, 2.236, dan 4.684 unit rakit budidaya rumput laut berukuran 50 x 50 m.  Sangihe Archipelago Regency with its three outlying islands has the potential for seaweed farming development (Kappaphycus alvarezii), regrettably reliable water quality data are scarcely available in this region. The study was aimed to determine the characteristics, suitability, and carrying capacity of waters for seaweed farming in the coastal areas of Sangihe Archipelago Regency. The observed environmental quality of coastal waters included physical environment and water quality. A weighted linear combination  in a GIS environment method was applied to determine the suitability of waters and the capacity of coastal water to accommodate the maximum surface area of the farm was used to determine the carrying capacity of waters. The results of the study indicated that the characteristics of waters in Sangihe Archipelago Regency provide suitable environment for seaweed culture, however the relatively shallow waters and the existence of the shipping lanes in the study region can become major limiting factors for seaweed culture and development. Of 4,839.36 hectares of the coastal areas studied in Talengen Bay (Tabukan Tengah Subdistrict), Manalu Bay (South Tabukan Subdistrict), and Dagho Bay and surrounding areas (Tamako and Manganitu Selatan Subdistricts), a total of 181.80 ha were classified as very suitable; 852.82 ha were moderately suitable; 3,633.75 ha were less suitable; and 179.99 ha were not suitable for seaweed long-line culture method. Further analysis showed that seaweed culture of long-line method can be effectively practiced in Talengen Bay, Manalu Bay, and Dagho Bay and surrounding areas with the maximum development areas of 324, 559, and 1,171 ha respectively of which can be used for allocating 1,296, 2,236, and 4,684 culture raft units respectively, with the size of 50 x 50 m per unit.