Physical, chemical, and biological aspects of "Kolong-kolong" (tin mining pools) in Bangka island for fisheries development

anglais. "Kolong-kolong" are water bodies formed by extraction of tin (Sn) mining. The minings have been abandoned for more than five years. Studies on physical, chemical and biological characteristics of "kolong-kolong" in Bangka island was conducted to see if there is any chance to utilize these resources for fisheries development. Data of physical, chemical and biological aspects were required for these purposes. Sampled "kolong-kolong" located in west part of Bangka area which was still less developed compared to the east part of Bangka. From each twenty kolong kolong had been obtained general data (name, location, age, depth, area, current, water surface level amplitude, bottom soil texture, and utilization), dominant biota, and water quality. Heavy metals, particularly Pb and Sn, in bottom water, fish meat, and aquatic plant had also been investigated. Results showed that in general "kolong-kolong" could developed for fisheries both capture and culture fisheries. However, some water quality characteristics mainly high transparency, sandy bottom soil, low pH, and low alkalinity did not support waters fertility. Some recommendations for effective utilization of "kolong-kolong" i.e., reclamation need to be improved to accelerate reconditioning to natural balance of kolong-kolong. Most abandoned kolong-kolong need to be utilized not only for fisheries but also for other activities, such as drinking water, paddy field, water resource for ice-factory and recreation area

indonésien. Kolong-kolong adalah badan air yang terbentuk dari lahan bekas galian penambangan timah. Penelitian sumber daya perikanan kolong-kolong di Pulau Bangka bagian barat dilakukan untuk pemanfaatan kolong-kolong bagi perikanan. Untuk itu data aspek fisika, kimia dan biologi kolong-kolong tersebut diperlukan. Dari 20 kolong-kolong sampel telah didapatkan data umum (nama, lokasi, umur, kedalaman, luas, arus, amplitudo permukaan air, tanah dasar, dan pemanfaatan), kualitas air dan biota dominan. Disamping itu, beberapa kolong-kolong telah diamati kandungan logam Pb dan Sn dalam air dasar, daging ikan, dan tanaman air. Hasil penelitian menunjukkan bahwa secara umum kolong-kolong bisa dikembangkan untuk perikanan baik untuk penangkapan maupun untuk budidaya. Namun beberapa data yaitu kecerahan yang tinggi, tanah dasar berpasir, pH rendah, dan alkalinitas rendah, kurang mendukung terhadap kesuburan perairan. Beberapa saran dikemukakan antara lain perlu ditingkatkannya kegiatan reklamasi kolong-kolong untuk mengubah kembali pada keadaan alaminya yang seimbang. Disamping itu, kolong-kolong yang sebagian besar ditelantarkan perlu dimanfaatkan untuk perikanan selain untuk berbagai kegiatan lainnya, misal air minum, persawahan, sumber air untuk pabrik es, dan pariwisata