xi
RINGKASAN
Ikan palung Hampala macrolepidota (C.V.) merupakan sasaran utama penangkapan di Waduk P.B. Soedirman. Aktivitas penangkapan secara terus-menerus mempengaruhi struktur populasi ikan. Tujuan penelitian ini adalah mengetahui struktur populasi ikan palung yang meliputi sebaran ukuran panjang, pertumbuhan, laju mortalitas, dan hasil per rekruitmen relatif di lokasi inlet, tengah, dan outlet, mengetahui kualitas air di Waduk P.B. Soedirman, dan menentukan parameter kualitas air yang berpengaruh terhadap jumlah ikan palung di lokasi inlet, tengah, dan outlet.
Penelitian dilakukan di Waduk P.B. Soedirman, Kabupaten Banjarnegara dengan menggunakan metode survei dan teknik purposive random sampling pada 10 stasiun yang ditentukan berdasarkan pada lokasi yang mewakili aliran air yaitu inlet, tengah, dan outlet. Variabel yang diamati adalah struktur populasi ikan palung dan kualitas air. Kajian sebaran ukuran panjang dianalisis dengan FISAT II, pendugaan pertumbuhan dengan metode Bhattacharya, model von Bertalanffy, Response Surface, dan rumus Pauly, pendugaan mortalitas dengan rumus Pauly, dan hasil per rekruitmen relatif dengan persamaan Beverton & Holt. Analisis parameter kualitas air yang berpengaruh terhadap jumlah ikan palung menggunakan PCA.
Hasil penelitian menunjukkan bahwa ikan palung yang diperolah di lokasi inlet sebanyak 37 individu, di lokasi tengah tidak diperoleh ikan palung, dan di lokasi outlet sebanyak 18 individu. Ikan palung yang tertangkap di inlet memiliki sebaran ukuran panjang terbanyak pada selang 112-136 mm, dan di outlet pada selang kelas 119-150 mm. Kelompok umur ikan di lokasi inlet dibagi menjadi tiga yaitu pada panjang rata-rata 190,22 mm; 252,33 mm; dan 280,11 mm, sedangkan di lokasi outlet dibagi menjadi dua yaitu pada panjang rata-rata 208,86 mm dan 279,49 mm. Pendugaan panjang maksimum ikan palung di inlet yaitu 301,95 mm dan di outlet 355,00 mm dengan laju pertumbuhan cepat (0,51 per tahun) pada kedua lokasi. Pendugaan laju mortalitas alami di inlet lebih tinggi (0,9411 per tahun) dibandingkan laju mortalitas penangkapan (0,7815 per tahun), sebaliknya laju mortalitas penangkapan di outlet lebih tinggi (87,2636 per tahun) dibandingkan mortalitas alami (1,6764 per tahun). Pendugaan hasil per rekruitmen relatif menunjukkan bahwa di inlet terdapat 0,0367 g.ind-1 dan di outlet terdapat 246,9280 g.ind-1 ikan yang dapat diperoleh sebagai hasil tangkapan. Kondisi kualitas air di Waduk P.B. Soedirman masih layak dalam kelangsungan kehidupan ikan. Kualitas air yang berpengaruh terhadap jumlah ikan palung pada lokasi inlet adalah kedalaman, sedangkan pada lokasi outlet adalah pH.
xi
SUMMARY
Hampala barb Hampala macrolepidota (C.V.) is the main target for fishing in P.B. Soedirman Dam. Continuous fishing activity affects fish population structure. The aim of this study is to know hampala barb population structure which includes distribution of measurements such as length, growth, mortality rate, and yield per recruitment relative on inlet, middle, and outlet locations, to know the condition of water quality in P.B. Soedirman Dam, and to determine the water quality parameter that affects total number of hampala barb on inlet, middle, and outlet locations.
Study was conducted in P.B. Soedirman Dam, Banjarnegara Regency by using survey method with purposive random sampling on 10 stations which was determined based on locations that represent water flow such as inlet, middle, and outlet. Observed variables were hampala barb population structure and water quality. Study of length measurement distribution was analyzed with FISAT II, growth prediction was analyzed with Bhattacharya method, von Bertalanffy model,
Response Surface, and Pauly formula, mortality prediction was analyzed with Pauly formula, and yield per recruitment relative was analyzed with Beverton & Holt equation. Analysis of water quality parameter that affects total number of hampala barb used PCA.
Study results showed that 37 hampala barbs was collected in inlet location, no hampala barbs was collected in middle location, and 18 hampala barbs was collected in outlet location. Hampala barb that was captured in inlet had the highest length measurement distribution in class interval of 112-136 mm, while the outlet had the highest length measurement distribution in class interval of 119-150 mm. Hampala barb age class was divided into 3 group on average length of 190,22 mm 252,33 mm; and 280,11 mm, while outlet location was divided into 2 group on average length of 208,86 mm and 279,49 mm. Maximum length prediction of hampala barb in inlet was 301,95 mm and in outlet was 355,00 mm with fast growth rate (0,51 per year) in both location. Natural mortality rate prediction in inlet was higher (0,9411 per year) than fishing mortality rate (0,7815 per year), meanwhile the fishing mortality rate in outlet was higher (87,2636 per year) than natural mortality rate (1,6764 per year). Prediction of yield per recruitment relative showed that there were 0,0367 g.ind-1 barb in inlet and 246,9280 g.ind-1 barb in outlet that can be acquired as haul from fishing. Water quality condition in P.B. Soedirman Dam is still viable for hampala barb survivality. Water quality that affects total number of hampala barb in inlet location was depth, while in outlet location it was pH.
Keywords: hampala barb Hampala macrolepidota (C.V.), population structure, dam, water quality.
