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Abstrak : Penangkapan rajungan di perairan Pantai Purirano umumnya dilakukan oleh usaha perikanan rajungan skala kecil, yang menggunakan jaring insang (gillnet). Gillnet merupakan alat tangkap pasif yang pengoperasiannya tidak merusak sumberdaya hayati perairan. Walaupun demikian, gillnet merupakan alat tangkap yang tingkat selektivitasnya rendah, sehingga dikhawatirkan hasil tangkapan sampingan (bycatch) lebih banyak daripada hasil tangkapan utama (target species). Penelitian ini bertujuan untuk mengetahui proporsi hasil tangkapan rajungan (portunus pelagicus) sebagai target utama dan komposisi bycatch alat tangkap gillnet di perairan Pantai Purirano.Sampel rajungan ditangkap menggunakan jaring insang (gillnet) dengan ukuran mata jaring 4 inci & lebar jaring 80 cm. Hasil tangkapan selama penelitian diperoleh 29 jenis dari 25 famili. Hasil tangkapan yang diutamakan adalah rajungan dari famili Portunidae, tetapi terdapat juga jenis-jenis lain yang juga tertangkap (bycatch), yang sebagian dimanfaatkan (useable) dan sebagian lain dibuang ke laut (discarded). Jumlah total hasil tangkapan rajungan jantan selama penelitian adalah 58 ekor (54%) dan betina sebanyak 50 ekor (46%). Indeks dominansi hasil tangkapan tergolong rendah yaitu berkisar 0,21 -0,27. Hal ini mengindikasikan bahwa selektivitas alat tangkap jaring insang tergolong rendah. Kata Kunci : Rajungan (Portunus pelagicus), Bycatch, Gillnet, PuriranoAbstrack : Catching crabs in Purirano Beach is generally carried out by smallscale crab fishing businesses, which use gillnet. Gillnet is a passive fishing gear whose operation does not damage aquatic biological resources. However, gillnet is a fishing tool with a low selectivity level, so it is feared that bycatch by-catch is more than the main catch (target species). This study aims to determine the proportion of crab catches (portunus pelagicus) as the main target and the composition of gillnet fishing gear bycatch in Purirano Beach waters. Swimming crab samples were captured using gill nets with mesh sizes of 4 inches & net width of 80 cm. The catch during the study obtained 29 species from 25 families. The preferred catch is crabs from the family Portunidae, but there are also other species that are also caught (bycatch), some are used (useable) and some others are thrown into the sea (discarded). The total number of male crab catches during the study was 58 individuals (54%) and 50 females (46%). The catch index dominance is relatively low, in the range of 0.21 -0.27. This indicates that the selectivity of gill nets is relatively low.

Tujuan penelitian ini adalah untuk menganalisis hubungan lebar karapas dan bobot tubuh rajungan pada zona berbeda (intertidal dan seagrass zone) di perairan Bungin Permai Konawe Selatan. Pengambilan sampel rajungan dilakukan menggunakan alat tangkap bubu lipat ukuran (53 x 40 x 25) cm dengan ukuran mata jaring 1,5 inchi sebanyak 50 unit. Seluruh sampel yang diperoleh diidentifikasi jenis kelaminnya, diukur lebar karapasnya (CW) menggunakan kaliper ketelitian 0,1 mm, dan ditimbang bobotnya (W) menggunakan electronic balance ketelitian 1 g. Untuk mengetahui hubungan CW dan W rajungan digunakan analisis regeresi. Sampel yang diperoleh berjumlah 162 individu yang terdiri atas 89 individu jantan (54,93%) dan 73 individu betina (45,06%). Hubungan CW dan W rajungan tersebut dianalisis menggunakan regresi linear. Hasil analisis menunjukan persamaan regresi rajungan jantan pada zona intertidal dan seagrass masing-masing adalah W = 4,771(CW)3,2648 (r = 0,9643) dan W = 4,4673(CW)3,1273 (r = 0,9654), sedangkan  rajungan betina pada zona intertidal dan seagrass masing-masing adalah W = 4,3097(CW)3.0168 (r  = 0,9349) dan W = 3,8177(CW)2,7689 (r = 0,9407). Data tersebut menjelaskan bahwa terdapat hubungan yang kuat antara CW dan W rajungan dengan pola pertumbuhan relatif sama pada kedua zona penelitian. Kata Kunci: Portunus pelagicus, hubungan lebar karapas dan bobot tubuh, zona intertidal, zona seagrass

Based on similarity of natural features of salinity, turbidity, soil substrate, mangrove vegetations and intertidal flat of the stations studied, there were three habitats (A, B, and C) of Scylla serrata (Forskål, 1775) in Lawele Bay. The characteristics of habitat A were preferred by S. serrata since it had the highest relative abundance of S. serrata. With relative abundance of 11.87%, habitat B as transition habitat between habitats A and C was less preferred by S. serrata. The characteristics of habitat C were in contrary with habitat A and S. serrata caught was only 1.19%. The relative abundance of S. serrata at habitat A differed significantly with habitats B and C (p < 0.05), while at habitat B was not significantly different with habitat C (p > 0.05). It suggests that S. serrata tended to move forward at habitat A and occupying such habitat which was characterized by low salinity, high turbidity, the thickest mangrove vegetation, muddy substrate and the widest intertidal flat. The relative abundance of males was significantly different with females either during flood tide or ebb tide (p < 0.05). Both sexes had two peaks of abundance. A major peak was in July and August and a minor peak in February. The lowest relative abundance was in December. However, seasonal relative abundance was not significantly different (p > 0.05). It suggests that the relative abundance may depend on seasons but they are found all year round.