INDEKS KELIMPAHAN DAN KARAKTERISTIK DAERAH PENANGKAPAN RAJUNGAN (Portunus pelagicus) DI PERAIRAN MADURA
Authors: Syah Achmad Fachruddin , Fitriyah Nurul Lailatul , Yakin Ainul , Ramadana Andika Yoga , Putri Febri Cahyani , Laksmi Pinka Natasya 
Published: August 2024

Perairan Madura merupakan salah satu daerah penangkapan rajungan (Portunus pelagicus) yang ada di Jawa Timur. Parameter oseanografi dipercaya dapat mempengaruhi distribusi rajungan. Penelitian ini bertujuan untuk memahami hasil tangkapan rajungan dan faktor-faktor yang mempengaruhi distribusi rajungan yang ada di Perairan Madura. Data lokasi dan hasil tangkapan rajungan diperoleh dengan cara ikut secara langsung nelayan yang melakukan penangkapan rajungan di perairan Madura. Parameter oseanografi (suhu permukaan laut, salinitas, dan kedalaman) diperoleh dari oceancolor website (https://oceancolor.gsfc.nasa.gov/), Copernicus Marine Environment Monitoring Service (CMEMS) website (http://marine.copernicus.eu/), dan General Bathymetric Chart of the Oceans (Gebco) melalui website (https://www.gebco.net/data_and_products/gridded_bathymetry_data/). Data diproses dengan menggunakan SeaDas package ver. 7. 4 and ArcGIS 10.2. Pengaruh parameter oseanografi terhadap distribusi rajungan digunakan habitat modelling, maximum entropy model. Hasil menunjukkan bahwa indeks kelimpahan di Bangkalan (6.28 kg/trip) paling tinggi dibanding Pamekasan (2.21 kg/trip) dan Sumenep (3.09 kg/trip). Secara umum jumlah rajungan betina (52%) yang tertangkap lebih banyak dibandingkan rajungan jantan (48%). Berdasarkan beratnya, sebanyak 77% rajungan yang tertangkap merupakan rajungan yang layak tangkap (lebih besar dari ukuran legal minimum), sedangkan berdasarkan lebar karapas, 72% rajungan yang tertangkap layak tangkap. Hasil pemodelan menunjukkan bahwa bathimetry mempunyai pengaruh yang paling besar terhadap distribusi rajungan dikuti oleh suhu permukaan laut dan salinitas. Aktivitas penangkapan rajungan banyak dilakukan pada kedalaman 5 – 10 m. Selain itu,  hasil penelitian ini juga menunjukkan bahwa rajungan menyukai selang suhu permukaan laut antara 30 – 32°C dan salinitas antara 27 – 32 ppt. Madura waters is one of the fishing areas for blue swimming crab (Portunus pelagicus) in East Java. Oceanographic parameters are believed to affect the distribution of crabs. This study aims to understand the catch of crabs and the factors that influence the distribution of crabs in the Madura Strait. Location data and crab catches were obtained by direct participation of fishermen who caught crabs in the Madura waters. Oceanographic parameters (sea surface temperature, salinity, and depth) were obtained from the oceancolor website (https://oceancolor.gsfc.nasa.gov/), the Copernicus Marine Environment Monitoring Service (CMEMS) website (http://marine.copernicus.eu/), and General Bathymetric Chart of the Oceans (Gebco) through the website (https://www.gebco.net/data_and_products/gridded_bathymetry_data/). The data was processed using the SeaDas package ver. 7. 4 and ArcGIS 10.2. The effect of oceanography on the distribution of crabs, the maximum entropy model, was used. The results showed that the abundance index in Bangkalan (6.28 kg/trip) was the highest compared to Pamekasan (2.21 kg/trip) and Sumenep (3.09 kg/trip). In general, the number of female crabs (52%) was caught more than the male crabs (48%). Based on the weight, 77% of the crabs caught were suitable for catching (greater than minimum legal size), while based on the width of the carapace, 72% of the crabs caught were suitable for catching. The modeling results showed that bathimetry has the greatest influence on the distribution of crabs followed by sea surface temperature and salinity. Many crab catching activities are carried out at a depth of 5-10 m. In addition, the results of this study also showed that the crabs prefer the sea surface temperature between 30 - 32°C and salinity between 27 - 32 ppt.