ANALISIS HASIL TANGKAPAN RAJUNGAN (Swimming crab) DENGAN BUBU LIPAT BERDASARKAN FAKTOR HIDRO-OSEANOGRAFI DI PERAIRAN BETAHWALANG DEMAK

Abstract

Desa Betahwalang adalah salah satu desa di Kabupaten Demak yang merupakan suatu desa penghasil rajungan (swimming crab). Peningkatan teknologi maupun pengetahuan daerah penangkapan rajungan penting dilakukan sebagai faktor keberhasilan dalam memaksimalkan operasi penangkapan rajungan.Tujuannya adalah untuk menganalisa daerah penangkapan dan keadaan oseanografi dari daerah penangkapan rajungan di perairan Betahwalang Demak dengan menggunakan metode deskriptif dan metode purposive sampling. Hasil penelitian berupa gambaran keadaan oseanografi dan peta daerah penangkapan rajungan yang menunjukan persebaran daerah operasi penangkapan rajungan menggunakan bubu lipat di perairan Betahwalang. Persebaran daerah penangkapan rajungan menggunakan bubu tersebar dari kedalaman 17,9-31,2 m dengan subtrat perairan berupa lumpur liat. Kedalaman 15,1-20 m memiliki suhu 27-31⁰C dengan salinitas 29-31 ppt. Kedalaman 20,1-25 m suhu perairan 27-30⁰C dengan salinitas 29-32 ppt. Kedalaman 25,1-30 m suhu perairan 28⁰C-30⁰C dengan salinitas berkisar 30-31 ppt. Kedalaman 30,1-35 m suhu perairan 28^-29⁰C dan salinitas 30-31 ppt. Hasil penelitian menunjukan bahwa daerah penangkapan rajungan yang potensial pada kedalaman 25,1-35 m dengan salinitas berkisar 30-31 ppt dan hasil tangkapan terbanyak pada titik koordinat lintang 06°41'18.81" bujur 110°27'53.06" dengan berat 3.080 gram. 

Betahwalang village in Demak Regency is one of Rajungan ( swimming crab ) producers in Demak that has economical selling value and of export fishery commodity. The improvement of technology and knowledge about fishing ground in catching rajungan is greatly needed.The aim of this research was to analyze the fishing ground and oceanography of rajungan fishing ground in Betahlawang waters Demak Central Java using descriptive method. The results of this research were the oceanography description and rajungan fishing ground map that showed the spreading area of rajungan capture operation using folded trap in Betahlawang waters. It was spread from 17.9 m to 31.2 m in depth with water sediment of clay. The depth of 15.1 m to 20 m had average temperature of 27⁰C to 31⁰C with salinity of about 29 ppt to 31 ppt. The depth of 20.1 m to 25 m had average temperature of 27⁰C to 30⁰C with salinity of about 29 ppt to 32 ppt. The depth of 25.1 m to 30 m had average temperature of 28⁰C to 30⁰C with salinity of about 30 ppt to 31 ppt. The depth of 30.1 m to 35 m had average temperature of 28⁰C to 29⁰C with salinity of about 30 ppt to 31 ppt. The result of this research showed that the potential fishing ground was in the depth of 25.1- 35 m with salinity of 30- 31 ppt. The results showed that the potential crab fishing area at depths ranging from 25.1 to 35 m with a salinity of 30-31 ppt and most of the catch at point 06 ° latitude 41'18 .81 "longitude 110 ° 27'53 .06" with a weight of 3,080 grams.