Klasifikasi Habitat Mangrove untuk Pengembangan Silvofishery Kepiting Soka (Scylla serrata) di Pantai Utara Kabupaten Rembang

Abstract

Pemanfaatan mangrove untuk silvofishery mampu mendatangkan keuntungan bagi masyarakat sekitarnya, maka perlu dikembangkan agar hasilnya optimal dan berkelanjutan. Tujuan penelitian ini untuk mendapatkan klasifikasi karakteristik habitat mangrove yang sesuai untuk pengembangan kepiting soka yang selama ini sudah dikembangkan di Pantai Utara Pemalang. Penelitian dilakukan di Pantai Utara Kabupaten Rembang pada tahun tanam 2000, 2003, dan 2004. Masing-masing tahun tanam dibagi menjadi jalur-jalur tegak lurus garis pantai. Setiap jalur diletakkan 3 petak ukur 5 x 5m sesuai dengan zonasi yang ada pada hutan mangrove, kemudian diukur kerapatan tanaman mangrove, ketebalan lumpur, DO, salinitas, suhu, pH, dan kepadatan plankton. Sebagai pembanding, maka diambil pula data karakteristik habitat di mangrove Pemalang yang sudah digunakan silvofishery kepiting soka. Data pada setiap petak ukur dirata-rata dan dibedakan pada setiap zonasi. Data setiap zonasi dianggap sebagai relevé. Relevé-relevé pada kedua lokasi kemudian dianalisis menggunakan uji pengelompokan atau cluster analysis dengan metode jarak Mean Euclidean Distance (MED). Hasil penelitian menunjukkan bahwa pada umumnya cluster yang terbentuk kurang bervariasi. Sepintas terlihat hanya ada 2 kelompok besar yang terpisahkan, yaitu pada jarak cluster 10. Pengelompokan demikian ini cukup bagus karena kemiripan habitat ditunjukkan secara ekstrim oleh dua kelompok besar tersebut. Meskipun pada jarak cluster 5 terdapat kelompok yaitu relevé 3,6,8 dengan relevé 2, namun demikian kurang terlihat jika dibanding dengan jarak di atasnya. Pada umumnya habitat mangrove di Rembang kurang sesuai untuk pemeliharaan kepiting soka, karena hanya relevé 1 yang sesuai. Perlakuan lebih lanjut untuk perbaikan habitat diperlukan agar jenis kepiting ini dapat hidup dengan optimal.

Kata kunci: silvofishery, kepiting soka, habitat mangrove, Rembang, relevé.

Classification of mangrove habitat for  development of soka crab (Scylla serrata) silvofishery in the north coast of Rembang Regency

Abstract

Silvofishery practices as mangrove utilization have been providing various benefit for local societies, thus it needs to be developed for its product optimization and sustainability. Providing suitable area for silvofisheries is crucial for the development of silvofishery. This study was aimed to classify the mangrove habitat characteristics that were suitable for soka crab farming in the north coast of Rembang Regency, following the success of the north coast of Pemalang Regency. This research were conducted in the north coast
of Rembang Regency in 2000, 2003, and 2004 planting years. Perpendicular transects to the coastal line were established on each plantation area. On each transect, three plots of 5 x 5 m were established and distributed on each mangrove zone. Mangrove tree density, mud depth, dissolved oxygen, salinity, temperature, pH and plankton density were measured from each plot. The measurements of habitat characteristics were also conducted in the mangrove area of Pemalang, where soka crab farming was developed earlier as a comparison between areas with the same plantation period). Data collected from all plot were averaged and differentiated based on Mangrove zonation. Data of each zone were treated as relevé. The relevé of the two study sites (Rembang and Pemalang) were then analyzed using cluster analysis with Mean Euclidean Distance (MED). The results showed that the cluster was relatively less various. There were two main separated groups with cluster distance at 10. This grouping was relatively good, indicated by distinctive similarity of habitat within each group. At cluster distance of 5, there were two main groups which were relevé 3,6,8 with relevé 2 and the rest as other group. Whereas the cluster distance of 5 in the relevé 3,6,8 was grouped with relevé 2, but it was not clearer than above group. Commonly, mangrove habitat in Rembang was less suitable for soka crab farming because only relevé 1 was suitable for the habitat of this crab. Further intervention is required for habitat improvement.