Kepadatan dan Distribusi Kepiting Bakau Scylla SPP. Serta Hubungannya Dengan Faktor Fisik Kimia di Ekosistem Mangrove Belawan Sumatera Utara

Abstract

The research about The density and distribution of mud crab’s Scylla spp. and its correlation to physical and chemichal in mangrove ecosystem Belawan, Medan North Sumatra was done from Mei to Juli 2013. Sample were taken from four observation and were performed three times for each station. Sample point was determined by using Purposive Random Sampling. Sample were taken by using Crab’s net 25’s and identification was done in Natural and Environmental Resources Management Mathematic and Natural Science Laboratory, Faculty of North Sumatra University. The result of research showed that two species of the mud crabs were found mangrove ecosystem Belawan namely were Scylla oceanica and Scylla serrata which come from one gets. The result of research found the highest diversity index print of mud crabs Scylla spp. are between 30,05 ind/m3 and the lowest is 21,18 ind/m3. The distribution index Scylla oceanica and Scylla serrata types are distribution group. Pearson correlation analysis test result between water chemistry parameters of the physical factors with a population density of mud crabs Scylla spp. fractions obtained sand substrate and depth werw negatively correlated positively correlated. Fraction of sand substrate and depth was highly significant with a very strong degree of correlation to the population density of mud crab Scylla serrata types, physical and chemical parameters of water were obtained and the depth of the clay fraction of the substrate was highly significant positively correlated with the degree of correlation is very strong against the type of mud crab density Scylla oceanica.

Penelitian tentang kepadatan dan distribusi kepiting bakau Scylla spp. serta hubungannya dengan faktor fisik kimia di ekosistem mangrove Belawan Kota Medan Sumatera Utara telah dilakukan pada bulan Mei hingga Juli 2013. Sampel diambil dari empat stasiun pengamatan, dan setiap stasiun dilakukan tiga kali ulangan. Titik pengambilan sampel ditentukan dengan metode Purposive Random Sampling. Sampel diambil dengan menggunakan bubu masing-masing sebanyak 25 buah dan indentifikasi dilakukan di Laboratorium Pengelolaan Sumber Daya Alam dan Lingkungan (PSDAL), Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Sumatera Utara. Hasil penelitian didapatkan 2 jenis kepiting bakau yakni kepiting bakau Scylla oceanica dan Scylla serrata yang berasal dari 1 genus. Nilai kepadatan tertinggi Scylla spp. sebesar 30,05 ind/m3 dan terendah sebesar 21,18 ind/m3 . Pola distribusi kepiting bakau Scylla oceanica dan Scylla serrata termasuk distribusi berkelompok. Hasil analisis korelasi Uji Pearson antara parameter faktor fisik kimia perairan dengan kepadatan populasi kepiting bakau Scylla spp. didapatkan fraksi substrat pasir berkorelasi negatif dan kedalaman berkorelasi positif. Fraksi substrat pasir dan kedalaman berpengaruh sangat nyata dengan tingkat hubungan yang sangat kuat terhadap kepadatan populasi kepiting bakau jenis Scylla serrata, sedang parameter fisik kimia perairan didapatkan fraksi substrat liat dan kedalaman berkorelasi positif berpengaruh sangat nyata dengan tingkat hubungan yang sangat kuat terhadap kepadatan kepiting bakau jenis Scylla oceanica.