Distribusi dan Pola Pertumbuhan Kepiting Bakau Scylla Serrata Forskal di Ekosistem Mangrove Belawan Sumatera Utara

Abstract

Suatu kajian telah dibuat tentang distribusi dan pola pertumbuhan kepiting bakau Scylla serrata Forskal di ekosistem mangrove Belawan Sumatera Utara. Penelitian bertujuan untuk mengetahui keterkaitan karakteristik biofisik kimia ekosistem mangrove dengan distribusi kepiting bakau berdasarkan jenis kelamin dan kelas ukuran, mengetahui pola pertumbuhan kepiting bakau S. serrata di ekosistem mangrove Belawan Sumatera Utara. Karakteristik habitat kepiting bakau berdasarkan parameter biofisik kimia pada tiap stasiun dianalisa menggunakan analisis komponen utama, pola pertumbuhan dengan regresi linear dan distribusi kepiting bakau berdasarkan kelas ukuran dan jenis kelamin menggunakan analisis koresponden. Hasil analisis komponen utama memperlihatkan informasi penting terpusat pada dua sumbu utama sebesar 51,84% dan 27,43%, serta mampu mengelompokkan 3 kelompok stasiun. Hasil analisis koresponden memperlihatkan informasi distribusi spasial terpusat pada 2 sumbu utama sebesar 47,32% dan 46,59%. Kepiting bakau jantan dan betina berukuran kecil banyak ditemukan di habitat yang memiliki kecepatan arus serta substrat debu dan liat tinggi; kepiting bakau betina berukuran besar di habitat yang memiliki DO, kecerahan, kedalaman, pH, salinitas, dan substrat pasir tinggi, memiliki kerapatan mangrove jenis A. marina, A. alba,L. racemosa, R. apiculata, S. alba, S. caseolaris, N. fruticans, B. gymnorrhiza R. mucronata tinggi; kepiting bakau jantan dan betina berukuran sedang, kepiting jantan berukuran besar banyak ditemukan di habitat yang memiliki kecepatan arus, fraksi substrat debu dan liat tinggi, memiliki kerapatan mangrove jenis H. littoralis dan E. agallocha tinggi. Pola pertumbuhan kepiting bakau di ekosistem mangrove Belawan adalah allometrik negatif.

A study was made on distribution and growth pattern mud crab Scylla serrata. in Belawan mangrove ecosystem, North Sumatra. This study was aimed to know biophysical and chemical characteristics relationships among mangrove ecosystems with mud crab distribution based sex and size. To know growth patter of mud crab in Belawan mangrove ecosystem, North Sumatra. Mud crab habitat characteristic based on biophysical and chemical parameters at each station was evaluated using principal component analysis, growth pattern using linear regression, and mud crab spatial distribution based on sex and size using correspondence analysis. Principal component analysis results described that correlation between parameters centered on two main axes, explaining 51.84% and 27,43%, and can be classified three groups of station. Analysis of mud crab distribution based on sex and size class showed information which centered on two main axes, explaining 47,32% dan 46,59%. Small male and female-sized of mud crab were found in habitats which have current speed, high dust and clay substrate; big size female mud crab found in habitats which have DO, brightness, dept, pH, salinity, and high sand substrate. It have high mangrove density of spesies A. marina, A. alba,L. racemosa, R. apiculata, S. alba, S. caseolaris, N. fruticans, B. gymnorrhiza R. mucronata; midle size male and female and big size male of mud crab werw found in habitats which have current speed, high dust and clay substrate, It have high mangrove density of spesies H. littoralis and E. agallocha. Growth patter of mud crab in Belawan mangrove ecosystem included negative allometric