Studi Struktur dan Pertumbuhan Populasi Kerang Pokea (Batissa violacea var. celebensis, von Martens 1897) di Sungai Pohara Sulawesi Tenggara

Abstract

ABSTRAK
Pokea merupakan bivalvia air tawar yang hidup di segmen muara. Bivalvia ini terus
mengalami tekanan sejalan dengan peningkatan aktivitas kegiatan penangkapan dan
menurunnya kualitas perairan. Penelitian ini bertujuan untuk mengetahui struktur dan
pertumbuhan populasi kerang pokea di Sungai Pohara Sulawesi Tenggara. Penelitian ini
dilaksanakan di segmen muara Sungai Pohara selama setahun dari bulan Maret 2007-Februari
2008. Parameter populasi (LâËž dan K) dan to masing-masing dianalisis dengan menggunakan
pergerakan modus frekuensi panjang dan nilai L0=0.025. Pola pertumbuhan dianalisis
menggunakan inverse von Bertalanffy sedangkan struktur populasi dianalisis menggunakan
distribusi normal dari plot Bhattacharya yang secara keseluruhan terakomodasi pada program
FiSAT II versi 3.0. Hasil penelitian menunjukkan bahwa lebar asimtotik dan koefisien
pertumbuhan jantan dan betina masing-masing yaitu 7.16 cm, 0.59 dan 6.92 cm, 0.96. Oleh
karenai tu, pertumbuhan pokea betina lebih cepat dibandingkan pokea jantan. Populasi
kerang pokea tersebar pada berbagai kelompok ukuran yang mewakili ukuran muda, dewasa
dan tua dengan nilai tengah berada pada 1.49 dan 6.01 yang menyebar pada tiga kelompok
ukuran. Kelompok ukuran dominan pada jantan betina relatif berbeda yang tersebar pada
nilai tengah masing-masing 1cm dan 2cm. Secara umum, struktur populasi pokea di Sungai
Pohara relatif stabil.
Kata kunci : pokea, pertumbuhan, struktur, populasi, sungai, Pohara
ABSTRACT
Pokea clam was fresh water bivalve that lived on well into estuary segments. This
bivalve have experienced in under pressure as activity increase in fishing events and decrease
in water quality. This research aimed to understand the structure and growth population of
pokea clam in Pohara river on Southeast Sulawesi. This research was conducted in estuary
segment of Pohara river from March 2007 to February 2008. Parameters of population (LâËž
dan K) and to were analyzed by using movements in modus of length frequency and
Lo=0.025. Growth pattern was analyzed by using von Bertalanffy inverse, and population
structure was analyzed by using normal distribution from Bhattacharya plot with full
accommodation on FiSAT II version 3.0. The results of this research indicated that
asymptotic width and growth coefficient for male and female were 7.16 cm, 0.59 cm, and
0.96 cm. Therefore, the growth of female pokea was faster than male. Pokea clam population
spread to several size groups that represented as young, adult, and old with median 1.49 and
6.01. The dominant length measurement on male and female was relatively different which
propagated in median 1 cm and 2 cm. Generally, population structure of pokea clam in
Pohara river was relatively stable.
Keyword: pokea, growth, structure, population, river, Pohara