ANALISIS DIATOM EPIPELIC SEBAGAI INDIKATOR KUALITAS LINGKUNGAN TAMBAK UNTUK BUDIDAYA UDANG

Abstract

Manajemen kualitas air dan dasar tambak mempunyai peran yang sangat penting pada keberhasilan budidaya udang. Diatom epipelic merupakan salah satu microalgae yang banyak ditemui di sedimen tambak dan keberadaannya dipengaruhi oleh kualitas air maupun sedimen. Karena hidup di dasar tambak, jenis dan kelimpahannya sangat dipengaruhi kondisi dasar perairan. Pengembangan studi tentang diatom epipelic sebagai indikator kualitas air dan kesuburan suatu ekosistem budidaya masih terbatas jika dibandingkan dengan plankton. Penelitian ini bertujuan untuk mengevaluasi kemungkinan pemanfaatan diatom epipelic sebagai indikator kualitas lingkungan tambak untuk budidaya udang, yaitu dengan cara : (1) menganalisis keberadaan diatom epipelic yang ada di tambak budidaya udang dan (2) menganalisis hubungan antara berbagai parameter kualitas air dan kualitas sedimen dengan kelimpahan dan keragaman diatom epipelic pada tambak udang. Penelitian ini merupakan penelitian eksploratif untuk mempelajari struktur diatom epipelic yang ada di tambak udang. Pengumpulan data dilakukan terhadap 12 unit tambak udang pada masa persiapan air (pratebar) dengan letak tambak yang berbeda dari pintu masuk air. Pengumpulan data epipelic algae dilakukan dengan metode lens tissue trapping. Selain diatom epipelic, data yang dikumpulkan antara lain kualitas air dan kualitas sedimen tambak. Dari hasil penelitian menunjukkan bahwa diatom epipelic di lokasi tambak budidaya udang didominasi oleh Nitzschia dan Pleurosigma. Diatom epipelic dapat dijadikan indikator kualitas lingkungan tambak untuk budidaya udang. Hal ini dapat dilihat dari hubungan diatom epipelic dengan kualitas air dan sedimen. Keragaman diatom epipelic dipengaruhi oleh alkalinitas (rs = 0,75), TOM (rs = 0,71), dan nitrat (rs = 0,66), sedangkan kualitas sedimen yang berpengaruh terhadap keragaman diatom epipelic antara lain : KPK tanah (rs = 0,72), kandungan liat (rs = 0,65), dan kandungan bahan organik (rs = 0,62). Water quality and pond bottom management play an important role in the success of shrimp culture. Epipelic diatom is one of benthic microalgae that can be excessively found in the brackish water pond sediment and its existence are influenced by water quality and type of sediment. Due to living at the bottom of pond, the species type and abundance are extremely affected by the condition of pond bottom water. Study on the development of epipelic diatom as an indicator of water quality and of productivity certain ecosystem is still limited compared to the study of plankton. The use of epipelic diatom to support the quality analysis of the brackish water pond area may highly helpful especially for demersal-lived species cultivation just like shrimp. The aim of this research was to evaluate the possibility of using epipelic diatom as an indicator of the brackish water pond environment quality for shrimp culture, there were by : (1) analyzing the presence of epipelic diatom in the shrimp culture pond, and (2) analyzing the relation between various parameters of water and sediment quality with the abundance and epipelic diatom diversity in the shrimp pond. This research was an explorative one to study about epipelic diatom structure that present in the shrimp pond. Data collection was done in 12 shrimp pond units during water preparation period (pre-spreading) with the different locations of each pond from the watergate. The data collection of epipelic diatom was done by using lens tissue trapping method. In addition to epipelic diatom, other collected data was water and sediment quality. From the research results showed that epipelic diatom in the location of the brackish water pond were dominated by Nitzschia and Pleurosigma. Epipelic diatom could be an indicator of brackish water pond environment quality, because of relation among them. Epipelic diatom diversity was influenced by alkalinity (rs = 0.75), TOM (rs = 0.71), and nitrate (rs = 0.66), meanwhile sediment quality parameter influential on epipelic diatom diversity were among others: cation exchange capacity (rs = 0.72), clay content (rs = 0.65), and organic matter content (rs = 0.62).