Kemelimpahan larva chironomidate berdasarkan gradien lingkungan di Sungai Winongo, Yogyakarta

WIDYASTUTI, Ririn, Dr. Suwarno Hadisusanto

2009 | Tesis | S2 Biologi

Chironomidae berperan penting dalam habitat perairan sehingga dapat dijadikan tolok ukur kualitas perairan. Penelitian ini bertujuan untuk mengkaji kualitas air dan sedimen, kemelimpahan larva Chironomidae dan pengaruh parameter lingkungan perairan terhadap kemelimpahan larva Chironomidae di Sungai Winongo Yogyakarta. Penelitian dilakukan bulan Juni 2008 sampai dengan bulan November 2008, dilakukan di 8 stasiun dengan 2 kali pengulangan tiap stasiun penelitian. Pencuplikan sedimen menggunakan vertical core sampler yang dibuat dari pipa PVC dan sedimen disaring menggunakan saringan Tyler no. 20, 40 dan 60. Larva diisolasi dan diawetkan dalam alkohol 70 % dan formalin 2 %. Analisis data meliputi indeks diversitas Shannon-Wiener dan indeks dominansi, selanjutnya dilakukan analisis regresi korelasi. Kualitas perairan Sungai Winongo secara keseluruhan berada dalam ambang batas lingkungan. Larva Chironomidae yang tercuplik pada penelitian ini terdiri atas 2 genus, Chironomus dan Ablabesmyia. Berdasarkan stasiun penelitian kemelimpahan larva tertinggi di Ngampilan 60.39 ind/m3, di Mlati 10.97 ind/m3 dan di Jlagran 7.84 ind/m3. Sedangkan berdasarkan bulan pencuplikan, kemelimpahan larva Chironomidae tertinggi di bulan Juli yaitu sebesar 51.36 ind/m3 dan bulan Agustus sebesar 34.51 ind/m3. Parameter lingkungan yang mempengaruhi kemelimpahan larva Chironomidae adalah kandungan DO dan BOD.

Chironomidae plays important roles in waters habitat, so that it can serve as the yardstick of waters quality. The present research aimed to investigate water and sediment quality, the abundance of Chironomidae larvae and the influence of waters environment parameter on the abundance of Chironomidae larvae in River Winongo at Yogyakarta. The research was conducted from June 2008 to November 2008, at 8 stations with 2 times of replication at each research station. Sediments were sampled by using vertical core sampler made from PVC pipes, and then the sediments were sieved through Tyler filter numbers 20, 40 and 60. Larvae were isolated and preserved in 70% alcohol and 2% formalin. Data analysis involved Shannon-Wiener diversity index and dominance index; afterward, correlation regression analysis was carried out. The waters quality of River Winongo, in general, was on the environmental threshold. Chironomidae larvae sampled in this research consisted of 2 genera, i.e. Chironomus and Ablabesmyia. Based on the research station, the highest abundance of larvae was identified at Ngampilan, Mlati and Jlagran, i.e. 60.39 ind/m3, 10.97 ind/m3 and 7.84 ind/m3, respectively. While based on the month of sampling, the highest abundance of Chironomidae larvae were found in July and August, namely 51.36 ind/m3 and 34.51 ind/m3, respectively. Environmental parameter affecting the abundance of Chironomidae larvae involved the contents of DO and BOD.

Kata Kunci : Larva Chironomidae,gradien Lingkuganya,kualitas air,Chironomidae larvae, environmental gradient, water quality