STATUS PENCEMARAN SUNGAI WAKAK KENDAL DITINJAU DARI ASPEK TOTAL PADATAN TERSUSPENSI DAN STRUKTUR KOMUNITAS MAKROZOOBENTOS

Abstract

Sungai Wakak merupakan perairan penerima limbah dengan volume cukup besar. Hal ini disebabkan adanya berbagai aktivitas ‘penyumbang’ limbah yang terdapat di kawasan ini, seperti kegiatan industri, pertanian, pemukiman, dan pertambakan. Peristiwa ini menyebabkan erosi, abrasi dan sedimentasi yang  berdampak pada kehidupan biota perairan khususnya makrozoobentos dan kultivan pada tambak yang memanfaatkan pengairan  Sungai Wakak . Tujuan penelitian ini adalah untuk mengetahui pengaruh konsentrasi total padatan tersuspensi terhadap struktur komunitas makrozoobentos, serta status pencemaran Sungai Wakak. Metode sampling yang digunakan adalah sistematic sampling. Penelitian ini dilaksanakan pada tiga stasiun yang berbeda selama tiga kali waktu sampling dimana stasiun 1 berada didaerah hulu sungai, stasiun 2 berada dilokasi yang terdekat dengan aktivitas masyarakat dan industri, dan stasiun 3 berada di hilir sungai yang dekat dengan muara . Hasil rata-rata konsentrasi total padatan tersuspensi antar waktu dan antar lokasi terendah yaitu sebesar 540 mg/l dan tertinggi sebesar 920 mg/l. Nilai kelimpahan individu dan kelimpahan relatif tertinggi yaitu makrozoobentos jenis Floridobia dengan KI 784 ind/m³. Indeks keanekaragaman (H’) tergolong rendah (tercemar sedang), indeks keseragaman (e) masuk dalam kategori tinggi. Indeks dominansi (D) mendekati nilai nol yang berarti tidak ada spesies yang mendominasi. Sedangkan berdasarkan analisis data dalam aspek Kurva ABC Makrozoobentos, diperoleh hasil bahwa perairan tersebut dalam kategori tercemar berat. Konsentrasi total padatan tersuspensi dapat berpengaruh terhadap struktur komunitas makrozoobentos meskipun dalam hal ini jumahnya sangat kecil. Berdasarkan konsentrasi total padatan tersuspensi dan kurva ABC makrozoobentos, Sungai Wakak termasuk sungai golongan tercemar berat.

Wakak river is a large volume of water waste disposite. Various 'contributor' activities which are contained in this area are industrial activities, agricultural, domestic, and aquaculture. Real effects arising from such activities in the form of river pollution and erosion as well as the river bank abrasion. This causes the sedimentation process that impact on the aquatic biota, especially macrozoobenthos. The purpose of this study was to determine the effect of the concentration of total suspended solids makrozoobentos community structure and Wakak River pollution status. The sampling method is systematic sampling method. This study was conducted at three different stations during the three sampling times where first station located in the upstream of the river, second location is located in the closest area of the community and industrial activities, and third station is located in the downstream near the estuary. The average of total suspended solids concentration over time and between the lowest locations is in the amount of 540 mg/l and the highest was 920 mg/l. Abundance of individual values and the highest relative abundance of macrozoobenthos kind of Floridobia with KI 784 ind/m³. Diversity index (H') is low (modaretely polluted), uniformity index (e) included in the high category. The Dominance index (D) was nearly zero, which means there is no dominated species. Based on the concentration of total suspended solid and the macrozoobenthos ABC curve, the results showed that the water is highly polluted. The concentration of total suspended solids can affect the community structure of macrozoobenthos although in this case the amount is very small. Based on the concentration of total suspended solids and macrozoobenthos ABC curve, River Wakak is highly polluted.