Hubungan Amonia (NH3) dan Fosfat (PO4) Terhadap Keanekaragaman Makrozoobentos di Sungai Belawan

Abstract

The flow of the Belawan River through a dense populated areas and factories causes waste pollution containing ammonia and phosphate which affects the diversity of aquatic organisms such as macrozoobenthos. This research aimed to analyze the macrozoobenthos diversity, the ammonia and phosphate content and the relationship between physico-chemical factors and macrozoobenthos diversity in the Belawan River.The water of the river and the macrozobenthos samples were taken by Purposive Sampling at 5 stations, starting from upstream at Salam Tani village and downstream at Sicanang Belawan Village. The number and type of macrozobenthos were counted and then the density, relative density, frequency of presence, diversity and uniformity were determined. The level of ammonia, phosphate and physico-chemical factors were measured. Next, analyze of the correlation between ammonia, phosphate content and physical and chemical factors of river water to the macrozoobenthos diversity were done. From all of the five research stations, 20 macrozoobenthos genera were obtained which belonged to 4 classes, 11 orders and 18 families. The density value of macrozoobenthos in the Belawan River ranges from 1.23 to 19.75 ind/m2 with the highest density at station 5. The diversity index (H’) value of macrozoobenthos is 0.36-2.56, categorize as the low-medium. Meanwhile, the uniformity index (E) value is 0.85 categorize as the low-high category with the highest value at station 5th. The ammonia content ranges from 0.013 to 0.185 mg/l while the phosphate content ranges from 0.24 to 0.48 mg/l. Measurements of the physico-chemical factors of Belawan River water show that Belawan River water remains within the ideal range of river water quality standards. Correlation analysis of the relationship between ammonia and macrozoobenthos diversity has very strong effect, while phosphate has a positive (strong) effect. Correlation analysis of physico-chemical factors, especially temperature, light penetration and current speed, has a positive (very strong) effect on the macrozobenthos diversity, while pH and Dissolved Oxygen (DO) give a negative effect.