REMOVAL EFECTIVITY OF NITROGENOUS DAN PHOSPOROUS WASTE BY AQUAPONIC SUBSTRATE AND AQUATIC PLANT IN THE INTEGRATED MULTI-TROPHIC AQUACULTURE (IMTA)-BASED FISH CULTURE  

Lies Setijaningsih* and Bambang Gunadi
 
Research and Development Institute for Freshwater Aquaculture
Jalan Sempur No. 1 Bogor 16154
West Java, Indonesia
liessetijaningsih@yahoo.com
 

Implementation of intensive fish culture lead to fish waste accumulation. Integrated Multi-Trophic Aquaculture (IMTA) is one of the zero-waste aquaculture based intensive aquaculture system which is suitable to be developed to overcome this pollution issue in the shrimp and fish farming, especially in the location suffered water and land scarcity. In the integrated fish culture, primary organism (i.e. freshwater prawn Macrobrachium rosenbergii de Mann) excrete metabolite waste which is then recycled as nutrient input for secondary organisms (i.e. kissing gouramy Helostoma temminckii and  aquatic plants). This study aimed to observe  the removal effectivity of nitrogenous compounds and total phosphorus by aquaponic components (substrate and aquatics plants) in the IMTA-based polyculture fish farming. The prawn stocked in this experiment were sized of 1.5-2.5 g, while the gouramy were sized of 2-2.5 g of average individual weight. This experiment consisted of three treatments, i.e. (A) U30T100 (30 prawns/m2 and 100 kissing gouramy/m2), (B) U20T50 (20 prawns/m2 and 50 kissing gouramy/m2), (C) U30T50 (30 prawns/m2 and 50 kissing gouramy/m2), and (D) U30T100 (30 prawns/m2 and 100 kissing gouramy/m2). Fish were reared in aquaponic ponds which involved aquatic plant water spinach (Ipomoea aquatica Forsk.). This study was conducted for 120 days. Observed parameters included fish growth, survival rate and water quality performance, especially on ammonia (NH3), nitrite (NO2) and nitrate (NO3).  Samplings were performed in the interval of 10 days. Removal of total-P and total-N from water by aquatic plant water spinach  Ipomea aquatica were measured when it was harvested.

The results showed a different removal efficiency among  treatments. The highest removal of NH3, NO2, and NO3 were obtained in the treatment of C (U30T50), i.e. 64.70%, 4.85%, and 37.26%, respectively. While, the removal of those compounds in the other of A, B and D treatments were  55.91%, 42,55% and 35,95% for NH3; 3.62%, 3.59% and 3,38% for NO2, and 21.85%, 17.40% and 18.68% for NO3, respectively. The highest removal of Total-N and Total-P by aquatic plant water spinach (Ipomea Aquatica) were also found in treatment of C(U30T50), i.e. ranged from 25.97 to 34.1% and 39.25 to 45.38%, respectively. The highest final weight and survival rate of prawn and kissing gouramy were found in the treatment of C (U30T50) (Table 1). The stocking combination of 30 of prawn and 50 of kissing gouramy per m2 accomplished best performances in the IMTA-based fish polyculture system.