The Ability of Some Vegetables to Reduce Nutrients from Fish Culture Waste to Support Environmentally Friendly Floating Net Cage Culture

Abstract

Aquaculture activities with floating net cages are considered sources of organic pollution through the accumulation of uneaten feed and excretion of fish metabolism in reservoir waters. Thus it is required to have aquaculture technology that can reduce the pollutant load of floating net cages. One of the technologies used is plants to absorb nutrients, such as aquaponics technology applied in reservoir waters. This study aimed to determine the ability of vegetables to reduce nutrients from aquaculture activities. The study was conducted in 2016 in a laboratory-scale experiment using green spinach (Amaranthus hybridus L), red spinach (Amaranthus tricolor L), pakcoy (Brassica rapa), and water spinach (Ipomea reptans) to treat nutrient waste from a carp fish culture. The results showed that the highest NO2 removal efficiency was pakcoy (98.44%), followed by water spinach (88.15%). The highest removal efficiency of NO3 was water spinach (69.49%). The highest removal efficiency of PO4 was also water spinach (48.38%), while the highest removal efficiency of total organic matter was in water spinach (42.86%) and pakcoy (51.28%). Water spinach plants have the highest ability to absorb nutrients N, P, and organic matter so that they can be used as nutrient-reducing plants in friendly floating net cage culture.