The current and escalating extent of soil degradation, water scarcity and environmental concern
plaguing agricultural productivity, demands re-assessing the direction of food production. Aquaponics
is a concept relatively new to modern food production methods and can contribute to food security.
This study was conducted to establish sustainable aquaculture systems that maximize benefits and
minimize the accumulation of detrimental compounds and other types of negative impacts on both
natural and social environments. This study carried out at an average inflow rate of 1.28 m/day to
evaluate the operation of the aquaponics recirculation system (ARS) on nutrients removal and growth
and yield of African catfish as well as water spinach. A special design of ARS was used to provide
nitrification of fishery wastewater, where the combination of sands and gravels in hydroponics trough,
providing both surfaces for biofuel development and cultivation area for plants. Removal efficiencies
of 5-day biochemical oxygen demand (BOD5), total suspended solids (TSS), total ammonia nitrogen
(TAN), nitrite-nitrogen (NO2-N), nitrate-nitrogen (NO3-N), and orthophosphate (PO4
3-
) were 82%, 89%,
93%, 94%, 81%, and 80%, respectively. The feed conversion ratio (FCR) and specific growth rate
(SGR) of African catfish were 1.08 and 3.34% day-1
, respectively. The average water spinach
production was 3.56 kg per m2
. This study showed that ARS is a method of producing crop along with
a healthy protein source and among the best alternatives for achieving economic and environmental
sustainability.
The hydrology hydraulic model is established to assess environmental information on hydrology which
can be used to investigate causes of various environmental problems at the river and natural lake
catchment. This study reports on sediment concentrations at a river using a gravimetric method to
investigate the hydrology system at a lake catchment. The measurement was carried out at the
upstream, midstream, and downstream stations on the river in normal, rainy and post-rainy seasons.
The stations are located along the Chini River, which are connected to a catchment lake (located at
latitude 3°26’36.41”E-3°27’03.26”E and longitude 102°54’31.94”N-102°53’35.49”N). From the
measurements, it is estimated that on average 787.621 tonne/km2 of sediment is transferred into the
natural lake via Chini River annually. The correlation of statistical analysis between the sediment load
and discharge study was very significant (R2 = 0.980). There is a linear relation between the area of
the catchment and sediment load of the connecting river as supported by other studies in Malaysia.
The outcome of the study suggests that the high sedimentation is due to land use activity, existence of
the dam at the downstream of Chini River that traps the sediment, reverse flow from the Pahang River
into Chini River and riverbank erosion factors. From this study, the sediment control steps are
suggested such as creating conservation partially at the lake catchment, modifying the dam system,
riverbank erosion control, and application of “Monkey Cheek” system. These sediment control steps
may help to clean up the high suspended sediment at the whole lake system area, hence solving and
mitigating the environmental problems in the natural lake catchment.