The purpose of this study was to analyze the trophic structures and the energy flows
in the lower reaches of the Nakdong River using the Ecopath model (Walter et al., 1997). The
sampling and analyses were carried out at 6 sampling sites of the lower reaches of the Nakdong
River on May and November in 2007. Total of 9 groups detritus, macrophytes, phytoplankton,
zooplankton, zoobenthos, Cyprinus carpio, Hemibarbus labeo, Micropterus salmoides and other
fishes were considered to assess the trophic relationship, energy flows and interactions among
them in the study. As a result, it was concluded that the lower reaches of the Nakdong River was
consisted of producers (Detritus, Macrophytes, Phytoplankton), primary consumers (Zooplankton,
Zoobenthos, Cyprinus carpio, Hemibarbus labeo, Other fishes) and secondary consumer (Micropterus
salmoides). The total system throughput was estimated at 2.7 kg m-2 year-1 including a consumption
of 52%, exports of 9.1%, respiratory flows of 18.0% and flows into detritus of 20.9%.
MTI(mixed trophic impacts) analysis demonstrated that Pseudobagrus fulvidraco had positive impact
on Cyprinus carpio, Carassius cuvieri and Carassius auratus. On the other hand, other fishes
had negative impact on Cyprinus carpio, Carassius cuvieri and Carassius auratus. Also, all the functional
groups except detritus had a negative impact on themselves.
The purpose of this study was to analyze the trophic structures and the energy flows
in the lower reaches of the Nakdong River using the Ecopath model (Walter et al., 1997). The
sampling and analyses were carried out at 6 sampling sites of the lower reaches of the Nakdong
River on May and November in 2007. Total of 9 groups detritus, macrophytes, phytoplankton,
zooplankton, zoobenthos, Cyprinus carpio, Hemibarbus labeo, Micropterus salmoides and other
fishes were considered to assess the trophic relationship, energy flows and interactions among
them in the study. As a result, it was concluded that the lower reaches of the Nakdong River was
consisted of producers (Detritus, Macrophytes, Phytoplankton), primary consumers (Zooplankton,
Zoobenthos, Cyprinus carpio, Hemibarbus labeo, Other fishes) and secondary consumer (Micropterus
salmoides). The total system throughput was estimated at 2.7 kg m-2 year-1 including a consumption
of 52%, exports of 9.1%, respiratory flows of 18.0% and flows into detritus of 20.9%.
MTI(mixed trophic impacts) analysis demonstrated that Pseudobagrus fulvidraco had positive impact
on Cyprinus carpio, Carassius cuvieri and Carassius auratus. On the other hand, other fishes
had negative impact on Cyprinus carpio, Carassius cuvieri and Carassius auratus. Also, all the functional
groups except detritus had a negative impact on themselves.