To study the abundances of ichthyoplankton in the Nakdong River estuary, ichthyoplankton were sampled with standard net at approximately one month intervals from February, 1987 to January, 1988. Temperature and salinity in the study area showed large seasonal fluctuations due to the inflow of Nakdong River. Among 8 taxa of pelagic eggs occured in the study area, Sillago spp. occupied 37.3% of the total eggs; Coilia spp., 35.8%; Repomucenus spp., 13.7%; Engraulis japonica, 9.4%. These 4 taxa occupied 96.4% of the total eggs. Among 26 taxa of fish larvae, Engraulis japonica was the most abundant species and occupied 36.8% of the total larvae; Gobiidae, 15.3%; Repomucenus spp., 15.0%; Coilia spp., 14.0%; Hexagrammos otakii, 6.8%; Omobranchus elegans, 4.4%. These 6 taxa occupied 92.3% of the total larvae, The densities of pelagic eggs were more than 100 eggs/ 1,000m super(3) from May to October. The densities of larvae were 3.8~221.3 larvae/1,000m super(3). They were relatively high in May, July, and August.

To investigate the ichthyofauna and habitat type of the fish in Tamjin River system, Korea, fishes were collected with cast net (5×5 mm, 8×8 mm) and dip net (4×4 mm) at eight stations seasonally during five years from 2000 to 2004. 56 species belonging to 18 families were collected and 15 Korean endemic species(26.8%) were investigated. While Coreoperca kawamebari was occurred at every station, the number of individuals and composition were decreased. Anguilla marmorata was not collected and the exotic species didn't appeared. Dominant species were Zacco platypus(34.2%), Squalidus gracilis majimae (9.4%), Microphysogobio yaluensis(8.1%), Zacco temmincki(6.8%) and Acheilognathus lanceolatus(5.1%). The surveyed stations were clustered into 3 groups : up stream, main stream and estuary. With the cluster analysis using the relative abundance of major fishes at each habitat, fishes were separated into 5 habitat types : U (upstream type), UM (up and main stream type), M (main stream), ME (main stream and estuarine type), and E (estuarine type).