The effects of the addition of nutrients (nitrate: N; phosphate: P; and vitamin B₁) and trace metals (iron: Fe; Copper: Cu; and selenium: Se) on the growth of Gymnodinium catenatum, which was isolated from Korean coastal waters, were investigated. The Korean isolate of G. catenatum grew under a wide range of concentrations of N and P. Whilst high concentrations of N (> N: P ratio of 23.5) did not stimulate the growth rate, an enhanced growth rate and cell density were observed with the addition of P. The experimental addition of vitamin B₁ revealed that G. catenatum is not dependent on vitamin B₁ for growth. Moreover, the addition of Fe and Cu resulted in no significant differences in the growth patterns and rates of G. catenatum between the controls and treatments. It is thus possible that growth of the Korean isolate of G. catenatum does not require high concentrations of Fe and Cu. However, the cell densities were enhanced in the stationary phases of treatments upon addition of Se, and the maximum cell densities were higher than those in the culture experiments upon additions of other nutrient and trace metals. Our findings indicate that G. catenatum prefers P and Se for proliferation, rather than other nutritional sources.

Late Holocene diatoms were identified from four sediment cores from the Gonggeomji Wetland in Korea. In total, 52 diatom species belonging to three classes, 21 families, and 29 genera were investigated. Of these, 14 species were new records for Korea: Caloneis wardii, Cocconeis klamathensis, Encyonema vulgare, Eunotia myrmica, Fallacia californica, Gomphonema asiaticum, Gomphonema insigniturris, Gomphonema neoapiculatum, Gomphonema tumens, Pinnularia fusana, Pinnularia parvulissima, Punctastriata lancettula, Sellaphora capitata, and Staurosira dimorpha. Eleven taxa could not be identified to the species level. All identified diatoms are illustrated by high-quality scanning electron microphotographs, reference taxonomic data, dimensions of the observed cells, and information on ecology and distribution are included.