Abstract
The temporal patterns of nutrient inputs into coastal marine systems are affected by changes in precipitations, hydrological runoff, and release of treated wastewater. Those further affects quantitatively and qualitatively marine primary producers. We conducted a continuous incubation experiment of the diatom species Skeletonema marinoi-dohrnii under two different supply patterns of inorganic nitrogen and phosphorous: short-term intensive supply (pulse treatment) and continuous low-concentration supply (press treatment). In the pulse treatment, the concentration of diatom cells showed apparent production-wethering cycles, and reached relatively higher concentrations at the steady state. While the content of essential fatty acids in the diatom cells was also relatively higher in the pulse treatment, the contents of some of the saturated and monosaturated fatty acids were higher in the diatoms produced under the press treatment. In the press treatment, the continuous depletion of nutrients may have caused an adaptive response of the diatoms leading to their lower growth rate as well as lower contents of the essential fatty acids.
