This thesis has advanced understanding of the relationships between dissolved organic matter (DOM) quality and its indirect and direct effects on aquatic organisms, and points to new directions for future work. DOM in natural waters is a heterogeneous mixture of organic molecules with direct and indirect influences on aquatic organisms. Aquatic natural organic matter (NOM) is composed of extremely heterogeneous mixtures of organic compounds. The major constituents of NOM are humic substances generated from dead organic biomass through humification, a process which is poorly understood yet one of the most important ecosystem functions on the earth.Doctor of Philosoph
