Mycosporine-like amino acids (MAAs) are found in a variety of prokaryotic and eucaryotic algae, as well as higher plants, fungi, and animals. These compounds function as a photoprotective sunscreen to prevent ultra-violet light damage. MAAs may thus be one of the competitive advantages that facilitated development of ozone (by oxytrophs), and thereby may be a competitive advantage for the proliferation of cyanobacteria and other harmful algal species. Numerous difficulties exist with assessment of MAAs, including identification of the compounds, conversion of isomers during HPLC preparation as a result of pH shifts, as well as the ecological implications of the presence, concentration, and forms of these compounds (see J. Phycology 35: for relevant papers). This symposium will provide opportunities for inter-calibration of laboratories involved in MAA analyses, suggestions regarding standardization of extraction protocols, as well as results from field and laboratory based studies.

Key words: macroalgae, microalgae, mycosporine-like amino acids