Few data are available on distribution, abundance, and ecology of scyphozoans in the Northern California Current (NCC). This thesis is divided into four chapters, each of which contributes to our understanding of a different stage of the scyphozoan life history. The first study describes the settlement preferences of Chrysaora fuscescens planulae in the laboratory. Planulae were found to respond to the interaction of substrate and orientation. Artificial substrates were identified as viable habitat for C. fuscescens. In the second chapter, a population of scyphistomae in Charleston, Oregon were identified to species-level using DNA barcoding techniques. The third and fourth chapters focus on the medusa stage of the life history. Using surveys mailed to fishers in the Pacific Region, this study provides baseline data on the types and magnitudes of economic damages caused by jellyfish on different fisheries and helps assess fishers' perceptions of jellyfish population trends in the NCC. This thesis includes previously unpublished co-authored material.