A distributed real-time system for monitoring and characterizing the underwater soundscape is presented in the context of environmental impact baseline assessment for the ocean energy industry. We discuss the development and deployment of an offshore acoustic monitoring buoy with real-time acoustic signal transmission capabilities and an accompanying sea floor-based sensor platform utilizing hydrophone and particle velocity detector technologies. In addition, high bandwidth point-to-point communications for the buoy to shore communications and data streaming architectures with failover protection in a high speed networking environment are described. An integrated stream analytical processing platform has been developed for the real-time signal processing of multiple high bandwidth acoustic data streams in parallel that incorporates multiple preprocessing steps as well as event detection and classification techniques. Real-time dynamic filtering approaches are also being developed using supplemental data such as sea state and weather to compensate for varying environmental conditions. These technologies are being incorporated in the Marine Institute of Ireland's multipurpose research and development SmartBay Ireland system, which provides a flexible and agile monitoring and management platform that is being extended to include additional environmental variables relevant to the ocean energy domain. The platform is deployed for the Galway Bay Quarter Scale Wave Energy Test Site and will capture, store, and analyze one year of continuous acoustic data., © 2013 IEEE.