What are the effects of sewage waste discharge (from vessels) on coral reefs?
Typically vessel sewage impacts manifest themselves in the form of excess nutrients and pathogens in the water column. In poorly flushed areas, such as bays and inlets, this results in excess macro-algae growth that will smother corals and impede their growth. It will also result in an excess of micro-algae or phytoplankton growth. These phytoplankton blooms may pose a health risk to humans while also being toxic to other species. When the phytoplankton bloom crashes the bottom waters may become anoxic and therefore toxic to bottom dwelling organisms. The Great Barrier Reef Marine Park Authority has vessel sewage Regulations that require vessels with holding tanks to retain sewage onboard and only discharge at least 500m away from reefs. The Great Barrier Reef Marine Park Authority is encouraging the development of pump-out facilities to allow for collection and treatment of ship sourced sewage, and has developed guidelines for best environmental construction of marina facilities to in
