There have to be enough primary containers (for example tanks) to house the aquatic organisms the facility will hold. Where aerosols carrying viable GMOs (for example larvae of some crustaceans and of bivalves, or GM micro-organisms), or carrying reproductive material might be produced, those aerosols must be kept from escaping the primary container; the guideline suggests sealed primary containers or filtering exhaust air and water as possible options.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.