Ballast water transport of non-indigenous zooplankton to Canadian ports

Ballast water is one of the primary transport vectors for the transfer and introduction of non-indigenous zooplankton (NIZ). Regulations require vessels from overseas to conduct mid-ocean exchange before discharging ballast in Canadian ports. Intracoastal vessels from nearby ports may be exempt from exchange, whereas intracoastal vessels from more distant ports are required to exchange. Zooplankton in the ballast water of transoceanic exchanged (TOE), intracoastal exchanged (ICE), and intracoastal unexchanged (ICU) vessels arriving at Canada’s west (WC) and east (EC) coasts were examined.