where neither form of open ocean ezchange is practicable, ballast exchange may be accepted by the port State in designated areas; and
other ballast exchange options approved by the port State
9.2.2 Non-release or minimal release of ballast water
In cases where ballast exchmge or other treatment options are not possible, ballast water may be retained in tanks or holds. Should this not be possible, the ship should only discharge the minimum essential amount of ballast water in accordance with port States' contingency strategies.
9.2.3 Distharge to reception facilities
If reception facilities for ballast water and/or sediments are provided by a port Sute, they should, where appropriate, be utilized.
9.2.4 Emergent and new technologies and freatments
9.2.4.1 lf suitable new and emergent treatrnents and technologix prove viable, these may substitute for, or be used in conjmction with mrrent optiors. Such treahents could include thermal methods, filuatration disinfection including ultraviolet light, and other such means acceptable to the port State.
9.2.4.2 Resulg concerning the applicaion and efectiveness of new ballast water management technologies and associated control equipment should be notifed to the Organiztion with a view to evaluation and incorporation, as appropriate, into these Guidelines.
10 Port State considerations
The following is provided for the guidance of port State authorities inthe implemaladon of their ballast water management programme, and to assess risks in relation to the ballast water containing harmful aquatic organisms and pathogens.
10.1 Highly disparate conditions between uptake and discharge porfs
Sipificantly different conditions may exist between port(s) of origin and the port in which ballast water is discharged. Examples include feshwatr ballast being released into highly saline ports. There may be organisms capable of surviving such cxtreme transfers; however, there is a lower probability of species establishment under such transport events.
10.2 Ballast water age
The length of time during wbich ballast water is within an enclosed ballast tank may also be a factor in determining the ntmber of surviving orgamisms, because of the absence of light, decreasing nutrients and oxygeq changes of salinity and other factors. However, the maximum lenght of survival of organisms in ballast water varies, and in many cases is not known. Water of an age of 100 days should be considered the minimum for applving his consideration. Ballast water and sediments may contain dinoflagellate cysts and other organisms capable of surviving for a much longer lenger of time.
