Ingangsdatum: 04-07-1991 7.3.1
In the absence of more scientifically based means of control, exchange of ballast water in
deep ocean areas or open seas currently offers a means of limiting the probability that fresh water
or coastal species will be transferred in ballast water. Responsibility for deciding on such action
must structural factor and influences at the time
Unlike coastal and estuarine waters that are rich in nutrients and life forms, deep ocean water
or open seas contain few organisms. Those that do exist are unlikely to adapt readily to a new
coastal or fresh water environment, hence the probability of transferring unwanted organisms,
through ballast water discharges, can be greatly reduced by ocean or open sea ballast exchanges
preferably in water depths of 2,000 m or more. In those cases where ships do not encounter water
depths of at least 2,000 m, exchange of ballast water should occur well clear of coastal and
estuarine influences. there is evidence to suggest that, despite contact with water of high salinity,
the cysts of some organisms can survive for protracted periods in the sediment within ballast tanks
and elsewhere on a ship. Hence, where ballast water exchange is being used as a control measure,
care should be taken to flush out ballast tanks, chain lockers and other locations where silt may
accumulate, to dislodge and remove such accumulations, wherever practicable.
Care should also be taken when removing sediment deposits while a ship is in port or in
coastal waters to ensure that the sediment is not disposed of directly into adjacent waters. Sediment
should be removed to land-fill locations designated by the port State Authority or, alternatively,
sterilized to kill all living organisms that it may contain prior to being discharged into local water
bodies or otherwise disposed.
Ships likely to be required to exchange ballast during a voyage should take into account the
stability to be maintained at all times to values not less than those recommended by the
Organization (or required by the Administration);
longitudinal stress values not to exceed those permitted by the ship's classification society
with regard to prevailing sea conditions; and
exchange of ballast in tanks or holds where significant structural loads may be generated by
sloshing action in the partially filled tank or hold to be carried out in favourable sea and
swell conditions such that the risk of structural damage is minimized.
Where the requirements of paragraph 7.3.4 cannot be met during an "at sea" exchange of
ballast water, a "flow through" exchange of ballast water may be an acceptable alternative for those
tanks. Procedures for exchange of this type should be approved by the Administration.
Where the requirements of paragraph 7.3.4 can be met during an "at sea" exchange of ballast
water, before taking on exchange of ballast water, tanks should be drained until pump suction is
lost. this will minimize the likelihood of residual organism survival.
Where a port State Authority requires that an "at sea" exchange of ballast water, and, due to
weather, sea conditions or operational impracticability such action cannot be taken, the ship should
report this fact to the port State Authority prior to entering its national waters, so that appropriate
alternative action can be arranged.
Alternative action will also be necessary in those instance where ships may not leave a
continental shelf during their voyage. Unless specific alternative instructions gave been issued by a
port State Authority applying ballast water and sediment controls, ships should report
non-compliance prior to entering the port State's waters.
Port State Authorities applying ballast water exchange and sediment removal procedures may
require ships to complete a ballast water control form or some other acceptable system of
reporting. A model form for this purpose is in the appendix. Port State Authorities should arrange
for such reporting forms to be distributed to ships, together with instructions for completion of the
form and procedures for its return to the appropriate authorities.
In those cases where a ship arrives at a port without having carried out an "at sea" ballast
water exchange, or has otherwise failed to carry out any alternative procedures acceptable to port
State Authorities, the ship may be required to proceed to an approved location to carry out the
necessary exchange, treat the ballast water "in situ", seal the ballast tanks against discharge in the
port State's waters, pump the ballast water to a shore reception facility, or prove, by laboratory
analysis, that the ballast water is acceptable.
To facilitate administration of ballast water exchange and sediment removal procedures on
board ships, a responsible officer familiar with those procedures should be appointed to maintain
appropriate records and to ensure that all ballast water exchange and sediment removal procedures
are followed and recorded. Written ballast water and sediment removal procedures should be
included in the ship's operational manual.
Port State Authorities applying ballast water exchange and sediment discharge procedures
may wish to monitor compliance with and effectiveness of their controls.
Effectiveness monitoring may also be undertaken by port State Authorities, by taking and
analysing ballast water and sediment samples from ships complying with prescribed exchange
procedures, to test for the continued survival of unwanted aquatic organisms and pathogens.
Where ballast water or sediment sampling for compliance or effectiveness monitoring is
being under taken, port State Authorities should minimize delays to ships when taking such
samples. Use of plankton nets, either by a vertical tow through ballasted deep tanks or cargo
holds, or by attachment to an open firemain hydrant, suitable cross-connected to the ballast main,
is one suggested means of ballast water sapling. Sediment samples may be taken from areas where
sediment is most likely to accumulate such as around outlet pipes, bulkhead and hold corners, etc.
to the extent that these are accessible. Appropriate safety precautions must be employed wherever
the taking of water or sediment samples requires tank entry.
Port State Authorities may also wish, subject to relevant safety considerations, to sample
sediment in suction wells, chain lockers or other areas where sediment may accumulate.
In some cases, ships bound for ports which apply strategies for preventing the introduction
of unwanted aquatic organisms and pathogens from ships' ballast water and sediments may avoid "
at sea" exchange of ballast water, or other control procedures, by having their ballast water or
harbour source samples analysed by a laboratory that is acceptable to the port State Authority.
where sampled and analysed ballast or harbour source water is found to be free from unwanted
aquatic Port State Authorities may, an analyst's certificate, attesting to that fact, should be made
available to port State Authorities. When analysis of ballast or harbour source water or sediment is
being used as a control procedure, port State Authorities should provide Administrations with a
target listing of unwanted aquatic organisms or pathogens.
Port State Authorities may sample or require samples to analyse ballast water or sediment,
before permitting a vessel to proceed to discharge its ballast water in environmentally sensitive
locations. In the event that unwanted aquatic organisms or pathogens are found to be present in the
samples, ships may be prohibited from discharging ballast or sediment, except to shore reception
facilities or in designated marine areas.