Risk Assessment in Ballast Water Management - Global Maritime Transport and Ballast Water Management: Issues and Solutions - page 157

￿ If the salinity difference between donor and recipient ports is less than between
freshwater (<0.5 psu) and polyhaline conditions (>18 psu), than a species-
specifi c RA is needed.
￿ Species-specifi c RA should consider non-indigenous, cryptogenic and harmful
native species to identify target species, and human pathogens.
￿ The presence of any human pathogens in the donor port means unacceptable risk.
￿ The presence of any target species in the donor port not yet present in the recipi-
ent port, and which could not easily spread to the recipient port naturally, means
an unacceptable risk.
￿ The presence of any target species in the donor port and its occurrence in lower
abundance in the recipient port, and which could not easily spread to the recipi-
ent port naturally, means an unacceptable risk.
￿ The presence of any target species in the donor port also present in the recipient
port, which could not easily spread to the recipient port naturally, but is under a
control or eradication program in the recipient port, means unacceptable risk.

For a species-specifi c RA, an assessment is deemed unacceptable risk if it iden-
tifi es at least one target species that meets all of the following:

￿ likely to cause unacceptable harm;

￿ present in the donor port or biogeographic region, but not in the recipient port;

￿ likely to be transferred to the recipient port through ballast water; and

￿ likely to survive in the recipient port.

The Risk Assessment Model for Granting Exemptions

In the fi rst step the data reliability is checked to ascertain that this is at the required
level. If the data are not reliable the process ends with an unacceptable risk. If the
data quality is adequate, then the model proceeds to the environmental matching RA
with verifi cation of the water salinity in the donor and recipient ports. If the salinity
is of an acceptable difference, i.e., between freshwater (<0.5 psu) and fully marine
conditions (>30 psu), the process ends with an acceptable risk result. If this condi-
tion is not met, than the model proceeds to verify if the salinity difference is between
freshwater (<0.5 psu) and euryhaline conditions (>18 psu). If this condition is met
then the model proceeds with a species-specifi c approach, but considering human
pathogens and only high salinity tolerant target species. While if none of the envi-
ronmental (miss)-matching conditions are met, then the process proceeds with a
complete species-specifi c approach, i.e., considering all target species and human
pathogens. The model in the next steps checks if species could spread naturally to
the recipient port, if these are already present in the recipient port and in which
abundance, and if these are under any control or eradication program. The RA result
depends on answers to all these questions.