Risk Assessment in Ballast Water Management - Global Maritime Transport and Ballast Water Management: Issues and Solutions - page 134

Risk Assessment of Harmful Species Introductions
Most RAs of marine biological invasions used in the past by different regulatory
institutions are based on, or refl ect the Offi ce Internationale des Epizooties (OIE)
framework (Hewitt and Hayes 2002 ). Here bioinvasions are understood as the
culmination of a chain of events (see chapter “ The Transfer of Harmful Aquatic
Organisms and Pathogens with Ballast Water and Their Impacts ” ). A RA process to
determine invasiveness requires an assessment of each event to attribute the degree
of probability of successfully proceeding through that stage. The fi nal RA of a 'suc-
cessful' invasion is the result of the degree of probability attributed to each sepa-
rately evaluated event. The OIE framework is effi cient and simple to use for
bioinvasions. Its effi ciency may be improved further through the inclusion of quan-
titative RA fundamental principles. The quantitative RA includes fi ve steps: (1) -
hazard identifi cation, (2) - frequency assessment, (3) - consequence assessment,
(4) - risk estimation, and (5) - uncertainty analysis (e.g., Hayes 2000 ). The quanti-
tative RA approach was developed for the application in complex industrial sys-
tems, but its constituent techniques and principles may also be adopted successfully
within complex ecological systems.
An alternative approach bases the bioinvasion RA on environmental matching
between the points of origin and destination (i.e., ballast water donor and recipient
regions). One example of such an approach is that of the Queensland Ports
Corporation, Australia which is based on a comparison of 40 environmental param-
eters (Hilliard and Raaymakers 1997 ). Other approaches have also addressed the
issue of including environmental conditions including: a RA considering 34 param-
eters (GloBallast 2003 ), a German study based on climatic conditions and salinity
(Gollasch 1996 ), a U.S. study considering salinity comparison alone (Carlton 1985 ),
and a Slovenian study considered salinity as the only environmental parameter next
to other species specifi c considerations (David 2007 ). In addition, an environmental
match related RA was prepared for the Nordic Council of Ministers (Gollasch and
Leppäkoski 1999 ) which was further developed for HELCOM (Leppäkoski and
Gollasch 2006 ; Gollasch and Leppäkoski 2007 ).
Another approach is to consider target species, which was earlier adopted by the
U.S. and Australia. This approach is based on a selection of species whose invasive-
ness in the examined area is likely and was confi rmed in other areas. These RA
activities resulted in two lists: 'America's Least Wanted' and the Australian 'Target
Species List'.
These RA approaches may be supplemented by other elements. GloBallast's
RA, further to the environmental matching method, includes some target species
and additional risk quantifi ers, such as voyage length and ballast tank size
(GloBallast 2003 ). DNV's EMBLA also includes numerous parameters (Behrens
et al. 2002 ; Endresen et al. 2004 ). Environmental matching combined with vessel
voyage lengths and a target species list was also used in the Baltic to assess the
risk of non-indigenous species introductions (Gollasch and Leppäkoski 1999 ,
2007 ). The Slovenian RA included ballast water sampling to confi rm the presence