Risk Assessment in Ballast Water Management - Global Maritime Transport and Ballast Water Management: Issues and Solutions - page 132

Risk Assessment in Ballast Water
Management

Matej David , Stephan Gollasch , Erkki Leppäkoski , and Chad Hewitt

Abstract The risk assessment (RA) developed according to the BWM Convention
is the most recently agreed global RA for bioinvasions. It was developed to enable
a selective ballast water management (BWM) approach according to the BWM
Convention and the G7 Guidelines. It describes three different BWM RA methods,
“environmental matching”, “species' biogeographical” and “species-specifi c”
RA. The environmental matching RA between the areas of ballast water origin and
discharge considers non-biological parameters as surrogates for the species survival
potential in the new environment. The species' biogeographical RA identifi es spe-
cies with overlapping distribution in the donor and recipient ports and biogeographic
regions which is taken as direct indications of the similarity of the environmental
conditions and hence species survival in the new environment. The species-specifi c
RA is focused on life history information and physiological tolerances to identify a
species' physiological limits estimating its potential to survive or complete its life
cycle in the new environment and considers target species. There are two fundamen-
tally different RA approaches under the BWM Convention, the selective and the
blanket approach. A blanket approach means that all ships intending to discharge
ballast water in a port are required to conduct BWM. The selective approach means
that appropriate BWM measures are required depending on different risk levels
posed by the intended ballast water discharge. In one instance ships may be
exempted from BWM requirements provided that the risk level of a ballast water
discharge is acceptable. In another instance, if the risk is identifi ed as (very) high,