Risk Assessment in Ballast Water Management - Global Maritime Transport and Ballast Water Management: Issues and Solutions - page 141

Fig. 2 Map of large marine ecosystems (Source NOAA, http://www.lme.noaa.gov/ , last accessed
in November 2013)
two ports to be assessed is a strong indication that species of the donor port will
survive when released in the recipient port water.
The data needed to enable a RA using the environmental matching approach to
determine the degree of environmental similarity between the donor and recipient
environments (IMO 2007 ) include:
￿ the origin of the ballast water to be discharged in the recipient port,
￿ the biogeographic region of donor and recipient ports, and
￿ the average and range of environmental conditions, also considering seasonal
differences, in particular salinity and temperature.
The analysis of the environmental similarity may be followed by an evaluation of
species known to occur in the donor region, which tolerate extreme environmental
differences. If such species are found, a species-specifi c approach should be used
for RA associated with these species (IMO 2007 ). Such species include:
￿ species which migrate between fresh and marine environments to complete their
life-cycle (anadromous species, such as salmon spend most of their life in the sea
and return to fresh water to spawn, whereas the catadromous species, e.g., the
Chinese mitten crab, do the opposite);
￿ species with a wide tolerance of temperature (eurythermal species) or salinity
(euryhaline species).