Assessing the Relationship Between Propagule Pressure and Invasion Risk in Ballast Water (2011) / Chapter Skim
Currently Skimming:
5 Other Approaches to Setting a Ballast Water Discharge Standard
5 Other Approaches to Setting a Ballast Water Discharge Standard
Pages 114-121
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 114... ...
California's Zero Detectable Living Organism standard setting approach, and (3) Natural Invasion Rates as a basis for a standard.
|
From page 115... ...
had little or no invasion history prior to colonizing North America, and expert opinion based on invasion history likely would have concluded that these species pose little risk. While risk assessments based upon performance (effect)
|
From page 116... ...
The ICES Study Group, predominantly aquatic invasion biologists, reviewed available data sets to date related to concentrations of organisms in untreated ballast, characterizing the range and distribution across many vessels for different types of organisms. This expert group recommended that to "significantly reduce the risk of invasions associated with ballast water beyond the present situation, permissible discharge concentrations identified by any treatment/management standards should fall greatly below the median values observed presently for untreated/unmanaged ballast water." This would have the effect of reducing high concentration discharges, and the group considered empirical and theoretical evidence indicating that invasion likelihood increases with increasing concentration (International Council for the Exploration of the Sea, 2003)
|
From page 117... ...
This group took a precautionary approach, while acknowledging that enforcement against a standard of zero living organisms has practical constraints. Unlike the IMO D-2 standard, the zero detectable discharge standard applies to all size classes and taxa (if the word "living" may be considered applicable to viruses)
|
From page 118... ...
NATURAL INVASION RATES The Natural Invasion Rate (NIR) approach to standard setting incorporates both a risk assessment and a risk management component.
|
From page 119... ...
identified some difficulties inherent in estimating natural invasion rates and provided coarse estimates based on expert opinion that span three orders of magnitude. Providing any validation or better assessment is problematic because there is insufficient information to determine a natural invasion rate.
|
From page 120... ...
. In the area of discharge limits for live organisms in ballast water, expert opinion has been tapped as an alternative to scientifically derived standard setting processes in light of scientific uncertainties.
|
From page 121... ...
2010. Using a self-organizing map to predict invasive species: sensitivity to data errors and a com parison with expert opinion.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.