Vessels and Ballast Water - Global Maritime Transport and Ballast Water Management: Issues and Solutions - page 29

Ballast Water Discharge Assessment

Different ballast water studies around the globe involved an assessment of ballast
water discharges in a port or wider area (e.g., AQIS 1993 ; Walters 1996 ; Wiley
1997 ; Carlton et al. 1995 ; Farley 1996 ; Dobes 1997 ; Cohen 1998 ; Hay and Tanis
1998 ; Behrens et al. 2003 ; Perkovi

et al. 2004 ). This is clearly one of the informa-
tion needed for understanding how biological invasions are facilitated (Bailey et al.
2011 ; Briski et al. 2012 ; Chan et al. 2013 ), and this information had impacted the
wider public opinion and consequently government administrations, policies etc.
It is also very important to understand the ballast water operation patterns to enable
provisions of adequate decision support tools for ballast water management (David
et al. 2012 ), i.e., horses for courses. However, having in mind the complexity of
ballast water operations, it becomes clear that such assessments are very challenging,
and that an accurate ballast water discharge assessment for each vessel call to a port,
especially for those that only partially load and unload cargo in the same ports, is
almost impossible.
A ballast water discharge assessment model was prepared during two ballast
water management studies conducted in Slovenia and the model was applied to the
Port of Koper data. For the purpose of a wider application of the model a detailed
model verifi cation study was conducted (David et al. 2012 ) and the model has been
applied in different studies to assess ballast water discharges in some ports around
Europe (EU FP7 VECTORS project, 6 IPA Adriatic BALMAS project 7 ). The model
can be used for the assessment of ballast water discharges in past years as well as for
a prediction of ballast water operation of a ship calling to a port. In more biological
terms, historical data may be helpful when studying vessels and ballast water
patterns through time and relating them to known introduced species, to assess
biological propagule pressure, as well as background data for RA assumptions.
In terms of ballast water management, the ballast water discharge assessment model
provides responsible authorities with many tools; e.g., for targeting vessels for
adequate BWM measures based on the risk posed, check for false BWM reporting,
targeting vessel for compliance monitoring, etc. Furthermore, model calculations
may also be used to identify the dimensions of land-based ballast water reception
facilities should it be planned to make such facilities available. A ballast water
discharge assessment is also helpful to evaluate the environmental acceptability of
ballast water treatment systems which use active substances (chemical treatment) to
kill organisms. The model may be used to calculate, e.g., the annual amount of ballast
water discharges, and in a worst case scenario where all ballast water discharged
was assumed to be treated with the same active substance, it could be evaluated if
the remaining toxicity of the ballast water at discharge is environmentally acceptable
(David et al. 2012 ).

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6 European Community's Seventh Framework Programme under Grant Agreement No. [266445]
for the project Vectors of Change in Oceans and Seas Marine Life, Impact on Economic Sectors
(VECTORS). http://www.marine-vectors.eu/
7 IPA Adriatic Cross-Border Cooperation Programme - strategic project Ballast Water Management
System for Adriatic Sea Protection (BALMAS), http://www.balmas.eu/