Ballast Water Sampling and Sample Analysis for Compliance Control - Global Maritime Transport and Ballast Water Management: Issues and Solutions - page 170

Introduction
The purpose of a ballast water sampling studies was so far limited to general scientifi c
interest, awareness raising or the determination of organism numbers per water volume.
Each study objectives triggers the use of different sampling gear and strategies.
Further the high variability of organism type, size and behaviour observed in ballast
water samples combined with the complexity of physical and chemical characteris-
tics of ballast water implies to use a variety of sampling methods to catch all organ-
isms present in the water (e.g., Medcof 1975 ; Hallegraeff and Bolch 1991 ; McCarthy
and Khambaty 1994 ; Gollasch 1996 ; MacDonald and Davidson 1997 ; Hay et al.
1997 ; Sutton et al. 1998 ; Oemcke and van Leeuwen 1998 ; Lenz et al. 2000 ; Ruiz
et al. 2000 ; Murphy et al. 2002 ; Gollasch et al. 2003 ; David and Perkovic 2004 ;
David et al. 2007 ; IMO 2010a ).
In this chapter we focus on compliance control sampling with the standards as
set forth in the IMO BWM Convention. However, before we describe suitable com-
pliance control sampling methods and approaches, we briefl y address how different
sampling results are when different sampling methods are used. This is addressed
here to amplify the need for a harmonised sampling approach to avoid that the bal-
last water of a vessel is proven compliant in one port, but would not be proven
compliant in another port just because of different sampling methods used.
During a comparison of sampling technologies previously used for ballast water
studies it was observed how different the performance of the individual methods
was. In this experiment it became clear that some methods over- and other methods
undersample the organism concentration. Therefore, by the selection of the wrong
sampling method samples may be wrongly identifi ed as compliant with BWM stan-
dards although the organism concentration could have been above the compliance
threshold.
Noting the infl uence on results by the use of different sampling methods and
approaches a clear need for an international harmonised ballast water compliance
control sampling approach was stated. Consequently the ballast water working group
of IMO developed a sampling guideline, i.e., Guidelines for Ballast Water Sampling
(G2 Guidelines), adopted in 2008. The G2 Guidelines and all additional BWS related
developments at IMO prepared after the adoption of G2 were reviewed and taken
into account during the preparation of this chapter. This refers especially to the:
• aide-memoire for the sample analysis developed at BLG13 (March 2009). BLG
agreed that a detailed guidance document on sampling procedures could not yet
be developed because of the lack of results of relevant sampling studies (IMO
2009 ). This aide-memoire is limited to different types of sample analysis, includ-
ing recommendations for indicative and detailed sample processing.
• preparational documents of a BWS circular (e.g., IMO 2010a , b , c , d , e ). This
IMO Circular was aimed to provide guidance on BWS and sample analysis,
including sample representativeness and sample analysis protocols.
• report of the Ballast Water and Biofouling Working Group from the last BLG
meeting (BLG17, February 2013). It contains the draft BWS circular (i.e.,