2 Definitions
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Statutory Documents - IMO Publications and Documents - Circulars - Ballast Water Management - BWM.2/Circular.42/Rev.2 – International Convention for the Control and Management of Ships' Ballast Water and Sediments, 2004 – (9 December 2020)... - Annex 1 – Guidance on Ballast Water Sampling and Analysis for Trial Use in Accordance with the BWM Convention and Guidelines (G2) - 2 Definitions

2 Definitions

 For the purpose of this Guidance, the definitions in the BWM Convention apply and:

  • .1 A sample means a relatively small quantity intended to show what the larger volume of interest is like.

  • .2 Representative sampling reflects the relative concentrations and composition of the populations (organisms and/or chemicals) in the volume of interest. Samples should be taken in accordance with the annex, part 1 and/or part 2 of the Guidelines on ballast water sampling (G2).

  • .3 Analysis means the process of measuring and determining the concentrations and composition of the populations of interest (organisms and/or chemicals) within the sample.

  • .4 An indicative analysis means a compliance test that is a relatively quick indirect or direct measurement of a representative sample of the ballast water volume of interest:

    • .1 an indirect, indicative analysis may include measurements whose parameters do not provide a value directly comparable to the D-2 standard, including biological, chemical or physical parameters (e.g. dissolved oxygen levels, residual chlorine levels, Adenosine triphosphate (ATP), nucleic acid, chlorophyll a, and that by variable fluorescence, etc. The practicalities, applicability and limitations of these methods should be understood before they are used in compliance testing;

    • .2 a direct measurement, which is directly comparable to the D-2 standard (i.e. the determination of the number of viable organisms per volume) may also be indicative if it has:

      • .1 a large confidence interval, or

      • .2 high-detection limits; and

    • .3 an indicative analysis is an analysis performed in accordance with sections 4.1 and 4.2.

  • .5 A detailed analysis means a compliance test that is likely to be more complex than indicative analysis and is a direct measurement of a representative sample used to determine the viable organism concentration of a ballast water volume of interest. The result of such measurement:

    • .1 should provide a direct measurement of viable organism concentration in the ballast water discharge which is directly comparable to the D-2 standard (number of viable organisms per volume);

    • .2 should be of sufficient quality and quantity to provide a precise measurement of organism concentration (+/- [X] organisms per volume) for the size category(ies) in the D-2 standard being tested for; and

    • .3 should use a measurement method with an adequate detection limit for the purpose for which it is being applied.

    • A detailed analysis is an analysis performed in accordance with the methods and approaches in sections 4.3 and 4.4. Detailed analysis should usually be undertaken on a sample taken in accordance with the procedures in section 4.4.

  • .6 Testing for compliance using indicative analysis and detailed analysis can employ a range of general approaches or standard methods. These approaches or methods are divided into those that sample a small proportion of the volume of interest to indicate or confirm compliance or a larger proportion of the volume of interest that can be utilized to indicate and confirm compliance. Those that provide a wide confidence interval should not be used to confirm compliance unless the result and confidence limit are demonstrably over the D-2 standard as measured directly or indirectly. Approaches/Standards are highlighted in sections 4.1, 4.2 and 4.4 for indicative analysis and sections 4.3 and 4.4 for detailed analysis.

  • .7 Method means a detailed step-by-step analysis procedure (for indicative or detailed analysis) or sampling methodology, which the laboratory or organization undertaking the work can follow, be audited against and be accredited to.

  • .8 Approach means a detailed step-by-step analysis procedure (for indicative or detailed analysis) or sampling methodology, which the laboratory or organization undertaking the work can follow. These procedures will not have been validated by an international or national standards organization.

  • .9 General approach means a conceptual description or broad methodology of sample collection or analysis.

  • .10 The precision of a measurement system is the degree to which repeated measurements under unchanged conditions show the same results.

  • .11 The detection limit is the lowest concentration level that can be determined to be statistically different from a blank sample within a stated confidence interval. Limits of detection are method and analysis specific.

  • .12 Plankton means phytoplankton (e.g. diatoms or dinoflagellates) and zooplankton (e.g. bivalve larvae or copepods) that live in the water column and are incapable of swimming against a current.

  • .13 Confidence interval means a statistical measure of the number of times out of 100 that test results can be expected to be within a specified range. For example, a confidence level of 95% means that the result of an action will probably meet expectations 95% of the time.

  • .14 Operational indicator means a parameter used to monitor and control the operation of the BWMS as defined during testing for Type Approval, e.g. limit values of physical or chemical parameters such as flow rates, dose, etc.

  • .15 Performance indicator means a biological parameter (e.g. ATP, chlorophyll a, direct counts) used to estimate or measure the performance of the BWMS in achieving the D-2 standard.

Parent topic: Annex 1 – Guidance on Ballast Water Sampling and Analysis for Trial Use in Accordance with the BWM Convention and Guidelines (G2)
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