Figure 3 - uploaded by John J Cullen
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The influence of method precision on the efficacy of TA testing. Stain-Motility (S-M) refers to the FDA/CMFDA + Motility methodology. This figure is from Cullen (2018), where the context is fully explained.
Source publication
The Vessel Incidental Discharge Act of 2018 (VIDA) became law on December 4, 2018, instructing the United States Coast Guard (USCG) in coordination with the United States Environmental Protection Agency (USEPA), to publish a draft policy letter, “based on the best available science, describing type-approval testing methods and protocols for ballast...
Contexts in source publication
Context 1
... it would be concluded that the MPN-based methods were inferior to Stain-Motility methods because they are subject to random measurement error that could lead to a greater rate of false approvals of BWMS. If type approval depended on the results of single test cycles, the conclusion would hold (Figure 3, single test). However, it was demonstrated quantitatively that the requirement for 5 consecutive successful results in BWMS type approval testing fundamentally changes the relationship between a method's precision and its effectiveness in ensuring compliance with regulations. ...
Context 2
... it was demonstrated quantitatively that the requirement for 5 consecutive successful results in BWMS type approval testing fundamentally changes the relationship between a method's precision and its effectiveness in ensuring compliance with regulations. As shown in Figure 3 (5-test results), false approval due to random measurement error is effectively eliminated for both MPN and the Stain-Motility method because it requires 5 consecutive underestimates, and false rejection due to a single erroneously high measurement is more likely for the method with wider confidence limits, imposing an extra margin of safety for MPN. The results of this study reverse conventional interpretations of efficacy based on method precision alone: ...
Context 3
... criteria for comparative validation included a maximum limit of detection for MPN (easily satisfied: see Section 6.1) and the demonstration that MPN showed no negative bias relative to Stain-Motility. The latter criterion is conservative because as illustrated in Figure 3, an MPN-based method will be more effective than a Stain-Motility method in TA testing if neither is biased relative to the other. Further, the MPN-based method can have superior efficacy even if it underestimates living organisms (i.e., has a negative bias) relative to Stain-Motility (Cullen, 2018). ...
Context 4
... magnitude of bias from including non-reproductive organisms in enumerations of living heterotrophs after treatment with UV can be estimated roughly by comparing FDA/CMFDA enumerations with those from MPN (Blatchley III et al., 2018). Results for 307 separate samples (their Fig. 3) indicate that after treatment with polychromatic UVC radiation, reproductive organisms as enumerated with MPN were overestimated by a factor of roughly 1000 when assessed with FDA/CMFDA. That is, about 99.9% of the UV-treated organisms showed signs of life but could not reproduce. Considering that concentrations of heterotrophs are ...
Context 5
... statistical consequences of the 5-test requirement in TA testing (Section 6.2.2) provide a margin of safety that allows MPN testing methods to perform effectively even under the influence of moderate negative bias. That is, true concentrations of viable organisms in treated discharge must be below 5 per mL rather than the nominal standard of 10 per mL for a BWMS to have a 50% probability of passing ( Figure 3). Available science suggests strongly that applications of MPN+M would satisfy stringent acceptance criteria (Cullen, 2018, Table 2), but there is not yet enough available information to apply the framework's single-method validation criteria rigorously to either MPN+M or FDA/CMFDA + Motility methods. ...
Citations
... This means the work at IMO (and elsewhere) on BWM subject will keep a priority, and it is expected that many new outcomes will be delivered, which likely also result in further amendments to the BWM Convention and its supporting guidelines and guidance documents. At the most recent MEPC meeting considered here (MEPC 80, July 2023), it became clear that the development and validation of new analysis methods of ballast water samples (Compliance Monitorng Devices) becomes more prominent (see also Peperzak et al. 2018;Cullen 2018Cullen , 2019Lundgreen et al. 2018;Outinen and Lehtiniemi 2019;IMO 4 Vectors of Change in Oceans and Seas Marine Life, Impact on Economic Sectors (VECTORS), European Community's Seventh Framework Programme (FP7/2007. 5 Ballast Water Management System for Adriatic Sea Protection (BALMAS), IPA Adriatic Cross-Border Cooperation Programme strategic project. ...
Not to repeatedly write another general ballast water management (BWM) introduction chapter, we here instead update the reader on selected ballast water issues with a focus on new developments since the first edition of this book was published in 2015. Possibly the most important key achievement in BWM in these times was the entry into force of the International Convention for the Control and Management of Ships’ Ballast Water and Sediments, 2004 (BWM Convention) in September 2017. Undoubtedly, this will globally be a major step to manage ballast water as species transfer vector. Further, we described the amendments to guidelines, which support the BWM Convention implementation and which were agreed since the first edition of this book was released. To illustrate the BWM Convention implementation complexity, we present, as an example, the phase-in schedule of the Ballast Water Exchange Standard (Regulation D-1) and Ballast Water Performance Standard (Regulation D-2). This phase-in ends in 2024, and from this time onwards, all ballast water discharges from ships, for which BWM Convention applies, need to meet the D-2 standard. We further report that the number of approved BWM systems (BWMS) has more than doubled since the first edition of this book was released, and also new technologies are considered for the purpose of ballast water management. We further report that vessel inspections for compliance with BWM requirements have begun and that penalties are in place for non-compliance with BWM standards. Further, we describe that, according to IMO guidance, biological BWMS commissioning testing is now required after each BWMS installation on each vessel. In addition, the intention of this book and a brief overview of its content are also included below.
