Indicative analysis techniques offer Port State Control inspectors a ballast breathalyser for quickly assessing vessel compliance
“Indicative analyses can be achieved by relatively fast indirect or direct measurements of a representative sample from the ballast water tank”
Despite the IMO’s Ballast Water Management Convention (BWMC) coming into force in 2017, the introduction of invasive species continues unabated fourteen years after the introduction of the convention. Aquatic invasions cost the U.K. national exchequer an estimated £1.7 billion every year and with a projected increase in global ship traffic, the environmental impact and costs are likely to grow.
Globally up to 70,000 ships will need to comply with international discharge regulations set out by the Convention. Its revised timetable, arising from the seventy-first meeting of IMO’s Marine Environmental Protection Committee (MEPC71), has provided some relief from an almost impossible logistical timetable for Ballast Water Management System (BWMS) installation. With mandatory system installation expected by a vessel’s first International Oil Pollution Prevention renewal survey, the utmost date of enforcement could be as late as 2024. The Experience Building Phase has allowed ship owners some breathing space. However, they will still have to contend with complex regulations, uncertain BWMS performance and potentially inconsistent international enforcement.
Whilst challenges exist for ship owners regarding compliance with the Convention; Port State Control (PSC) is also facing challenges of their own. It seems unlikely that PSC will have the capacity to conduct thorough assessments during a typical port visit, given that tests needed to demonstrate compliance within the requirements laid down in the BWMC can take anywhere from hours to several days to complete. Additionally, with over 450 major ports and nearly 5,000 ‘significant ports’ worldwide, ensuring consistent global enforcement will be nigh on impossible.
In some respects, the complexity of the regulations governing ballast water management reflects the complexity of tackling the spread of aquatic invasive species. Irrespective of this complexity, it is critical that port inspections are effective and consistently applied so that ship operators can be confident that inspections passed in one jurisdiction will pass in another. Responsibility for inspecting the 26,000 ships offloading 43 million tonnes of ballast in U.K. waters each year will be shouldered by the U.K. Maritime and Coastguard Agency.
Building on a blueprint
Naturally, ship and port operators will still have to adhere to existing legal requirements, such as presenting up-to-date ballast water record books and management plans and demonstrating that crews are knowledgeable in the function of BWMS. However, given current doubts surrounding system design limitations and the consequential performance of management systems currently on the market, a simple ‘records check’ will be insufficient to satisfy environmental concerns and regulations.
To devise a ‘blueprint’ for managing this imminent responsibility, it is worth studying the scenario in the U.S. where federal regulations require vessels to abide by the U.S. Environmental Protection Agency and vessel general permit requirements for ballast water, which comprises a biological endpoint – namely heterotrophic bacteria counts.
California inspects a quarter of the 9,000 or so vessels visiting the state annually. The information gathered in this process feeds into the U.S. Smithsonian Environmental Research Centre that acts as a clearinghouse for ballasting records for nearly 40,000 vessels visiting the country. With this as a starting point, David Wright (2018) Emeritus Professor of Environmental Toxicology from the University of Maryland, Cambridge, U.S., has proposed a potential new approach for inspection that would fulfil legal requirements and create a robust analytical capability that could evolve to incorporate the most up-to-date testing equipment and methodology.
Reducing inspection time
While rapid testing for full compliance won’t be developed for some time, certain analytical procedures would give PSC a sufficient degree of confidence that the BWMS under inspection is working effectively. Indicative analysis tools can provide a quick estimate of the numbers of live organisms in discharge, thus offering a useful marker of a ship’s compliance.
As the name suggests, indicative analyses gauge compliance using indicator species of different classification sizes or indicator bacteria. Such analyses can be performed by relatively fast indirect or direct measurements of a representative sample from the ballast water tank.
Indirect measures are based on physical, chemical or biological parameters that require an understanding of the nature of the biological endpoint. Residual compounds used in treatment, such as chlorine disinfection, can indicate system usage, however, gives no direct efficacy measure unless notably high residual levels are recorded. Salinity measurements similarly suffer such efficacy issues, as they struggle to reliably detect ballast water originating in Pacific Rim ports, as many localities in the region experience high salinity all year round.
Direct measurements can be a more reliable signature, such as the incidence of fluorescence by naturally occurring dissolved organic matter (FDOM), where long-wavelength fluorescence is an effective indicator of ballast water exchange. Mid-ocean ballast water exchange represents a strong option for vessels yet to install management systems. However, once such installations become mandatory, both salinity measurements and FDOM designed to track ballast exchange will be phased out with no effective substitute, as neither technique can perform efficacy testing. Such testing should, therefore, be part of a PSC inspection.
Establishing a U.K. framework
Taking account of such issues and assessment techniques, building a BWMC monitoring and compliance network based on freight tonnage handled could be the answer for the U.K. Allowing modification based on cargo and vessel type and likely source of ballast water would be crucial to ensure that compliance testing is only conducted where it is most needed.
Dover, as an example, accounts for the largest number of annual ship arrivals (17,000). However, visits are predominantly short-haul ferry traffic, so ballast will likely originate from relatively nearby waters. Southampton, on the other hand, has significantly less traffic but docks the largest share of deadweight tonnage, thus likely to have ballast from more remote waters, increasing the risk of an invasive species being contained within the ballast.
Such a network would best focus on the top ten ports, with a centralised headquarters coordinating sampling and analysis all across the U.K., acting as a national repository for discharge/monitoring records. If a framework based on the U.S. model were applied to the U.K., an inspection rate of 10% would produce a comparable number of 2,600 vessels. When distributed amongst ten ports, this would equate to one sample analysis conducted daily. These numbers are, of course, for scaling purposes only and do not account for pre-existing inspection activities and more numerous simple paperwork inspections.
The bottom line
Monitoring instruments currently available to PSC for ballast water testing are incapable of determining treatment efficacy to the level required by international standards. This is unlikely to change for several years and under such conditions, it is not possible to demonstrate compliance with the BWMC through PSC inspections as they stand today unless the standards are revised.
Ensuring full compliance according to the IMO and U.S. Federal regulations would require analyses that are prohibitively long and expensive to be suitable. This, coupled with lingering uncertainties over the BWMS performance, make a strong case for the utilisation of ‘indicative instruments’, with comprehensive testing reserved only for when indicative analysis remains inconclusive.
While some techniques may use different endpoints to determine biomass and viability, all would indicate a ‘high’ (acceptable) or ‘low’ (unacceptable) degree of efficacy and could be used in combination to provide a composite ‘compliance index’ encompassing different size classes of organisms. Such prognostic instruments could be regarded as analogous to blood alcohol ‘breathalysers’ and would be capable of rapid BWMS assessment within the duration of an average port visit. If followed, this framework would set a precedent and allow the U.K. to assume a leading role in ballast water management.
This is a summary of the paper: D. A. Wright (2018): Compliance assessment for the ballast water convention: time for a re-think? A U.K. case study, Journal of Marine Engineering & Technology, DOI: 10.1080/20464177.2018.1513686. You can subscribe to the journal here.