28th Jan 2026

Navigating the New Era of Ballast Water Management: Compliance, Challenges and What Lies Ahead

More than a year has passed since the International Maritime Organization’s (IMO) Ballast Water Management (BWM) Convention’s D-2 discharge standard became fully applicable to all ships. This milestone marks the culmination of a multi-decade international effort to reduce the transfer of invasive aquatic species through ships’ ballast water.

As the industry moves from implementation into enforcement, ship owners and operators face a mature and increasingly more demanding compliance landscape. The following article draws on insights from Dr. Linda Churcher, Senior Environmental Editor at Witherby Publishing Group, to examine where the industry stands today, the challenges that persist and what to expect as we navigate 2026 and beyond.

Industry Adaptation and the BWMS Landscape

The shipping industry has had a significant lead time to prepare for ballast water compliance. The International Convention for the Control and Management of Ships' Ballast Water and Sediments (BWM Convention) was adopted in 2004 and ratified in 2017, allowing extensive research and development into ballast water treatment technologies.

This long preparation period has led to considerable technological expansion. In 2010, the IMO listed just six Type Approved Ballast Water Management Systems (BWMS), one of which was later withdrawn. Since that time there has been a substantial increase in the number of IMO Type Approved BWMS. This provides ship owners with more options for both newbuilds and retrofit installations. For additional reference, the 45 IMO Type Approved systems are listed in the new ‘Ballast Water Management, 16^th Edition’ edited by Dr Linda Churcher.

Although an increased choice of BWMS is beneficial to ship owners, there remain many interconnected factors that must be evaluated when selecting a BWMS:

Cost and time, including purchase, installation, lead times, system lifespan and ongoing operational expenses
manufacturer considerations, such as technical specifications, reliability, safety, maintenance, company longevity and reputation
type of BWMS, including technology used, initial and ongoing costs, safety and consumables
ship-specific factors, including ship size/type, routes/trading patterns, ballasting requirements and local regulations.

Taking these factors into consideration can greatly assist with the process of choosing a BWMS suitable for your specific ship.

Inspections, Documentation and Regulatory Scrutiny

With the BWM Convention now in force, Port State Control (PSC) inspections have intensified. Compliance is increasingly assessed through documentation, operational consistency and crew competence.

The Convention is currently in its experience-building phase (EBP), which includes a temporary non-penalisation period for certain non-compliant discharges. This period runs until September 2026, but the non-penalisation is subject to strict conditions and penalties may still be imposed if:

The BWMS is not properly Type Approved
the system has not been installed correctly
maintenance does not follow manufacturer instructions
the approved BWMP has not been followed
system self-monitoring does not indicate proper operation, or authorities were not notified of defects prior to discharge.

Reflecting this increased focus, the Paris and Tokyo MoUs conducted a three-month concentrated inspection campaign (CIC) on BWM compliance in 2025, with other MoU regions also increasing inspection activity.

Under the BWM Convention, guidelines outlining a four-stage PSC inspection are discussed in ‘Ballast Water Management, 16^th Edition’ along with the predefined questionnaire for the PSC Officers in the Paris and Tokyo MoU assessments. This edition also has a new chapter on ‘Preparing for Inspections’, which includes a useful checklist to prepare for a PSC inspection.

The United States is not a party to the BWM Convention. Ships operating in US waters must comply with separate national ballast water regulations. This is covered in the Witherbys’ title ‘US Ballast Water Management Regulations’.

Essential Onboard Documentation

Documentation and recordkeeping remain among the primary focus areas during PSC inspections. BWM documentation and the accurate recording of ballast water and sediment management operations are early-stage checks for PSC officers to verify compliance with the Convention. Three documents must be maintained on board at all times:

International Ballast Water Management Certificate (IBWMC). Issued on behalf of the flag administration and subject to initial, annual, intermediate and renewal surveys. Biological sampling is now mandatory during the initial survey following BWMS installation
Ballast Water Management Plan (BWMP). A ship-specific plan providing operational instructions, contingency procedures and training records. An approved, comprehensive BWMP is central to long-term compliance
Ballast Water Record Book (BWRB). The official log documenting all ballast water operations, including uptake, treatment, circulation, exchange and discharge. The approved format is set out in the Witherbys’ title ‘Ballast Water Record Book – 6th Edition'.

Crew Familiarisation and Operational Competence

Beyond documentation, crew competence is a key inspection priority. PSC officers conduct early-stage checks to confirm that designated crewmembers are familiar with the installed BWMS and capable of operating it safely.

Designated crewmembers must be able to:

Demonstrate system operation
troubleshoot common issues
follow BWMP procedures accurately.

Although the Convention has been in full effect for over a year, many ships were already starting to operate a BWMS on board as their compliance date was reached in the five years before this cut-off date. This time would have raised operational issues and tested the maintenance and safety support network provision to the ships. There have been many changes in the landscape of BWMS manufacturers over the years, with ownership changes, mergers and companies leaving the BWM market altogether. This can lead to uncertainty for owners and operators. Having a strong maintenance and support package in place for the BWMS on board provides confidence that the BWMS will be compliant with the BWM Convention.

Managing Challenging Water Quality and System Failures

Under the D-2 standard, which was phased in following the use of ballast water exchange under the D-1 standard as an interim measure, all applicable ships were required to comply with ballast water discharge requirements by September 2024. Certain environmental factors can create challenging water quality (CWQ) that negatively impacts BWMS performance. These factors include high levels of total suspended solids (TSS), dissolved organic carbons (DOC) and particulate organic carbons. For example, high sediment loads can clog BWMS filters, compromising the treatment process.

To manage these situations, the BWMP should define clear procedures, which may include:

Confirming alarms are due to CWQ
completing troubleshooting and maintenance steps
reducing BWMS flow rates
deciding whether to continue ballasting
documenting actions and informing port authorities.

In cases of BWMS failure, ballast water exchange (BWE) remains an important contingency option. While BWE is no longer permitted as a primary compliance method under the D-2 standard, it may be used where:

It is defined as a contingency in the BWMP
its use is agreed with the local maritime authority.

One practical example is the Intra North Sea Contingency Area recently adopted by several North Sea states, allowing BWE under defined prerequisites.

The BWMS Lifecycle: From Retrofitting to Replacement

While the peak period for retrofitting BWMS occurred between 2019 and 2024, a steady market for replacing legacy systems has now emerged. Ship owners are finding the need to replace existing systems for several reasons:

Loss of the manufacturer or BWMS from the market, and therefore no availability of spares and maintenance support
poor quality systems which do not meet required standards when operating on board
an initially poor choice of system for the operating conditions of the ship.

It is important to retain the extensive knowledge needed for the steps involved in planning and retrofitting a BWMS. The considerations are described in detail throughout the ‘Practical Installation and Retrofitting Considerations’ section of ‘Ballast Water Management – 16th Edition’.

Ballast Water, Biofouling and Decarbonisation

The management of ships’ ballast water and biofouling are both effective measures for limiting the transfer of potentially invasive aquatic species and reducing associated environmental and economic impacts, although the organisms involved are often different. Species taken up in ballast water are those present in the water column at the time of ballasting and can range from viruses to fish, while organisms that foul underwater ship surfaces and internal seawater systems (ISS) represent a smaller subset that must attach to surfaces for part or most of their life cycle; however, both often share a high tolerance to changes in salinity, temperature and pollution levels.

Although ballast water management has little immediate impact on fuel efficiency or decarbonisation, the consequences of invasive species establishment can be costly and time-consuming, with potential impacts including:

Damage to aquaculture and fisheries
clogging of waterways and power plant intake pipes
predation on, or competition with, indigenous wildlife.

In contrast, managing biofouling on ship’s underwater surfaces can have a significant effect on fuel efficiency and emissions. Increased hull resistance requires more fuel to maintain speed, leading to higher GHG emissions; research has shown that a 320 m tanker with just 1% of its hull covered by 5mm barnacles experienced a 55% increase in GHG emissions, highlighting the relevance of biofouling management to the IMO Net-Zero Framework.

Biofouling can also accumulate in a ship’s internal piping, sea chests and other niche areas, where it may affect cooling and heat exchangers, stability and fire suppression systems. This internal biofouling is often more difficult to remove and can present a greater risk as a source of invasive aquatic species than hull or propeller fouling, which is generally easier to manage.

Looking Ahead to 2026 and Beyond

The conclusion of the EBP in September 2026 will mark a significant transition. Based on data gathered during this phase, the IMO aims to implement consistent sampling and analysis procedures, enabling more streamlined and uniform PSC inspections worldwide.

At the same time, regulatory focus on biofouling is increasing. Building on the IMO’s 2023 Biofouling Guidelines, MEPC 83 agreed to develop a legally binding global biofouling framework. While a mandatory convention will take time to develop, the regulatory direction is clear.

Environmental compliance is becoming increasingly integrated, data-driven and stringent. Ship owners and operators must prepare now for a future where ballast water management, biofouling control and decarbonisation objectives are closely linked.

Further Reading and Guidance

The topics discussed are explored in detail in the following Witherby publications:

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