The maritime industry is at a turning point. For decades, biofouling management was treated as a maintenance afterthought; something shipowners dealt with when fuel costs crept up or vessel performance declined.
That era is over. Today, biofouling sits at the intersection of environmental protection, regulatory compliance, and operational strategy. And the direction of travel is unmistakable: the world is moving toward mandatory, enforceable standards for hull cleanliness and biofouling management.
A Global Regulatory Wave
Around the world, countries and port states are no longer waiting for the industry to self-regulate. Australia was among the first to act decisively, enforcing biofouling management requirements under its Biosecurity Regulation since June 2022, requiring all international vessels to demonstrate proactive biofouling management before arrival or face additional inspections, risk assessments, and potential delays.
New Zealand goes even further. Vessels entering New Zealand waters must carry a biofouling management plan, and those deemed high-risk can be denied entry outright. California has had biofouling management regulations in place since 2017 for vessels of 300 gross tons or more, mandating management plans, performance standards and reporting requirements making it one of the most stringent sub-national regulations in the world.
Most recently, Brazil has adopted robust new rules under NORMAM-401/DPC, requiring all vessels over 24 metres to arrive with clean hulls and documented biofouling management, with full penalty enforcement beginning in 2026 and fines of up to BRL 2,000,000 in severe cases.
These are not isolated initiatives. They represent a clear trend of port states taking biofouling seriously and preparing to back their requirements with real consequences.
MEPC 83 and the Path to Mandatory Global Standards
At the international level, the IMO's Marine Environment Protection Committee took a decisive step forward at MEPC 83, approving guidance on in-water cleaning of ships' biofouling and critically greenlit a new work item to develop a mandatory, legally binding instrument focused on biofouling management, possibly by 2029.
One standout element in these discussions is the growing consensus that hull cleaning must be performed with full capture of waste and not simply scrubbed off into the surrounding waters. In a webinar poll following MEPC 83, just 4% of industry respondents supported routine cleaning without capture.
This signals a fundamental shift. Hull cleaning with waste collection is no longer a "nice to have." It is becoming the baseline expectation.
What We Are Actually Putting into the Ocean
C-Leanship recently commissioned a project to analyse collection matter from a typical hull cleaning. And the preliminary findings are sobering.
The lab analysis of the collected hull cleaning waste revealed that:
- Copper levels in the waste were 428 times the median toxicity level defined by the National Oceanic and Atmospheric Administration (NOAA).
- Zinc levels exceeded 84 times NOAA thresholds.
- There were also moderate levels of mercury, lead, nickel, cadmium, chromium, and arsenic – heavy metals that, in the absence of capture systems, would be discharged directly into the marine environment.
- Microplastic concentrations reached 96.5 million particles, equivalent to approximately 0.68 kg of microplastics per 100 kg of collected material.
These numbers represent the output from a single hull cleaning. Now consider the scale: the global commercial fleet comprises over 112,500 vessels, and industry research indicates that vessels typically undergo hull cleaning approximately once per year. That translates to a rough estimate of over 300 hull cleanings taking place every single day around the world.
It begs the question on the amount of copper, zinc, mercury, lead, and microplastics being discharged into our oceans daily from hull cleanings performed without capture.
The answer, when extrapolated from what we collect in just one operation, is staggering and should concern every stakeholder in this industry.
Reasons for Optimism
Despite the gravity of these findings, there is optimism on the direction we are heading. The fact that Australia, New Zealand, Brazil, California, and a growing number of port states are proactively implementing biofouling regulations is encouraging.
The IMO's commitment at MEPC 83 to develop a binding global framework demonstrates that the international community recognises the urgency. Industry bodies like the Clean Hull Initiative are working toward recognised standards for proactive hull cleaning, and leading shipowners are already integrating biofouling management into their operational strategies rather than treating it as a reactive afterthought.
The shipping industry now has both the regulatory impetus and the technology to do better. At C-Leanship, we have been advocating for, and delivering, hull cleanings with full capture for over a decade. The conversation has shifted from whether the industry needs to act to how quickly it can scale responsible practices globally.
The tide is turning – and this time, it is carrying the industry in the right direction.