Biofouling on deepwater applications: how big a problem?

When it comes to projects undertaken in the oil and gas industry, there’s a persistent assumption that biofouling isn’t a problem once you get below depths of around 200 metres.

But, while the number of photosynthetic organisms drops off almost entirely around 150 metres down, marine growth is still an issue.

Let’s take a look at why that is.

Deepwater environments and the kinds of biofouling 🐚

Deep sea environments aren’t the friendliest places for organisms to inhabit.

But, there is still clear evidence to show that there are species between 200m and 7,000m that will make their homes on structures deployed by the oil and gas industry.

Indeed, the presence of hard, flat surfaces at these depths – where there are few other surfaces to colonise – is something of a treat for the organisms that live down there.


📩 No time to read now? Subscribe to get future articles in your inbox.


We see some of the same organisms known to colonise surfaces in shallower waters: hydroids, sponges, tunicates, barnacles and bryozoan.

In addition, bacterial biofilms, tubeworms and deepwater hydroids adhere to surfaces, causing initial and even secondary biofouling as the softer species make their home on a base of harder organisms.

And while these organisms grow more slowly than those in shallower waters, they can still obscure signage, causing safety problems during the inspection and maintenance of deepwater assets.

Challenges for the oil and gas industry

As technology improves, we’re seeing more and more deepwater activity in the oil and gas industry. This presents a number of particular challenges that are pertinent to us as subsea signage specialists:

  • Inhospitable environment
  • Marine growth
  • Maintenance and repair
Image Sourced from article on Theon Ltd website “Subsea Pipeline Inspection, Repair and Maintenance”
Image Sourced from Theon Ltd website

Inhospitable environment

Markers used on deepwater applications need to be able to withstand the cold and high-pressure environment in which they’re deployed, not to mention the rigours of submersion.

Marine growth

Biofouling is still an issue on structures deployed in deeper waters. Some species of tubeworm, for example, can grow to 15cm long and 1cm thick, quickly obscuring crucial signage.

Maintenance and repair

Markers without antifouling properties will need to be cleaned or replaced at relatively short intervals. This will need to be carried out by ROV due to the high pressure of the environment.

How can AQUASIGN help?

Our subsea signage has been developed with deepwater applications in mind. We’ve put our markers through every kind of third-party testing you can think of to ensure they’re up to the challenges faced by the oil and gas industry.

Pressure tested

Our markers have been pressure tested to make sure that the pressure levels in deepwater environments won’t damage or compromise them in any way. That goes for the markers themselves and the installation methods we offer – both mechanical and adhesive.

You can download full reports on Aquasign’s pressure testing in our downloads centre.

Tested against low temperatures ❄️

Temperatures below 200m never reach more than around 4℃, regardless of latitude. Further down, they drop to around 0℃, so if there’s one thing we needed to make sure of, it’s that Aquasign can withstand the chill.

Our markers, adhesives and mechanical installation methods have all been tested in extreme temperatures. We’ve also made sure they can go from one extreme to the other without any problems.

View our reports on Aquasign’s temperature tests here.

No cleaning required

Thanks to their smart silicone surface and proprietary oil, Aquasign subsea markers don’t need cleaning.

Marine growth can’t get a foothold on our signage, so there’s no biofouling to contend with and no need to send your best ROV down with a squeegee. Always a relief!

60-year performance guarantee

AQUASIGN products are guaranteed to do the job for 60 years – long enough for any installation we’ve come across!

Our signs, adhesives and mechanical installation methods are guaranteed to stay put and remain clear of biofouling in any marine environment, offering companies in the oil and gas industries serious long-term value.

Retrofit ready 👍🏻

While we always recommend installing Aquasign pre-deployment, there’s always going to be a time when retrofitting is required.

We’ve got a range of installation methods suited to deepwater installation by ROV, including industrial strength magnets for flat surfaces and super-strength spring clips for tubular sections.

You can take a look at all our installation options here or watch this short video showing how Aquasign works:


So, the short version

Is biofouling a problem for deepwater applications? Yes. While marine growth takes place at a slower rate in deeper waters, there are still plenty of organisms waiting for a nice flat surface to colonise and obscure.

Aquasign subsea markers are guaranteed to stay in place and remain free of biofouling for 60 years in any marine environment, making them the perfect choice for installations in the progressively deeper waters inhabited by oil and gas installations.

Contact a member of the team to discuss your deepwater signage needs.

We hope you’ve found this article helpful. Why not subscribe to our Knowledge Hub for instant access to all of our documents, guides and videos?

➡️ Related content: read up on our range of onshore marker fixing options or visit our Download Centre for access to all our test reports, specification documentation and product guides.

Get in touch

Translate »