Environmental Benefits of Marine Growth Preventing Systems

Marine biofouling, which involves attachment of microbes, seaweeds, crustaceans, mollusks such as barnacles to submerged surfaces, is not only operationally problematic for vessels and structures but also environmentally hazardous. Classic anti biofouling systems such as the copper based types and ones using a dangerous compound Tributyltin or TBT release toxic biocides into the environment thereby damaging the other organisms, flora, fauna and more and thereby ending up in to a deposit in the sea bed. However, there are biofouling control systems which run on electrochemical principle of anti fouling control with no release of chemicals into the environment by continuous discharge, Marine Growth Preventing Systems (MGPS) and this technology has been proven very eco friendly. SME, has retrofitted, Installed, and serviced several hundreds of such MGPS in to ships and offshore installation and seen the practical and effective marine growth prevention result which in the bargain reduced harmful biocide effects on the marine environment very substantially.

How MGPS Works: Electrolytic Action Without Biocide Release

MGPS works through a simple but extremely effective electrochemical process. The device is designed with one pair of anodes (usually copper and aluminum but can be iron) which are mounted inside the seawater pipeline, or directly on the vessel’s sea chest. When a low voltage DC current is applied to the anodes the copper slowly releases a trace amount of copper ions into the circulating seawater. The ions prevent metabolic functions of the marine growth at parts-per-billion(ppb) levels which stops attachment and growth of fouling. Simultaneously, the aluminum or iron anode produces flocculent hydroxides that then film internally over the pipes inhibiting corrosion.

Importantly, the generation of ions is actively controlled to deliver a flow that starts only upon activation of the MGPS, and this flow can be shut down for sensitive marine environments, or during port operations, whereas biocides from antifouling paints continuously seep out when underwater whether the vessel is operating or moored. Concentrations are far below those levels known for immediate marine toxicity and copper quickly complexes with organics or precipitate as non-bioavailable species.

Reduction in Biocide Discharge and Heavy Metal Loading

Perhaps the most striking environmental benefit is that MGPS results in zero, or dramatically reduced, copper discharge compared to traditional self polishing copolymer SPC coatings. SPC formulations are permitted to emit 10 to 50 micrograms of copper per square centimeter per day. This can mean more than hundreds of kilograms of copper per vessel per year. Copper becomes trapped in port sediment and poses a chronic risk to fish and shellfish in sensitive areas like the Baltic Sea, the Great Lakes, harbors in China, all areas where there is or will soon be effective regulation limiting the emission of anti-fouling copper.

However, MGPS disperses dissolved copper ions only on the wetted surface area of seawater inside the pipework, and annual copper loss is just a few grams, not many kilos for any particular vessel. MGPS units also generate non polluting aluminum and iron hydroxide byproducts to settle. MGPS units can actually contribute to lowering a vessel's heavy metal impact while complying with green initiatives and IMO conventions, such as the IMO’s Anti-Fouling Systems Convention.

Protection of Non-Target Marine Species and Habitats

An often overlooked advantage of the MGPS approach is the selectivity. The biofouling inhibitors used in anti-fouling biocides are non selective by nature, being formulated to be toxic to all life that the coatings encounter, not just biofouling. This means plankton larvae, juvenile fish, and all non-foulers are subject to toxicity each time they are in proximity to the coating layer's leaching layer, resulting in a lack of biodiversity and fragmented food webs in harbors and marinas over time.

MGPS creates a highly focused field of electrostatic charge around the affected area, inhibiting the establishment of colonies on treated surfaces and surfaces directly in its vicinity. The diluted ion field leaving the outlet is dispersed and neutralized quite effectively. Many ecological and toxicity assessments have been performed and the consensus is that MGPS fitted vessels show no detectable ecotoxicological impact on water columns or seabed communities in any waters in their immediate vicinity. Here at SME, we offer MGPS as an excellent, low environmental impact solution for owners operating within ‘green listed waters’, in other words marine protected areas, coral reefs and farmed species (including fish and oysters) sectors.

Energy Efficiency and Associated Emission Reductions

MGPS has an often understated, but certainly environmentally significant, impact on vessel efficiency. Accumulation of biological growth makes hulls more hydrodynamically difficult to move through the water creating an effect we know as foul or rough in addition to increased resistance on sea chests and strainers creating system pressure and thus requiring higher fuel input for engines. IMO suggests that on a moderately foul hull performance can be impacted by 10 to 20%, resulting in similar percentage impacts to CO₂, SOₓ, NOₓ, and particulate emissions.

When used in combination with an advanced high performance fouling-release coating, such a system can maintain levels of fouling throughout dry-docking to virtually zero per vessel, leading directly to proven savings in fuel and reduced greenhouse gases per voyage. For those who are subject to carbon taxes or emission control area (ECA) rules, MGPS offers both ecological responsibility, and cost efficiency.

Compliance and Certification with Environmental Standards

MGPS system design and manufacture are handled within our Quality Management Systems, which is certified to ISO9001, ISO14001 and ISO45001 and accredited to ANAB, IAF and UKAS. Our systems conform to the IMO requirements for marine anti-fouling and satisfy local environmental discharge requirements. SME actually provides comprehensive documentation, including MSDSs, ion release data, and EPA & EA environmental risk assessment reports, to facilitate compliance and assist clients with permit submissions. Annually, over 500 new projects are manufactured, supported by our 100+ strong technical team to actually ensure you receive MGPS system that is as effective environmentally as it is technically.

Conclusion: SME Delivers Green Corrosion and Fouling Control

Marine Growth Preventing Systems are a new concept of fouling management, from general biocides release into the water, towards selective, automated control system and environmentally friendly solution. SME utilizes engineering’s best practices, 5,000 m² production hall and worldwide support to deliver the marine solutions which are protective for your vessels and the marine environment; for example our MGPS products come with 12 months warranty on the services of the project and hence SME can guarantee sustainable results on long terms with regard to your project success. For more information on marine growth prevention and its eco friendly benefits, reducing fuel costs and extending asset life, contact SME. We share your vision for performance that protects both your vessel and ocean.