Bantry scientists leading the search for sustainable plastics

RESEARCHERS at the Daithi O’Murchu Marine Research Station, Bantry are leading the way in the search for sustainable, biodegradable plastics as part of a major international research project.

Dr Julie Maguire is leading the team as part of the SEABIOPLAS project which is looking at using seaweed to create biodegradable plastic.

Currently the main materials used for biodegradable plastics are also major food sources such as corn, wheat, sugar beet and sugar cane.

The SEABIOPLAS project aims to develop seaweed as an alternative to human and animal food crops to produce plastics.

Europe produced 57 million tonnes of plastics in 2010, with the majority (39%) being used in the packaging sector.

The production of plastics puts a strain on our already depleting fossil fuel resources. It also impacts on the environment in terms of recyclability and biodegradability. There is a need for increased production of biomass-based, biodegradable plastics in order to achieve the EU2020 target of 10% of market plastics being bioplastics.

With the production of bioplastics expected to rise, the use of resources will also increase and compete with food and energy production. This in turn will have effects on biomass prices and environmental degradation. SEABIOPLAS is developing a greener alternative to petrochemically-produced plastics.

In 2010 world seaweed production (almost exclusively from aquaculture) was 19.9 million tonnes. Of this, Europe was only responsible for 0.4%. The main markets for seaweed are food, industrial specialities, fertilizers, cosmetics, pharmaceuticals and feed. Controlled cultivation of seaweeds allows for high traceability, management of biomass composition and properties, high quality and sustainability.

Sustainability is further increased when cultivation of seaweed is carried out in Integrated Multi-Trophic Aquaculture (IMTA) systems. IMTA systems work by incorporating the waste products produced by one species into the diet of another species. Aquaculture produces phosphorus and nitrogen in large quantities that are lost to the surrounding ecosystem. Over 67-80% of nitrogen and 50% of phosphorus fed to farmed fish goes into the environment, either directly from the fish or from solid wastes.

Seaweed is able to utilise this nitrogen and phosphorus and produce new biomass through photosynthesis, thus removing these excess nutrients from the surrounding area. As well as the benefits of seaweed in IMTA, it also has several advantages over using the raw materials currently used in biomass-based plastics, including a reduction of CO2 emissions, higher productivity, no risk of potential deforestation, no freshwater consumption and no fertilisers or pesticides used.

After the sustainably grown seaweed has been processed to produce lactic acid (the precursor to PLA), seaweed residues will be generated. These by-products have potential market value in the animal feed sector and can also be used as ingredients or supplements/additives. Currently, many additives come from South East Asia so the possibility of a European supply will be beneficial. The capacity of both the cattle sector and fish aquaculture sector to absorb seaweed by-products as new ingredients is huge. Waste represents enormous losses of resources and so by utilising the by-products as additives and an ingredient to animal feeds, waste is minimised.