A group of researchers from College of Creative Studies in Detroit, USA, developed blue glass made from two types of invasive mussel species.

Invasive species are species of plants or animals that are not native to an area, but when introduced thrive, usually because a lack of natural predators, and harm native species and even dispel them. Once introduced, invasive species are difficult to get rid of.

In their research, the researchers focus on Quagga mussels (Quagga Dreissena rostriformis bugensis) and Zebra Mussels (Zebra Dreissena polymorpha). These mussels arrived in the Great Lakes in the USA from the Ukraine and Russia in the 1980’s. Since their introduction, they transformed the lakes’ ecosystems, growing at densities of 7,790 mussels per cubic meter and proliferating at depths of 540 feet. Each mussel can lay a million eggs per year, live 2 to 5 years, and begin producing eggs of their own after just 12 months. Zebra mussels attach themselves to nearly any surface. Once attached, they clog water treatment and power station pipes, cling to boat hulls, and make beaches inhospitable. In addition, they overwhelm native mussels by growing over them and suffocating them, and also outcompeting them for food.

Earlier attempts to get rid of the mussels were largely ineffective due to high costs, and molluscicide harms other species in the ecosystem.

The Great Lake region has a long history of glass making. Typical Soda Lime Glass consist of three ingredients: a former (silica), a flux (soda or sodum oxide) which helps reduce the melting temperature, and a stabiliser (lime or calcium oxide). The latter helps stabilise the glass, which becomes water soluble with the addition of soda.

Zebra and quagga mussel shells consist of 95% of calcium carbonate (CaCo3), which can be converted into calcium oxide (CaO). The researchers collected the mussels off of the beaches of Muskegon and Lake St. Clair. They were boiled to get rid of excess organic matter, ground into a fine texture.

They made two recipes for the glass, one with a higher and one with a lower lime (mussel) content. The former resulted in an iceberg blue glass with veins of green, and the latter in a deeper aqua blue one. The colour is a result from minerals and metals that occur in the bedrock of the lakes, in this case copper. This could mean that mussels collected from different lakes could produce different colours of glass. The researchers also found that Zebra Glass, as they called their material, is an excellent glaze.

By turning the mussels into a material, in this case glass, the researchers hope to make the removal of the invasive species more cost effective.

Photos: College of Creative Studies