News | October 6, 1998

Chile-Based Repellent Controls Zebra Mussels

Scientists at the New Mexico Institute of Technology (Socorro) have developed a chile-pepper-based additive for paints and other coatings that repels the zebra mussel, a serious nuisance for water systems, boats and power plants that use the Great Lakes. Most recently, controlled bench tests and field tests involving the zebra mussel and other freshwater species were conducted in the waters of Lake Michigan under the auspices of the East Chicago, IN-based Aquatic Research Institute.

"The zebra mussel could easily be termed 'Aquatic Enemy No. 1'‚ in the upper Midwest regions of our country," says Daniel Lopez, president of New Mexico Tech.

Timothy Early, director of the Aquatic Research Institute, said, "We have extensively bench tested the repellent material in our controlled aquarium environment and for the last four months have field tested it in Lake Michigan. Throughout all phases of the study, we observed no attachment on test materials by either the larvae or juvenile mussels. We believe the repellent created by this new process will be of significant benefit in our efforts to reduce the industrial and environmental impact of the zebra mussel."

Earlier research confirms that saltwater animals such as sea anemones, scallops and barnacles, which normally attach to solid surfaces, will actively avoid materials treated with the chile pepper-based repellent.

Scientists at New Mexico Tech invented and patented the process that allows the naturally repelling qualities of chile peppers to be molecularly bonded into paints, stains, plastics and other rubberized materials. The process is relatively simple, says Ed Hall of Medd4, a technology transfer company that is marketing the treatment. Chile powder (either from Habanero or African Birdseye pepper) contains capsaicin, a terpene that is the source of the pepper's hotness. The powder is dissolved in a solvent at a ratio of 4-6 oz powder to 1 L of solvent, then mixed in with paint formulations. The result is an effective, natural and environmentally sensitive repellent for land and aquatic animals, birds and insects. The Aquatic Research Institute is an independent, not-for-profit organization dedicated to increasing understanding and awareness of the aquatic environment through science, research and education.

Zebra mussels (Dreissena polymorpha) are believed to have been introduced into the Great Lakes of North America in 1985 or 1986 when one or more transoceanic ships discharged larvae contaminated ballast water that had been picked up in European freshwater ports. The mussel's reproductive cycle is key to its rapid spread in that mature females are capable of producing more than 100,000 eggs/yr. The zebra mussel is reported to have colonized every firm object in the southern portions of Lake Erie within a year after having been discovered there in 1988. Water intake structures used by power plants, water treatment facilities and other industries are routinely colonized and ultimately clogged by zebra mussels. Docks, boat bottoms, boat engines and drive mechanisms, and all other unprotected hard surfaces are susceptible to colonization. Although concerted efforts have been made to control the mussel and prevent its spread, the invasion of the zebra mussel has extended into other fresh waters of the United States and Canada.

The patented repellent is exclusively marketed by Medd4, a Santa Fe, NM-based company with offices in Houston and Ogden, UT. Medd4 is a limited liability company which specializes in technology transfers, financing, implementation and production of new products and innovations developed by New Mexico‚s universities and laboratories.

For more information: Ed Hall, MEDD4 6542, Prairie Dunes Houston, TX 77069. Tel: 281-895-7999.