Aquatic Monsters Lurking in Our Waters

With Halloween right around the corner, most of us are waiting for tiny goblins, ghosts and monsters to visit our houses and ask for treats.  But maybe what we should be more scared of are the aquatic monsters, like zebra mussels, that are dishing out expensive and damaging tricks in our ecosystem.

Zebra Mussels -

Zebra mussels entered the Great Lakes via ballast water from ocean-going ships. This small creature might not seem destructive but they have invaded all five Great Lakes and over 100 inland lakes in less then 10 years. “They are successful invaders because they can live and feed in many different aquatic habitats, and they breed prolifically - each female produces 1 million eggs per year”, explained Derek Scheer, Water Program Director for Clean Wisconsin.

Young zebra mussels are the diameter of a human hair and are invisible to the naked eye. Because young zebra mussels are so small, they can spread easily by water currents and can drift for miles before settling. Adult zebra mussels are larger (<2 inches in length) and attach to hard objects and remain stationary. They can attach themselves to boats and boat trailers, and move between water bodies in this way.

Economic Impacts of Zebra Mussels

This small monster might not make a person jump or scream, but their economic impacts are creepy to the average taxpayer. Current estimates on the effect of the zebra mussel invasion range from $500 million to $5 billion per year. Who’s covering these costs? The usual suspects include - utility companies, municipalities and other government agencies.  This means that taxpayers are really footing the bill.

Most of the damage caused by zebra mussels occurs when they attach to water-intake pipes and cause blockage and other issues. In 1989, the town of Monroe, MI lost its water supply for three days due to massive numbers of zebra mussels clogging the city’s water-intake pipeline. Since then, water users such as power companies, steel plants, city water suppliers, and golf courses have had to retool their water-intake systems or apply chemical treatment to prevent zebra mussel related problems. Many cities with swimming areas on the Great Lakes have had increased costs associated with removing tons of mussel shells that wash up on beaches during storms.

Ecological Impacts of Zebra Mussels

These small monsters have been wreaking havoc on our ecosystems by gobbling up more then their share of food, destroying food for others and eliminating some native Great Lakes species. Zebra mussels are filter feeders and process up to 1 gallon of water per day/mussel. During this process, every particle in the water that they filter is either eaten by the mussels or wrapped in mucus and spit out. This feeding ability, in combination with high population densities, rapidly clears the water in even the largest lakes. Since zebra mussels became established in Lake Erie, water clarity has increased from 6 inches to 30 feet in some areas. Unfortunately, the material removed from the water consists of other live animals and algae that supply food for fish and invertebrates. In response to this diminishing food supply populations of some animals have begun to decline.

As the lakes clear more light reaches aquatic plants.  This lead plants to increase in number and size. This increased growth can be beneficial to some fish such as northern pike and to yellow perch. However, the plants do cause problems for recreational boaters, beaches, increase taste-and-odor problems in drinking water supplies, and can block water-intake pipes during storms.

One drastic impact of the zebra mussel invasion is the near extinction of native American unionid clams in Lake St. Clair and in the western basin of Lake Erie. Zebra mussels attach and build colonies on the clams, inhibiting their ability to move, feed, and breed. This eventually leads to their death within a couple of years.

Solutions for Great Lakes Monsters

The Zebra Mussel is one of many invasive species that are harming and potentially destroying our water. Successful control of Aquatic invasive species will require the creation of environmentally protective standards for ballast water and the evaluation and use of effective ship-board treatments and management measures.  Legislation must be enacted to:

• Establish a state program with ballast water management guidelines and incentives to eliminate introductions of new invasive species.
• Allow sampling of ships to limit introduction of new invasive species.
• Allow the DNR to inspect boats at boat ramps to ensure they are not transporting invasive species from one lake to another.
• Hold those responsible for introduction of aquatic invasive species accountable.

Unlike the trick and treaters that will be visiting our houses soon, these aquatic species are invading and destroying our native waters and aquatic species. Now is the time to protect our greatest natural resource – our water. For more information on invasive species and what you can do to help please contact Clean Wisconsin at 608-251-7020 or visit the website: www.cleanwisconsin.org.

Clean Wisconsin, an environmental advocacy organization, protects Wisconsin’s clean water and air and advocates for clean energy by being an effective voice in the state legislature and by holding elected officials and corporations accountable.  Founded in 1970 as Wisconsin’s Environmental Decade, Clean Wisconsin exposes corporate polluters, makes sure existing environmental laws are enforced, and educates citizens and businesses. On behalf of its 10,000 members and its coalition partners, Clean Wisconsin protects the special places that make Wisconsin such a wonderful place to live, work and play.  Phone: 608-251-7020, Fax: 608-251-1655, Email: info@cleanwisconsin.org, Website: www.cleanwisconsin.org.